Triterpene quinone-methides from Gymnosporia montana

Iguesterin, pristimerin, tingenone, beta-amyrin, beta-sitosterol and maytenonic acid have been isolated from the light petroleum extract of the stem bark and iguesterin, pristimerin, tingenone, beta-amyrin and beta-sitosterol from the root bark of Gymnosporia montana.     

Constituents from the non-polar fraction of<Emphasis Type="Italic">Artemisia apiacea</Emphasis>

Five compounds of terpenoids and coumarins were isolated from the non-polar fraction of Artemisia apiacea by open column chromatography. Their structures were elucidated as alpha-amyrin (1), beta-amyrin (2), beta-sitosterol (3), 5,6,7-trimethoxycoumarin (4) and 6-methoxy-7,8-methylenedioxycoumarin (5) by chemical and spectroscopic analysis. This is the first report of the isolation of alpha-amyrin, beta-amyrin, 5,6,7-trimethoxycoumarin and 6-methoxy-7,8-methylenedioxycoumarin from this plant.     

Terpenoids and sterols from Nepeta cataria L. var. citriodora (Lamiaceae)

Isolation and GC/MS quantitative determination of ursolic acid in the herb of Nepeta cataria var. citriodora have been performed. The content of this compound was in the range 0.95-1.30%. Daucosterol (beta-sitosterol 3-O-beta-D-glucoside) was also isolated from the plant, in addition to small amounts of beta-sitosterol, campesterol, alpha-amyrin and beta-amyrin. The content and composition of essential oil in samples of the Nepeta cataria var. citriodora herb have been analysed as well.     

Release of intermediate reactive hydrogen peroxide by macrophage cells activated by natural products

By determining the hydrogen peroxide (H2O2) released in cultures of peritoneal macrophage cells from Swiss mice, we evaluated the action of 27 vegetable compounds (pristimerin, tingenone, jatrophone, palustric acid, lupeol, cladrastin, ocoteine, boldine, tomatine, yohimbine, reserpine, escopoletin, esculine, plumericin, diosgenin, deoxyschizandrin, p-arbutin, mangiferin, and others) using a 2 mg/ml solution of each compound (100 microg/well). Macrophages are cells responsible for the development of the immunological response reaction, liberating more than one hundred compounds into the extracellular environment. Among these are the various cytokines and the intermediate compounds of nitrogen (NO) and oxygen (H2O2). This coordinated sequence of biochemical reactions is known as the "oxidative burst." When we compared the results with those obtained with zymosan (an important stimulator of H2O2) we observed that the compounds showing the highest activity were substances 2 (tingenone), 16 (reserpine) and 20. Other substances such as compounds 1, 4, 5, 6, 8, 12, 13, 14, 15, 17, 19, 23, 24, 26, and 27 also showed a certain activity, but with less intensity than the aforementioned ones. Compounds 3, 7, 9, 10, 11, 18, 21, 22 and 25 presented no activity. These results suggest that natural products (mainly tingenone and reserpine and others) with different chemical structures are strong immunological modulators. However, further tests are needed to determine the 'oxidative burst' in future studies.     

Eudesmanolides and Other Constituents from Artemisia argyi

The phytochemical investigation of the aerial parts of ARTEMISIA ARGYI afforded beta-sitosterol, stigmasterol, alpha-amyrin, beta-amyrin, friedelin, naringenin, quercetin, and four eudesmane derivatives, two of which were new eudesmanolides. The structures of the novel compounds were elucidated by high field NMR techniques.     

Artemisterol, a new steryl ester from the whole plant of Artemisia apiacea

A new steryl ester, artemisterol (1), together with known compounds alpha-amyrin (2), beta-amyrin (3), beta-sitosterol (4), 5,6,7-trimethoxycoumarin (5), and 6-methoxy-7,8-methylenedioxycoumarin (6), were isolated from the methanolic extracts of Artemisia apiacea by repeated column chromatography. The structure of 1 was elucidated as stigmast-5-en-3beta,29-diol 29-p-hydroxycinnamate by spectral data analyses.     

Isolation and frontier molecular orbital investigation of bioactive quinone-methide triterpenoids from the bark of Salacia petenensis

The crude dichloromethane bark extract of Salacia petenensis (Hippocrateaceae) from Monteverde, Costa Rica, shows antibacterial and cytotoxic activity. Bioactivity-directed separation led to the isolation of tingenone and netzahualcoyonol as the biologically active materials. Also isolated from the extract were 3-methoxyfriedel-2-en-1-one (a new natural product) and 29-hydroxyfriedelan-3-one. The structures of these compounds were elucidated on the basis of NMR spectral analysis. Molecular orbital calculations have been carried out using the semi-empirical PM3 and Hartee-Fock 3-21G ab initio techniques on the quinone-methide nortriterpenoids tingenone and netzahualcoyonol, as well as on the nucleotide bases adenine, guanine, cytosine, and thymine. The molecular orbital calculations suggest that a possible mode of cytotoxic action of quinone-methide triterpenoids involves quasi-intercalative interaction of the compounds with DNA followed by nucleophilic addition of the DNA base to carbon-6 of the triterpenoid.     

南蛇藤中扁塑藤素对照品的制备及鉴定

目的 建立从南蛇藤(Celastrus orbiculatus Thunb.) 根皮中制备扁塑藤素(pristimerin)对照品的方法.方法 采用溶剂提取、硅胶柱层析和重结晶等方法对南蛇藤根皮丙酮提取物进行分离纯化,通过MS、IR、1H-NMR和13C-NMR进行结构鉴定,通过薄层色谱(TLC)和高效液相色谱(HPLC)对对照品进行纯度检测.结果 从南蛇藤根皮中分离纯化出扁塑藤素对照品,质量分数＞99.0%.结论 该方法制备的扁塑藤素对照品符合中药化学对照品的相关要求,可作为南蛇藤及其制剂质量控制用的化学对照品.     

Potentially Cytotoxic Triterpenoids from the Root Bark of Siphonodon celastrineus Griff.

A new oleanane-triterpene, 3beta-acetoxy-11alpha-benzoyloxy-13beta-hydroxyolean-12-one (1), was isolated along with a known quinone-methide triterpene, pristimerin (2), from the root bark of Siphonodon celastrineus Griff., a Thai medicinal plant of the family Celastraceae. Their structures were determined based on spectroscopic analysis.     

Isolation of constituents and anti-complement activity from<Emphasis Type="Italic">Acer okamotoanum</Emphasis>

A novel acylated sterol glucoside (1) along with four known compounds, beta-amyrin acetate (2), 3beta,24-dihydroxytaraxer-14-ene (3), cleomiscosin A (4), and cleomiscosin C (5), were isolated from the leaf and twig of Acer okamotoanum Nakai (Aceraceae). The structure of the new compound was determined to be beta-sitosterol glucoside-3'-O-hexacosanoicate based on chemical and spectroscopic analyses. In addition, the novel compound was found to exhibit a significant inhibitory effect (IC50 value of 0.2 microM) on the complement system activated by the classical pathway.     

Sterolic and triterpenoidic constituents of stem bark of Drypetes gossweileri

Four compounds have been identified from the stem bark of Drypetes gossweileri by means of 1H- and 13C-NMR spectroscopy, stearic acid, methyl putranjate, and two new compounds: stigmasterol stearate and beta-sitosterol stearate.     

A new bisabolane sesquiterpenoid from Euphorbia chrysocoma

The new sesquiterpenoid (6R)-2-chloro-6-[(1S)-1,5-dimethylhex-4-en-1-yl]-3-methylcyclohex-2-en-1-one (1), together with ten known compounds, (6R)-6-[(1S)-1,5-dimethylhex-4-en-1-yl]-3-methylcyclohex-2-en-1-one (2), bauerenol acetate (3), lupenone (4), alpha-amyrenone (5), beta-sitosterol (6), stigmasterol (7), beta-amyrin (8), ursolic acid (9), betulinic acid (10), scopolin (11), have been isolated from the roots of Euphorbia chrysocoma Lévl. et Vant. Their structures have been elucidated by spectroscopic data.     

Triterpenes and phytosterols as human leucocyte elastase inhibitors

Ten triterpenes and phytosterols beta-amyrin, lupeol, lupeol acetate, ursolic acid, friedelin, canophyllol, 29-hydroxy-friedelan-3-one, beta-sitosterol, 3- O-beta- D-glucopyranosyl-beta-sitosterol, 3-O-(6'- O-palmitoyl)-beta-D-glucopyranosyl-beta-sitosterol, were evaluated as potential inhibitors of human leucocyte elastase (HLE). In this series, lupeol, ursolic acid and canophyllol showed marked HLE inhibitory activity with IC(50) values at 1.9 microM, 4.4 microM, and 2.5 microM, respectively. It appeared that HLE inhibition depended on the presence and the orientation of two reactive groups in the tested molecules, distant from 10-12 A, reacting with Arg-217 in S(4) -S(5) subsites of the extended substrate-binding domain of HLE, and S(3), respectively.     

Plant Anticancer Agents XXXVII. Constituents of Amanoa oblongifolia1

4'-Demethyldeoxypodophyllotoxin was isolated as the sole cytotoxic constituent of a chloroform-soluble extract of the stem bark of AMANOA OBLONGIFOLIA. Also identified from this extract were a number of noncytotoxic isolates that comprised the lignans, (+)-sesamin and paulownin, the triterpenes, friedelin, canophyllol, betulin, betulinic acid, and ursolic acid, and the sterols, beta-sitosterol and daucosterol.     

Alkaloids from Strychnos floribunda.

From STRYCHNOS FLORIBUNDA stem bark. extracts, the alkaloids bisnordihydrotoxiferine, akagerine, decussine, rouhamine, Strychnocarpine, desacetylisoretuline and isorosibiline were isolated as well as a mixture of the sterols beta-sitosterol, stigmasterol and campesterol. Isorosibiline is a new indole alkaloid derived form desacetylisoretuline, having C-16 configuration inverted to that of rosibiline.     

Alkaloids from Strychnos floribunda

From Strychnos floribunda stem bark extracts, the alkaloids bisnordihydrotoxiferine, akagerine, decussine, rouhamine, Strychnocarpine, desacetylisoretuline and isorosibiline were isolated as well as a mixture of the sterols beta-sitosterol, stigmasterol and campesterol. Isorosibiline is a new indole alkaloid derived form desacetylisoretuline, having C-16 configuration inverted to that of rosibiline.     

A Contribution to the Phytochemistry of Zanthoxylum tessmannii1

Root bark extracts of ZANTHOXYLUM TESSMANNII (Engl.) Ayafor COMB. NOV. (Syn. FAGARA TESSMANNII Engl.) yielded, besides chelerythrine, dihydrochelerythrine, fagaramide and lupeol previously reported from this taxon, ten other compounds viz:nitidine, dihydronitidine, 9-methoxychelerthrine, gamma-fagarine, skimmianine, arctigenin methylether, savinin and a mixture of campesterol, beta-sitosterol and stigmasterol. The implications of the present results for the taxonomic position of ZANTHOXYLUM TESSMANNII is discussed.     

Lipoxygenase inhibition by anadanthoflavone, a new flavonoid from the aerial parts of Anadenanthera colubrina

Chemical investigation of the aerial parts of Anadenanthera colubrina led to the isolation of a new flavonoid named anadanthoflavone ( 1), along with 11 known compounds: alnusenol, lupenone, lupeol, betulinic acid, alpha-amyrin, beta-amyrin, beta-sitosterol, stigmasterol, apigenin, 4-hydroxybenzoic acid and cinnamic acid. The isolated compounds were evaluated for their inhibitory activity on human platelet 12-lipoxygenase (12-hLO), human reticulocyte 15-lipoxygenase (15-hLO) and soybean lipoxygenase-1 (15-sLO). Compound 1 was found to be active against 12-hLO and 15-hLO with IC50 values of 13 +/- 3 microM and 17 +/- 3 microM, respectively. Apigenin selectively inhibited the activity of 15-hLO (IC50 : 4.0 +/- 1 microM), while lupenone, lupeol and alpha-amyrin were found active against 15-sLO (IC50 : 22 +/- 3 microM, 35 +/- 9 microM and 15 +/- 3 microM, respectively).     

In vitro cytotoxicity of norviburtinal and isopinnatal from Kigelia pinnata against cancer cell lines

Crude dichloromethane extracts of Kigelia pinnata stem bark and fruit showed cytotoxic activity in vitro against cultured melanoma and other cancer cell lines using the Sulphorhodamine B assay, which was used for bioassay-guided fractionation. Thin layer chromatography (TLC) examination of the most active fractions of both stem bark and fruits showed the presence of the same major components which were found to be norviburtinal and beta-sitosterol. Norviburtinal was found to be the most active compound but had little selectivity for melanoma cell lines whilst isopinnatal also showed some cytotoxic activity. beta-Sitosterol was found to be comparatively inactive. HPLC analysis of the crude extract showed that the amount of norviburtinal present in the plant material did not account for all of the activity of the total extracts.     

A new diterpenoid glucopyranoside from Erythrophleum fordii

A phytochemical investigation of the bark of Erythrophleum fordii furnished six compounds, of which one is a new diterpenoid glucopyranoside, named 15Z-[dodecahydro-18-hydroxymethyl-17,19,20-trimethyl-15(1H)-phenanthrenylidene]-acetic acid-16-O-beta-D-glucopyranoside (1). Five known compounds were identified as (+)-taxifolin (2), (-)-robinetinidol (3), palmaitic acid (4), beta-sitosterol (5) and baucosteyl (6), and were all isolated from the species for the first time. The structure of the new compound was elucidated on the basis of spectroscopic analyses and chemical methods.