Devasagayam T P, Subramanian M, Singh B B, Ramanathan R, Das N P
Radiation Biology and Biochemistry Division, Bhabha Atomic Research Center, Bombay, India.
J Photochem Photobiol B. 1995 Oct;30(2-3):97-103. doi: 10.1016/1011-1344(95)07159-y.
Flavonoids, the dominant colouring pigments of plants, as well as the related polyphenol tannic acid significantly inhibit single-strand breaks in plasmid pBR322 DNA induced by singlet molecular oxygen ((1)O2). This reactive species of oxygen was generated in an aqueous buffer system by the thermal dissociation of the endoperoxide of 3,3'-(1,4-naphthylene)dipropionate. Among the antioxidants examined, myricetin showed the highest protective ability, followed by tannic acid, (+)catechin, rutin, fisetin, luteolin and apigenin, when the inhibitory abilities were compared at 90 min after incubation. The protective abilities of these compounds were both time and concentration dependent. At equimolar concentrations (100 microM) the antioxidant effect of myricetin was better than that of other known antioxidants such as lipoate, alpha-tocopherol and beta-carotene. Data, when analysed in relation to the structures of various compounds, showed a rough correlation with protective abilities. Owing to the abundance of these compounds in our normal diet, they may play significant roles in preventing oxidative damage resulting from potentially deleterious (1)O2.
黄酮类化合物是植物中的主要色素，相关的多酚单宁酸能显著抑制单重态分子氧（¹O₂）诱导的质粒pBR322 DNA中的单链断裂。这种活性氧物种是通过3,3'-（1,4-亚萘基）二丙酸内过氧化物的热分解在水性缓冲体系中产生的。在所检测的抗氧化剂中，杨梅素的保护能力最强，其次是单宁酸、（+）儿茶素、芦丁、非瑟酮、木犀草素和芹菜素，在孵育90分钟后比较抑制能力时发现如此。这些化合物的保护能力既依赖于时间也依赖于浓度。在等摩尔浓度（100微摩尔）下，杨梅素的抗氧化效果优于其他已知的抗氧化剂，如硫辛酸、α-生育酚和β-胡萝卜素。当结合各种化合物的结构分析数据时，显示出与保护能力的大致相关性。由于这些化合物在我们日常饮食中含量丰富，它们可能在预防由潜在有害的¹O₂引起的氧化损伤方面发挥重要作用。
