Isolation and characterization of N6-succinyladenosine from human urine.

From the urines of colon carcinoma patients and normal subjects we have isolated a nucleoside in which an amino group of aspartic acid is attached to the six position of purine ribonucleoside. The structure, N6-succinyladenosine, N-(9-B-D-ribofuranosylpurin-6-yl)aspartic acid was assigned on the basis of spectral data, chemical degradation, and by synthesis. The ultraviolet and mass spectra, chromatographic and electrophoretic mobilities, and the chemical properties of the naturally occurring nucleoside were identical to those of the synthetic N6-succinyladenosine. In contrast to the methylated and hypermodified nucleosides which are products of RNA catabolism, this urinary nucleoside appears to be derived from adenylosuccinic acid, a key intermediate required in the biosynthesis of ubiquitous, natural purine nucleotide adenosine-5'-monophosphate (AMP).