摘要:

The stems ofHomalium longifoliumhas yielded two isocoumarins, identified as 3-phenylisocoumarin (1) and 3-(3, -dihydroxyphenyl)isocoumarin (2), and the related compound 2-(1-benzoylmethyl)benzoic acid (3). In addition two unusual new glucosides are identified as 6ξ-{4-(para-coumaroyl)-β-glucopyranosyloxy}-3-(1-hydroxy-1-phenyl)-methyl-2,4,5,6-tetrahydrobenzofuran-2-one (4) and 7ξ-hydroxy-2,8′;7,8′-diepoxy-5-(β-glucopyranosyloxy)-(2′-methyl)-benzyl benzoate (5).

ISSN:1057-5634    

DOI:10.1080/10575639508043218

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

N-nitroso-N-ethylurea (NEU) has been used as a mutagen to generate a range of plants of feverfew,Tanacetum parthenium, with altered morphologies and growth habits, to study the quantitative patterns of secondary metabolism in this medicinal species. Morphological and albino mutations were observed in a proportion of plants grown invitrofrom seeds treated with 5 mM NEU. Selective micropropagation of variegated and semi-chlorophyllous lines led to the isolation of normal green, variegated mosaics, semi-chlorophyllous and true albino lines, together with shoots independently exhibiting abnormal growth. Differences in leaf photosynthetic pigment contents of such axenic cultured shoots were assessed spectrophotometrically, with mean chlorophyll concentrations in albino and semi-chlorophyllous tissues of 6% and 34%, and carotenoid concentrations of 8% and 43%, respectively, of mean values in normal green control leaves. HPLC assessments of selected NEU-treated lines for parthenolide, the major bioactive compound in feverfew, indicated that mean (± s.d.) concentrations were consistently lower (P < 0.005) in albino leaf explants (0.52 ± 0.11% dry wt; n = 5) than in normal green leaf tissues (1.85 ± 0.67% dry wt; n = 5). In contrast, some plant accessions, which displayed a chlorophyl;-deficient characteristic, manifested as a uniform, semi-chlorophyllous leaf type, contained exceptionally high levels of parthenolide (maximum 3.54 ± 0.64% dry wt; n = 9). Feverfew seeds exposed to higher concentrations of NEU (10 and 20 mM) gave dysfunctional seedlings, arrested at the cotyledonary leaf-stage; callus induction from the latter seedlings was also impaired.

ISSN:1057-5634    

DOI:10.1080/10575639508043219

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A new eunicellin-type diterpene (2) was isolated from the gorgonianEunicella cavoliniand its structure was proposed by means of spectroscopic data. Brine shrimp and fish lethalities of2are reported.

ISSN:1057-5634    

DOI:10.1080/10575639508043220

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The structure (3S, 5R, 6S, 7E, 9R)-3-hydroxy-5,6-epoxy-β-ionyl-3-O-β-D-glucopyranoside has been attributed to stratioside I, the major component of the methanolic extract ofPistia stratioteson the basis of its spectroscopic features and by analysis using the Mosher method.

ISSN:1057-5634    

DOI:10.1080/10575639508043221

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Three new monoterpene indole alkaloids, 16-hydroxymethyl-pleiocarpamine2, 16-epi-deacetylakuammiline4and 14α-hydroxycondylocarpine8, have been isolated from the stem bark ofKopsia deverrei(Apocynaceae). The proposed structures were assigned after detailed analysis of their1H and13C NMR spectra and by chemical correlation.

ISSN:1057-5634    

DOI:10.1080/10575639508043222

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Kopsilactone and kopsone, two monoterpene alkaloids, have been isolated fromKopsia macrophylla(Apocynaceae) from Malaysia. The structure elucidation involved spectral data analysis and chemical transformations.

ISSN:1057-5634    

DOI:10.1080/10575639508043223

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Reinvestigation of the ascidianDidemnumsp. from Palau revealed that the previously reported metabolites, didemnaketals A (1) and B (2), are artifacts formed as a result of prolonged storage of the ascidian in methanol. Fresh extracts gave a single terpenoid, didemnaketal C (3), which on methanolysis yielded didemnaketal B (2).

ISSN:1057-5634    

DOI:10.1080/10575639508043224

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Extracts of the Palauan spongeIgernellasp. yielded the new sesterterpene igernellin (1) together with halisulfate 3 (2), which had previously been reported from an halichondriid sponge.

ISSN:1057-5634    

DOI:10.1080/10575639508043225

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The biological activities and the structure determination by spectroscopic methods of humicolactone, a new 10-membered lactone possessing antimicrobial and cytotoxic activities isolated from the cultural fluids of the fungusGilmaniella humicola, is reported. The antimicrobial activity of humicolactone was abolished by preincubation with cysteine, suggesting that it is caused by the reactivity of humicolactone.

ISSN:1057-5634    

DOI:10.1080/10575639508043226

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

An antifungal sordaricin derivative containing a tricyclic uronic acid moiety was isolated from the culture fluids of a wood-inhabitingXylariaspecies. The isolation, structure determination and biological activities of the metabolite is described.

ISSN:1057-5634    

DOI:10.1080/10575639508043227

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor