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Updated: Aug 23, 2026

Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
Published on: August 14, 2019
Conformational analysis of the biflavanoid GB2 and a polyhydroxylated flavanone-chromone of Cratoxylum neriifolium
Vineet Kumar1, Volker Brecht, August Wilhelm Frahm
1Department of Pharmaceutical Chemistry, Albertstrasse 25, 79104 Freiburg, Germany.
Abstract:
Three compounds, namely the interesting biflavanonol GB-2(naringenin 1-3, 11-8-dihydroquercetin, 1), 1-4',1-5,11-5,1-7,11-7-pentahydroxyflavanone(l-3,11-8)chromone [naringenin-(3 -8) 5,7-dihydroxychromone, 21 and stigmasterol, have been isolated from the leaves of Cratoxylum neriifolium Kurz. Compounds 1 and 2 show rotameric behavior due to the presence of a single bond between the highly substituted flavanone and flavanonol part and the flavanone and chromone part, respectively. Complete NMR spectral assignments of 1 and 2 have been done at 27 C and 90 C for the first time followed by a study of conformational behavior at room temperature by ROESY.
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