(±)-Hyperpyran A: Terpenoid-based bicyclic dihydropyran enantiomers with hypoglycemic activity from Hypericum perforatum (St. John's wort)

Abstract

(±)-Hyperpyran A (1a/1b), a pair of new terpenoid-based bicyclic dihydropyran enantiomers, were isolated from the aerial parts of Hypericum perforatum (St. John's wort). Their structures and absolute configurations were elucidated by NMR spectroscopic analyses, ECD comparison, and X-ray crystal diffraction. Compounds 1a/1b possess hexahydrocyclopenta[c]pyran ring system and a plausible biosynthetic pathway was also proposed. In addition, compound 1a exhibited a moderate promotion of glucose uptake activity in hepatocytes.

Keywords: Bicyclic dihydropyran; Enantiomers; Hypericum perforatum L.; Hypoglycemic activity; St. John's wort.