烟草色素蛋白复合物中多酚类物质对其抗紫外性能的影响

Effect of Phenols in Tobacco Pigments-protein Complex on Anti-uv Function

采用不同的方法获得烟草色素蛋白复合物(tobacco pigments protein,TPP),研究其抗紫外性能及机理。分别通过等电点沉降和硫酸铵沉降从烟草中分离得到TPP,运用高效液相色谱对其所结合的酚类物质进行了分析检测,并对其进行紫外可见图谱扫描,同时通过日光辐照,观察其降解速度,确定其抗紫外辐射活性。结果表明,多酚类物质如芸香苷、咖啡酸、绿原酸和莨菪葶,在抗紫外辐射过程中扮演重要角色;pH 4.5、pH 5.0、pH 5.3沉降的TPP的总酚酸含量高,其中pH 4.5沉降的TPP的酚类物质含量最高,抗紫外活性也最强;另外,85%硫酸铵沉降获得的TPP总酚酸含量低,抗紫外活性也较弱。在长时间的日光照射试验中,TPP的抗紫外性能表现稳定。

Anti-Ultraviolet properties and mechanism of pigments protein complex from tobacco leaves were studied.Proteins were precipitated by ammonium sulphate solution of 85% saturation or isoelectric point precipitation from tobacco leaves.The profiles of binding phenolic acids such as chlorogenic acid,rutin,scopoletin and caffeic acid were analyzed by High Performance Liquid Chromatography,the anti-UV function of pigments-protein were determined with UV spectrum after being irradiated by sunshine,and the speed of its degradation under UV was observed.The data showed that the pigments-protein precipitated at pH 4.5,pH 5.0,pH 5.3 contained higher total levels of polyphenols,and pigments-protein at pH 4.5 had the strongest anti-UV function due to the richest content of phenolic acids.Meanwhile,proteins sedimentated by ammonium sulphate solution of 85% saturation from tobacco leaves exhibited low anti-UV activity,containing low total levels of polyphenols.Polyphenols was the major anti-UV substance.Under the long time exposure under UV,pigments-protein performed high stabilility.