Studies on the Constituents of Lonicera Species. X. Neolignan Glycosides from the Leaves of Lonicera gracilipes var. glandulosa MAXIM.

Four new 8-O-4'-neolignan glycosides, 4, 9, 9'-trihydroxy-3, 3'-dimethoxy-8-O-4'-neolignan-7-O-β-D-glucopyranosides [7S, 8S-threo form (1) and 7S, 8R-erythro form (2)], 7R, 8R-threo-4, 7, 9, 9'-tetrahydroxy-3-methoxy-8-O-4'-neolignan-3'-O-β-D-glucopyranoside (3) and 7S, 8R-erythro-7, 9, 9'-trihydroxy-3, 3'-dimethoxy-8-O-4'-neolignan-4-O-β-D-glucopyranoside (4), and two known compunds, 4, 7, 9-trihydroxy-3, 3'-dimethoxy-8-O-4'-neolignan-9'-O-β-D-glucopyranosides [7R, 8R-threo form (5) and 7S, 8R-erythro form (6)], have been isolated from the leaves of Lonicera gracilipes var. glandulosa MAXIM. Their absolute stereostructures have been determined on the basis of spectral and chemical evidence.