Chemical constituents from the leaves of Castanopsis orthacantha and their α-glucosidase inhibitory activities
AIM To study the chemical constituents form the leaves of Castanopsis orthacantha Fance and their α-glucosidase inhibitory activities.METHODS The methanol extract form the leaves of C.orthacanth was isolated and purified by various column chromatography methods,such as MCI gel CHP 20P,Sephadex LH-20,Diaion HP20SS,then the structures of obtained compounds were identified by physicochemical properties and spectral data.The α-glucosidase inhibitory activities were determined by PNPG method.RESULTS Eighteen compounds were isolated and identified as protocatechuic acid(1),gallic acid(2),3-O-α-L-arabininopyranosyl-4-hydroxybenzoic acid(3),3-O-galloyl shikimic acid(4),methyl 4-epi-shikimate-3-O-gallate(5),5-O-galloyl shikimic acid(6),5-O-caffeoylshikimic acid(7),6-O-galloyl-glucoside(8),1,6-di-O-galloyl-β-D-pyranogluloside(9),1,3-di-O-galloyl-α-D-glucoside(10),2,3-di-O-galloyl-D-glucoside(11),β-O-methylgluco-2,3-digalloyl esters(12),(3R,1'S)-[1'-(6"-O-galloyl-β-D-gluco-pyranosyl)oxyethyl]-3-hydroxy-dihydrofuran-2(3H)-one(13),4-O-D-(6'-O-galloyl)glucopyranyl-(E)-p-coumaryl acid(14),chestanin(15),1-desgalloyl eugeniin(16),picrorhiza acid(17),11-methyl chebulate(18).The IC50 values of compounds 2 and 16 were(0.12±0.059),(0.00089±0.00025)mmol/L,respectively.CONCLUSION All compounds are isolated from the leaves of C.orthacantha for the first time.Compounds 2 and 16 have strong α-glucosidase inhibitory activities.
Castanopsis orthacantha Fanceleaveschemical constituentsisolation and identificationα-glucosidase