Dammarane triterpenes of Commiphora confusa resin

Fractionation of a steam distilled residue of Commiphora confusa resin has yielded four novel dammarane triterpenes characterised as (20S)-3beta-acetoxy-12beta,16beta-trihydroxydammar-24-ene, (20S)-12beta,16beta-trihydroxydammar-24-ene-3beta-O-beta-glucopyranoside, (20S)-3beta-acetoxy-12beta,16beta,25-tetrahydroxydammar-23-ene, and (20S)-3beta,12beta,16beta,25-pentahydroxydammar-23-ene. The known compounds beta-amyrin, 3beta-amyrinacetate, 2-methoxyfuranodienone, 2-acetoxyfuranodienone, (20R)-3beta-acetoxy-16beta-dihydroxydammar-24-ene, (20R)-3beta,16beta-trihydroxydammar-24-ene, 3beta-acetoxy-16beta-hydroxydammar-24-ene, 3beta-hydroxydammar-24-ene, 3beta-acetoxydammar-24-ene, and beta-sistosterol were also isolated from the same extract. The structures of the compounds were determined using spectroscopic, physical, and chemical methods.     

New dammarane triterpenes from Maytenus macrocarpa

Two new dammarane triterpenes have been isolated from the stem bark exudates of Maytenus macrocarpa. Their structures were determined by extensive 1D and 2D NMR spectroscopic studies as 24(Z)-3-oxodammara-20(21),24-dien-27-oic acid (1) and octa-nor-13-hydroxydammara-1-en-3,17-dione (2). These compounds were tested for antitumoral activity.     

A mass spectrometric study of some triterpenes of the dammarane series

Summary 1. The mass spectra of tetracyclic triterpenes of the dammarane series with substituents at C-3, 6, and 12 and with side chains of various structures have been studied.2. The main direction of fragmentation is the formation of ions as the result of the decomposition of the side chain and of ring C, the second type of fragmentation being controlled by the structure of the side chain.Institute of Biologically Active Substances of the Far-Eastern Scientific Center of the Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 286–294, May–June, 1971.     

Semialactone, isofouquierone peroxide and fouquierone, three new dammarane triterpenes from Rhus javanica

Three new dammarane triterpenes and semialactic acid were isolated from the stem bark of Rhus javanica. The structures of these triterpenes, named semialactone, isofouquierone peroxide and fouquierone, were elucidated by 2D-NMR analysis (HMQC, 1H-1H COSY and HMBC), and the 13C-NMR data of semialatic acid is revised.     

Trevoagenins C and D,dammarane triterpenes from Trevoa trinervis miers.

Trevoagenins C and D are minor triterpenes isolated from Trevoa trinervis Miers. The structure of trevoagenin C was established by chemical and spectroscopic means that of trevoagenin D by X-ray diffraction techniques.     

13C NMR Study of ginseng sapogenins and their related dammarane type triterpenes

In connection with structure studies on dammarane type triterpenes and their glycosides, assignments of ¹³C NMR signals of fifteen 20-hydroxy-dammarane derivatives including Ginseng sapogenins have been achieved by the aid of shift reagents and deuterated compounds. It has been found that the differences of the 17 C, 21 C and 22 C chemical shifts between pairs of C-20 epimers are remarkable especially in the case of 12β-hydroxy derivatives, being significant for the study of the C-20 stereochemistry.     

Protective effects of Commiphora erythraea resin constituents against cellular oxidative damage

By bioguided fractionation of the hexane extract of Commiphora erythraea resin we isolated four furanosesquiterpenoids that were tested for their protective activity against oxidative stress. Furanodienone and 1,10(15)-furanogermacra-dien-6-ones showed to be potent inhibitors of lipid peroxidation (IC(50) of -0.087 μM), being more active than the methoxylated analogues. Furthermore, using BV2 microglial cells, we found that furanodienone from C. erythraea is able to counteract LPS-induced cell death and decrease LPS-induced NO generation thus protecting microglial cells from LPS-induced cytotoxicity. Finally, docking studies were undertaken to gain insight into the possible binding mode of the isolated compounds at 5-LOX binding site.     

Hydroxylation of dammarane type triterpenes with m-chloroperbenzoic acid

Dammaran-20(S)-ol and 20(S)-hydroxydammaran-3β-yl acetate were reacted with $\text{m}$-CPBA to give the corresponding 5α-ol, 7β-ol, 12β-ol, 25-ol, 2α-ol, and 5α,25-diol.     

Antioxidant and antibacterial activities of bark extracts from Commiphora berryi and Commiphora caudata

This study investigates the in vitro antioxidant and antimicrobial activities of eight extracts obtained from the dried barks of Commiphora berryi and Commiphora caudata (Burseraceae). The radical scavenging activity was assessed by 1,1-diphenyl-2-picryl hydrazyl (DPPH) and nitric oxide assays. The methanolic extracts of C. berryi and C. caudata showed significant DPPH radical scavenging activity, with IC?? values of 26.92 and 21.16?μg?mL?1, respectively, and low radical scavenging activity against the nitric oxide assay. The antimicrobial activity of the plants was tested against the Gram-positive and Gram-negative bacteria. The ethyl acetate, chloroform and petroleum ether extracts of C. berryi showed good antibacterial activity against Pseudomonas aeruginosa, with a minimum inhibitory concentration (MIC) of 0.26?mg?mL?1, whereas the ethyl acetate and methanol extracts of C. caudata showed moderate antimicrobial activity with an MIC of more than 2.0?mg?mL?1 against P. aeruginosa compared to the petroleum ether and chloroform extracts, which showed an MIC of 1.1?mg?mL?1. The methanolic extracts of C. berryi and C. caudata also showed moderate cytotoxic activity against a human mammary carcinoma cell line (MCF-7), with values IC?? of 82.6 and 88.4?μg?mL?1, respectively.     

Absolute stereostructures of polypodane-type triterpenes, myrrhanol A and myrrhanone A, from guggul-gum resin (the resin of Balsamodendron mukul)

Two new polypodane-type triterpenes, myrrhanol A and myrrhanone A, were isolated from the 50% aqueous methanolic extract of guggul-gum resin [the resin of Balsamodendron (=Commiphora) mukul HOOK]. The structures of the new constituents, including their absolute configurations, were determined on the basis of chemical and physicochemical evidence.     

Structural analysis of pentacyclic triterpenes from the gum resin of Boswellia serrata by NMR spectroscopy

3α‐Acetyl‐β‐boswellic acid ( 1 ), 3α‐acetyl‐α‐boswellic acid ( 2 ), 3α‐acetyl‐9,11‐dehydro‐β‐boswellic acid ( 3 ), 3α‐acetyl‐9,11‐dehydro‐α‐boswellic acid ( 4 ) and 3α‐acetyl‐11‐keto‐β‐boswellic acid ( 5 ) were isolated from the gum resin of Boswellia serrata. 1D and 2D NMR (COSY45, HMQC, HMBC, ROESY) spectra at 500 MHz were used for shift assignments and structure verification. All boswellic acids investigated share the cis conformation at ring D/E and the 3α orientation of the acetyl ester group. Owing to high‐order spectra, NMR could not determine the exact conformation of H‐20/H‐30 of the β‐boswellic acids. 3α‐Acetyl‐β‐boswellic acid methyl ester ( 1 ^′) was synthesized for experiments with a shift reagent, Eu(fod)₃, that enhanced the resolution considerably. The oxygen atoms of the 3α‐acetyl group form the apparent complex binding site for the shift reagent. Copyright © 2003 John Wiley & Sons, Ltd.     

Chemistry of ayurvedic crude drugs—II : Guggulu (resin from Commiphora mukul)-2: Diterpenoid constituents

Structures of two new diterpenoids, cembrene-A and mukulol are reported. Cembrene-A is one of the two most elementary tetraenes derivable from geranyl-geranyl pyrophosphate by C₁ → C₁₄ cyclization. Mukulol is also a cembrane derivative and is biogenetically closely related to cembrene-A.     

Polymeric derivatives of dipterocarpol, a dammarane triterpenoid

Polymeric derivatives of dammarane triterpenoids with both labile and strong (covalent) polymer-triterpenoid bonds were prepared from N-vinylpyrrolidone copolymers.     

Phytochemical and biological studies on Saudi Commiphora opobalsamum L

The aerial part of Commiphora opobalsamum L. (Burseraceae) growing in Saudi Arabia was subjected to a phytopharmacological investigation in order to identify its major chemical constituents and to evaluate its extracts and isolated compounds in preliminary in vitro assays for antimicrobial, antimalarial, antitumor, anti-inflammatory (COX-2 inhibition), antioxidant and estrogenic activity. Six compounds were isolated and identified as the triterpenes friedelin, canophyllal, and oleanonic acid; the flavonols mearnsetin and quercetin; and syringic acid. The ethyl acetate extract was moderately active against Staphylococcus aureus, Pseudomonas aeruginosa, and Plasmodium falciparum; while the petroleum ether and chloroform extracts inhibited COX-2 at 5 and 10 microg mL(-1), respectively. Of the isolated compounds, syringic acid showed moderate antimalarial, anticandidal, and antimycobacterial activity; while mearnsetin and quercetin exhibited antioxidant activity comparable to ascorbic acid and trolox. This is the first detailed phytochemical investigation of C. opobalsamum L. growing in Saudi Arabia and elsewhere. The isolated compounds are reported from this plant for the first time and their full (1)H and (13)C NMR assignments are included.     

Enzymatic synthesis of cyclic triterpenes

This review covers recent advances in the chemistry and enzymology of squalene cyclase and oxidosqualene cyclase. The enzymatic cyclizations of squalene and oxidosqualene are the most remarkable steps in the biosynthesis of sterols and triterpenes. The polyenes are converted to various polycyclic triterpenes by different enzyme systems employing only small modification of the active-site. Recent crystallographic and structure-based mutagenesis studies as well as utilization of chemically synthesized active-site probes have begun to reveal intimate structural details of the enzyme-templated cyclization reactions. 126 References are cited.