Mechanism of the mutagenic action of hydroxylamine. X. Certain specificities in the mutagenesis of N-hydroxy and N-methoxy analogs of cytosine and adenine derivatives.

In contrast with N4-methoxycytidine, N6-methoxyadenosine and the corresponding 2'-deoxynucleosides, N4-hydroxycytidine readily penetrates cells of Escherichia coli. Apparently this explains the non-mutagenicity of the N-methoxy compounds when added to an E. coli suspension, and the potent mutagenic effects of the N4-hydroxy analogs under the same conditions. 1-Deazaadenosine and N9- and N1-hydroxyalkyl-substituted adenines and cytosines, inhibitors of adenosine and cytidinedeaminases, are also incapable of crossing the E. coli cell wall.