Studies on the Constituents of Cyclanthera pedata (Caigua) Seeds: Isolation and Characterization of Six New Cucurbitacin Glycosides

Six new cucurbitacin glycosides were isolated from the seeds of Cyclanthera pedata Schrab (Cucurbitaceae). Their structures were elucidated on the basis of spectral and chemical data to be 2-[(6- O -β- d -glucopyranosyl-β- d -glucopyranosyl)oxy]-3,16α,20,22,25-pentahydroxy-29-norcucurbita-1,3,5(10)-trien-11-one ( 1 ), 25-acetoxy-2-[(6- O -β -d -glucopyranosyl-β -d -glucopyranosyl)oxy]-3,16α,20,22-tetrahydroxy-29-norcucurbita-1,3,5(10)-trien-11-one ( 2 ), 25-acetoxy-2-(β -d -glucopyranosyloxy)-3,16α,20,22-tetrahydroxy-29-norcucurbita-1,3,5(10)-trien-11-one ( 3 ), 25-acetoxy-2-[(4- O -α- l -rhamnopyranosyl-6- O -β -d -glucopyranosyl-β -d -glucopyranosyl)oxy]-3,16α,20-trihydroxy-29-norcucurbita-1,3,5(10) triene-11,22-dione ( 4 ), 3β-[(6- O -β -d -glucopyranosyl-β -d -glucopyranosyl)oxy]-16α,20,22,25-tetrahydroxycucurbit-5-en-11-one ( 5 ), 3-β-(β -d -glucopyranosyloxy)-25-acetoxy-16α,20,22,-trihydroxycucurbit-5-en-11-one ( 6 ).