title: Chemical carcinogenesis. II. Imidazole-ring-opened derivatives from 7-ethyl- and 1,7-diethylguanosine.
abstract: The UV-spectral and chromatographic analyses of the derivatives of the two synthetic standards 7-ethylguanosine and 1,7-diethylguanosine are here reported. The derivatives obtained from the dialkyl compound exhibit a striking similarity to those found in the "pyrimidine-nucleotide-like" fraction of rat liver tRNA ethylated in vivo by ethionine. The finding of imidazole-ring-opened products in tRNA ethylation by ethionine could be significant from the point of view of chemical carcinogenesis: in fact, imidazole-ring-opening of 1,7-dialkylguanosines directly at level of RNA with consequent formation of substituted pyrimidines is a transversion, i.e. a mutagenic event which would cause a change in the expression of genetic information since a purine has been transformed into a pyrimidine.
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D005001:Ethionine / Q000378:metabolism; D006151:Guanosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D008099:Liver / Q000378:metabolism; D012314:RNA Cap Analogs / Q000138:chemical synthesis*; D012315:RNA Caps / Q000138:chemical synthesis*; D051381:Rats; D013056:Spectrophotometry, Ultraviolet
chemical_list: C042934:1,7-diethylguanosine; D012314:RNA Cap Analogs; D012315:RNA Caps; D006151:Guanosine; C020321:7-ethylguanosine; D005001:Ethionine