Identification Of An Anti-diabetes Constituent From Potentilla Chinesis And Study On Its Extraction And Separation Process

Potentilla chinensis Bge (Rosaceae) is widely distributed in most place of China. As a folk medicine, it has been used to reduce swelling and staunch bleeding, and has anti-inflammatory and detoxification properties. In the previous study, the EtOH extracts from P. chinensis revealed significant anti-diabetic activities.During the first part, we searched the active fractions from P. chinensis. Anti-diabetes experiment was taken by using alloxan-induced diabetic mice. Tested fractions were obtained by P.E., EtOAC, and BuOH solvents-partition from 95% ethanol-extracts of Potentilla chinesis, and tested compound was isolated by repeated chromatography. Fraction F revealed significant hypoglycemic effect, ths tested group showed no obvious difference comparing with the phenformin group (P<0.01),and their reduction rates was 32.97% for the fraction F group and 33.30% for the phenformin group. A main constituent was isolated from the fraction F. By using spectroscopic method, the structure was elucidated as a flavonoid, named potentilla flavone. In the anti-diabetes experiment, potentilla flavone revealed the significant hypoglycemic effect in alloxan-induced diabetic mice, its reduction rate of blood glucose was 52.19%, and reduction rate of phenformin group was 29.26%(dose, 75 mg/kg). This observation suggests that potentilla flavone is promising for anti-diabetic drug development.In the second part of the paper, the extraction and isolation process of potentilla flavone from Potentilla chinesis. By single factor test, such as ethanol comcentration, extraction times, the ratio of material and solvent,along with orthogonal test, the optimum extraction conditions of potentilla flavone from P. chinesis were determined as follow: reflux for 3 times, 1.5 hours each time, and 10-6-6 for the multiple of 60% EtOH and material. Under this condition, the content of potentilla flavone is 2.7‰and the extraction ratio of potentilla flavone is up to 76.7%.During the isolation of potentilla flavone from P. chinesis, the comparing experiment of performance isolation for polyamide and two types of macro-resin (AB-8, D101) indicated that AB-8 macro-resin was the best. Further considering the isolation conditions of AB-8 macro-resin column, the optimum purification conditions were determined as follow: 30% ethanol solution [material (kg) : 30% ethanol (L), 4.5 : 10] of EtOH extract from P. chinesis was centrifuged (4000r/min, 15min), and the supernatant fluid was separated by AB-8 macroporous resin column (ration of column diameter to height, 1 : 3), the volume ratio of sample solution to resin was 10:1, eluting speed was 2 BV/h; eluting solvent was 3BV of 30% ethanol, 5BV of 60% ethanol, and 4BV of 95% ethanol. By concentration of 60% ethanol elute in vacuo, the fracion of potentilla flavone was obtained (content of potentilla flavone: 3.8-4%). Further purification with polyamide column, the content of flavonoe was up to 27%.