Study On Hypoglycemic Parts And Constituents From Leaves Of Eucalyptus Globulus

Purpose: Study on hypoglycemic activities of five parts from leaves of Eucalyptus globulus and chemical constituents.Methods: The influence of five extract parts of from leaves of Eucalyptus globulus on random blood glucose, fasting blood glucose, body weight, oral glucose tolerance, and insulin tolerance in diabetic mice were observed by applying diabetes model.Chemical constituents from a hypoglycemic part of leaves of Eucalyptus globulus isolated and elucidated by traditional chemical methods and modern chromatographic techniques, including TLC, silica gel column chromatography, HPLC, etc. Total triterpene acids were determined by UV-visible spectrophophotometry.The content determination method of 3β-hydroxy-11-ursen 28,13-olide and ursolic acid were established by HPLC.Results: Experimental results showed that five extract parts can reduce the levels of random blood glucose, fasting blood glucose, body weight as well as the area of the oral glucose tolerance curve in diabetic mice. Both ethyl acetate extracts and 95% ethanol parts can reduce the area under the curve of insulin tolerance. Six compounds were isolated from hypog-lycemic ethyl acetate extract part. The structures of five compounds were identified by modern spectroscopic techniques(1H NMR, 13 C NMR, etc), as follow: 3β-formyloxyurs-11-ursen-28,13-olide(I), 5-hydroxy-4’,7-dimethoxy-6,8-dimethylflavone(II), 3β-hydroxy-11-urse n-28,13-olide(III), ursolic acid(IV), 4’,5-dihydroxy-7-methoxy-6,8-dimethylflavone(V). By UV-visible spect-rophotometry, content of total triterpene acids was determinated as 40.51%. The contents of 3β-hydroxy-11-ursen-28,13-olide and ursolic acid were determinated by HPLC.Conclusion: 5 extract parts of leaves of Eucalyptus globulus have hypoglycemic activity. A large number of triterpenoid acid substances, mainly including 3β-hydroxy-11-ursen- 28,13-olide and ursolic acid were isolated from ethyl acetate extract.