PURPOSE: To obtain the titled substance simply, by treating a novel nucleoside oxidase with a nucleoside, e.g., adenosine, guanosine, etc. under aerobic conditions in an aqueous medium.
CONSTITUTION: A bacterium capable of producing nucleoside oxidase, e.g., Pseudomonas putida B-0781 (FERM-P 5664), etc. is cultivated conventionally to give a culture mold, from which nucleoside oxidase is prepared by lysozyme treatment, ultrasonic treatment, etc. A 5'-hydroxymethyl group-containing nucleoside, e.g., adenosine, thymidine, cythidine, etc. as a raw material is treated with the above- mentioned nucleoside oxidase in an aqueous medium under aerobic conditions, to form a nucleoside-5'-carboxylic acid. the prepared reaction solution is adjusted to a pH of about 2W3, the desired substance is precipitated, and it is collected and purified by recrystallization, etc.
IKUTA SHIGERU
MATSUURA KAZUO
