Enzymatic degradation of parvifloside

Abstract

Parvifloside (1), a new furostanol pentaglycoside, was isolated from the fresh rhizomes of Dioscorea parviflora C. T. Ting. On the basis of spectroscopic and chemical methods, its structure was elucidated as (25R)-26-O-beta-glucopyranosyl-furost-5-en-3beta,22xi,26-trio13-O-beta-D-glucopyranosyl (1-->3)-beta-D-glucopyranosyl (1-->4)-[alpha-L-rhamnopyranosyl (1-->2)]-beta-D-glucopyranoside. Six prosapogenins (2-7) were obtained from the enzymatic degradation of 1 by cellulase, but only 3 and 4 were obtained by beta-glucosidase. The structures of all compounds were determined by spectroscopic data. The activity of the isolated compounds on deformation of mycelia germinated from Pyricularia oaryzae P-2b conidia was evaluated.