Researches On Chemical Constituents Of The Parts Of Hypoglycemic Activity Of Litchi Seeds

Objective: Searching for the active ingredients from the TCM Litchi （Litchi chinensisSonn.） seeds which can produce the function of decrease the blood sugar, and elucidated thestructures of the isolated compounds. A method was established for determination of thephlorizin in Litchi seeds.Method: Using a bioactivity-guided method, a research was taken to study the chemicalconstituents possessed the α-glucosidase inhibitory activity from Litchi seeds. Silica gelcolumn chromatography and Sephadex LH-20methods were used to separate and purify thecompounds, and the spectroscopy method was used to identify the structures of compounds.The condition of HPLC method was developed: Aglient SB C₁8Column （4.6×250mm,5μm）,mobile phase: Acetonitrile-H₂O （17.5:82.5）, flow rate:1.0ml/min, column temperature:20℃,detection wavelength:285nm.Result: The ethanol extracted fraction from litchi seeds show the inhibition toα-glycosidase, stronger than the same concentration of acarbose, the control. Sevencompounds were separated and identified from the fraction of50%ethanol extracts of litchiseeds, five compounds of them were determined as the following:α-（D）-frucofuranoside（1）,ananosmosideA（2）,6-hydroxyhexanoicacid（3）,5’-β-D-glucopyranosyloxyjasmonicacid（4）,stigmasterol-3-O-β-D-glucopyranoside（5）,n-Butylshikimate（6）.The α-（D）-frucofuranoside（1）, ananosmoside A（2）,5’-β-D-glucopyranosyloxyjasmonicacid（4）,n-Butyl shikimatewere（6） isolated and found from the lichi nuclear fist time.Linearity of determination of the phlorizin was found in the range of0.04048-0.16192μg,the average recovery was99.6%, RSD=0.7%（n=6）.Conclusion: In the experiments, the method of determination of phlorizin is easy and convenient to be operated, and this research established the substantial and theoretical groundby using Litchi seeds as a treatment for diabetes on clinical application. This method isreliable, recurrent well and suitable for the determination of phlorizin.