摘要:

The spectral data of the crystalline samples of 11α-H and 11β-H epimers of Azadirachtin H is presented. 11α-H epimer is converted to the 11β-H epimer under extremely mild conditions while the reverse conversion cannot be achieved.

ISSN:1057-5634    

DOI:10.1080/10575639908048780

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Caryophyllene-6,7-episulfide (3), humulene-9,10- (4) and -6, 7-episulfide (5) found in hop oil, were prepared by heating caryophyllene or humulene with sulfur at 120°C. Examination of various types of olefins showed that this peculiar reaction occurred only to the medium ring olefins.

ISSN:1057-5634    

DOI:10.1080/10575639908048781

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

(-)11α-Hydroxy-7-13-abietadiene (1) was isolated from wood oil of an elite clone of sugiCryptomeria japonica. Its structure was established by a ID and 2D NMR study.

ISSN:1057-5634    

DOI:10.1080/10575639908048782

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Two novel bicyclic taxane diterpenoids were isolated from the needles of the Chinese yew,Taxus mairei, the structures were established as (3E,8E)-5α-hydroxy-2α,7β,9,10β,20-pentaacetoxy-3,8-secotaxa-3,8,11-trien-13-one and (3E,8E)-2α,5α, 20-trihydroxy-7β,9 10β-triacetoxy-3,8-secotaxa-3,8,11 -trien-13-one with the aid of spectroscopic techniques.

ISSN:1057-5634    

DOI:10.1080/10575639908048783

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Nine taxane diterpenoids were isolated from the seeds ofTaxus mairei. One of them was a novel compound with the structure (1) which was established as 9α, 10β, 13α-triacetoxy-5α(3′ -methylamino-3′ -phenyl)-propionyloxy-taxa-4(20), 11 -diene on the basis of1H NMR data and HR-EI-MS analysis.

ISSN:1057-5634    

DOI:10.1080/10575639908048784

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Two new triterpenes have been obtained from the aerial part of Salvia mellifera and their structures identified on the basis of spectroscopic data and chemical correlations as 11α-hydroxy-urs-12-en-3-one and 11β-hydroxy-3-oxo-urs-12-en-28-oic acid. the known triterpenes ursolic acid, oleanolic acid, ursa-9(11),12-dien-3-one, ursa-9(11),12-dien-3β-ol, β-amirine and the sterol β-sitosterol were also isolated from the same source.

ISSN:1057-5634    

DOI:10.1080/10575639908048785

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Ophrypetalin, a new bis-tetrahydrofuran acetogenin, was isolated from Ophrypetalum odoratum (Annonaceae) together with the known acetogenins desacetyluvaricin, rolliniastatin-1, dieporeticenin and a mixture of dieporeticanin-1, dieporeticanin-2, and diepoxyrollin. the structures were elucidated by spectroscopic methods. the absolute configurations were established by Mosher's method and by CD measurements.

ISSN:1057-5634    

DOI:10.1080/10575639908048786

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Thirteen new 5-alkylpyrrole-2-carboxaldehydes 1,3,5,6,7,8,9,10, 11,12,13,14 and 15 were isolated from the sponges Mycale microsigmatosa and Desmapsamma anchorata. Their structures were assigned by analysis of the spectroscopic data. the nitrile 1 showed moderate activity againstLeishmania mexicana.

ISSN:1057-5634    

DOI:10.1080/10575639908048787

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Two new cytotoxic dioxopiperazine dimers, 11,11′-dideoxyverticillin A (1) and 11′-deoxyverticillin A (2), and the previously described verticillin A (3), have been isolated from the mycelium of a marine-derived fungus of the genusPenicillium. an inactive, but newbisdethio-bis(methylthio)-dioxopiperazine, 4, was also obtained by extraction of the culture broth. the structures and absolute stereochemistries of the new compounds were assigned on the basis of NMR and CD experiments. Compounds 1 and 2 exhibit potentin vitrocytotoxicity against HCT-116 human colon carcinoma (IC50= 30ng/ml).

ISSN:1057-5634    

DOI:10.1080/10575639908048788

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Phytochemical studies on Senna skinneri and Senna wislizeni have resulted in the isolation of rutin (1), quercetin (2), the new flavonol 5,7-dimethoxyrutin (la) and the aglycon 5,7-dimethoxyquercetin (2a), which is reported for the first time from a natural source. These compounds showed mutagenic activity in Salmonella thyphimurium. D-3-O-methyl-chiro-inositol (3) is reported for the first time in the genus Senna. the stilbenoid piceatannol (4) was isolated from roots of Senna skinneri, and showed antimicrobial activity against S. typhimurium and E. coli.

ISSN:1057-5634    

DOI:10.1080/10575639908048789

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor