PLANT CONSTITUENTS BIOLOGICALLY-ACTIVE TO INSECTS .6. ANTIFEEDANTS FOR LARVAE OF THE YELLOW BUTTERFLY, EUREMA-HECABE-MANDARINA, IN OSMUNDA-JAPONICA

Three antifeedants for larvae of the yellow butterfly, Eurema hecabe mandarina de l'orza were isolated from Osmunda japonica thunb. and identified as osmundalin, parasorboside and methyl (3*S ‘,5S)-5-hydroxy-3-(^-D-glucopyranosyloxy)hexanoate. In the course of isolation of the antifeedants, a new glycoside, dihydroisoosmudalin (9), was isolated together with maltol il-D-glucopyranoside 2-deoxy-L-ribopyranolactone, 5-hydroxymethyl.2-furfural and glycerin. The structure of 9 was elucidated as (4^,55,)-5-(^-D-glucopyranosyloxy)hexan-4-olide on the basis of chemical and spectroscopic evidence. © 1990, The Pharmaceutical Society of Japan. All rights reserved.