排序方式: 共有19条查询结果,搜索用时 250 毫秒
1.
Summary Optically pure (+)-beta-eudesmol is a possible starting material for the synthesis of several termite defense compounds. A
two step procedure for the isolation of gram quantities of (+)-beta-eudesmol from commercially availableAmyris balsamifera oil (syn. West Indian sandalwood oil), containing 8% beta-eudesmol, was developed. Step one consisted of an efficient vacuum
distillation of the total oil. Step two was a medium pressure LC separation with an AgNO3 impregnated silica gel stationary phase. Several other separation procedures failed due to the presence of many closely related
sesquiterpene alcohols (75% of the oil). 相似文献
2.
Vardamides JC Sielinou VT Akone SH Nkengfack AE Abegaz BM 《Natural product communications》2010,5(10):1535-1538
Chemical investigation of the root bark of Turraeanthus mannii and the stem of T. longipes resulted in the isolation of two new diterpenes, 13-methyl-labda-8(17)-en-15-oic acid (1) and 13-(hydroxymethyl)-14-hydroxy-ent-labda-8(17)-en-15-oic acid (2), along with two known diterpenes, 19-hydroxy-ent-labda-8(17),13-dien-15,16-olide (3) and 19-acetoxy-ent-labda-8(17),13-dien-15,16-olide (4), and the phytosterol, stigmasterol. The structure elucidation of the new compounds has been achieved using spectroscopic techniques. 相似文献
3.
Kamdem Waffo AF Mulholland D Wansi JD Mbaze LM Powo R Mpondo TN Fomum ZT König W Nkengfack AE 《Chemical & pharmaceutical bulletin》2006,54(4):448-451
Two new prenylated xanthones, afzeliixanthones A (1) and B (2), together with three known xanthones (3-5) and two phytosterols, beta-sitosterol and stigmasterol, were isolated from the CH2Cl2/MeOH (1:1) extract of the stem bark of Garcinia afzelii ENGL. collected in the South West Province of Cameroon. Structures were mainly established using one and two-dimensional NMR and mass spectroscopies. The antioxidant activities of the crude extracts as well as the new compounds (1) and (2) were evaluated. 相似文献
4.
Messi BB Ndjoko-Ioset K Hertlein-Amslinger B Lannang AM Nkengfack AE Wolfender JL Hostettmann K Bringmann G 《Molecules (Basel, Switzerland)》2012,17(5):6114-6125
A new flavanone-chromone biflavonoid, preussianone (1), has been isolated from the leaves of Garcinia preussii, along with four known biflavonoids. The absolute stereostructures were elucidated by chemical, spectroscopic, and chiroptical methods. The biological properties of the new biflavonoid against several bacterial strains were evaluated. 相似文献
5.
6.
7.
J. C. Vardamides H. El Alaoui D. L. Massoma A. G. B. Azebaze B. Ndemangou V. T. Sielinou M. Meyer C. P. Vivares Z. T. Fomum A. E. Nkengfack 《Chemistry of Natural Compounds》2008,44(6):696-700
In order to study some biological active products, phytochemical investigation of the stem bark of Turraeanthus africanus have led to the isolation of a novel compound 1, a new benzoic acid derivative, named turraeanthin C, and two known compounds sesamin (2) and stigmasterol. The structures of these compounds were established by spectral analysis, including two-dimensional nuclear
magnetic resonance. The extract and the isolated compounds 1 and 2 showed noteworthy activity against Toxoplasma gondii intracellular parasite in mammals.
Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 564–566, November–December, 2008. 相似文献
8.
Bankeu JJ Mustafa SA Gojayev AS Lenta BD Tchamo Noungoué D Ngouela SA Asaad K Choudhary MI Prigge S Guliyev AA Nkengfack AE Tsamo E Shaiq Ali M 《Chemical & pharmaceutical bulletin》2010,58(12):1661-1665
Two new sphingolipids mucusamide (1) and mucusoside (2) have been isolated from methanol soluble part of the stem bark of Ficus mucuso WELW., together with fifteen known secondary metabolites including cellobiosylsterol (3), β-sitosterol (4), stigmasterol (5), β-sitosterol 3-O-β-D-glucopyranoside (6), lupeol acetate (7), ursolic acid (8), procatechuic acid (9), 2-methyl-5,7-dihydroxychromone 8-C-β-D-glucoside (10), apigenin (11), (-)-epicatechin (12), (+)-catechin (13), N-benzoyl-L-phenylalanilol (14), α-acetylamino-phenylpropyl α-benzoylamino-phenylpropionate (15), asperphenamate (16) and bejaminamide (17). Structures of compounds 1 and 2 were elucidated by spectroscopic analysis and chemical methods. 相似文献
9.
Vardamides JC Dongmo AB Meyer M Ndom JC Azebaze AG Zounda MR Sielinou VT Ndemangou B Nkengfack AE Ngando TM Fomum ZT 《Chemical & pharmaceutical bulletin》2006,54(7):1034-1036
Fractionation of the methanol extract of the stem bark of Turraeanthus africanus led to the isolation of two new alkaloids designated turraeanthin A and B, together with two known alkaloids. The structures of the new alkaloids were elucidated by means of spectroscopic analysis and characterized as 10-O-demethyl-17-O-methyl isoarnottianamide and 11-demethoxyl-12-methoxyl oxynitidine respectively. 相似文献
10.
Kuete V Nono EC Mkounga P Marat K Hultin PG Nkengfack AE 《Natural product research》2011,25(4):432-443
This study was designed at evaluating the antimycobacterial, antibacterial and antifungal activities of the CH2Cl2-CH3OH (1:1) extracts and isolated compounds, namely 3,4-dimethoxy-3',4'-methylenedioxy-7,7'-epoxylignan (1), genkwainin (2), pycnanthulignene C (3), 4,5-dimethoxy-3',4'-methylenedioxy-2,7'-cycloligna-7,7'-diene (4), pycnanthulignene A (5) from the roots, and calycosin (6), biochanin A (7) and prunetin (8), from the fruits of Pycnanthus angolensis. The microplate alamar blue assay and the broth microdilution method were used to determine the minimal inhibitory concentration (MIC) and minimal microbicidal concentration of the samples. The H+-ATPase-mediated proton pumping assay was used to evaluate one of the possible mechanisms of action of the extracts and isolated compounds. The results of MIC determinations showed that the extract from roots was able to prevent the growth of all the studied organisms, including mycobacteria, fungi, and Gram-positive and Gram-negative bacteria. All tested compounds showed antimicrobial activities to different extents, compound 1 and 8 exhibiting the best antimicrobial spectrum, with 92.3% of the tested organisms being sensitive. The results obtained in this study also showed that the extracts as well as most of the compounds were able to inhibit the H(+)-ATPase activity. The overall results provided evidence that P. angolensis and some of its components might be potential sources of antimicrobial drugs against tuberculosis, bacterial and fungal diseases. 相似文献