Three isoflavanones with cannabinoid-like moieties from Desmodium canum

Three further derivatives of 5,7,2',4'-tetrahydroxy-6-methyl isoflavanone have been isolated from the root extract of Desmodium canum and assigned the structures 2,3-dihydro-5,7-dihydroxy-6-methyl-3-(1a,2,3,3a,8b,8c-hexahydro-6-hydroxy-1,1,3a-trimethyl-,6,9-trimethyl 1H-4-oxabenzo[f]cyclobut[c,d]inden-7-yl)-4H-1-benzopyran-4-one (1) 2,3-dihydro-5,7-dihydroxy-6-methyl-3-(6a,7,8,10a-tetrahydro-3-hydroxy-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-2-yl)-4H-1-benzopyran-4-one (2) 2,3-dihydro-5,7-dihydroxy-6-methyl-3-(3-hydroxy-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-2-yl) 4H-1-benzopyran-4-one (3). The three compounds and the previously isolated chromene 4 all derive from the geranylated precursor 5 by a series of cannabinoid-like oxidative rearrangements. (C) 2003 Elsevier Ltd. All rights reserved

A biphenyl, a dihydrophenanthrene and a xanthone from Clusia paralycola

A prenylated biphenyl was isolated in a re-examination of the roots of Clusia paralycola and attributed the structure (5a) and the name clusiaparalycoline D for the similarity with other biphenyls isolated from the same source. A second product, isomeric with the previously isolated paralycolin A, was assigned a 9,10-dihydrophenanthrene structure (6a) and named paralycolin B

New naphthopyrone derivatives from Cassia pudibunda

Further examination of the methanolic extract of the roots of Cassia pudibunda led to isolation of four new angular γ-naphthopyrones identified as 10-demethylflavaspe-rone (1), 10-demethylflavasperone-10-sulphate (2), 10-demethylflavasperone-10-O-β-D-apiof uranosyl-(1→-6)-O-β-D-glucopy-ranoside (3), and cassiapyrone-10-sulphate (7-methyl-10-deme-thylflavasperone-10-sulphate) (4). The antimicrobial activity of the compounds is also reported

(-)-Salzol, an isopimarane diterpene, and a chalcone from Hyptis salzmanii

From the leaves of Hyptis salzmanii a new isopimarane diterpene, named (-)-salzol, and the new 4,2′,6′-trihydroxy-4′-methox,ychalcone were isolated, together with three known lignans, i.e. (+)-sesamin, (-)-cubebins, (-)-hinokinin, three known flavanones, i.e. (-)-isosakuranetin, (±)-sakuranetin, (+)-naringenin-7,4′-dimethylether, and p-methoxycinnamic acid. The structure of 20-benzoyloxy-6β,7β,8β,9α-tetrahydroxyisopimar-15-ene, assigned to (-)-salzol, and the structure of the chalcone were determined on the basis of chemical and spectral dat

Three new flavanone derivatives from the root bark of Sorocea bonplandii Baillon

Three new flavanone derivatives named sorocein C (2), sorocein D (1) and sorocein H (3) together with the known artonin D, kuwanon C, cyclomorusin, and kuwanon J were isolated from the methanolic extract of the roots of Sorocea bonplandii. The structures were assigned on the basis of spectroscopic evidences

Oxazolidin-2-one ring, a popular framework in synthetic organic chemistry: Part 1. The construction of the oxazolidin-2-one ring

The 1,3-oxazolidin-2-one nucleus is a popular heterocycle framework in synthetic organic chemistry, as well as in medicinal chemistry. This paper deals with the huge number of synthetic approaches addressed to the construction of this five-member ring, with a particular care for the mechanistic and stereochemical outcome

Abietane diterpenoids from callus cultures of Taxus baccata

A new compound was isolated from calli of Taxus baccata L. and assigned the structure 3β,11-dihydroxy-12-methoxyabieta-8, 11,13-triene-7-one. Two other metabolites were identified as 3-oxocryptojaponol and taxamairein C, both previously isolated from Taxus mairei

beta-glucosyltransferase in cell cultures of Verbesina caracasana

(E)-3,4-Dimethoxycinnamic acid, inoculated in cell cultures of Verbesina caracasana, was converted to the corresponding beta-glucopyranoside ester, revealing the presence of an exoglucosyltransferase. An extensive study on other cinnamic acid derivatives showed that the aromatic ring must contain at least one methoxy substituent, but no hydroxy group, for the esterification to be performed. Moreover, the presence of the double bond was shown to have no influence. The glucosylation reaction may involve also the hydroxyl of benzyl alcohols, with the same specificity towards the substitution of the aromatic ring as shown by the cinnamic acids