石榴花可水解单宁及抗糖尿病活性研究

Hydrolyzable tannins from flowers of Punica granatum and their anti-diabetic activities

为了研究石榴花中抗糖尿病活性成分,采用MCI、反向ODS、Sephadex LH-20凝胶、HPLC等色谱技术从石榴花乙酸乙酯相中分离得到了8个可水解单宁类化合物,经多种波谱数据分析和文献比对,分别鉴定为1-O-galloyl-6-O-feruloyl-β-D-glucose(1)、1,2,3,4,6-penta-O-gally-β-D-glucopyranose(2)、punicafolin(3)、柯里拉京(4)、tellimagrandinⅠ(5)、1,2-di-O-galloyl-4,6-O-(S)-HHDP-β-D-glucose(6)、heterophylliin A(7)、eugeniin(8)。其中,化合物1为新化合物,化合物5~8为首次从石榴中分离得到。并对这8个化合物进行了抑制α-葡萄糖苷酶活性与抑制DPP-Ⅳ酶活性测定。结果显示化合物2、3、5~8对α-葡萄糖苷酶活性抑制作用显著,化合物1和4对α-葡萄糖苷酶具有一定的抑制活性。化合物5、7、8对DPP-Ⅳ酶具有一定的抑制活性。同时对化合物5进行了酶抑制类型的确定。

To investigate the active components against diabetes,the present study isolated eight hydrolyzable tannins from the ethyl acetate extract of Punica granatum flowers by MCI,reversed-phase chromatography(ODS),Sephadex LH-20 chromatography,and HPLC,and the structures were elucidated as 1-O-galloyl-6-O-feruloyl-β-D-glucose(1),1,2,3,4,6-penta-O-gally-β-D-glucopyranose(2),punicafolin(3),corilagin(4),telimagrandinⅠ(5),1,2-di-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-β-D-glucose(6),heterophylliin A(7),and eugeniin(8)on the basis of spectral data and literature records.Among them,compound 1 is a new compound,and compounds 5-8 were isolated from this species for the first time.All isolated compounds were tested for inhibitory activities againstα-glucosidase and DPP-Ⅳ.The results indicated that compounds 2,3,and 5-8 showed significant inhibitory activities againstα-glucosidase,while compounds 1 and 4 exhibited moderate inhibitory activities.Compounds 5,7,and 8 showed moderate inhibitory effects on DPP-Ⅳ.In addition,the type of enzyme inhibition of compound 5 was determined.