α-glucosidase inhibitor from Kothala-himbutu (Salacia reticulata WIGHT)

A polyhydroxylated cyclic 13-membered sulfoxide (1) was isolated from an aqueous extract of Kothala-himbutu (Salacia reticulata WIGHT). The structure of compound 1 was elucidated by 1D and 2D NMR and APCI-MS methods. The alpha-glucosidase inhibitory activity of compound 1 (IC50: maltase, 0.227 mu M; sucrase, 0.186 mu M; isomaltase, 0.099 mu M) was much greater than the inhibitory activity of salacinol and kotalanol, which were previously isolated from Kothala-himbutu.