ABSTRACT
AIM To study the chemical constituents from the leaves of Cyanocarya paliurus(Batalin)Iljinskaja and their α-glucosidase inhibitory activities.METHODS The 95%ethanol extract from the leaves of C.paliurus was isolated and purified by macroporous resin,silica gel,Sephadex LH-20,polyamide,C18 reversed-phase silica gel and semi-preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.Their α-glucosidase inhibitory activities were evaluated by PNPG.RESULTS Fifteen compounds were isolated and identified as cyclopaloside C(1),cyclopaloside A(2),juglanosides E(3),vaccinin A(4),ent-murin A(5),kaempferol 3-O-α-L-rhamnopyranoside(6),kaempferol-3-O-β-D-glucopyranoside(7),kaempferol-3-O-β-D-glucuronide methyl ester(8),kaempferol-3-O-β-D-glucuronide ethyl ester(9),kaempferol-3-O-β-D-glucuronide butyl ester(10),quercetin-3-O-α-L-rhamnopyranoside(11)quercetin-3-O-β-D-glucopyranoside(12),quercetin-3-O-β-D-galactopyranoside(13),quercetin-3-O-β-D-glucuronide butyl ester(14),dihydrokaempferol(15).The IC50 value of total extracts ihibited α-glucosidase was(1.83±0.04)μg/mL,and the IC50 values of compounds 1,4-5 were(29.48±1.86),(0.50±0.07),(0.71±0.07)μmol/L,respectively.CONCLUSION Compound 1 is a new tetrahydronaphthalene glycoside.Compounds 4-5,8-10 and 14 are isolated from the leaves of C.paliurus for the first time.Compounds 4-5 are relatively rare flavonoid lignans with potential inhibitory activities against α-glucosidase.