Studies On The Chemical Constituents And Antihyperglycemic Action Of Abelmoschus Manihot L. Medic

The antihyperglycemic action of 19 Chinese herbs were investigated in 3T3-L1 adipocyte cells .A stimulatory effect of Abelmoschus manihot L. Medic on glucose uptake of mature 3T3-L1 adipocyte cells induced by hormones from 3T3-L1 preadipocytes ,was obtained in a concentration-dependent manner from 1 to 100 g/L. Medic significantly attenuated the increase of plasma glucose in streptozotocin-induced diabetes rates(STZ-diabetic rats).Abelmoschus manihot L Medic has been used as a folk herbal drug in China. However, few studies on the chemical constituents and bioactivities have been reported. To find small molecular compounds with activity of antidiabetes, we studied its chemical constituents.From the 80% ethanol extracts of Abelmoschus manihot L Medic,36 compounds were isolated. On the basis of chemical and spectral analysis(¹HNMR,¹³CNMR, ¹H-¹HCOSY,1D-TOCSY,HMQC,HMBC),the structures of 30 compounds were identified ,which were α -spinasterol (1), stigmasterol (2), β-Sitosterol (3), β -sitosterol-3-O- β -D-glucopyranoside (4), caffeic acid (5), 6-methoxyl -7-hydroxyl coumarin (6), palmitic acid (7), Hexacosoic acid (8), quercetin (9), quercetin-3-O-β -D-glucopyrancoside (10), hyperoside (11), quercetin-3-O-β -D-glucoside (12), gossypetin-3'- O - β -D-glucoside (13), 3-O-caffeoylquinic acid (14), myricetin (15),5-hydroxyl-3',4',7,,8-tetramethoxyl flavone (16), 3',5-dihydroxyl-4',7,8-trimethoxyl flavone (17), gossypetin (18), gallic acid (19), 3',5-dihydroxyl-7,8-dimethoxyl flavonol-4'-O- β -D-glucoside (20),4',5,7,8-tetramethoxyl flavone (21), myricetin-3-O- β -D-glucoside (22), quercetin-3-robinobioside (23), quercetin-3-rutinoside (24), 4'-methoxyl -5,7-dihydroxylflavone-[-O- β -D-xylopyranosyl- (1→3) ]-O- β -D-glucopyra noside (25), 4',7-dimethoxyl-5,7-dihydroxyl flavone-[-O-β-D-xylopyranosyl (1→ 2 ) ]-O- β -D-glucopyranoside(26), 3,5-di-O-caffeoylquinic acid (27), 4,5-di-O-caffeoylquinic acid (28), 3,4-di-O-caffeoylquinic acid (29) and 55-hydroxyl -4',7,8-trimethoxyl flavone (30).Among them, 25, 26 were new compounds and 7, 8,14, 16, 17, 20, 21, 22, 24, 27, 28, 29, 30 were isolated from Abelmoschus manihot L Medic for the first time.Five compounds and "flavonoides" increased the effect of glucose uptake in mature 3T3-L1 adipocyte cells, "flavonoides" , compoundes 27 decreased the plasma glucose concentrations in STZ-diabetic and attenuated the increase of plasma glucose induced by an intravenous glucose challenge test in STZ-diabetic.