耐辐射动球菌类胡萝卜素提取物的抗氧化活性研究

Antioxidant Activities of Carotenoid Extracts From Kineococcus radiotolerans

耐辐射动球菌(KR)是一种从高放射性污染环境中分离出来的具有抗辐射、抗氧化特性的橘黄色球菌。为探明KR抗氧化特性与菌体内代谢物活性的关系,从KR中分离提取纯化类胡萝卜素,利用高效液相色谱(HPLC)和液质联用(LC-MS)分析提取物的组成和性质,通过体外高铁离子还原能力和DPPH自由基清除试验、体外脂类氧化抑制试验和DNA氧化损伤的抑制试验,比较KR类胡萝卜素提取物与番茄红素、β-胡萝卜素的体外抗氧化能力及生物大分子氧化保护能力。结果表明,KR提取物中,其中一种产物的最大吸收波长在471.9 nm和501.1 nm处,分子式C_(48)H_(66)O_2;另一种产物的最大吸收波长在464.6 nm,分子式C_(24)H_(34)O。KR类胡萝卜素提取物的高铁离子还原能力在浓度为2μg·mL^(-1)时达到1.22;DPPH自由基清除率在浓度为4μg·mL^(-1)时达到94.26%;对脂类氧化的抑制率在浓度为8μg·mL^(-1)时达到54.29%;对DNA氧化损伤的抑制率在浓度为8μg·mL^(-1)时达到84.78%。本研究结果为进一步探究KR抗氧化作用及其机制,以及医疗、保健等领域的抗氧化药物研发奠定了基础。

A coccus-shaped, orange organism which demonstrates anti-radiation and antioxidation characteristics was isolated from radioactive environment. In order to clear the relationship between the antioxidation of Kineococcus radiotolerans and the biological activity of bacteria metabolites in vitro, a research was gaven on carotenoids by HPLC and LC-MS for their composition and property. The results illustrated that one product with a molecular formula C4sH66 02 has a maximum absorption at 471.9 nm and 501.1 nm, and the other with a molecular formula C24H340 has a maximum absorption at 464.6 nm. By measurement of ferric reducing antioxidant power （FRAP） and DPPH radical scavenging activities, antioxidant capacities of different carotenoids were investigated. The results showed that the carotenoid extracts of KR had stronger antioxidant capacities in vitro, which about 1.22 of FRAP were scavenged at the concentration of 2 μg·mL-（-1）and 94.26% DPPH radical were scavenged at the concentration of 4 μg·mL-（-1）. Furthermore, the protection of lipid oxidation and protective effects of DNA break caused were compared. At the concentration of 8μg·mL-（-1）, results showed that carotenoid extracts of KR had strong pretective abilities of lipid oxidation which is about 54.29% inhibition of lipid oxidation, and inhibition effect of it on DNA break caused is about 84.78%. The present study generates the basic data for in-depth research of the oxidation and mechanism of KR, and provides a basis for the antioxidant drag development of medical and health area.