ISOTOPIC STUDIES ON 2′-DEOXYINOSINE-8-C¹⁴ FORMATION FROM INOSINE-8-C¹⁴ BY WASHED CELL SUSPENTION OF VITAMIN B¹²-REQUIRING STRAIN OF LACTOBACILLUS

Abstract

1. Isolation and confirmation of 2′-deoxyinosine and related compounds which appeared in the reaction mixture were made by two-dimensional ascending paper chromatography, and each spot was applied to bioautography, autoradiography and chromatoscanning. The recoveries of the standard compounds previously added to the reaction mixture were satisfactory.
2. Formation of 2′-deoxyinosine-8-C¹⁴ from inosine-8-C¹⁴ In the presence of vitamin B₁₂ was tested by two-dimensional paper chromatography, and paper chromatoscanning, and the labeled deoxyinosine was detected in the amount of 8% of the added C¹⁴.
3. Using the similar method, the incorporation of the labeled carbon of hypoxanthine-8-C¹⁴ or D-ribose-1-C¹⁴ in deoxyinosine was studied. In the presence of hypoxanthine-8-C¹⁴, D-ribose and CN-B₁₂, the labeled carbon was found in the deoxyinosine fraction by paper chromatoscanning in the amount of 2.7% of the added C¹⁴, but in the presence of hypoxanthine, D-ribose-1-C¹⁴ and CN-B₁₂, the incorporation of the labeled carbon into deoxyinosine was scarcely detected.