维生素C对紫外线诱发DNA损伤的保护作用

用拉曼光谱探讨维生素C对紫外线诱发DNA损伤的保护作用。测量了小牛胸腺DNA水溶液及其添加微量维生素C并经过9min和30min紫外辐射的拉曼光谱，紫外线的辐射照度为18．68W／m^2。实验结果表明：在浓度为O．2mmol／L的维生素C存在的条件下，全波段的紫外辐射对DNA只造成了轻微的损伤。DNA被保护可能是因为紫外辐射虽然产生了对DNA损伤很大的自由基，但维生素C具有清除自由基的能力。另外由于DNA和维生素C在260nm处对紫外线都有很强的吸收能力，因此也可能是维生素C对紫外线的吸收能力强于DNA，从而保护了DNA。

Protective Effect of Vitamin C on Ultraviolet Radiation-Induced DNA Damage

The protection effect of vitamin C on ultraviolet radiation-induced DNA damage was discussed. The Raman spectra of the mixture of small amount vitamin C and DNA sdution with ultraviolet radiation of 9 min and 30 min were measured. The intensity of ultraviolet radiation is 18.68 W/m2. When vitamin C (0.2 mmol/L) was add ed to DNA solution, ultraviolet radiation only had a slightly influence on the DNA. Though free radicals generated by ultraviolet radiation in the mixture of DNA solution and vitamin C can cause DNA damage, vitamin C has antioxidative property and it can scavenge free radicals and prevent the reaction between DNA and free radicals. In the other way, both vitamin C and DNA have strong absorbancy at 260 nm ultraviolet. Maybe the vitamin C absorbancy of ultraviolet radiation is stronger than DNA′s, so DNA was protected.