Gymsyloside F and Gymsyloside G, Two New Pregnane Glycosides From the Leaves of Gymnema sylvestre and Their α-Glucosidase and α-Amylase Inhibitory Activities

Two new pregnane glycosides were isolated from the leaves of Gymnema sylvestre (Retz.) R.Br. ex Sm. Their chemical structures were determined as (20 S)−12 β-tigloyloxy-5 α-hydroperoxy-3 β,8 β,14 β,17 β,20-pentahydroxypregn-6-ene 3- O-β-D-glucopyranosyl-(1→4)‐6-deoxy-3- O-methyl- β-D-allopyranosyl-(1→4)- β-D-oleandropyranosyl-(1→4)- β-D-cymaropyranosyl-(1→4)- β-D-cymaropyranoside (1) and (20 S)−12 β-benzoyloxy-5 α-hydroperoxy-3 β,8 β,14 β,17...