CUCURBITACINS WITH UNUSUAL SIDE-CHAINS FROM PICRORHIZA-KURROA

From the roots of Picrorhiza kurroa six new cucurbitacin glycosides, (2beta,9beta,10alpha,16alpha,20xi,24xi)-20,24-epoxy-2-(beta-D-glucopyranosyloxy)-16,25-dihydroxy-9-methyl-19-norlanost-5-ene-3,11-dione, (2beta,3beta,9beta,10alpha,16alpha,20xi,24xi)-20,24-epoxy-24beta-D-glucopyranosyloxy)-3,16,25-trihydroxy-9-methyl-19-norlanost-5-en-11-one, (2beta,9beta,10alpha,16alpha,20xi,24xi)-20,24-epoxy-24beta-D-glucopyranosyloxy)-16,25,26-trihydroxy-9-methyl-19-norlanost-5-ene-3,11-dione, (2beta,3beta,9beta,10alpha, 16alpha,20xi,24xi)-20,24-epoxy-2-(beta-D-glucopyranosyloxy)-3,16,25,26-tetrahydroxy-9-methyl-19-norlanost-5-en-11-one, (2beta,9beta,10alpha,16alpha,20beta,24Z)-24beta-D-glucopyranosyloxy)-16,20,26-trihydroxy-9-methyl-19-norlanost-5,24-diene-3,11-dione and (2beta,9beta,10alpha,16alpha,20beta,24Z)-2-(beta-D-glucopyranosyloxy)-3,16,20,26-tetrahydroxy-9-methyl-19-norlanost-5,24-diene-11-one have been isolated. Their structures were established by usual spectroscopic and two-dimensional (2D) NMR techniques (COSY, HMQC and HMBC).