3. Frankincense/History

Bei den verschiedenen Boswelliaarten handelt es sich um großzweigige Bäume, die in Indien, Nordafrika und im Mittleren Osten heimisch sind. Zur Gewinnung werden Streifen der Borke geritzt, wobei ein Harz austritt, welches ätherisches Öl, Terpenoide und Schleim enthält.

Allgemeiner Name in Deutsch ist Weihrauch, der pharmazeutische Name ist Olibanum.

Spezies Vorkommen Produkt
B. carteri Birdw. Somalia Olibanum
B. sacra Flueck Nubien, Südarabien Olibanum
B. frereano Birdw. Somalia Olibanum
B. bhau-dajiana Birdw. Nord-Somalia Olibanum
B. papyrifera Hochst. Äthiopien Olibanum
B. neglecta S. Moore Somalia Olibanum
B. odorata Hutsch Tropisches Africa Olibanum
B. dalzielli Hutsch Tropisches Africa Olibanum
B. serrata Roxb. Indien Salai guggal
Afrikanischer Weihrauchbaum
Afrikanischer Weihrauchbaum
Afrikanischer Weihrauch
Afrikanischer Weihrauch
Indischer Weihrauchbaum (Boswellia serrata Roxb.)
Indischer Weihrauchbaum (Boswellia serrata Roxb.)
Indischer Weihrauch (salai guggal)
Indischer Weihrauch (salai guggal)

Zusammensetzung des Harzes

Mehr als 200 verschiedene Substanzen wurden bisher in den Harzen von verschiedenen Boswelliaspezies identifiziert. Hauptkomponenten sind flüchtiges Öl, das reine Harz sowie Schleim. Der Gehalt dieser Stoffe variiert von Spezies zu Spezies und ist abhängig von Erntezeitpunkt und Standort. Eine ungefähre Zusammensetzung einiger Harze zeigt die untenstehende Tabelle. Die reinen Harze der Boswelliaspezies enthalten pentazyklische und tetrazyklische Triterpene. Unter den pentazyklischen Triterpenen sind besonders einige Boswelliasäuren für viele der pharmakologischen Wirkungen verantwortlich. Weitere Verbindungen sind tetrazyklische Triterpensäuren. Zu ihnen gehören auch die Tirukalsäuren, bei denen ebenfalls beobachtet wurde, dass sie biologische aktiv sind.

Zusammensetzung des Harzes von zwei verschiedenen Boswelliaspezies (aus Kreck und Saller, 1998):

Bosw. carteri Birdw. Bosw. serrata Roxb.
Flüchtige Öle: 5-9% 7,5-9% bis zu 15%
Reines Harz: ca. 66% 55-57%
Schleim: 12-20% ca. 23%

Boswellic Acids from Acid Fraction of Boswellia-Species

  • 11-keto-β-boswellic acid (KBA)
  • 3-acetyl-11-keto-β-boswellic acid (AKBA)
  • 3-acetyl-11-hydroxy-β-boswellic acid
  • β-boswellic acid
  • α-boswellic acid
  • 3-acetyl-β-boswellic acid
  • 3-acetyl-α-boswellic acid



Chemical Composition of the Oleogum Resin Essential Oils of from Burkina Faso.
DeCarlo A, Johnson S, Ouédraogo A, Dosoky NS, Setzer WN

Frankincense, the oleogum resin from members of , has been used as medicine and incense for thousands of years, and essential oils derived from frankincense are important articles of commerce today. A new source of frankincense resin, from West Africa has been presented as a new, alternative source of frankincense. In this work, the oleogum resins from 20 different trees growing in Burkina Faso, West Africa were collected. Hydrodistillation of the resins gave essential oils that were analyzed by GC-MS and GC-FID. The essential oils were dominated by α-pinene (21.0%-56.0%), followed by carvone (2.1%-5.4%) and α-copaene (1.8%-5.0%). Interestingly, there was one individual tree that, although rich in α-pinene (21.0%), also had a substantial concentration of myrcene (19.2%) and α-thujene (9.8%). In conclusion, the oleogum resin essential oil compositions of , rich in α-pinene, are comparable in composition to other frankincense essential oils, including , , and . Additionally, the differences in composition between samples from Burkina Faso and those from Nigeria are very slight. There is, however, a rare chemotype of that is dominated by myrcene, found both in Burkina Faso as well as Nigeria.

Plants (Basel). 2019 Jul;8(7):.
PMID: 31337133 [PubMed - as supplied by publisher]


Bioactive cembrane-type diterpenoids from the gum-resin of Boswellia carterii.
Wang YG, Ren J, Ma J, Yang JB, Ji T, Wang AG

Chemical examination of the gum-resin of Boswellia carterii resulted in the isolation and characterization of eighteen new cembrane-type diterpenoids, named as Boscartins P-AG (1-18) and eight known ones. Their structures were established on the basis of extensive spectroscopic (2D NMR, IR, CD, MS and X-ray) analysis in combination with modified Mosher's method. All compounds featured unusual 1,12-oxygenated tetrahydrofuran functionalities, and were evaluated for hepatoprotective activity against D-galactosamine-induced HL-7702 cell damage and cytotoxic activity against MCF-7 human breast cancer cell in vitro. Compounds 1, 6-10, 12-13, 16-17 and 21-25 (10 μM) showed some hepatoprotective activity against D-galactosamine-induced HL-7702 cell damage.

Fitoterapia. 2019 Sep;137():104263.
PMID: 31295512 [PubMed - indexed for MEDLINE]


Comparative Analysis of Pentacyclic Triterpenic Acid Compositions in Oleogum Resins of Different Species and Their In Vitro Cytotoxicity against Treatment-Resistant Human Breast Cancer Cells.
Schmiech M, Lang SJ, Werner K, Rashan LJ, Syrovets T, Simmet T

Pentacyclic triterpenic acids from oleogum resins of species are of considerable therapeutic interest. Yet, their pharmaceutical development is hampered by uncertainties regarding botanical identification and the complexity of triterpenic acid mixtures. Here, a highly sensitive, selective, and accurate method for the simultaneous quantification of eight boswellic and lupeolic acids by high-performance liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS) was developed. The method was applied to the comparative analysis of 41 oleogum resins of the species , , , , , , , , and . Multivariate statistical analysis of the data revealed differences in the triterpenic acid composition that could be assigned to distinct species and to their geographic growth location. Extracts of the oleogum resins exhibited cytotoxicity against the human, treatment-resistant, metastatic breast cancer cell line MDA-MB-231. Extracts from were the most potent ones with an average IC of 8.3 ± 0.6 µg/mL. The oleogum resin of the was further fractionated to enrich different groups of substances. The cytotoxic efficacy against the cancer cells correlates positively with the contents of pentacyclic triterpenic acids in extracts.

Molecules. 2019 Jun;24(11):.
PMID: 31181656 [PubMed - as supplied by publisher]


Analytical investigations on Boswellia occulta essential oils.
Ayubova M, Guelleh ZO, Guelleh MO, Brévard H, Baldovini N

Three samples of Boswellia occulta gum resin (Grades I, II and III) were analyzed by GC-MS and GC-FID. Fifty constituents could be identified, and several of them were isolated by flash chromatography and characterized by NMR. The combinatorial synthesis of homologous series of reference constituents permitted the unambiguous identification of five 1-methoxyalkanes and one 1-methoxyalkene. In addition, we measured the C content of one sample of essential oil and of a methoxyalkanes rich fraction and demonstrated that the origin of these materials is totally natural.

Phytochemistry. 2019 Aug;164():78-85.
PMID: 31102998 [PubMed - indexed for MEDLINE]


Compositional analysis of the essential oil of Boswellia dalzielii frankincense from West Africa reveals two major chemotypes.
DeCarlo A, Johnson S, Okeke-Agulu KI, Dosoky NS, Wax SJ, Owolabi MS, Setzer WN

Frankincense, an oleoresin produced by Boswellia species, has historical medicinal and religious significance, and is today used extensively for its essential oil. Boswellia dalzielii, a species found in West Africa, is one of the few frankincense species for which there is no information on the oleoresin essential oil. In order to correct this deficiency, the chemical compositions of the essential oil hydrodistilled from 21 samples of oleoresin taken directly from B. dalzielii trees in northern Nigeria, were analyzed by gas chromatography - mass spectrometry as well as chiral gas chromatography. In addition, a hierarchical cluster analysis was performed on the essential oil compositions from the 21 oleoresin samples from northern Nigeria as well as two samples from Ghana. The essential oil fractions obtained by hydrodistillation of B. dalzielii oleoresins were dominated by α-pinene (21.7-76.6%), followed by α-thujene (2.0-17.6%), myrcene (up to 35.2%), p-cymene (0.3-15.6%), and limonene (1.1-32.9%). The levorotatory enantiomers predominated for the monoterpenes with 98.1 ± 1.5% (-)-α-thujene, 99.2 ± 0.5% (-)-α-pinene, and 96.8 ± 1.4% (-)-β-pinene. Limonene showed the largest variation in enantiomeric distribution [67.3 ± 12.1% (-)-limonene]. The cluster analysis revealed two major chemotypes, one dominated by α-pinene and one much rarer chemotype rich in myrcene.

Phytochemistry. 2019 Aug;164():24-32.
PMID: 31071599 [PubMed - indexed for MEDLINE]


Boscartins L-O: Cembrane-type diterpenoids from the gum resin of Boswellia sacra Flueck.
Wang J, Zhen B, Hu J, Shi M, Wei C, Wang X, Sun H, Ji T

Four undescribed cembrane-type diterpenoids, boscartins L-O, as well as five known compounds (1S, 3R, 11S, 12R, 7E)-1,12-epoxy-4-methylenecembr-7- ene- 3,11-diol, isoincensole oxide, incensole oxide, incensole acetate and incensole oxide acetate were isolated from the gum resin of Boswellia sacra Flueck. (Burseraceae). The structures of these compounds were elucidated by extensive 1D and 2D NMR spectroscopic and mass spectrometric analysis, as well as comparisons with known compounds. The absolute configurations of the known compound (1S, 3R, 7E, 11S, 12R)-1,12-epoxy-4-methylenecembr-7-ene-3,11-diol was unequivocally confirmed by single-crystal X-ray diffraction analysis with Cu Kα radiation. Incensole acetate exhibited significant hepatoprotective activity at 10 μM against paracetamol-induced HepG2 cell damage.

Phytochemistry. 2019 Jul;163():126-131.
PMID: 31059964 [PubMed - indexed for MEDLINE]


Isolation, structure elucidation, and immunostimulatory activity of polysaccharide fractions from Boswellia carterii frankincense resin.
Hosain NA, Ghosh R, Bryant DL, Arivett BA, Farone AL, Kline PC

Frankincense has a long history in religious, cultural, and medicinal use. In this study polysaccharides were extracted from frankincense from Boswellia carterii. The polysaccharides were purified by anion exchange chromatography on a DEAE-Sepharose Fast Flow 16/10 FPLC column. Six fractions were obtained and the three most active immunomodulatory fractions were further purified by size exclusion chromatography on a Superdex-200 column. The composition showed the monosaccharides present were predominantly galactose, arabinose, and glucuronic acid along with small amounts of rhamnose and glucose. The monosaccharide composition and glycosyl linkage analysis revealed the polysaccharides belong to the type II arabinogalactans. Fourier-transform infrared spectroscopy and bicinchoninic acid assay showed that the amount of protein in the samples was <1 wt%. One-dimensional H NMR were consistent with high molecular weight compounds. The monosaccharides were primarily in the β conformation. The three fractions exhibited an immunostimulatory effect on RAW 264.7 murine macrophage cells. The most active immunostimulatory fraction FA2, stimulated a range of pro-inflammatory mediators including iNOS, NO, TNF-α, and IL-6 in RAW 264.7 cells. The fractions were effective in proliferating primary murine splenocytes. The results indicate that the polysaccharides isolated from frankincense have the potential to be used as an immunological stimulant or nutraceutical.

Int J Biol Macromol. 2019 Jul;133():76-85.
PMID: 30981779 [PubMed - as supplied by publisher]


Endogenous phytohormones of frankincense producing Boswellia sacra tree populations.
Khan AL, Mabood F, Akber F, Ali A, Shahzad R, Al-Harrasi A, Al-Rawahi A, Shinwari ZK, Lee IJ

Boswellia sacra, an endemic tree to Oman, is exposed to man-made incisions for commercial level frankincense production, whereas unsustainable harvesting may lead to population decline. In this case, assessment of endogenous phytohormones (gibberellic acid (GA), indole-acetic acid (IAA), salicylic acid (SA) and kinetin) can help to understand population health and growth dynamics. Hence, it was aimed to devise a robust method using Near-Infrared spectroscopy (NIRS) coupled with multivariate methods for phytohormone analysis of thirteen different populations of B. sacra. NIRS data was recorded in absorption mode (10000-4000 cm-1) to build partial least squares regression model (calibration set 70%). Model was externally cross validated (30%) as a test set to check their prediction ability before the application to quantify the unknown amount of phytohormones in thirteen different populations of B. sacra. The results showed that phytohormonal contents varied significantly, showing a trend of SA>GA/IAA>kinetin across different populations. SA and GA contents were significantly higher in Pop13 (Hasik), followed by Pop2 (Dowkah)-an extreme end of B. sacra tree cover in Dhofar region. A similar trend in the concentration of phytohormones was found when the samples from 13 populations were subjected to advance liquid chromatography mass spectrophotometer and gas chromatograph with selected ion monitor analysis. The current analysis provides alternative tool to assess plant health, which could be important to in situ propagation of tree population as well as monitoring tree population growth dynamics.

PLoS One. 2018;13(12):e0207910.
PMID: 30566477 [PubMed - indexed for MEDLINE]


Optimal Processing Conditions of Birdw. Using Response Surface Methodology.
Yoon JH, Kim JH, Ham SS, Gang BY, Lee SH, Choi G, Kim YS, Lee G, Ju YS

Background: Bridw. is being widely used for its anti-inflammatory properties, as well as for wound healing, antimicrobial, and immunomodulatory properties, and boswellic acids (BAs) are considered to be the main active constituents.

Objectives: To investigate optimal conditions of stir-baking process for the resin of with vinegar of using response surface methodology (RSM).

Materials and Methods: The concentration of acetic acid, heating temperature, and heating time were set as influential factors, and the yields of chemical compounds were the response values which were optimally designed by a Box-Behnken design. The amounts of 11-keto-β-boswellic acid (KBA) and α-boswellic acid (αBA) in resin were quantified using high-performance liquid chromatography analysis.

Results: Maximum amounts of KBA and αBA in resin were obtained using 6% acetic acid for 10 min at 90°C in preliminary test. Two factor interactions, such as acetic acid concentration-heating temperature and heating temperature-heating time, were significantly observed by multiple regression analysis. Optimal processing conditions from RSM were 5.83% for acetic acid concentration, 9.56 min for heating time, and 89.87°C for heating temperature. Under the modified conditions, the experimental value of the response was 11.25 mg/g, which was similar to the predicted value.

Conclusions: The results suggest that the optimal conditions for the stir-baking process of resin were determined by RSM, which was reliable and applicable to practical processing of herbal medicine.

SUMMARY: The resin of was macerated in aqueous acetic acid and heated using an oven for stir baking processThe interaction between heating temperature and heating time was the most significantOptimal conditions for processing resin were determined as 5.83% acetic acid, 9.56 min for heating time, and 89.87°C for heating temperature. BAs: Boswellic acids; KBA: 11 keto β boswellic acid; αBA: α boswellic acid; BBD: Box-Behnken design; RSM: Response surface method; HPLC: High performance liquid chromatography; LOD: Limits of determination; LOQ: Limits of quantification; RSD: Relative standard deviation; ANOVA: Analysis of variance.

Pharmacogn Mag. 2018 Apr-Jun;14(54):235-241.
PMID: 29720838 [PubMed - as supplied by publisher]


New α-Glucosidase inhibitors from the resins of Boswellia species with structure-glucosidase activity and molecular docking studies.
Ur Rehman N, Khan A, Al-Harrasi A, Hussain H, Wadood A, Riaz M, Al-Abri Z

Phytochemical investigation of the oleo-gum resins from Boswellia papyrifera afforded one new triterpene, named 3α-hydroxyurs-5:19-diene (1) together with twelve known compounds including eight triterpenoids (2-9), two diterpenoids (10 and 11) and two straight chain alkanes (12 and 13). Similarly ten more known compounds were isolated from the resin of Boswellia sacra including one triterpene (20) and nine boswellic acids (14-19 and 21-23). Herein the compound 2 was first time reporting from natural source along with complete NMR assignment, while compounds 3-11 are known, but reported for the first time from the resin of B. papyrifera. The structure elucidation was done by advance spectroscopic D and D NMR techniques viz., H, C, DEPT, HSQC, HMBC, and COSY, and NEOSY, ESI-MS and compared with the reported literature. All compounds were evaluated for their α-glucosidase inhibitory activity and as result eight of them 1, 3, 10, 11, 15, and 17-19 were found significantly active against α-glucosidase with an IC value ranging from 15.0 ± 0.84 to 80.3 ± 2.33 µM, while 21 exhibited moderate activity with IC of 799.9 ± 4.98 µM. Furthermore, two compounds 24 and 25 were synthesised from 16 and 17 to see the effect of carboxyl group in structural-activity relationship (SAR) study. Compounds 24 and 25 retained good α-glucosidase inhibition as compared to 16 and 17, indicating that carboxylic group play a key role in SAR. In addition, the aforementioned activity of all the active compounds was first time reported for their α-glucosidase inhibition potential. The molecular docking studies showed that all the active compounds well accommodate in the active site of the enzyme. Moreover pharmacokinetic properties of the compounds were predicted in silico, suggesting that the compounds possess drug like properties and excellent ADMET profile.

Bioorg Chem. 2018 09;79():27-33.
PMID: 29715636 [PubMed - indexed for MEDLINE]


Chemical Variation in Essential Oils from the Oleo-gum Resin of Boswellia carteri: A Preliminary Investigation.
DeCarlo A, Johnson S, Poudel A, Satyal P, Bangerter L, Setzer WN

Frankincense, the oleo-gum resin of Boswellia species, has been an important element of traditional medicine for thousands of years. Frankincense is still used for oral hygiene, to treat wounds, and for its calming effects. Different Boswellia species show different chemical profiles, and B. carteri, in particular, has shown wide variation in essential oil composition. In order to provide insight into the chemical variability in authentic B. carteri oleoresin samples, a hierarchical cluster analysis of 42 chemical compositions of B. carteri oleo-gum resin essential oils has revealed at least three different chemotypes, i) an α-pinene-rich chemotype, ii) an α-thujene-rich chemotype, and iii) a methoxydecane-rich chemotype.

Chem Biodivers. 2018 Jun;15(6):e1800047.
PMID: 29696822 [PubMed - indexed for MEDLINE]


The amino analogue of β-boswellic acid efficiently attenuates the release of pro-inflammatory mediators than its parent compound through the suppression of NF-κB/IκBα signalling axis.
Gupta S, Ahsan AU, Wani A, Khajuria V, Nazir LA, Sharma S, Bhagat A, Raj Sharma P, Bhardwaj S, Peerzada KJ, Ali Shah B, Ahmed Z

Natural product derivatives have proven to be cutting edge window for drug discovery and development. BA-25 (3-α-o-acetoxy-4β-amino-11-oxo-24-norurs-12-ene) an amino analogue of β-boswellic acid exhibited inhibition of TNF-α and IL-6 in THP-1 cells as demonstrated previously, however, the effect on principal inflammatory mediators such as cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and the pathways that mediate this function remains unknown. This study was designed to examine the comparative anti-inflammatory activity of BA-25 with its parent compound, β boswellic acid both in vitro and in vivo. The effect of BA and BA-25 on suppression of NO, PGE LTB, COX-2 in LPS-stimulated RAW 264.7 cells was determined by ELISA, RT-PCR and ROS by flow cytometry. Phosphorylation of NF-kBp65, IKB degradation was determined by western blotting and also the nuclear localization of NF-kBp65 was assessed by immunofluorescence. Furthermore, this study was extended on Carrageenan induced paw oedema modelled BALB/c mice. A novel derivative BA-25, reported first time notably decreased the LPS (1 μg/mL) induced upregulation in the transcription of TNF-α, IL-6, iNOS and COX-2. Also the protein expression of iNOS and COX-2 as well as their downstream products NO and PGE2 respectively, were also decreased efficiently at a concentration of 10 μM than BA. Moreover, LPS upregulated NF-kB p65 expression and IκB degradation was significantly decreased after BA-25 treatment. In addition, the treatment of BA-25 also restored the paw oedema and decreased the magnitude of histopathological alterations. Our data together suggested that BA-25 might be regarded as prospective therapeutic anti-inflammatory alternative and demands further investigation in pharmacological studies.

Cytokine. 2018 07;107():93-104.
PMID: 29229421 [PubMed - indexed for MEDLINE]


A novel boswellic acids delivery form (Casperome®) in the management of musculoskeletal disorders: a review.
Riva A, Allegrini P, Franceschi F, Togni S, Giacomelli L, Eggenhoffner R

Standard pharmacological treatment of musculoskeletal conditions is often associated with relevant side effects. Botanical preparations endowed with a good tolerability profile, therefore, could have a role in the management of these disorders. Among different natural products, Boswellia serrata extracts have long been used for the treatment of musculoskeletal disorders, given their marked anti-inflammatory activity and their ability to promote tissue regeneration. However, standard preparations of Boswellia serrata show overall modest pharmacokinetic properties, a limitation which may ultimately lead to reduced efficacy. In an effort to improve the pharmacokinetic properties, Casperome®, a lecithin-based formulation of Boswellia serrata extract representing the whole natural bouquet, has been developed. This formulation was effective in the treatment of Achilles tendonitis, epicondylitis, radiculopathies, ankle sprains and sport injuries as shown in several clinical studies, the majority of which with a randomized design and all evaluating a number of well-recognized parameters of efficacy for the therapy of musculoskeletal disorder. All studies were consistent in showing a prompt decrease of pain and improvement of functionality of the affected area after supplementation with Casperome®, without any relevant adverse effect. Remarkably, these symptomatic improvements were paralleled by reduced plasmatic levels of inflammatory markers and by a diminished need for rescue analgesics. On these bases, Casperome® may have a role in the treatment of musculoskeletal disorders. Clinical studies in other similar conditions (e.g., osteoarthritis) appear warranted to further investigate the efficacy of this botanical product in more specific settings.

Eur Rev Med Pharmacol Sci. 2017 Nov;21(22):5258-5263.
PMID: 29228442 [PubMed - indexed for MEDLINE]


Chemical Composition and Monoterpenoid Enantiomeric Distribution of the Essential Oils from Apharsemon (Commiphora gileadensis).
Dudai N, Shachter A, Satyal P, Setzer WN

(Hebrew: apharsemon) has been used since Biblical times to treat various ailments, and is used today in the traditional medicine of some Middle Eastern cultures. The essential oils from the stem bark, leaves, and fruits of -collected at the Ein Gedi Botanical Garden, Israel-were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. In addition, the enantiomeric distributions of the monoterpenoids in the essential oils have been determined by chiral gas chromatography. The essential oils were dominated by monoterpene hydrocarbons, followed by oxygenated monoterpenoids. The major components in oils were the monoterpenes α-pinene (11.1-18.4%), sabinene (15.8-35.9%), β-pinene (5.8-18.0%), -cymene (4.8-8.4%), limonene (1.3-6.2%), γ-terpinene (0.7-8.1%), and terpinen-4-ol (5.3-18.5%). The (-)-enantiomers predominated for α-pinene, sabinene, β-pinene, limonene, and terpinen-4-ol. The chemical compositions of the essential oils from Israel are markedly different from previously reported samples, which were rich in sesquiterpenoids. Likewise, the enantiomeric distribution of monoterpenoids is very different from spp. essential oils.

Medicines (Basel). 2017 Sep;4(3):.
PMID: 28930280 [PubMed - as supplied by publisher]


Extraction and purification of five terpenoids from olibanum by ultrahigh pressure technique and high-speed countercurrent chromatography.
Yu J, Zhao H, Wang D, Song X, Zhao L, Wang X

Five terpenoids, including two new ones, 3,7-dioxo-tirucalla-8,24-dien-21-oic acid (2) and 3α-acetoxyl-7-oxo-tirucalla-8,24-dien-21-oic acid (3), and three known ones, boscartol A (1), 11-keto-β-boswellic acid (4), and acetyl-11-keto-boswellic acid (5), have been extracted by the ultrapressure extraction and purified by pH-zone-refining countercurrent chromatography and high-speed countercurrent chromatography from olibanum. For ultrapressure extraction, the optimal condition including 200 MPa of extraction pressure, ethyl acetate of extraction solvent, 1:20 (g/mL) of solid/liquid ratio, and 2 min of extraction time were obtained. For the separation, from 1.5 g of the terpenoid extract, 220.1 mg of 4, 255.5 mg of 5, and 212.3 mg of the mixture of 1, 2, and 3 were obtained by pH-zone-refining countercurrent chromatography under the solvent system of chloroform/ethyl acetate/methanol/water (3:1:3:2, v/v/v/v) with aqueous ammonia and trifluoroacetic acid as retention and eluter agents. The enriched mixture (210 mg) was further separated by conventional high-speed countercurrent chromatography with petroleum ether/ethyl acetate/methanol/water (1:0.8:1.1:0.6, v/v/v/v), yielding 30.1 mg of 1, 35.5 mg of 2, 12.3 mg of 3. The structures of these five terpenoids were elucidated by extensive spectroscopic methods.

J Sep Sci. 2017 Jul;40(13):2732-2740.
PMID: 28544633 [PubMed - indexed for MEDLINE]


Quantitative Determination of 3-O-Acetyl-11-Keto-βBoswellic Acid (AKBA) and Other Boswellic Acids in Boswellia sacra Flueck (syn. B. carteri Birdw) and Boswellia serrata Roxb.
Mannino G, Occhipinti A, Maffei ME

Boswellia serrata and Boswellia sacra (syn. B. carteri) are important medicinal plants widely used for their content of bioactive lipophilic triterpenes. The qualitative and quantitative determination of boswellic acids (BAs) is important for their use in dietary supplements aimed to provide a support for osteoarthritic and inflammatory diseases. We used High Performance Liquid Chromatography (HPLC)-Diode Array Detector (DAD) coupled to ElectroSpray Ionization and tandem Mass Spectrometry (ESI-MS/MS) for the qualitative and quantitative determination of BAs extracted from the gum resins of B. sacra and B. serrata. Limit of detection (LOD), limit of quantification (LOQ), and Matrix Effect were assessed in order to validate quantitative data. Here we show that the BAs quantitative determination was 491.20 g·kg-1 d. wt (49%) in B. sacra and 295.25 g·kg-1 d. wt (30%) in B. serrata. Lower percentages of BAs content were obtained when BAs were expressed on the gum resin weight (29% and 16% for B. sacra and B. serrata, respectively). The content of Acetyl-11-Keto-β-Boswellic Acid (AKBA) was higher in B. sacra (70.81 g·kg-1 d. wt; 7%) than in B. serrata (7.35 g·kg-1 d. wt; 0.7%). Our results show that any claim of BAs content in either B. sacra or B. serrata gum resins equal to or higher than 70% or AKBA contents of 30% are simply unrealistic or based on a wrong quantitative determination.

Molecules. 2016 Oct;21(10):.
PMID: 27782055 [PubMed - indexed for MEDLINE]


Chemical composition and biological activities of extracts and essential oil of Boswellia dalzielii leaves.
Kohoude MJ, Gbaguidi F, Agbani P, Ayedoun MA, Cazaux S, Bouajila J

CONTEXT: Boswellia dalzielii Hutch. (Burseraceae) is an aromatic plant. The leaves are used for beverage flavouring.

OBJECTIVE: This study investigates the chemical composition and biological activities of various extracts.

MATERIALS AND METHODS: The essential oil was prepared via hydrodistillation. Identification and quantification were realized via GC-MS and GC-FID. Consecutive extractions (cyclohexane, dichloromethane, ethyl acetate and methanol) were carried out and various chemical groups (phenolics, flavonoids, tannins, antocyanins and sugar) were quantified. The volatile compounds of organic extracts were identified before and after derivatization. Antioxidant, antihyperuricemia, anti-Alzheimer, anti-inflammatory and anticancer activities were evaluated.

RESULTS: In the essential oil, 50 compounds were identified, including 3-carene (27.72%) and α-pinene (15.18%). 2,5-Dihydroxy acetophenone and β-d-xylopyranose were identified in the methanol extract. Higher phenolic (315.97 g GAE/kg dry mass) and flavonoid (37.19 g QE/kg dry mass) contents were observed in the methanol extract. The methanol extract has presented remarkable IC=6.10 mg/L for antiDPPH, 35.10 mg/L for antixanthine oxidase and 28.01 mg/L for anti-5-lipoxygenase. For acetylcholinesterase inhibition, the best IC (76.20 and 67.10 mg/L) were observed, respectively, with an ethyl acetate extract and the essential oil. At 50 mg/L, the dichloromethane extract inhibited OVCAR-3 cell lines by 65.10%, while cyclohexane extract inhibited IGROV-1 cell lines by 92.60%.

DISCUSSION AND CONCLUSION: Biological activities were fully correlated with the chemical groups of the extracts. The ethyl acetate and methanol extracts could be considered as potential alternatives for use in dietary supplements for the prevention or treatment of diseases because of these extracts natural antioxidant, antihyperuricemic and anti-inflammatory activities.

Pharm Biol. 2017 Dec;55(1):33-42.
PMID: 27650786 [PubMed - indexed for MEDLINE]


Chemical composition, antiproliferative, antioxidant and antibacterial activities of essential oils from aromatic plants growing in Sudan.
Yagi S, Babiker R, Tzanova T, Schohn H

OBJECTIVE: To explore the potential of essential oil, as therapeutic molecule source, from olibanum of Boswellia papyrifera (Burseraceae), leafy stems of Cymbopogon schoenanthus (Poaceae) and Croton zambesicus (Euphorbiaceae) and rhizome of Cyperus rotundus (Cyperaceae) found in Sudan. Respective essential oil was evaluated for anti-proliferative, antibacterial and antioxidant activity.

METHODS: Essential oils were extracted by hydrodistillation and then analysed by gas chromatography coupled to mass spectrometry (GC-MS). Anti-proliferative activity was determined against human cell lines (MCF7 and MDA-MB231, HT29 and HCT116) by the thiazolyl blue tetrazolium bromide (MTT) procedure. Antioxidant activity was evaluated by diphenyl 2 pycril hydrazil (DPPH) assay. Antibacterial activity was determined against two Gram-positive and two Gram-negative bacteria by microdilution method.

RESULTS: The essential oil from olibanum of Boswellia papyrifera contained mainly alcohol and ester derivatives (46.82%) while monoterpenes (69.84%) dominated in Corton zambesicus oil. Sesquiterpenes were the most highly represented classes of terpene derivatives in Cyperus schoenanthus (71.59%) and Cyperus rotundus (44.26%). Oil of Cymbopogon schoenanthus revealed the best anti-proliferative activity against HCT116 cell line with IC50 value at (19.1 ± 2.0) μg/mL. Oil of Croton zambesicus showed the best antioxidant activity [EC50 (4.20 ± 0.19) mg/mL]. All oils showed good antibacterial activity against Escherichia coli, Bacillus subtilis and Staphylococcus aureus with minimum inhibitory concentration (MIC) value ranged from 16 to 250 μg/mL.

CONCLUSIONS: The results suggest that the essential oils of these plants could be used as a source of natural anti-proliferative, antioxidant and antibacterial agents.

Asian Pac J Trop Med. 2016 Aug;9(8):763-70.
PMID: 27569885 [PubMed - as supplied by publisher]


Simultaneous quantification of triterpenoic acids by high performance liquid chromatography method in the extracts of gum resin of Boswellia serrata obtained by different extraction techniques.
Sharma N, Bhardwaj V, Singh S, Ali SA, Gupta DK, Paul S, Satti NK, Chandra S, Verma MK

BACKGROUND: Boswellia serrata, also known as Indian frankincense is a commercially important medicinal plant which has been used for hundreds of years as an Ayurvedic medicine for the attempted treatment of arthritis. It contains naturally occurring triterpenoic acids, called as boswellic acids (BA's).

RESULTS: A highly reproducible High performance liquid chromatography-ultraviolet diode array detection (HPLC-UV-DAD) method was developed for the simultaneous determination and quantitative analysis of eight major triterpenoic acids in Boswellia serrata gum resin obtained by different extraction techniques. All the calibration curves exhibited good linear regression (R(2) > 0.997) within the test ranges. The established method showed good precision and overall recoveries of the boswellic acids.

CONCLUSIONS: The eight triterpenoic acids coded as BS-1 (11-keto-beta-boswellic acid), BS-2 (3-O-acetyl-11-keto-beta-boswellic acid), BS-3 (3-keto tirucallic acid), BS-4 (3-O-acetyl-alpha-tirucallic acid), BS-5 (3-O-acetyl-beta-tirucallic acid), BS-6 (alpha-boswellic acid), BS-7 (beta-boswellic acid) and BS-8 (3-O-acetyl-beta-boswellic acid) were isolated from the processed gum resin of Boswellia serrata by column chromatography. The proposed HPLC method is simple, reliable and has been very useful for the qualitative as well as quantitative analysis of boswellic acids in the gum resin of Boswellia serrata. The proposed method allows to quantify boswellic acids in appreciable amounts by HPLC-UV (DAD) method in the extracts and the available marketed formulations.Graphical abstractIsolation & separation of eight Triterpenoic acids from Boswellia serrata.

Chem Cent J. 2016;10():49.
PMID: 27493682 [PubMed - as supplied by publisher]


Endophytic Fungi from Frankincense Tree Improves Host Growth and Produces Extracellular Enzymes and Indole Acetic Acid.
Khan AL, Al-Harrasi A, Al-Rawahi A, Al-Farsi Z, Al-Mamari A, Waqas M, Asaf S, Elyassi A, Mabood F, Shin JH, Lee IJ

Boswellia sacra, an economically important frankincense-producing tree found in the desert woodlands of Oman, is least known for its endophytic fungal diversity and the potential of these fungi to produce extracellular enzymes and auxins. We isolated various fungal endophytes belonging to Eurotiales (11.8%), Chaetomiaceae (17.6%), Incertae sadis (29.5%), Aureobasidiaceae (17.6%), Nectriaceae (5.9%) and Sporomiaceae (17.6%) from the phylloplane (leaf) and caulosphere (stem) of the tree. Endophytes were identified using genomic DNA extraction, PCR amplification and sequencing the internal transcribed spacer regions, whereas a detailed phylogenetic analysis of the same gene fragment was made with homologous sequences. The endophytic colonization rate was significantly higher in the leaf (5.33%) than the stem (0.262%). The Shannon-Weiner diversity index was H' 0.8729, while Simpson index was higher in the leaf (0.583) than in the stem (0.416). Regarding the endophytic fungi's potential for extracellular enzyme production, fluorogenic 4-methylumbelliferone standards and substrates were used to determine the presence of cellulases, phosphatases and glucosidases in the pure culture. Among fungal strains, Penicillum citrinum BSL17 showed significantly higher amounts of glucosidases (62.15±1.8 μM-1min-1mL) and cellulases (62.11±1.6 μM-1min-1mL), whereas Preussia sp. BSL10 showed significantly higher secretion of glucosidases (69.4±0.79 μM-1min-1mL) and phosphatases (3.46±0.31μM-1min-1mL) compared to other strains. Aureobasidium sp. BSS6 and Preussia sp. BSL10 showed significantly higher potential for indole acetic acid production (tryptophan-dependent and independent pathways). Preussia sp. BSL10 was applied to the host B. sacra tree saplings, which exhibited significant improvements in plant growth parameters and accumulation of photosynthetic pigments. The current study concluded that endophytic microbial resources producing extracellular enzymes and auxin could establish a unique niche for ecological adaptation during symbiosis with the host Frankincense tree.

PLoS One. 2016;11(6):e0158207.
PMID: 27359330 [PubMed - indexed for MEDLINE]


Sensitivity of clinical isolates of Candida to essential oils from Burseraceae family.
Nikolic M, Smiljkovic M, Markovic T, Cirica A, Glamoclija J, Markovic D, Sokovic M

The aim of this study was to investigate the chemical composition and antifungal activity of four commercial essential oils from the Burseraceae family - two Boswellia carterii Flueck oils, Canarium luzonicum (Blume) A. Gray oil, and Commiphora myrrha (Nees) Engl oil, against most common Candida spp. recovered from the human oral cavity. The essential oil samples were analyzed by GC-FID and GC/MS. The analysis showed that major essential oils' components were α-pinene (23.04 % and 31.84 %), limonene (45.62 %) and curzerene (34.65 %), respectively. Minimum inhibitory (MIC) and minimum fungicidal (MFC) concentrations were determined using a microdilution standardized technique. All tested Candida spp. clinical isolates and ATCC strains showed susceptibility to tested essential oils in a dose dependent manner. The strongest antifungal activity was shown by essential oil of B. carterii, sample 2; the average MIC values ranged from 1.25 to 1.34 mg/ml, and MFC values ranged from 2.50 to 3.75 mg/ml, depending on the fungus. This study supports the possible use of essential oils from the Bursecaceae family in reduction and elimination of Candida spp. populations in patients with oral cavity fungal infections.

EXCLI J. 2016;15():280-9.
PMID: 27330531 [PubMed - as supplied by publisher]


Ursane and tirucallane-type triterpenes of Boswellia rivae oleo-gum resin.
Manguro LO, Wagai SO

Two new ursane-type triterpenes characterized as 3-oxo-24-acetoxy-11α-hydroxy-urs-12-ene (1) and methyl 3α-acetoxy-11α-methoxy-urs-12-en-24-oate (2), together with known compounds 3-11, were isolated from Boswellia rivae oleo-gum resin exudate. Their structural elucidation was accomplished using physical, chemical, and spectroscopic methods. The compounds exhibited weak to moderate antibacterial activities against some Gram-positive and Gram-negative bacteria.

J Asian Nat Prod Res. 2016 Sep;18(9):854-64.
PMID: 27049028 [PubMed - indexed for MEDLINE]


Frankincense Revisited, Part II: Volatiles in Rare Boswellia Species and Hybrids.
Niebler J, Eslamieh J, Buettner A

In this second part of the investigation of volatiles and semivolatiles in Boswellia gum resins, an additional five less common species were analyzed by (SPME-)GC/MS, namely B. ameero, B. elongata, B. neglecta, B. popoviana, and B. rivae. Moreover, the results of hybridization experiments are reported in combination with the volatile composition of their gum resins. Our study shows that B. sacra benefits from an intraspecific cross-pollination, as the resulting hybrid B. sacra var. supersacra has a far higher seed germination rate and viability.

Chem Biodivers. 2016 May;13(5):630-43.
PMID: 27012302 [PubMed - indexed for MEDLINE]


Frankincense Revisited, Part I: Comparative Analysis of Volatiles in Commercially Relevant Boswellia Species.
Niebler J, Buettner A

The genus Boswellia comprises many species which are famous for their production of frankincense, a fragrant gum resin. In the published literature, manifold studies on the volatiles and semivolatiles in individual samples of these gum resins exist, yet very few studies have investigated multiple samples. Contradictory results with regard to the volatile composition exist in literature. In this first part of the study, a large sample set (n = 46) of mostly commercially obtained gum resins and essential oils was investigated by solid-phase microextraction gas chromatography/mass spectrometry. A total of 216 compounds were identified or tentatively identified from the four commercially relevant species, namely B. sacra, B. serrata, B. papyrifera, and B. frereana, and the statistical evaluation of the resulting chemical profiles allowed a clear distinction between the species by their volatile profile. With only few exceptions, the designated species was found to be in accordance with the composition reported in reliable literature sources and detected in botanically identified samples. Chemotaxonomic marker substances were suggested to facilitate the differentiation of commercial gum resins or essential oils based on their volatile profile.

Chem Biodivers. 2016 May;13(5):613-29.
PMID: 27012219 [PubMed - indexed for MEDLINE]


Fragrant Sesquiterpene Ketones as Trace Constituents in Frankincense Volatile Oil of Boswellia sacra.
Niebler J, Zhuravlova K, Minceva M, Buettner A

In a previous study, two highly potent yet unidentified odorants were detected that were present at trace levels in the volatile fraction of Boswellia sacra gum resin. These two compounds were isolated semipreparatively from the volatile oil by a sensory-guided fractionation process involving microscale bulb-to-bulb distillation, countercurrent chromatography, and preparative gas chromatography. In this manner, the two oxygenated sesquiterpenes could be identified as rotundone (1) and mustakone (2). Compound 2 is described for the first time as a potent odorant with a very low odor threshold.

J Nat Prod. 2016 Apr;79(4):1160-4.
PMID: 27010489 [PubMed - indexed for MEDLINE]


Extraction and Characterization of Boswellia Serrata Gum as Pharmaceutical Excipient.
Panta S, Malviya R, Sharma P

BACKGROUND: This manuscript deals with the purification and characterization of Boswellia serrata gum as a suspending agent. The Boswellia serrata gum was purchased as crude material, purified and further characterized in terms of organoleptic properties and further micromeritic studies were carried out to characterize the polymer as a pharmaceutical excipient. The suspending properties of the polymer were also evaluated. The results showed that the extracted gum possesses optimum organoleptic as well as micromeritic and suspending properties.

OBJECTIVES: To characterize Boswellia serrata gum as a natural excipient.

MATERIAL AND METHODS: Boswellia serrata gum, paracetamol, distilled water.

RESULTS: The results showed that the extracted gum possesses optimum organoleptic as well as micromeritic and suspending properties.

CONCLUSIONS: It is concluded from the research work that the gum extracted from Boswellia serrata shows the presence of carbohydrates after chemical tests. All the organoleptic properties evaluated were found to be acceptable. The pH was found to be slightly acidic. Swelling Index reveals that the gum swells well in water. Total ash value was within the limits. The values of angle of repose and Carr's Index of powdered gum powder showed that the flow property was good. IR spectra confirmed the presence of alcohol, amines, ketones, anhydrides and aromatic rings. The suspending properties of Boswellia serrata gum were found to be higher as compared to gum acacia while the flow rate of Boswellia serrata gum (1% suspension) was less than gum acacia (1% suspension). The viscosity measurement of both Boswellia serrata gum suspension and gum acacia suspension showed approximately similar results.

Polim Med. 2015 Jan-Jun;45(1):25-30.
PMID: 26630726 [PubMed - indexed for MEDLINE]


Phytochemical Analysis and Anti-cancer Investigation of Boswellia serrata Bioactive Constituents In Vitro.
Ahmed HH, Abd-Rabou AA, Hassan AZ, Kotob SE

Cancer is a major health obstacle around the world, with hepatocellular carcinoma (HCC) and colorectal cancer (CRC) as major causes of morbidity and mortality. Nowadays, there isgrowing interest in the therapeutic use of natural products for HCC and CRC, owing to the anticancer activity of their bioactive constituents. Boswellia serrata oleo gum resin has long been used in Ayurvedic and traditional Chinese medicine to alleviate a variety of health problems such as inflammatory and arthritic diseases. The current study aimed to identify and explore the in vitro anticancer effect of B. Serrata bioactive constituents on HepG2 and HCT 116 cell lines. Phytochemical analysis of volatile oils of B. Serrata oleo gum resin was carried out using gas chromatography- mass spectrometry (GC/MS). Oleo-gum-resin of B. Serrata was then successively extracted with petroleum ether (extract 1) and methanol (extract 2). Gas-liquid chromatography (GLC) analysis of the lipoidal matter was also performed. In addition, a methanol extract of B. Serrata oleo gum resin was phytochemically studied using column chromatography (CC) and thin layer chromatography (TLC) to obtain four fractions (I, II, III and IV). Sephadex columns were used to isolate β-boswellic acid and identification of the pure compound was done using UV, mass spectra, 1H NMR and 13C NMR analysis. Total extracts, fractions and volatile oils of B. Serrata oleo-gum resin were subsequently applied to HCC cells (HepG2 cell line) and CRC cells (HCT 116 cell line) to assess their cytotoxic effects. GLC analysis of the lipoidal matter resulted in identification of tricosane (75.32%) as a major compound with the presence of cholesterol, stigmasterol and β-sitosterol. Twenty two fatty acids were identified of which saturated fatty acids represented 25.6% and unsaturated fatty acids 74.4% of the total saponifiable fraction. GC/MS analysis of three chromatographic fractions (I,II and III) of B. Serrata oleo gum resin revealed the presence of pent-2-ene-1,4-dione, 2-methyl- levulinic acid methyl ester, 3,5- dimethyl- 1- hexane, methyl-1-methylpentadecanoate, 1,1- dimethoxy cyclohexane, 1-methoxy-4-(1-propenyl)benzene and 17a-hydroxy-17a-cyano, preg-4-en-3-one. GC/MS analysis of volatile oils of B. Serrata oleo gum resin revealed the presence of sabinene (19.11%), terpinen-4-ol (14.64%) and terpinyl acetate (13.01%) as major constituents. The anti-cancer effect of two extracts (1 and 2) and four fractions (I, II, III and IV) as well as volatile oils of B. Serrata oleo gum resin on HepG2 and HCT 116 cell lines was investigated using SRB assay. Regarding HepG2 cell line, extracts 1 and 2 elicited the most pronounced cytotoxic activity with IC50 values equal 1.58 and 5.82 μg/mL at 48 h, respectively which were comparable to doxorubicin with an IC50 equal 4.68 μg/mL at 48 h. With respect to HCT 116 cells, extracts 1 and 2 exhibited the most obvious cytotoxic effect; with IC50 values equal 0.12 and 6.59 μg/mL at 48 h, respectively which were comparable to 5-fluorouracil with an IC50 equal 3.43 μg/ mL at 48 h. In conclusion, total extracts, fractions and volatile oils of B. Serrata oleo gum resin proved their usefulness as cytotoxic mediators against HepG2 and HCT 116 cell lines with different potentiality (extracts > fractions > volatile oil). In the two studied cell lines the cytotoxic acivity of each of extract 1 and 2 was comparable to doxorubicin and 5-fluorouracil, respectively. Extensive in vivo research is warranted to explore the precise molecular mechanisms of these bioactive natural products in cytotoxicity against HCC and CRC cells.

Asian Pac J Cancer Prev. 2015;16(16):7179-88.
PMID: 26514509 [PubMed - indexed for MEDLINE]


Cembranoids from the Gum Resin of Boswellia carterii as Potential Antiulcerative Colitis Agents.
Ren J, Wang YG, Wang AG, Wu LQ, Zhang HJ, Wang WJ, Su YL, Qin HL

Eight new cembranoids, boscartins A-H (1, 2, and 4-9), and the known incensole oxide were isolated from the gum resin of Boswellia carterii. The absolute configurations of 1, 2, 4, and incensole oxide were unequivocally resolved using single-crystal X-ray diffraction analysis with Cu Kα radiation, and the absolute configuration of 5 was resolved via electronic circular dichroism data. The antiulcerative colitis activities of the compounds were evaluated in an in vitro x-box-binding protein 1 (XBP 1) transcriptional activity assay using dual luciferase reporter detection. At 10 μM, compounds 1, 5, 6, and 7 significantly activated XBP 1 transcription with EC50 values of 0.34, 1.14, 0.88, and 0.42 μM, respectively, compared with the pGL3-basic vector control.

J Nat Prod. 2015 Oct;78(10):2322-31.
PMID: 26457560 [PubMed - indexed for MEDLINE]


Identification of dehydroabietc acid from Boswellia thurifera resin as a positive GABAA receptor modulator.
Rueda DC, Raith M, De Mieri M, Schöffmann A, Hering S, Hamburger M

In a two-microelectrode voltage clamp assay with Xenopus laevis oocytes, a petroleum ether extract (100 μg/mL) of the resin of Boswellia thurifera (Burseraceae) potentiated GABA-induced chloride currents (IGABA) through receptors of the subtype α₁β₂γ₂s by 319.8% ± 79.8%. With the aid of HPLC-based activity profiling, three known terpenoids, dehydroabietic acid (1), incensole (2), and AKBA (3), were identified in the active fractions of the extract. Structure elucidation was achieved by means of HR-MS and microprobe 1D/2D NMR spectroscopy. Compound 1 induced significant receptor modulation in the oocyte assay, with a maximal potentiation of IGABA of 397.5% ± 34.0%, and EC₅₀ of 8.7 μM ± 1.3 μM. This is the first report of dehydroabietic acid as a positive GABAA receptor modulator.

Fitoterapia. 2014 Dec;99():28-34.
PMID: 25200370 [PubMed - indexed for MEDLINE]


Micropropagation and non-steroidal anti-inflammatory and anti-arthritic agent boswellic acid production in callus cultures of Boswellia serrata Roxb.
Nikam TD, Ghorpade RP, Nitnaware KM, Ahire ML, Lokhande VH, Chopra A

Micropropagation through cotyledonary and leaf node and boswellic acid production in stem callus of a woody medicinal endangered tree species Boswellia serrata Roxb. is reported. The response for shoots, roots and callus formation were varied in cotyledonary and leafy nodal explants from in vitro germinated seeds, if inoculated on Murshige and Skoog's (MS) medium fortified with cytokinins and auxins alone or together. A maximum of 8.0 ± 0.1 shoots/cotyledonary node explant and 6.9 ± 0.1 shoots/leafy node explants were produced in 91 and 88 % cultures respectively on medium with 2.5 μM 6-benzyladenine (BA) and 200 mg l(-1) polyvinylpyrrolidone (PVP). Shoots treated with 2.5 μM IBA showed the highest average root number (4.5) and the highest percentage of rooting (89 %). Well rooted plantlets were acclimatized and 76.5 % of the plantlets showed survival upon transfer to field conditions. Randomly amplified polymorphic DNA (RAPD) analysis of the micropropagated plants compared with mother plant revealed true-to-type nature. The four major boswellic acid components in calluses raised from root, stem, cotyledon and leaf explants were analyzed using HPLC. The total content of four boswellic acid components was higher in stem callus obtained on MS with 15.0 μM IAA, 5.0 μM BA and 200 mg l(-1) PVP. The protocol reported can be used for conservation and exploitation of in vitro production of medicinally important non-steroidal anti-inflammatory metabolites of B. serrata.

Physiol Mol Biol Plants. 2013 Jan;19(1):105-16.
PMID: 24381442 [PubMed - as supplied by publisher]


11α-Ethoxy-β-boswellic acid and nizwanone, a new boswellic acid derivative and a new triterpene, respectively, from Boswellia sacra.
Al-Harrasi A, Ali L, Ur Rehman N, Hussain J, Hussain H, Al-Rawahi A, Shamim Rizvi T

A new boswellic acid derivative, 11α-ethoxy-β-boswellic acid (EBA; 1) and a new ursane-type triterpene, named nizwanone (2), were isolated from Omani frankincense Boswellia sacra Flueck. together with two known compounds papyriogenin B and rigidenol. The structures of 1 and 2 were elucidated by detailed spectroscopic analysis using (1) H- and (13) C-NMR, (1) H,(1) H-COSY, HMQC, HMBC, and HR-EI-MS techniques. The relative configurations of 1 and 2 were assigned by comparative analysis of the NMR spectral data with those of known analogs together with NOESY experiments. Structures of known compounds were identified by comparison with the reported data.

Chem Biodivers. 2013 Aug;10(8):1501-6.
PMID: 23939798 [PubMed - indexed for MEDLINE]


Chemistry and biology of essential oils of genus boswellia.
Hussain H, Al-Harrasi A, Al-Rawahi A, Hussain J

The properties of Boswellia plants have been exploited for millennia in the traditional medicines of Africa, China, and especially in the Indian Ayurveda. In Western countries, the advent of synthetic drugs has obscured the pharmaceutical use of Boswellia, until it was reported that an ethanolic extract exerts anti-inflammatory and antiarthritic effects. Frankincense was commonly used for medicinal purposes. This paper aims to provide an overview of current knowledge of the volatile constituents of frankincense, with explicit consideration concerning the diverse Boswellia species. Altogether, more than 340 volatiles in Boswellia have been reported in the literature. In particular, a broad diversity has been found in the qualitative and quantitative composition of the volatiles with respect to different varieties of Boswellia. A detailed discussion of the various biological activities of Boswellia frankincense is also presented.

Evid Based Complement Alternat Med. 2013;2013():140509.
PMID: 23533463 [PubMed - as supplied by publisher]


[Determination of alpha-pinene and octyl acetate contents in Boswellia serrata].
Song Z, Xia L, Wei Z, Cao Y, Zhang L, Liu Z

OBJECTIVE: To establish method for determining the contents of alpha-pinene and octyl acetate in Boswellia serrata, in order to provide preference for making quality standards for B. serrata and processed B. serrata.

METHOD: Application of orthogonal design was employed to optimize the solvent, solvent quantity and extraction time. The GC-MS analysis was performed on a Rxi-5ms silica capillary column, running in the electron impact (EI) mode, with ion trap and injector temperature of 200 degrees C and 250 degrees C, respectively. The column oven was initially 50 degrees C and was held for 1 min after injection, followed by temperature ramping at 5 degrees C x min(-1) up to 130 degrees C, holding for 1 min. 1 microL of samples solution were injected in the split mode (1:60). Helium was the carrier gas. The mass spectrometer was set to scan m/z 45450 with an ionizing voltage at 70 eV.

RESULT: Sample solutions were prepared for 50-fold dose by ultrasonic extraction with hexane for 30 min. The content of alpha-pinene and octyl acetate in 10 batches of B. serrata were 0.021 3-0.149 5, 2.519 6-9.098 0 mg x g(-1), respectively. And, those of alpha-pinene and octyl acetate in processed B. serrata were 0.015 9-0.065 9, 0.801 0-12.812 2 mg x g(-1).

CONCLUSION: The method is a stable and reliable for determining the contents of alpha-pinene and octyl acetate in B. serrata.

Zhongguo Zhong Yao Za Zhi. 2012 May;37(10):1431-3.
PMID: 22860456 [PubMed - indexed for MEDLINE]


[Does a positive finding of tetrahydrocannabinol in the blood result from ingestion of Indian frankincense (Boswellia serrata)?].
Skopp G, Schmitt G

The exculpatory statement that a positive THC finding in the blood is due to the consumption of hemp products or passive exposure to cannabis smoke has been disproved by the monitoring of hemp products and recent passive inhalation studies conducted in social settings, which showed that these conditions are unlikely to produce a positive result in the blood. The defense that the ingestion of Indian olibanum may result in a positive THC concentration in the blood is unusual; it is based on older publications where authors had speculated on a possible association of the synthetic pathways of THC from terpenoid precursors also being present in olibanum and the biogenesis of THC in hemp. It had further been speculated whether chemical or plant-derived pathways may also occur in humans. A thorough understanding of the different pathways and recently published results have outdated these speculations.

Arch Kriminol. 2012 May-Jun;229(5-6):154-62.
PMID: 22834359 [PubMed - indexed for MEDLINE]


Proteoglycans from Boswellia serrata Roxb. and B. carteri Birdw. and identification of a proteolytic plant basic secretory protein.
Herrmann A, König S, Lechtenberg M, Sehlbach M, Vakhrushev SY, Peter-Katalinic J, Hensel A

Water-soluble high molecular weight compounds were isolated in yields of 21-22% from the oleogum of Boswellia serrata and B. carteri. Using anion exchange chromatography and gel permeation chromatography, different proteoglycans were purified and characterized, leading to four principally different groups: (i) Hyp-/Ser-rich extensins with O-glycosidic attached arabinan side chains; (ii) Modified extensins, with arabinogalactosylated side chains containing GlA and 4-O-Me-GlcA; (iii) Glycoproteins with N-glycosidic side chains containing higher amounts of Fuc, Man and GluNH(2,) featuring a 200 kD metalloproteinase that has been de novo sequenced and is described for the first time; (iv) Type II arabinogalactans-proteins. Significant differences between the gums from the two species were observed in the protein content (6% vs 22%), offering the possibility of a quick differentiation of gums from both species for analytical quality control. The data also offer an insight into the plant response towards wound-closing by the formation of extensin and AGP-containing gum.

Glycobiology. 2012 Nov;22(11):1424-39.
PMID: 22773449 [PubMed - indexed for MEDLINE]


Efficient preparation of incensole and incensole acetate, and quantification of these bioactive diterpenes in Boswellia papyrifera by a RP-DAD-HPLC method.
Paul M, Jauch J

Incensole and incensole acetate, found in incense, are encouraging potent bioactive diterpenic cembrenoids, inhibiting Nuclear Factor-kappaB activation. Furthermore, incensole acetate elicits psycho-activity in mice by activating the TRPV3 channels in the brain. Starting from crude extracts of the incense species Boswellia papyrifera Hochst., a convenient procedure for the efficient large-scale synthesis of incensole and its acetate is presented. Additionally, a reversed-phase, diode-array-detection, high-performance liquid chromatography (RP-DAD-HPLC) method for the quantification of incensole and incensole acetate is reported, indicating that these two compounds are typical biomarkers for B. papyrifera.

Nat Prod Commun. 2012 Mar;7(3):283-8.
PMID: 22545396 [PubMed - indexed for MEDLINE]


Composition and antibacterial activity of the essential oils of four commercial grades of Omani luban, the oleo-gum resin of Boswellia sacra FLUECK.
Al-Saidi S, Rameshkumar KB, Hisham A, Sivakumar N, Al-Kindy S

The essential oil compositions of four botanically certified and commercially available samples of Omani lubans (oleo-gum resins of Boswellia sacra Flueck.), locally known as Hoojri, Najdi, Shathari, and Shaabi in Jibali Arabic, obtained from plants growing in four different geographic locations of the Dhofar region of Oman, were analyzed by GC-FID, GC/MS, and (13) C-NMR spectroscopy. The market price of these four grades of lubans differed considerably, according to their color, clump size, and texture. However, this study revealed that Hoojri, the first grade luban, and Shaabi, the fourth grade luban, which greatly differed in their price, closely resembled each other in their essential oil composition, yield, and physicochemical characteristics, except the color and texture. The composition, yield, and specific rotation of the oils of Najdi and Shathari, the second and the third grade lubans, respectively, were different from those of Hoojri and Shaabi, but they both had high limonene contents. Najdi oil was different from the other three oils in terms of its high myrcene content. α-Pinene was the principal component in all the oils and can be considered as a chemotaxonomical marker that confirms the botanical and geographical source of the resins. All the oils showed pronounced activity against a panel of bacteria, and the trend in their bioactivity and their mode of action are discussed.

Chem Biodivers. 2012 Mar;9(3):615-24.
PMID: 22422529 [PubMed - indexed for MEDLINE]


[Determination of five boswellic acids in Boswellia serrata].
Wang C, Xia L, Song Z, Li Q, Wang C, Zeng L, Liu Z

OBJECTIVE: To develop an HPLC method for determinating the contents of five boswellic acids in Boswellia serrata.

METHOD: Analysis was performed on a zorbax SB C18 column eluted with acetonitrile-0.1% phosphoric acid in water as mobile phases in gradient elution and the detection wavelengths were 210 nm and 250 nm.

RESULT: The five ingredients were separated well. The content ranges of alpha-boswellic acid, beta-boswellic acid, 3-acetyl-beta-boswellic acid, 11-keto-beta-boswellic acid and 11-keto-beta-acetyl- boswellic acid were 8.68-16.1, 53.5-246.9, 38.4-192.9, 4.48-5.81, 32.7-44.2 mg x g(-1), respectively.

CONCLUSION: The contents of five individual boswellic acids were different in 12 batches of B. serrata samples.

Zhongguo Zhong Yao Za Zhi. 2011 May;36(10):1330-3.
PMID: 21837977 [PubMed - indexed for MEDLINE]


Two new triterpenoids from the resin of Boswellia carterii.
Wang F, Li ZL, Cui HH, Hua HM, Jing YK, Liang SW

Two new triterpenoids, 3-oxotirucalla-7,9(11),24-trien-21-oic acid (1) and 18Hα,3β,20β-ursanediol (2), along with 15 known triterpenes, α-amyrin, α-boswellic acid, β-boswellic acid, acetyl α-boswellic acid, acetyl β-boswellic acid, 9,11-dehydro-β-boswellic acid, 9,11-dehydro-α-boswellic acid, acetyl 11α-methoxy-β-boswellic acid, 11-keto-β-boswellic acid, acetyl 11-keto-β-boswellic acid, acetyl α-elemolic acid, 3β-hydroxytirucalla-8,24-dien-21-oic acid, elemonic acid, 3α-hydroxytirucalla-7,24-dien-21-oic acid, and 3α-hydroxytirucall-24-en-21-oic acid, were isolated from the resin of Boswellia carterii Birdw.

J Asian Nat Prod Res. 2011 Mar;13(3):193-7.
PMID: 21409679 [PubMed - indexed for MEDLINE]


Four new ursane-type triterpenes, olibanumols K, L, M, and N, from traditional egyptian medicine olibanum, the gum-resin of Boswellia carterii.
Morikawa T, Oominami H, Matsuda H, Yoshikawa M

Four new ursane-type triterpenes, olibanumols K (1), L (2), M (3), and N (4), were isolated from traditional Egyptian medicine olibanum, the exuded gum-resin from Boswellia carterii BIRDW. Their structures were elucidated on the basis of chemical and physicochemical evidence.

Chem Pharm Bull (Tokyo). 2010 Nov;58(11):1541-4.
PMID: 21048352 [PubMed - indexed for MEDLINE]


New terpenoids, olibanumols D-G, from traditional Egyptian medicine olibanum, the gum-resin of Boswellia carterii.
Morikawa T, Oominami H, Matsuda H, Yoshikawa M

A new prenylaromadendrane-type diterpene, olibanumol D (1), and three new oleanane- and lupane-type triterpenes, olibanumols E (2), F (3), and G (4), were isolated from the traditional Egyptian medicine olibanum, the exuded gum-resin from Boswellia carterii Birdw. Their structures were established mainly on the basis of 1D and 2D NMR spectral data. Compounds 1 and 2 exhibited nitric oxide production inhibitory activity in lipopolysaccharide-activated mouse peritoneal macrophages.

J Nat Med. 2011 Jan;65(1):129-34.
PMID: 20953724 [PubMed - indexed for MEDLINE]


Chemical composition and antimicrobial activity of some oleogum resin essential oils from Boswellia spp. (Burseraceae).
Camarda L, Dayton T, Di Stefano V, Pitonzo R, Schillaci D

The chemical composition of Boswellia carteri (Somalia), B. papyrifera (Ethiopia), B. serrata (India) and B. rivae (Ethiopia) oleogum resin essential oils was investigated using GC-MS to identify chemotaxonomy marker components. Total ion current peak areas gave good approximations to relative concentrations based on GC-MS peak areas. B. carteri and B. serrata oleogum resin oils showed similar chemical profiles, with isoincensole and isoincensole acetate as the main diterpenic components. Both n-octanol and n-octyl acetate, along with the diterpenic components incensole and incensole acetate, were the characteristic compounds of B. papyrifera oleogum resin oil. Hydrocarbon and oxygenated monoterpenes were the most abundant classes of compounds identified in the B. rivae oleogum resin oil. The antimicrobial activities of the essential oils were individually evaluated against different microorganisms including fungi, Gram-positive and Gram-negative bacteria strains. The essential oils with the best activity against fungal strains were those obtained from B. carteri and B. papyrifera with MIC values as low as 6.20 microg/ml. The essential oil of B. rivae resin showed the best activity against C. albicans with a MIC value of 2.65 microg/ml.

Ann Chim. 2007 Sep;97(9):837-44.
PMID: 17970299 [PubMed - indexed for MEDLINE]


Cytotoxic and apoptotic activities of novel amino analogues of boswellic acids.
Shah BA, Kumar A, Gupta P, Sharma M, Sethi VK, Saxena AK, Singh J, Qazi GN, Taneja SC

4-Amino analogues prepared from beta-boswellic acid and 11-keto-beta-boswellic acid, wherein the carboxyl group in ursane nucleus was replaced by an amino function via Curtius reaction, displayed improved cytotoxicity than the parent molecules. The same molecules also exhibited apoptotic activity by inducing DNA fragmentation.

Bioorg Med Chem Lett. 2007 Dec;17(23):6411-6.
PMID: 17950603 [PubMed - indexed for MEDLINE]


Incensole acetate, a novel anti-inflammatory compound isolated from Boswellia resin, inhibits nuclear factor-kappa B activation.
Moussaieff A, Shohami E, Kashman Y, Fride E, Schmitz ML, Renner F, Fiebich BL, Munoz E, Ben-Neriah Y, Mechoulam R

Boswellia resin is a major anti-inflammatory agent in herbal medical tradition, as well as a common food supplement. Its anti-inflammatory activity has been attributed to boswellic acid and its derivatives. Here, we re-examined the anti-inflammatory effect of the resin, using inhibitor of nuclear factor-kappaB alpha (IkappaB alpha) degradation in tumor necrosis factor (TNF) alpha-stimulated HeLa cells for a bioassay-guided fractionation. We thus isolated two novel nuclear factor-kappaB (NF-kappaB) inhibitors from the resin, their structures elucidated as incensole acetate (IA) and its nonacetylated form, incensole (IN). IA inhibited TAK/TAB-mediated IkappaB kinase (IKK) activation loop phosphorylation, resulting in the inhibition of cytokine and lipopolysaccharide-mediated NF-kappaB activation. It had no effect on IKK activity in vitro, and it did not suppress IkappaB alpha phosphorylation in costimulated T-cells, indicating that the kinase inhibition is neither direct nor does it affect all NF-kappaB activation pathways. The inhibitory effect seems specific; IA did not interfere with TNFalpha-induced activation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase. IA treatment had a robust anti-inflammatory effect in a mouse inflamed paw model. Cembrenoid diterpenoids, specifically IA and its derivatives, may thus constitute a potential novel group of NF-kappaB inhibitors, originating from an ancient anti-inflammatory herbal remedy.

Mol Pharmacol. 2007 Dec;72(6):1657-64.
PMID: 17895408 [PubMed - indexed for MEDLINE]


Bioactive constituents from Boswellia papyrifera.
Atta-ur-Rahman , Naz H, Fadimatou , Makhmoor T, Yasin A, Fatima N, Ngounou FN, Kimbu SF, Sondengam BL, Choudhary MI

Phytochemical investigation of the stem bark extract of Boswellia papyrifera afforded two new stilbene glycosides, trans-4',5-dihydroxy-3-methoxystilbene-5-O-{alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranoside (1), trans-4',5-dihydroxy-3-methoxystilbene-5-O-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranoside (2), and a new triterpene, 3alpha-acetoxy-27-hydroxylup-20(29)-en-24-oic acid (3), along with five known compounds, 11-keto-beta-boswellic acid (4), beta-elemonic acid (7), 3alpha-acetoxy-11-keto-beta-boswellic acid (8), beta-boswellic acid (9), and beta-sitosterol (10). The stilbene glycosides exhibited significant inhibition of phosphodiesterase I and xanthine oxidase. The triterpenes (3-9) exhibited prolyl endopeptidase inhibitory activities.

J Nat Prod. 2005 Feb;68(2):189-93.
PMID: 15730241 [PubMed - indexed for MEDLINE]


Aromatic components of the leaves of the New Zealand lemonwood tree Pittosporum eugenioides.
Weston RJ

The major aromatic components of the essential leaf oil of the New Zealand lemonwood tree Pittosporum eugenioides are octyl acetate (33%), terpinen-4-ol (13%), decanol (6%) and (Z)-hex-3-enol (5%). These products are responsible for the characteristic Citrus-like aroma which is detected when the leaves are crushed, a phenomenon which provided the species with its common name. The major component of the oil, octyl acetate is also an abundant component of the essential oils of Heracleum and Boswellia species.

Z Naturforsch C J Biosci. 2004 Jan-Feb;59(1-2):32-4.
PMID: 15018048 [PubMed - indexed for MEDLINE]


Two new macrocyclic diaryl ether heptanoids from Boswellia ovalifoliolata.
Lakshmi Niranjan Reddy V, Ravinder K, Srinivasulu M, Venkateshwar Goud T, Malla Reddy S, Srujankumar D, Prabhakar Rao T, Suryanarayana Murty U, Venkateswarlu Y

The stems of Boswellia ovalifoliolata BAL. & HENRY (Burseraceae) afforded two new macrocyclic diaryl ether heptanoids, ovalifoliolatin A (1) and B (2) together with three known compounds; acerogenin C (3), 3 alpha-hydroxyurs-12-ene (4), and sitost-4-en-3-one (5). The structures were established by means of spectroscopic analysis and compounds 1, 3-5 were evaluated for their antibacterial activity.

Chem Pharm Bull (Tokyo). 2003 Sep;51(9):1081-4.
PMID: 12951452 [PubMed - indexed for MEDLINE]


Immunomodulatory triterpenoids from the oleogum resin of Boswellia carterii Birdwood.
Badria FA, Mikhaeil BR, Maatooq GT, Amer MM

The immunomodulatory bioassay-guided fractionation of the oleogum resin of frankincense (Boswellia carterii Birdwood) resulted in the isolation and identification of 9 compounds; palmitic acid and eight triterpenoids belonging to lupane, ursane, oleanane, and tirucallane skeleta were isolated form the resin. These triterpenoids are lupeol, beta-boswellic acid, 11-keto-beta-boswellic acid, acetyl beta-boswellic acid, acetyl 11-keto-beta-boswellic acid, acetyl-alpha-boswellic acid, 3-oxo-tirucallic acid, and 3-hydroxy-tirucallic acid. The structures of the isolated compounds were deduced based on spectroscopic evidences. The lymphocyte transformation assay of the isolated compounds proved that the total extract retained more activity than that of any of the purified compounds.

Z Naturforsch C J Biosci. 2003 Jul-Aug;58(7-8):505-16.
PMID: 12939036 [PubMed - indexed for MEDLINE]


Analysis of pentacyclic triterpenic acids from frankincense gum resins and related phytopharmaceuticals by high-performance liquid chromatography. Identification of lupeolic acid, a novel pentacyclic triterpene.
Büchele B, Zugmaier W, Simmet T

An HPLC gradient method with photodiode array detection was developed for the simultaneous analysis of 12 different pentacyclic triterpenic acids in Indian and African frankincense gum resins as well as in related phytopharmaceuticals. The triterpenic acids were obtained by an exhaustive extraction procedure. Identification of the compounds was based on retention times, UV-spectra and add on technique with standards isolated from African frankincense. The method allows differentiation of frankincense of different origin and standardization of frankincense-based phytopharmaceuticals. Further, this is the first report identifying a novel pentacyclic triterpene, lupeolic acid, as a constituent of frankincense gum resins.

J Chromatogr B Analyt Technol Biomed Life Sci. 2003 Jul;791(1-2):21-30.
PMID: 12798161 [PubMed - indexed for MEDLINE]


[Study on the detecting methods of the imported materia medica--olibanum].
Shi SM, Tian JG, Wang BQ

OBJECTIVE: To analyse the chemical components of the essential oil of Gum olibanum somalilnds and Gum olibanum Ethiopia, and to set up determination methods of their main components.

METHOD: Two kinds of essential oil are identified by GC-MS, and assayed by Gas chromatography, using SE-54 as the packing material (column 2.1 m x 3.2 mm), with column temperature starting from 80 degrees C, holding for 1 min, and then rising at the rate of 15 degrees C per minute to 170 degrees C.

RESULT: 40 kinds of chemical compounds in the essential oil of Gum olibanum somalilnds and 22 kinds of those of Gum olibanum Ethiopia were identified by GC-MS, the main component in the essential oil of Gum olibanum somalilnds being alpha-pinene, and the main one of Gum olibanum Ethiopia being Octyl acetate 17 batches of samples were determined with the linear range of alpha-pinene being 0-10.80 micrograms, the correlation coefficient being 0.9995, the recovery being 98.16%, RSD being 1.83%; the linear range of Octyl acetate being 0-10.32 micrograms, the correlation coefficient being 0.9996, the recovery being 99.56%, and RSD being 1.36%.

CONCLUSION: This study can be used for the setting up of the specification of Olibanum.

Zhongguo Zhong Yao Za Zhi. 2002 Mar;27(3):170-3.
PMID: 12774394 [PubMed - indexed for MEDLINE]


[Chemical components of Boswellia carterii].
Zhou JY, Cui R

AIM: To investigate the chemical components of Boswellia carterii.

METHODS: Chromatographic technologies were used for separation and purification, while spectral analysis was used for structure elucidation.

RESULTS: Six compounds were isolated and their structures were identified as acetyl-alpha-boswellic acid (1), acetyl-beta-boswellic acid (2), lup-20(29)-ene-3 alpha-acetoxy-24-oic acid (3), alpha-boswellic acid (4), beta-boswellic acid (5) and acetyl-11-keto-beta-boswellic acid (6).

CONCLUSION: Compound 3 is a new constituent.

Yao Xue Xue Bao. 2002 Aug;37(8):633-5.
PMID: 12567779 [PubMed - indexed for MEDLINE]


A lupane triterpene from frankincense (Boswellia sp., Burseraceae).
Culioli G, Mathe C, Archier P, Vieillescazes C

A new lupane-type triterpene, 3alpha-hydroxy-lup-20(29)-en-24-oic acid, was isolated from the methanolic extract of "Erytrean-type" resin of commercial frankincense together with the known 3alpha-hydroxy-olean-12-en-24-oic acid (alpha-boswellic acid) and 3alpha-hydroxy-urs-12-en-24-oic acid (beta-boswellic acid). Their structures were characterized on the basis of chemical and spectral evidence including two dimensional NMR experiments and mass spectrometric techniques.

Phytochemistry. 2003 Feb;62(4):537-41.
PMID: 12560022 [PubMed - indexed for MEDLINE]


Isolation and structure of a 4-O-methyl-glucuronoarabinogalactan from Boswellia serrata.
Sen AK, Das AK, Banerji N, Vignon MR

Carbohydr Res. 1992 Jan;223():321-7.
PMID: 1596930 [PubMed - indexed for MEDLINE]


Triterpenes of Boswellia frereana.
Proietti G, Strapaghetti G, Corsano S

Planta Med. 1981 Apr;41(4):417.
PMID: 17401871 [PubMed - as supplied by publisher]