天然色素アントシアニンの合成とその機能の解明

天然色素花色苷的合成及其生物学功能的阐明花色苷是花卉的主要色素，具有基因保护、抗光、抗虫、清除自由基等多种生物学功能。我们开发了（1）从黄酮醇糖苷合成酰化花青素的新方法，并证明了（2）酰化花青素（HBA）对日光、UV-A和B的保护作用。(1)利用金属还原反应实现了芦丁及其衍生物-黄酮醇糖苷直接转化为花色苷。将各种反应条件应用于还原。芦丁在无水3%盐酸-甲醇中，于0℃下与锌汞化合物反应，得到矢车菊素3-芸香糖苷，产率24%。此外，过苯甲酰芸香苷被还原以得到相应的花色苷，Ox（3E）产率为5%。用锌粉代替锌汞，得到黄酮-3-烯-3-芸香糖苷，收率65%。因此，我们找到了一条新的高效合成天然黄-3-烯的路线。(2)从化学上证明了三色牵牛花蓝色花瓣色素天兰花青素（HBA）对UV-A和B具有一定的屏蔽作用，对DNA具有一定的保护作用。经纤维素酶处理后分离出的蓝色原生质体，经显微光度测定，证实HBA存在于花瓣表皮细胞中，浓度为10 ~（-2）M。我们建立了一个模式系统的花瓣保护DNA从紫外线照射。用胸苷二聚体抗体ELISA法检测DNA损伤。将aq. HBA溶液与活细胞溶液一样，完全阻断了紫外线对DNA的损伤，表明开放花中的花青素具有保护基因免受阳光照射的功能。

Synthesis of anthocyanin, a natural pigment, and clarification of its biological functionAnthocyanin is major flower pigment and might play role of amount biological functions such as gene protection form sunlight, entomophily, and radical scavenger. It is used for a food colorant and eye therapeutic medicine.We developed the new synthesis (1) of acylated anthocyanins from flavonol glycoside and proven protection (2) of DNA by acylated anthocyanin (HBA) from sunlight, UV-A and B.(1) We realized the direct transformation to anthocyanin from rutin and its derivatives, a flavonol glycoside by using metal reduction reaction. Various reaction conditions were applied to the reduction. Rutin was treated with Zn-Hg in absolute 3% HCl-methanol at 0℃ to give cyanidin 3-rutinoside in 24% yield. And also, perbenzoylrutins were reduced to afford the corresponding anthocyanin in Ox(3E)5% yield. Zn powder in replacing of Zn-Hg gave flav-3-ene 3-rutinoside in 65% yield. Therefore, we found the new efficient synthetic route to a natural flav-3-ene.(2) We provided chemical evidence that heavenly blue anthocyanin (HBA), a pigment of blue petal of Ipomoea tricolor, has a light shielding effect of UV-A and B to protect the DNA. That HBA exists at 10-2M in epidermis cell of the petal, was clarified by micro-photometery of a blue protoplast, which was isolated after treatment of the tissue with cellulase. We built up a model system of the petal for protection of DNA from UV-light exposure. The DNA damage was analyzed by ELISA method using antibody of thymidine dimers. The concentration (10-3M) of an aq. HBA solution just as that of living cell completely blocked the DNA damage under UV-irradiation, indicating that the anthocyanin pigment in open flower has a function of protection of the gene from sun-light.