三叶青茎部不同溶剂提取物的功能成分、抗氧化及酪氨酸酶抑制活性研究

目的 以三叶青茎部为原料,探究三叶青不同溶剂提取物的功能成分、抗氧化及酪氨酸酶抑制活性。方法 采用乙醇超声法提取三叶青,获得醇提液及残渣。醇提液依次用石油醚、乙酸乙酯、正丁醇对其进行分步萃取,残渣则采用蒸馏水多次提取,最终得到4种提取物。分别测定4种提取物总酚、总黄酮、总皂苷、总多糖、抗氧化及酪氨酸酶抑制活性,并进行相关性分析。结果 4种提取物中乙酸乙酯萃取物总酚、总黄酮、总皂苷含量最高,分别为40.22%±1.01%、38.56%±0.64%、6.15%±0.21%,正丁醇萃取物总多糖含量最高,为9.29%±0.25%。各萃取物均具有抗氧化和酪氨酸酶抑制活性,其中乙酸乙酯萃取物清除1,1-二苯基-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基、超氧阴离子、2-苯基-4,4,5,5-四甲基咪唑啉-3-氧代-1-氧(2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl,PTIO)自由基、羟自由基能力和铁离子还原能力(ferric reducing antioxidant power, FRA...

Functional components, antioxidant activity and tyrosinase inhibitory activity of extracts from different solvent extracts from stems of Tetrastigma hemsleyanum Diels et Gilg

Objective To compare and discuss the functional components, antioxidant and tyrosinase inhibitory activities of the different polar extracts from stems of Tetrastigma hemsleyanum Diels et Gilg. Methods In this study, the ultrasonification process and the absolute ethyl alcohol were used to deal with the stem of Tetrastigma hemsleyanum Diels et Gilg, obtaining the residues and alcohol extracts. The distilled water multiply extracted the residues, while the alcohol extract were extracted sequentially using a three-solvent combination order: Petroleum ether, ethyl acetate, and n-butanol. Finally, four extracts were obtained. The total content of flavonoids, polyphenols, saponin, or other functional components, their corresponding antioxidant activities, and tyrosinase inhibitory activities of the four extracts were measured, respectively, then the correlation analyses between in them were conducted. Results The results demonstrated that the extract obtained from the ethyl acetate contained the highest amount of flavonoids, polyphenols, and saponins, and the proportions reached 40.22%±1.01%, 38.56%±0.64%, and 6.15%±0.21%, respectively. The extract obtained from the n-butanol contained the highest amount of polysaccharide, and the proportions reached 9.29%±0.25%. Each extract owned antioxidant activity and tyrosinase inhibitory activities, but the ethyl acetate extract has the most robust ability to DPPH radical, superoxide anion, PTIO reactive oxygen radical, hydroxyl radical, and iron ion reduction among all the extracts, and the half inhibitory concentration (IC50) were 0.016, 0.014, 0.171, 0.335 and 0.412 mg/mL respectively. Moreover, the ethyl acetate extract was superior to other extracts in tyrosinase inhibition activity. The correlation showed that the total polyphenols, flavonoids, and saponins were all highly significant and positively correlated with the DPPH free radicals, superoxide anion free radicals, PTIO active oxygen free radicals, hydroxyl free radical scavenging ability, and iron ion reducing power (P<0.01). Conclusion In summary, our study reveals that the ethyl acetate extract is superior to other extracts in tyrosinase inhibition activity and antioxidant of T. hemsleyanum rhizome extract, and the main active components are total phenols, total flavonoids, and total saponins, providing some relevant technical support for further development and utilization of rhizome resources of this species.