Four new coumarin derivatives from Artemisia keiskeana

Four new coumarin monoterpene ethers, artekeiskeanols A-D (1-4), and three known coumarins, isofraxidin, fraxidin, and daphnoretin, were isolated from the whole plants of Artemisia keiskeana. All structures were determined from spectral data, and that of artekeiskeanol A (1) was confirmed by synthesis.     

Further pterocellins from the New Zealand marine bryozoan Pterocella vesiculosa

Four new alkaloids, pterocellins C-F (1-4), have been isolated from the New Zealand marine bryozoan Pterocella vesiculosa. Structural elucidation was achieved through NMR spectroscopic and mass spectrometric analysis and comparison of spectroscopic data with that of the known compounds pterocellins A and B. The biological activities of 1-4 were assessed in a number of different assay systems and compared with those of pterocellins A and B.     

Convolutindole A and convolutamine H,new nematocidal brominated alkaloids from the marine bryozoan Amathia convoluta

Nematocidal activity of an extract of the marine bryozoan Amathia convoluta, collected from Tasmania's east coast, was ascribed to two novel tribrominated alkaloids: convolutamine H (2) and convolutindole A (5), an indole possessing the unusual N-methoxy moiety. The structures were established by spectroscopic techniques.     

Four new sesquiterpenoid derivatives from the heartwood of Mansonia gagei

Four new sesquiterpenoid derivatives named mansonones N (1), O (2), P (3), and Q (4) were isolated from a dichloromethane extract of the heartwood of Mansonia gagei, a plant used in folk medicine in Thailand. Their structures were resolved on the basis of spectrometric data interpretation and the single-crystal X-ray analysis of 1 and 2.     

南海多室草苔虫甾醇类化学成分研究

目的:研究南海多室草苔虫(Bugula neritina L.)的甾醇类化学成分。方法:采用乙醇提取,硅胶柱色谱,Sephadex LH-20柱色谱等手段进行分离纯化,通过波谱分析,结合文献对照,鉴定化合物结构。结果:从多室草苔虫石油醚部位分离到10个甾醇类化合物,鉴定为:胆甾-4-烯-3-酮(Ⅰ);胆甾醇(Ⅱ);3β,5α,9α-三羟基-(22E,24R)-麦角甾-7,22-二烯-6-酮(Ⅲ);24-甲基-5α-胆甾-72,2-二烯-3β,56,β-三醇(Ⅳ);3β-羟基-7-甲氧基-胆甾-5-烯(Ⅴ);过氧化麦角甾醇(Ⅵ);3β-羟基-胆甾-5-烯-7-酮(Ⅶ);6β-羟基-胆甾-4-烯-3-酮(Ⅷ);胆甾-5-烯-3β,7β-二醇(Ⅸ);胆甾-5,22(E)-二烯-3β7,α-二醇(Ⅹ)。结论:化合物Ⅴ～Ⅹ为首次从该种多室草苔虫中得到。     

New cytotoxic beta-carboline alkaloids from the marine bryozoan, Cribricellina cribraria.

Bioactivity-directed separations led to the isolation of the new alkaloid, 1-vinyl-8-hydroxy-beta-carboline [1], as the major cytotoxic component of the marine bryozoan Cribricellina cribraria. Another new beta-carboline alkaloid 2 with the novel sulfone structure was isolated, together with a number of known beta-carboline compounds. Cytotoxicity and antimicrobial effects are reported for these compounds and for other synthesized beta-carbolines.     

The pterocellins,novel bioactive alkaloids from the marine bryozoan Pterocella vesiculosa

Two new alkaloids, pterocellins A and B, have been isolated from the New Zealand marine bryozoan Pterocella vesiculosa. Structural elucidation was achieved through NMR and mass spectral analysis in conjunction with a single-crystal X-ray diffraction study of pterocellin A. The pterocellins possess a novel heterocyclic skeleton and exhibit potent antitumor activity and antimicrobial activity in vitro but only modest activity in the in vivo hollow fiber assay at the National Cancer Institute.     

Two new xanthone derivatives from the algicolous marine fungus Wardomyces anomalus

A marine fungal isolate, identified as Wardomyces anomalus, was cultivated and found to produce two new xanthone derivatives, 2,3,6,8-tetrahydroxy-1-methylxanthone (1) and 2,3,4,6,8-pentahydroxy-1-methylxanthone (2), in addition to the known xanthone derivative 3,6,8-trihydroxy-1-methylxanthone (3) and the known fungal metabolite 5-(hydroxymethyl)-2-furanocarboxylic acid (4). The structures of all compounds were determined on the basis of extensive spectroscopic measurements (1D and 2D NMR, MS, UV, and IR). Compounds 1 and 4 showed significant antioxidant activities. The total extract and 1, 3, and 4 were shown to be inhibitors of p56(lck)tyrosine kinase.     

Four new bioactive pyrrole-derived alkaloids from the marine sponge Axinella brevistyla.

Four new alkaloids (1-4) were isolated from the marine sponge Axinella brevistyla, and their structures were determined on the basis of spectroscopic analysis. The alkaloids 1-4 were antifungal against the yeast Saccharomyces cerevisiae at <1.0, <1.0, 30, and 100 microg/disk, respectively. Compounds 1-3 also exhibited cytotoxicity against L1210 cells with IC(50) values of 1.1, 0.66, and 2.5 microg/mL, respectively.     

Four new antibacterial sesterterpenes from a marine sponge of the genus Luffariella.

The structures of four new sesterterpenoid compounds 1-4 isolated from a marine sponge of the genus Luffariella, collected from The Great Barrier Reef, Australia, have been determined by analysis of their 1H-nmr, 13C-nmr, ir, uv, and eims spectral data. The new metabolites 1-4 were found to co-occur with the compounds manoalide, secomanoalide, Z-neomanolaide [5], and E-neomanoalide.     

Caulibugulones A-F, novel cytotoxic isoquinoline quinones and iminoquinones from the marine bryozoan Caulibugula intermis

An extract of the marine bryozoan Caulibugula intermis, collected in the Indo-Pacific off Palau, produced a distinct pattern of differential cytotoxicity in the National Cancer Institute's 60 cell line antitumor screen. Bioactivity-directed fractionation of the extract provided six new compounds, caulibugulones A-F (1-6). The structures of these novel metabolites were determined by spectrochemical analyses including LC-MS, HRFABMS, 1-D and 2-D NMR experiments, and by comparison with related compounds. The structures of compounds 2 and 3 were confirmed by chemical interconversion. The isolated compounds exhibited IC(50)'s of 0.03-1.67 microg/mL against murine tumor cells in an in vitro cytotoxicity assay.     

Two new acetylenic derivatives and a new meroditerpenoid from a Taiwanese marine sponge Strongylophora durissima

Further chemical examination of the sponge Strongylophora durissima yielded two new acetylenic derivatives, durissimols A (1) and B (2), and a new meroditerpenoid, strongylophorine-12 (5), in addition to the known acetylenic compounds, reneirin-2 (3), 18-hydroxyreneirin-2, melyne-C (4), duryne, siphanochalynol, and 24-ethylcholesterol (7). Among them, durissimol B (2) and duryne showed potent cytotoxicity against human gastric tumor (NUGC) cells.     

Three new furan derivatives and a new fatty acid from a Taiwanese marine sponge Plakortis simplex

Three new furan derivatives, plakorsins A-C (6-8), together with a new fatty acid, plakortic acid (9), have been isolated from the Taiwanese marine sponge Plakortis simplex in addition to the known metabolites chondrillin (1), 6-epi-chondrillin (2), 2-oxo-2,5-dihydrofuran-5-acetic acid methyl ester (methyl 1,4-epoxy-1-oxo-2-hexenoate) (3), dimethyl beta-ketoadipate (4), and the monomethyl ester of cis,cis-muconic acid (5). The structures of these compounds were established mainly on the basis of spectral data and chemical methods. Biological studies revealed that compound 7 exhibited cytotoxic activity against COLO-250 and KB-16 cells, and compound 1 is active against KB-16 cells.     

Identification and biosynthetic origins of sterols in the marine bryozoan bugula neritina

The sterols of Bugula neritina have been isolated and characterized spectroscopically. Cholesterol was found to be the predominant sterol with C28, C29, and C30 sterols recovered as minor components. In vivo biosynthetic experiments revealed that cholesterol is the only sterol produced by de novo biosynthesis, indicating that the other sterols are of dietary origin. Further, biosynthetic experiments using in vitro techniques indicated that 24-alkylated sterols (4, 5, 7, and 8) are produced by alkylation of dietary sterols, while others are exclusively of dietary origin.     

Antifungal metabolites from the marine sponge Pachastrissa sp.: new bengamide and bengazole derivatives.

This paper reports the studies of components of an undescribed sponge in the genus Pachastrissa sp., collected along the Djibouti coast. The extract showed activity against Candida albicans. Six new bengazoles (1-6) and a new bengamide, named bengamide L (16), in addition to the known bengazoles (7-11), bengamides A (12), B (13), E (14), and F (15), and a lactone (17) are described in this paper. All structures were determined on the basis of spectroscopic studies.     

海洋真菌Aspergillus sp.中的苯甲醛衍生物研究

目的 研究海洋真菌Aspergillus sp.的化学成分及其抗氧化活性.方法 采用硅胶柱色谱、高效液相色谱等方法进行分离纯化,以现代波谱技术和理化性质鉴定化合物的结构,并测定了所得化合物清除DPPH自由基的活性.结果 分离得到6个苯甲醛衍生物,分别鉴定为2-(E-3-庚烯基)-5-异戊烯基-3,6二羟基苯甲醛(1)、二氢金(色)灰绿曲霉素(2)、异二氢金(色)灰绿曲霉素(3)、曲霉素(4)、灰绿曲霉黄色素(5)和毛壳菌吡喃宁(6).结论 化合物1为新化合物,命名为异曲霉素,化合物1～6具有很强的清除DPPH自由基的活性.     

Bryoanthrathiophene,a new antiangiogenic constituent from the bryozoan Watersipora subtorquata (d'Orbigny, 1852)

A new antiangiogenic compound, bryoanthrathiophene (1), together with two known compounds, 5,7-dihydroxy-1-methoxycarbonyl-6-oxo-6H-anthra[1,9-bc]thiophene (2) and 1,8-dihydroxyanthraquinone (3), was isolated from the bryozoan Watersipora subtorquata (d'Orbigny, 1852) using bioassay-guided fractionation methods. Among them, bryoanthrathiophene (1) exhibited the most potent antiangiogenic activity on BAEC (bovine aorta endothelial cell) proliferation.     

Four new lactones from Botrytis cinerea

Four new lactones (1-4) have been isolated from Botrytis cinerea. Their structures were elucidated by interpretation of spectral data, mainly (1)H and (13)C NMR, including two-dimensional analysis (HOMOCOSY, HMQC, and HMBC). The phytotoxic activities of these new natural products have been evaluated. Compounds 1-3 were inactive, while 4 showed a phytotoxic effect when tested up to 250 ppm.     

Four new steroids from two octocorals

In search of analogues of isogosterones A-D (1-4), a group of antifouling 13,17-seco-steroids found in octocorals of the order Alcyonacea, we have isolated four new steroids possessing aromatic, enone, or dienone A-rings from two octocorals, Alcyonium gracillimum and Dendronephthya sp. These compounds, 3-methoxy-19-norpregna-1,3, 5(10),20-tetraene (5), 3-(4-O-acetyl-6-deoxy-beta-galactopyranosyloxy)-19-norpregna-1,3, 5(10),20-tetraene (6), 22,23-dihydroxycholesta-1,24-dien-3-one (7), and methyl 3-oxochola-4,22-dien-24-oate (8), showed no antifouling activity against barnacle (Balanus amphitrite) larvae, but lethality to barnacle larvae at a concentration of 100 &mgr;g/mL (LD(100)).