Study On High-polarity Constituents Of Potentilla Discolor And Preliminary Study On Their Anti-diabetic Activity

Potentilla discolor Bunge（fanbaicao）of Rosaceae is a plant of Potentilla L..In the 2015 edition of the Chinese pharmacopoeia,it was recorded that“fanbaicao”has a variety of pharmacological activities.It has been used in folk medicine for the treatment of dysentery,diarrhea,leucorrhea,malaria,and hematochezia.It is distributed in many provinces of China.In recent years,the anti-diabetic activity of Potentilla discolor Bunge has been widely concerned.Diabetes mellitus（DM）is a metabolic disorder characterized by glucose intolerance and changes in lipid and protein metabolism.Modern pharmacological research shows that Potentilla discolor’s decoction has notable protective effect on islet B cell and the flavones have significant effect on hypoglycemic activity.Inhibitors ofα-glucosidase constitute an important class of anti-diabetic drugs which prevent the sudden rise in postprandial hyperglycemia by inhibiting the hydrolysis of oligosaccharides into absorbable monosaccharides.The chemical study on PDB part came out 19 compounds which were purified and identified by ¹H NMR,¹³C NMR,IR,UV,DEPT,HMBC,HSQC,HR-ESI-MS and CD spectra,including PDB30-1（3-O-methylellagicacid-4’-O-α-L-rhamnopyranoside）,PDB30-2（3,3’-di-O-methylellagic acid 4’-O-β-D-glucopyranoside）,PDB30-3（kaempferol-3-O-β-D-glucuronide-6’’-methyl ester）,PDB30-4（kaempferol-3-O-β-D-glucuronide）,PDB30-5（quercetin-3-O-β-D-glucuronide-6’’-methyl ester）、PDB30-6（ellagic acid）,PDB30-7（chaenomiside F）,PDB30-8（（+）-seco-5’-methoxy-isolariciresinol-9’-O-α-L-rhamnopyranoside）,PDB30-9（angelicoidenol-2-O-β-D-glucopyranoside）,PDB30-10（benzyl 1-（6-O-α-L-rhamnopyranosyl-β-D-glucopyranosyloxy）-3-hydroxybenzoate）,PDB30-11（methy-4-hydroxylbenzoate-3-O-α-L-rhamnopyranosyl-（1→6）-β-D-glucopyranoside（xspolyphenol B））,PDB30-12（benzyl-（6-O-α-L-rhanmopyranosyl）-O-β-D-glucopyranoside）,PDB30-13（（7S,8R）-7,8-dihydro-8-hydroxymethyl-7-（4-hydroxy-3-methoxyphenyl）-1’-benzofuranpropanol 2’-O-β-D-glucopyranoside）,PDB30-14（（7R,8S）-7,8-dihydro-8-hydroxymethyl-7-（4-hydroxy-3-methoxyphenyl）-1’-benzofura npropanol 2’-O-β-D-glucopyranoside）,PDB30-15（vomifoliol-9-O-β-xylopyranosyl-（1’’→6’）-O-β-glucopyranoside）,PDB30-16（（7R,8S）-4,7,9,3’,9’-pentahydroxy-3-methoxy-8,4’-oxyneolignan-3’-O-β-D-glucopyranoside）,PDB30-17（（7S,8R）-4,7,9,3’,9’-pentahydroxy-3-methoxy-8,4’-oxyneolignan-3’-O-β-D-glucopyranoside）,PDB30-18（（7R,8R）-4,7,9,3’,9’-pentahydroxy-3-methoxy-8,4’-oxyneolignan-3’-O-β-D-glucopyranoside）and PDB30-19（（7S,8S）-4,7,9,3’,9’-pentahydroxy-3-methoxy-8,4’-oxyneolignan-3’-O-β-D-glucopyranoside）,and there were ten compounds isolated from Potentilla discolor for the first time,three compounds are new.Among of the 19 compounds,PDB30-7,PDB30-8,PDB30-9,PDB30-11,PDB30-12,PDB30-15,PDB30-16,PDB30-17,PDB30-18 and PDB30-19 were isolated from the Potentilla discolor for the first time;PDB30-10,PDB30-13,PDB30-14 were new compounds.The obtained 3 new compounds are one benzyl benzoate glycosides（PDB30-10）and two benzofuran neolignans（PDB30-13,PDB30-14）.α-Glucosidase inhibitory effects of extracts and some pure compounds from PDB part were evaluated,PDB30 part has goodα-glucosidase inhibitory effects and tannic acid has the best inhibitory activity,but its glycosides are basically have no inhibitory effects,and two kaempferol glucosides show good inhibitory activity,lignans and monoterpenes have some inhibitory activity,while sesquiterpenes have no inhibitory activity.Through the extraction and isolation of Potentilla discolor and the screening experiment ofα-glucosidase inhibitory activity,it can provide the scientific basis of pharmaceutical substances for its application.