Chemical constituents from the ethyl acetate fraction of branches of Morus nigra and their glucose uptake activities
AIM To study the chemical constituents from the ethyl acetate fraction of the branches of Morus nigra L.and their glucose uptake activities.METHODS The extract was isolated and purified by silica gel,Sephadex LH-20 and semi-preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.L6 cells were used to evaluate glucose uptake activities.RESULTS Sixteen compounds were isolated and identified as (R)-2-(3,4-dihydroxyphenyl)-3,5,9-trihydroxy-8,8-dimethyl-9,10-dihydropyranochromone ( 1 ),moracin C ( 2 ),nigranol C ( 3 ),nigragenon E (4),8-prenylquercetin (5),nigrasin I (6),sinopodophylline B (7),kuwanon C (8),gancaonin O (9),albanin A ( 10 ),6-O-methyl-moracin M ( 11 ),wittifuran W ( 12 ),8-hydroxy-2,2-dimethyl-2H,5H-pyrano[3,2-c]chromen-5-one (13),norartocarpanone (14),norartocarpetin (15),nigrasin D (16).The glucose uptake of compounds 4 and 13 was 1.97 times and 2.78 times that of the control group,respectively.CONCLUSION Compounds 1 is a novel natural product,5,7,9,12,13 and 15 are isolated from M.nigra for the first time.Compounds 4 and 13 can significantly promote the glucose uptake in L6 cells,showing strong hypoglycemic activities.
Morus nigra L.ethyl acetate fractionchemical constituentisolation and identificationglucose uptake