摘要:

Tyrosinase inhibitory and anti-tumor promoting activities of 14 compounds isolated from safflower and cotton oil cakes were evaluated together with the two genins of glycosides, trachorogenin (8a) and quercetin (12a). Catechin (11) and quercetin (12a) showed moderate tyrosinase inhibitory activity.N-(p-Coumaroyl)serotonin (1) and its 5-O-glucoside (3) exhibited weak anti-tyrosinase activity, but potent inhibitory activity on melanine production in the assay. Serotonin derivatives (1-4). 2-hydroxyarctiin (8), matairesinol glycoside (9) and sesquiterpene glucosides (13, 14) exhibited potent inhibitory activity on phorbol-12-myristate-13-acetate induced Epstein-Barr virus early antigen activation, which is the short termin vitroassay for anti-tumor-promoting activity.

ISSN:1057-5634    

DOI:10.1080/10575630008041225

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A new derivative of pantoic acid, (R-)pantoyllactone-6-O-β-D-xylopyranosyl-β-D-glucopyranoside or pantoyllactone-primeveroside, has been isolated for the first time from etiolated rice seedlings, and its structure determined. While pantoyllactone-glucoside is localized in the coleoptile, the primeveroside, after an initial build-up in the coleoptile, is found in the shoot.

ISSN:1057-5634    

DOI:10.1080/10575630008041226

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The aerial parts ofCentaurea thessalassp.drakiensisafforded, in addition to several known flavonoids and sesquiterpene lactones, a new eudesmanolide. The structure of the compound was elucidated by spectroscopic methods, particularly highfield NMR spectroscopy as 8α-hydroxy-4-epi-sonchucarpolide.

ISSN:1057-5634    

DOI:10.1080/10575630008041227

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A new cyanogenic glycoside, 2S-β-D-apio-D-furanosyl-(1→rightarrow2)-β-D-glucopyranosylmandelonitrile, has been isolated from the leaves ofSambucus nigraalong with the already known sambunigrin, prunasin, holocalin and the acetyl derivative of the latter. The structures were elucidated by chemical and physical methods.

ISSN:1057-5634    

DOI:10.1080/10575630008041228

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Baeyer-Villiger oxidation of acronycine and 2-nitroacronycine led to 6-methoxy-3,3,13-trimethyl-8,13-dihydro-3H-chromeno[5,6-b][4,1]benzoxazepin-8-one (4) and 6-methoxy-3,3,13-trimethyl-2-nitro-8,13-dihydro-3H-chromeno[5,6-b][4,1]benzoxazepin-8-one (6), respectively. Lead tetraacetate oxidation ofcis-1,2-dihydroxy-1,2-dihydroacronycine followed by treatment with sodium borohydride afforded 3-hydroxy-7-methoxy-4,4,13-trimethyl-3,4,8,13-tetrahydro-1H-[1,4]dioxepino[5,6-c]acridin-8-one (13).

ISSN:1057-5634    

DOI:10.1080/10575630008041229

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A novel rearranged limonoid, foritin (1), was isolated from the bark ofHarrisonia perforataand its structure elucidated by 2D NMR.

ISSN:1057-5634    

DOI:10.1080/10575630008041230

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Five diterpenoids of the cladiellin class have been isolated from the gorgonianMuricellasp. The structure of muricellin, a novel metabolite, has been determined by combined spectral methods. This compound and a previously reported diterpenoid exhibited moderate cytotoxicity and inhibitory activity against PLA2.

ISSN:1057-5634    

DOI:10.1080/10575630008041231

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Alkaloids and cytotoxic activity of two samples ofPapaver dubiumsubsp.dubiumand one sample ofP. dubiumsubsp.laevigatumhave been investigated. Berberine (1), thalifendine (2), corydine (3) and isocorydine (4) have been isolated from the first sample ofP. dubiumsubsp.dubium.The second sample of this species yielded berberine (1), thalifendine (2), isocorydine (4), stylopine (5) and tetrahydropseudocoptisine (6) which was isolated for the first time as a natural product. The existence of roemerine (8), mecambrine (9) and allocryptopine (10) has been shown inP. dubiumsubsp.laevigatum.The tertiary extract of the latter showed high cytotoxicity.

ISSN:1057-5634    

DOI:10.1080/10575630008041232

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A new triterpene, 13β-methyl isomer of bauerenol acetate, named mongolenin, has been isolated from the aerial parts ofArtemisia mongolica. The structure was elucidated by spectroscopic methods. Its13C- and1H-NMR chemical shifts have been assigned unambiguously on the basis of detailed 2D-NMR analyses.

ISSN:1057-5634    

DOI:10.1080/10575630008041233

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Transformation of dehydroepiandrosterone (1) was carried out by incubation with the fungusCephalosporium aphidicolato obtain 3β-hydroxyandrost-4-en-17-one (2) and 3β,4β-dihydroxyandrost-5-en-17-one (3). The fermentation of androsterone (4) byTrichothecium roseumafforded 3α, 17β-dihydroxyandrostane (5).

ISSN:1057-5634    

DOI:10.1080/10575630008041234

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor