白叶单枞黑茶抗氧化及体外降血糖活性研究  

Study on antioxidant and in vitro hypoglycemia activities of dark tea prepared from Camellia sinensis var. Baiye Dancong

作　　者：叶琼仙[1] 刘静[1] 苗爱清[2] 王冬梅[1] 

机构地区：[1]中山大学药学院,广东广州510006 [2]广东省农业科学院茶叶研究所,广东英德513000

出　　处：《食品工业科技》2014年第16期153-157,共5页Science and Technology of Food Industry

基　　金：广东省自然科学基金(9151064001000038);中山大学医科学生业余科研基金项目[2012]83号

摘　　要：采用DPPH法、FRAP法和α-胰淀粉酶、α-葡萄糖苷酶抑制活性评价白叶单枞黑茶醇提物及其不同萃取物的抗氧化活性及体外降血糖活性。结果表明,乙酸乙酯萃取物中总黄酮及总酚含量最高,分别为(155.68±4.34)mg/g(以芦丁当量计)和(313.84±9.79)mg/g(以没食子当量计);乙酸乙酯萃取物DPPH·清除活性的EC50为13.72μg/mL,FRAP铁离子还原能力EC1为43.38μg/mL;同时该萃取物也具有最强的体外降血糖活性,5mg/mL时对α-胰淀粉酶抑制率为95.83%,50μg/mL时对α-葡萄糖苷酶抑制率为91.30%。采用HPLC-DAD-MS/MS对乙酸乙酯萃取物进行分析,通过对紫外吸收光谱以及质谱信息进行分析,并参考相关文献,推定出12个化合物,这些化合物中包括茶生物碱以及多种以芹菜素、山奈酚为苷元的黄酮糖苷类成分。The antioxidant activity and in vitro hypoglycemia activity of ethanol extract of dark tea prepared from Camellia sinensis var. Baiye Dancong and its different solvent extracts were assayed by DPPH method,FRAP method and α-pancreatic amylase inhibitory assay,α-glucosidase inhibitory assay,respectively. The results showed that the contents of both total flavonoids and total phenolics in the ethyl acetate extract were highest among the different solvent extracts,and had （155.68±4.34）mg/g of total flavonoids（calculated as rutin equivalent） and （313.84±9.79）mg/g of total phenolics（calculated as gallic acid equivalent）,respectively. The ethyl acetate extract achieved the strongest antioxidant activity,and its EC50 of DPPH· assay was 13.72μg/mL while the Eel of FRAP capacity was 43.38μg/mL The ethyl acetate extract of dark tea also showed significant co-pancreatic amylase and α-glucosidase inhibitory activities,achieved 95.83% inhibition on a-pancreatic amylase at the concentration of 5mg/mL while 91.30% inhibition on α-glucosidase at the concentration of 50μg/mL. Using HPLC-DAD-MS/MS analysis,twelve compounds in the ethyl acetate extract were identified by comparing their ultraviolet absorption spectra and mass spectra with those of the standards and data in the literatures. Several flavone glycosides with apigenin and keampferol as the aglycone moieties were detected besides tea alkaloids.

关 键 词：白叶单枞黑茶 抗氧化 降血糖 HPLC—MS MS分析 

分 类 号：TS201.1[轻工技术与工程—食品科学]