Hypoglycemic constituents of Gynura divaricata subsp. formosana.

Gynura divaricata Kitam. subsp. formosana is a folk medicine used as a hypoglycemic agent for diabetes patients in Taiwan. Guided by the hexose transport assay, the hypoglycemic constituents of the aerial part of this plant were disclosed through chromatographic methods. They are fructooligosaccharides, including beta-D-fructofuranose, sucrose, 1-kestose, nystose, and 1(F)-beta-fructofuranosylnystose. The hexose transport assay indicated that nystose was the most potent among these compounds, showing a 46.7% difference from pinitol in the stimulation index at a concentration of 0.5 mg/mL.