Hypoglycemic Activity From Cyclocar Paliurus (Batal.)

Objective:Cyclocarya paliurus?Batal.?Iljinsk is the sole species in Cyclocarya genus and is mainly found at 420-2500 m altitude in the mountainous regions of Guizhou,Guangdong,Anhui,Fujian,Yunnan,Hubei,Hunan,Jiangsu,Jiangxi,Sichuan and Zhejiang provinces.They have been used in Traditional Chinese Medicine for the treatment of hypertension and diabetes,as well as for reducing cholesterol and regulating the functioning of the immune system.Pharmacological studies that Cyclocarya paliurus possessed avariety of bioactivities,such as hypoglycemic,blood lipid-lowering,blood press-lowering.Although a lot of pharmacological activities about the crude extract have been reported,the research about monomeric compounds is very few.It is very important to further study the chemical compounds of Cyclocarya paliurus inorder to better illuminate the material basis of it.The paper reported systematically the isolation and identification of Cyclocarya paliurus and evaluate monomeric compounds isolated for the antioxidant activities and?-glucosidase inhibitory activities,which provided scientific basis of better research of Cyclocarya paliurus.Methods:Chemical constituents were isolated and purified by column chromatography with silica gel,SePhadex LH-20,and semi-preparative HPLC.Meanwhile,the antioxidant activities and?-glucosidase inhibitory activities of twenty-one compounds isolated from Cyclocarya paliurus were determined.Results:Twenty-one compounds were isolated from the ethyl acetate extracts of the leaves of Cyclocarya paliurus.Their structures were elucidated as:kaempferol-3-O-?-L-rhamnoside?1?,kaempferol-3-O-?-L-?4"-Z-p-cumaroyl?-rhamnoside?2?,naringenin?3?,4'-hydroxywogonin?4?,hirsutrin?5?,contigoside B?6?,sterubin?7?,kaempferol?8?,?6S,7R,8R?-7?-[??-glucopyranosyl?oxy]lyoniresinol?9?,lyoniside?10?,?-?-lyoniresinol 3?-O-?-D-xylopyranoside?11?,dihydrodehydrodiconiferyl alcohol 4'-O-?-D-glucoside?12?,1-?3',4'-dihydroxy phenyl?-7-?4''-hydroxy-phenyl?-4-hepten-3-one?13?,grass-hopper ketone?14?,p-hydroxybenzonicacid?15?,syringicacid?16?,vanillicacid?17?,2-hydroxy-5-ethoxybenzoic acid?18?,2-methoxy-4-hydroxy cinnamic acid?19?,cis-p-hydroxycinnamic acid?20?,p-hydroxybenzaldehyde?21?.The antioxidant activities and?-glucosidase inhibitory activities of 5-8 and 15-21 isolated from Cyclocarya paliurus.Among them,compounds 5,6,16 and 19 showed obvious scavenging capabiliy against DPPH radical,with IC₅₀0 value of 1.83?g/ml,1.67?g/ml and 1.67?g/ml.Compounds 5,6,8,16,17,18 and 19 showed obvious reductive,with IC₅₀0 value of 15.00?g/ml,11.67?g/ml,3.33?g/ml,18.00?g/ml,11.33?g/ml,15.33?g/mland 16.00?g/ml.Compounds 6 and 8 showed obvious scavenging capabiliy against O^-₂ radical,with IC₅₀0 value of 1.74 mg/ml and 1.01mg/ml.Compound 16,17,19 and 20 showed strong?-glucosidase inhibitory effect with IC₅₀0 value of 32.67?g/ml,149.67?g/ml,3.30?g/ml and 5.00?g/ml.Conclusions:Compounds 2-7,9-14 and 16-21 were obtained from Cyclocarya paliurus for the first time.The flavonoids and phenolic acids showed strong antioxidant activity and?-glucosidase activity.