Study On Chemical Constituents Of Cyclocarya Paliurus (Batai.) Iljinskaja Leaves,Optimization Of Extracting Total Flavonoids And Its Hypoglycemic Effect

Objective:A key point of the study was to find active compounds from Cyclocarya paliurus（Batai.）Iljinskaja leaves and to improve its material foundation.Optimized the ultrasonic coupled with aqueous two-phase system conditions for the extraction of flavonoids of C.paliurus.The efforts of aqueous two-phase extracts of C.paliurus leaves on diabetes mellitus mice was studied.Methods:The chemical components of the petroleum ether and ethyl acetate fractions of C.paliurus were separated and purified by the chromatographic methods including silica gel,ODS,MCI and sephadex LH-20chromatography,etc.Their structures were elucidated by physical-chemical methods and EI-MS,¹³C-NMR,¹H-NMR techniques.Response surface methodology was applied to the optimization of the flavonoids of C.paliurus leaves.The mice were fed with high fat diet,then intraperitoneal injected streptozotocin（STZ）to establish the T2DM animal models.Administrated two weeks,the contents of insulin（INS）,total cholesterol（T-CHO）,serum triglyceride（TG）,high density lipoprotein（HDL-C）,low density lipoprotein（LDL-C）and very low density lipoprotein（VLDL-C）were measured.The changes of liver and pancreatic tissues pathology in experimental diabetic mice were observed by immunohistochemical method.Results:Ten compounds were separated and nine were identified as5-hydroxy-2-methoxy-1,4-naphthoquinone（1）,β-amyrin（2）,D:B-frienoolean-5-en-3β-ol（3）,β-sitosterol（4）,olean-12en-28-oic acid（5）,maslinic acid（6）,uvaol（7）,3β,23-dihydroxy-1-oxo-olean-12-en-28-oic acid（8）,arjunolic acid（9）.The optimal conditions for ATPS of C.paliurus flavonoids were ethanol concentration 33.00%,salt concentration 15.00%,duration of extraction time 52min and liquid-solid ratio 33:1.Under these conditions the total flavonoids extraction rate was up to 3.00±0.10%.Middle dose group of C.paliurus leaves extracts could significantly improve the loss of diabetic mice body weight（P<0.01）.Low dose group showed fasting blood glucose lowing and high dose group showed INS lowing（P<0.05）.C.paliurus leaves extracts could reduce the contents of T-CHO,TG,LDL-C and increased HDL-C.T2DM mice hepatocytes showed different degrees of edema and degeneration,the portal areas and lobule occurred inflammatory cell infiltration.The liver changes of mice administrated by C.paliurus leaves extracts and metformin hydrochloride alleviated compared with the model group.Compared with normal mice,there were fewer islets,irregular morphology,unevev cell distribution in the islets of T2DM mice.The pancresd structure was close to the normal mice after the treatment.Conclusions:Except compound 1 which is a naphthoquinone and compound4 which is a tetracyclic triterpene,others belong to pentacyclic triterpenoids.Compound 3,7 and 8 were isolated from C.paliurus firstly.The present study suggests that ATPS is a good choice for the extraction of flavonoids from C.paliurus leaves.C.paliurus leaves extracts possessed lowering fasting blood glucose,lowering lipid,improving insulin resistance and protective effects on STZ diabetic mice while its specific mechanisms are worth to further investigation.