PREGNANE GLYCOSIDES, GYMNEPREGOSIDES A-F FROM THE ROOTS OF GYMNEMA-ALTERNIFOLIUM

The structural elucidation of six new related polyoxypregnane glycosid es, gymnepregosides A (1), B (2), C (3), D (4), E (5) and F (6), toget her with two known compounds, from the roots of Gymnema alternifolium (Asclepiadaceae) was achieved through on a detailed study of H-1- and C-13-NMR spectral data and chemical means, The results obtained for ne w compounds, 1-6, show that they are (20S)-pregn-6-ene-3 beta,5 alpha, 8 beta,12 beta,14 beta,17 beta,20-heptaol or sarcostin 3-O-glycosides, and all the sugars at C-3 are beta(1-->4)-linked, Some of them posses sed benzoyl, cinnamoyl and tigloyl residues as the eater linkages loca ted at C-12 and/or C-20 of the aglycon.