... hypoxanthine, inhibitor of xanthine oxi-dase, the last enzyme involved in uric acid synthesis pathway. It catalyzes the conversion of hypoxanyhine into xanthine and this latter into uric acid. During ... useful for DNA and RNA synthesis, and inosine that will be degraded into hypoxanthine and xanthine and finally into uric acid. Hypoxanthine and guanine may enter in a sal-vage pathway, using ... with the syn-thesis of uricase. 3. Urate oxidase history The first molecule of this kind, synthetized in 1968 and introduced in France since 1975 and in Italy since 1984, was a non-recombinant...