Glucoindole alkaloids from bark of two Sickingia species

Abstract: A new glucoindolealkaloid, sickingine, together with the known alkaloids, 5α-carboxystrictosidine, ophiorine A, ophiorine B and lyalosidic acid, have been isolated from the barks of Sickingia tinctoria and S. williamsii. The new structure was derived from physical and spectroscopic data. An extensive NMR spectroscopic study led to the revision of the assignments for certain carbon atoms of ophiorines A and B given in the literature

p-hydroxyacetophenone derivatives from Werneria ciliolata

Abstract: The reinvestigation of Werneriaciliolata afforded, in addition to known benzofurans, two new p-hydroxyacetophenonederivatives. The structures were elucidated by spectroscopic methods. The chemotaxonomic relevance is discussed briefly

Antioxidant bibenzyl derivatives from Notholaena nivea Desv.

Four new bibenzyl derivatives were isolated, together with other known bibenzyls, by bioassay-guided fractionation of a CHCl3-MeOH extract of Notholaena nivea Desv. (Pteridaceae) aerial parts. The structures were elucidated by NMR, ESIMS and other spectral analyses. Their antioxidative effects towards superoxide, lipidic peroxidation and the 2,2'-azino-bis-3- ethilbenzothiazoline-6-sulfonic acid (ABTS) radical were assayed. Results showed that the compound 3,12-dihydroxy-5-methoxybibenzyl (6) is the most active compound in the ABTS free-radical scavenging test, while in the coupled oxidation of β-carotene and linoleic acid assay the compound 5,12-dihydroxy-3-methoxydibenzyl-6-carboxylic acid (1) exerted the highest activity after 1h. A superoxide anion enzymatic test was also carried out and the results were confirmed by an inhibition of xanthine oxidase activity assay. The putative protective role played by compounds 1 and 6 on the injurious effects of reactive oxygen metabolites on the intestinal epithelium, using a Caco-2 human cell line, was investigated. H2O2-induced alterations were prevented by preincubating the cells with compounds 1 and 6

Constituents of Werneria ciliolata and their in vitro anti-hiv activity

Abstract: The aerial part of Werneriaciliolata afforded a series of new diterpenes: two ent-kaurane derivatives, a nor-kaurane, an ent-manoyloxide derivative, a dimeric diterpene, as well as a rare diterpene. Their structures were elucidated by spectroscopic methods, including the concerted application of 1D NMR techniques (DEPT and NOEDS) and 2D NMR techniques (1H-1H COSY and HETCOR). In addition, four known kauranes, four coumarins and 6-hydroxytremetone were isolated. All isolated compounds from W. ciliolata and W. dactylophylla were tested in vitro for anti-viral activity against HIV-1, but only 6-hydroxytremetone showed a significant anti-HIV-1 activit

Quinovic acid glycosides from Uncaria guianensis

Abstract: From the bark of Uncariaguianensis, two new quinovicacidglycosides, quinovicacid 3β-O-β-d-quinovopyranoside and quinovicacid 3β-O-β-d-fucopyranosyl-(27 → 1)-β-d-glucopyranosylester, have been isolated, in addition to known quinovicacid 3β-O-[β-d-glucopyranosyl-(1 → 3)-β-d-fucopyranosyl]-(27 → 1)-β-d-glucopyranosyl ester and quinovicacid 3β-O-β-d-fucopyranoside. Their structures were elucidated by spectral and chemical studies