Two new pregnane glycosides were isolated from the leaves of Gymnema sylvestre (Retz.) R.Br. ex Sm. Their chemical structures were determined as (20S)−12β-tigloyloxy-5α-hydroperoxy-3β,8β,14β,17β,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 (20S)−12β-benzoyloxy-5α-hydroperoxy-3β,8β,14β,17β,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 (2) on the basis of the extensive spectroscopic methods, including 1D, 2D NMR, HRESIMS, and in comparison with the reported data. At the concentration of 200 µM, compounds 1 and 2 showed moderate anti α-glucosidase and α-amylase activities with inhibitory percentage of 31.1 ± 1.2 and 42.3 ± 1.7% (for α-glucosidase), and 27.8 ± 1.3 and 34.5 ± 1.5% (for α-amylase), respectively.

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