Components with Anti-Diabetic Activity Isolated from the Leaves and Twigs of Glycosmis pentaphylla Collected in Vietnam.

A phytochemical investigation of the leaves and twigs of Glycosmis pentaphylla (Rutaceae), collected in Vietnam, yielded three new compounds named glyfuran ( 1 ), glyphyllamide ( 2 ), and glyphyllazole ( 3 ), along with twenty-five known compounds ( 4 - 28 ). The structures of isolates were determined by IR, MS, NMR, and UV data analyses. In the anti-diabetic activity screening, (+)-isoaltholacton ( 4 ), glycoborinine ( 17 ), 2',4'-dihydroxy-4,6'-dimethoxychalcone ( 24 ), and flavokawain A ( 25 ) simultaneously exhibited inhibition of dipeptidyl peptidase-4 (DPP4) and stimulation of the glucagon-like peptide-1 (GLP-1) secretion on the murine intestinal secretin tumor cell line (STC-1).