Stöhrer G, Mathews R A
Chem Biol Interact. 1982 Jul 15;41(1):117-29. doi: 10.1016/0009-2797(82)90022-9.
The structure of the uridine adduct with the acetate ester of the carcinogen 3-hydroxy-1-methylxanthine has been determined. Covalent binding is between C-8 of xanthine and O-2 of uracil. This was determined from studies of the NMR spectrum, mass spectra and solvolysis in liquid hydrogen sulfide. The nucleoside adduct, formed with uridine, is identical with the adduct with polyuridylic acid after enzymatic hydrolysis. Treatment with aqueous ammonia or pH 7 at 100 degrees C leads to the loss of ribose. Thymidine also forms an adduct with 3-acetoxy-1-methylxanthine in a similar yield. Model studies with a space-filling model suggest that the methylxanthine moiety can fit into the major groove of DNA and cause minimal helix distortion if the thymine base is rotated into the unnatural syn conformation.
已确定致癌物3-羟基-1-甲基黄嘌呤的乙酸酯与尿苷加合物的结构。共价结合发生在黄嘌呤的C-8与尿嘧啶的O-2之间。这是通过对核磁共振谱、质谱以及在液态硫化氢中的溶剂解研究确定的。与尿苷形成的核苷加合物在酶促水解后与与聚尿苷酸形成的加合物相同。用氨水或在100℃的pH 7条件下处理会导致核糖的损失。胸苷也以类似的产率与3-乙酰氧基-1-甲基黄嘌呤形成加合物。用空间填充模型进行的模型研究表明，如果胸腺嘧啶碱基旋转到非天然的顺式构象，甲基黄嘌呤部分可以嵌入DNA的大沟中并引起最小的螺旋扭曲。
