Chemical assay for the antitumor agent inosine dialdehyde (NSC-118994) in biologic fluids

Inosine dialdehyde, an antitumor agent highly active against several murine tumors, ispresently undergoing clinical trial for potential activity in man. To aid in the clinical evaluation of this drug, a chemical assay has been developed for the determination of concentrations of inosine dialdehyde in biologic fluids. The method involves reaction of inosine dialdehyde with phenylhydrazine in an acetic acid medium, followed by extraction of the product into ether and determining its absorbance at 378 nm. The reaction is specific for free inosine dialdehyde and will quantitate amounts as low as 1.0 mug.