Biomedical subjects

JC Oberti

Publications and source records attributed to JC Oberti.

3 recordsLinked to original sources

PubMed1999

7-Hydroxywithanolides from datura ferox

Three new withanolides were isolated from leaves of Datura ferox. Their structures were established as (17R,20S,22R)-5alpha,6alpha, 7beta,12alpha-tetrahydroxy-1-oxowitha-2,24-dienolide (1), (17R,20S, 22R,24S,25S)-24,25-epoxy-5alpha,6alpha,7beta, 12alpha-tetrahydroxy-1-oxowitha-2-enolide (2), and (17R,20S, 22R)-5alpha,6alpha-epoxy-7alpha-hydroxy-1,12-dioxowitha-2, 24-dienolide (3), using spectroscopic methods (NMR, MS) and molecular modeling.

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PubMed1999

18,20-Hemiacetal-type and other withanolides from dunalia brachyacantha

Two Dunalia brachyacantha specimens collected at different locations in Argentina were investigated separately. The 18,20-hemiacetal-type withanolides (17S,20R,22R,24S,25R)-4beta-acetyloxy-5beta,6beta:18, 20-diepoxy-18-hydroxy-1-oxowitha-2-enolide (1) and (17S,20R, 22R)-4beta-acetyloxy-5beta,6beta:18, 20-diepoxy-18-hydroxy-1-oxowitha-2,24-dienolide (2) were isolated from the first collection, both as mixtures epimeric at C-18. The second collection contained instead (17R,20S,22R)-5beta, 6beta-epoxy-4beta,16alpha-dihydroxy-1-oxowitha-2,24-dienolide (3); (17R,20S,22R)-5beta,6beta-epoxy-4beta,18-dihydroxy-1-oxowitha-2, 24-dienolide (4), and (17R,20S,22R)-5beta,6beta-epoxy-4beta, 16alpha-dihydroxy-1,18-dioxowitha-2,24-dienolide (5). All five new withanolides (1-5) bear an A and B ring substitution pattern similar to that of withaferin A, and their structural elucidation was achieved by spectroscopic techniques.

Journal Article↗

PubMed1998

New Hydroxylated Withanolides from Salpichroa origanifolia

From the leaves of Salpichroa origanifolia three new withanolides, (20S,22R,24S,25S,26R)-5alpha,6alpha:22,26:24,25-triepoxy-15,26-dihydroxy-17(13-->18)-abeo-ergosta-2,13,15,17-tetraen-1-one (salpichrolide G, 1), (20S,22R,24S,25R)-5alpha,6alpha:22,26-diepoxy-24,25,26-trihydroxy-17(13-->18)-abeo-ergosta-2,13,15,17-tetraen-1-one (salpichrolide H, 2), and (20S,22R,25S)-5alpha,6alpha:22,26-diepoxy-25,26-dihydroxy-17(13-->18)-abeo-ergosta-2,13,15,17,23-pentaen-1-one (salpichrolide I, 3), were isolated and characterized by spectroscopic methods and with the aid of molecular modeling. The latter two compounds were obtained as an epimeric mixture at C-26.

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