On the reaction of nucleic acids with isoniazid

Abstract

Isoniazid the tuberculostatic drug, was shown to react with ribonucleic acids under mildly acidic conditions. When yeast tRNA was treated with 10% aqueous solution of isoniazid at pH 4.2 and 37°, an extensive derivatization of cytosine residues was observed. The characteristics of this reaction are analogous to those of the semicarbazide inodification of nucleic acids, namely, (1) the reaction takes place selectively toward cytosine residues to give corresponding 4-deainino-4-isoniazido-cytosine derivatives, and (2) the internucleotide linkage of RNA chain is not affected by this treatinent.