Study on the light-protecting effect of polyacylated anthocyanins

花青素是一种天然着色剂，不仅是一种安全的食用着色剂，还具有预期的抗氧化、抗癌、免疫刺激等作用。同时，即使花作为生殖器官在阳光下长时间开放，也不会发生遗传危害，因此可以估计紫外线的保护作用。这一功能不仅对基础科学研究具有重要意义，而且对高功能食品着色剂的开发也具有重要意义。为此，本论文研究了三色通天蓝花色苷(HBA)的稳定性及其对DNA损伤的保护作用。利用冈崎大型光谱仪(OLS)进行光照实验，将HBA溶解在0.5%TFA-甲醇溶液或pH 4、6和pH 7.5的缓冲溶液中，然后用OLS照射280~400 nm的单色紫外光。生理条件下，HBA最稳定，在酸性甲醇中最不稳定。结果表明：1.色素在280 nm处的分解速度比370 nm处快。将HBA和牛胸腺DNA溶解在pH 7.5的缓冲溶液中，然后用UV-B区的紫外线照射溶液。DNA损伤程度是在金泽大学的Nikaido教授的合作下通过酶联免疫吸附试验定量测定的。HBA对UV-B辐射对DNA的降解具有保护作用。

The antohcyanin is the natural colorant which is not only a safe food-colorant but also is expected antioxidant, cancer inhibition, and immunostimulating effect and, etc. In the meantime, ultraviolet ray protecting function can be estimated because the genetic hazard does not occur, even if the flower, a genital organ, blooms under the solar light for a long period. This function is very interesting for basic science study, and in addition, it is important from the viewpoint of the development of the highly functional food-coloring agent. For this purpose I studied on stability of heavenly blue anthocyanin (HBA) from Ipomoea tricolor and protection of DNA damage.1. Light irradiating experiment using the Okazaki Large Spectrograph (OLS).HBA was dissolved in 0.5% TFA-methanol solution, or pH4, 6, and pH 7.5 buffer solution, then using the OLS, monochromatic UV light from 280 nm to 400 nm was irradiated. Under the physiological condition, HBA was the most stable, and in acidic methanol the most unstable. The pigment decomposed more rapidly at 280 nm than 370 nm.2. A protection of DNA damage by the pigment.HBA and bovine thymus DNA was dissolved in pH7.5 buffer solution, and then the solution was irradiated by ultraviolet radiation of UV-B region. The degree of a DNA damage was determined quantitatively by the ELISA in the cooperation of Professor Nikaido of the Kanazawa University. HBA exhibited the protecting effect against degradation of DNA by UV-B irradiation.