W. Kraus

Structure determination by nmr of azadirachtin and related compounds from azadirachta indica a. Juss (Meliaceae)

Abstract Two novel limonoids 3-deacetyl-3-cinnamoylazadirachtin (6) and 1-tigloyl-3-acetyl-11-methoxyazadirachtinin (8) have been isolated from Azadirachta indica extracts in addition to azadirachtin (4), 22,23-dihydro-23β-methoxyazadirachtin (5) and 3-tigloylazadirachtol (7). The assignment of the structures (5) - (8) and the reassignment of the azadirachtin structure as (4) was achieved on the basis of detailed 1 H and 13 C n.m.r. spectroscopic analyses.

Nimbidiol, a modified diterpenoid of the root-bark of Azadirachta indica

Abstract Nimbidiol, a modified diterpenoid, isolated from the root-bark of Azadirachta indica (Indian ‘neem’), was characterized by spectroscopic method

Further evidence for the structure of vaticaffinol and a revision of its stereochemistry

Abstract The resveratrol tetramer, vaticaffinol, has been isolated from the bark of Stemonoporus canaliculatus . Further evidence has been obtained to support its structure. Its stereochemistry has been revised on the results of NOE and 1 HNMR homodecoupling experiments.

A hemolytic saponin, randianin, from Randia dumetorum

Abstract Randianin, a new triterpene diglucoside, was isolated from the methanolic extracts of the fruits of Randia dumetorum . Its structure has been established as β- d -glucopyranosyl (1→3)-β- d -glucopyranosyl(1→3)-3β-hydroxyolean-12-en-28-oic acid on the basis of hydrolysis and spectral evidence including COSY NMR and NOE studies.