Abstract: In order to elucidate the hypoglycemic components of C.paliurus,the chemical constituents and the inhibitory activity of α-glucosidase were systematic studied.13 compounds were isolated and identified from 80% ethanol extract of C.paliurus leaves by means of various chromatographic methods and spectroscopic methods.These compounds were characterized as afzelin (1),Kaempferol 3-O-(4″-O-acetyl)-α-L-rhamnopyranoside (2),juglanoside J (3),1α,2α,4β-triol-1,2,3,4-tetrahydronaphthalene (4),Cyclocarioside III (5),Cyclocarioside J (6),Progesterone (7),12-O-deacetylmetaplexigenin (8),20α-acetoxypregn-4-en-3-one (9),Oleanolic acid (10),5-O-P-coumaroylquinic acid methyl ester (11),Methyl linolenate (12),Palmitic acid (13).Among them,compound 9 was a new natural product;compounds 2-4,7,8,11,and 13 were isolated from this plant for the first time.The inhibitory activity of α-glucosidase was screened by PNPG method;the results showed that compounds 1 and 2 have strong α-glucosidase inhibitory activity.These results indicated that flavonoid is one kind of hypoglycemic active components of C.paliurus plant.

Key words: Cyclocarya paliurus, chemical constituents, α-glucosidase inhibitory activity