Two new ent-kaurane-type diterpene glycosides from zucchini (Cucurbita pepo L.) seeds

Two new ent-kaurane diterpene glycosides; 12α-(β-d-glucopyranosyloxy)-7β-hydroxykaurenolide (1) and 7β-(β-d-glucopyranosyloxy)-12α-hydroxykaurenolide (2), a new steroid; (24S)-stigmasta-7,22E,25-trien-3-one (12), and known compounds (3-11, 13-14) were isolated from zucchini (Cucurbita pepo L.) seeds. The absolute structures of 1 and 2 were determined by acid hydrolysis and application of a modified Moscher's method. Furthermore, isolated compounds (1-14), and a derivative, 1a, were evaluated for their inhibitory effects on macrophage activation by an inhibitory assay of nitric oxide (NO) production.