New Compounds from Siberian Gentiana Species. I. Iridoid Glycosides

Five new iridoid glycosides were isolated by chromatographic separation of extracts from the roots of three Gentiana species (Gentianaceae) growing in Eastern Siberia. Their structures were elucidated by spectral methods as 2′-O-(2′′-hydroxy-3′′ -O-β-D-glucopyranosyloxybenzoyl)swertiamarin (gentiridoid A), 2′-O-(2′′-hydroxy-3′′-O-β-D-glucopyranosyloxybenzoyl)gentiopicroside (gentiridoid B), and 3′,6′-di-Oacetyl-4′-O-(2′′,3′′-dihydroxybenzoyl)swertiamarin (gentiridoid C) from G. decumbens L. f.; 2′,3′,6′-tri-Oacetyl-4′-O-[2′′-hydroxy-3′′-O-(6′′′-O-β-D-glucopyranosyl)-β-D-glucopyranosyloxybenzoyl]swertiamarin (gentiridoid D) from G. dahurica Fisch.; and loganic acid 6′-O-(6′′ -O-β-D-glucopyranosyl)-β-Dglucopyranoside (gentiridoid E) from G. macrophylla Pall.