Stereoisomeric composition of two bioflavonoids from Larix sibirica

Nowadays the bioflavonoid complex of Larix is well-known and well-studied [1]. Current work is devoted to detailed studies of structure and stereoisomeric composition of two major bioflavonoids from Larix sibirica Ledeb.: dihydroquercetin (taxifolin, CAS № 480–18–2, 2,3-dihydro-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopiran-4-on) and dihydrokaempferol (aromadendrin, CAS № 480–20–6, 2,3-dihydro-2-(4-hydroxyphenyl)-3, 5, 7-trihydroxy-4H-1-benzopiran-4-on). Using preparative RP-HPLC both compounds were isolated from the extract of Larix wood and purified to the >99% of purity. Detailed analysis by RP- and chiral HPLC, UV, LC-MS and high resolution NMR spectroscopy allowed us to characterize these compounds as mainly 2R3R-isomers with small (up to 4%) content of 2S3S-enantiomers. So we can establish that Larix sibirica produces „high quality“ optical pure flavonoids.

References: 1. Kolesnik Yu et al. (2007) Abstr 55th Int Congr Ann Meet Soc Med Plant Res, Graz: 938.