Identification of some products from the reaction of trans-4-aminostilbene metabolites and nucleic acids in vivo.

Esters of N-hydroxy-N-acetylaminostilbene react with guanosine, adenosine and cytidine in vitro and yield a number of different reaction products, some of which have been recently identified. We have now demonstrated that Urd-N3,alpha-beta,OH-AABB, Guo-N1,alpha-beta,OH-AABB, AdoN1,alpha-N6,beta-AABB and a Guo-O6 derivative are also formed in vivo, when the precarcinogen trans-4-dimethylaminostilbene is orally administered to female Wistar rats. However, these reaction products constitute only a small fraction of the adducts formed with liver rRNA. N-Acetylaminobibenzyl-alpha,beta-threo-diol is released from liver RNA upon hydrolysis. Comparison of the adduct pattern resulting from the reaction of N-acetoxy-N-acetylaminostilbene with yeast RNA in vitro and that obtained from in vivo rat liver RNA reveals not only quantitative but also qualitative differences. This indicates that reactive metabolites other than hydroxamic acidesters may contribute to the in vivo binding.