摘要:

Three bioactive diketopiperazines,cyclo-(L-prolyl-L-glycine),cyclo-(L-prolyl-L-valine) andcyclo-(L-leucyl-L-proline) were isolated from the phytopathogen fungusFusarium oxysporum.

ISSN:1057-5634    

DOI:10.1080/10575639508043166

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Extracts from the fruits ofCapsicum frutescensLinn. were monitored for their mutagenic activities using the Micronucleus Test. The GC-MSD of the mutagenic fraction, FB4C4, gave 7 peaks. Repeated flash chromatography of FB4C4 gave 2 intractable mixtures, CF-1 and CF-2. CF-2 showed spectral properties comparable to those of natural capsaicin. Spectral analyses of CF-1 suggested that the major component is 3-acetamido-2-methyltetradecane. Results of the Micronucleus Test indicated that CF-1 is mutagenic.

ISSN:1057-5634    

DOI:10.1080/10575639508043167

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Bioassay-guided fractionation of an extract from the marine algaLaurencia majusculaprovided three brominated chamigrane sesquiterpenes (1–3). These compounds produced a novel pattern of antitumor activity against the National Cancer Institute'sin vitrocell line panel. They were cytotoxic to certain cell lines in the colon cancer subpanel at concentrations 10–100 fold lower than the mean cytotoxic concentration observed in the other tumor subpanels.

ISSN:1057-5634    

DOI:10.1080/10575639508043168

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Five new pimarane diterpenes were isolated from the aerial parts ofMomordica balsamina. The structures were established as1–5through spectroscopic studies and chemical methods. All the compounds isolated were tested in vitro for antiviral activity against HIV-1.

ISSN:1057-5634    

DOI:10.1080/10575639508043169

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

3α-Hydroxycarvotagenone and its epimer 3β-hydroxy carvotagenone were isolated as a minor mixture and its structure determined by spectral means. The mixture was then used in cytoprotection experiments. The mixture, in spite of possessing a Michael acceptor, did not show cytoprotective activity. The lack of activity was attributed to the presence of a -OH group next to the β-carbon of the Michael acceptor. This -OH group could react in a intramolecular way yielding an epoxide which would produce the inhibition of the Michael acceptor. In order to confirm this, the mixture was acetylated and the mixture of acetates used in our cytoprotection experiments. The mixture of acetates showed a moderate but significant cytoprotection probing the existence of some kind of stereoelectronic interaction between the acceptor and the nucleophile.

ISSN:1057-5634    

DOI:10.1080/10575639508043170

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A methanol extract of the Caribbean spongeIrcinia felixafforded a mixture of fatty acid esters of variabilin and its isomers. Among these the novel variabilin 11-methyloctadecanoate1was characterized on the basis of spectral, chromatographic and chemical evidence.

ISSN:1057-5634    

DOI:10.1080/10575639508043171

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Methylent-isocopalate, used in the synthesis of bioactive spongianes, was synthesized in four steps from labdanolic acid isolated fromCistus ladaniferus.

ISSN:1057-5634    

DOI:10.1080/10575639508043172

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Labdanolic acid1, an abundant and easily isolable natural product, was transformed by simple and high yielding reactions into drimadiene3, in multigram scale. Compound3could be a versatile synthon for the preparation of antifeedant drimanes.

ISSN:1057-5634    

DOI:10.1080/10575639508043173

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The total synthesis of an antifungal novel amino acid derivative, sphingofungin D (N-acetyl asperfungin) starting frommyo-inositol and (R)-epoxyoctane is described. This synthetic study showed that the undetermined stereochemistry at C-14 in sphingofungins should beR.

ISSN:1057-5634    

DOI:10.1080/10575639508043174

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Elijopyrones A-D (1–4) were isolated from a cultured marine actinomycete (isolate CNB-880). The producing strain was obtained from a sediment collected from the San Elijo Lagoon, Cardiff, California. The structures of the new compounds were determined by comprehensive spectral analyses.

ISSN:1057-5634    

DOI:10.1080/10575639508043175

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor