11. Inhibition of xanthine oxidase has been proposed as a mechanism for improving cardiovascular health. 12. *Alloxanthine is an inhibitor of xanthine oxidase. 13. It is also an isostere of xanthine , the normal substrate for the enzyme. 14. AO is very similar in amino acid sequence to xanthine oxidase ( XO ). 15. Biologically relevant molecules identified so far include uracil, an RNA nucleobase, and xanthine . 16. Xanthine oxidase inhibitors block uric acid production.17. Other enzymes capable of producing superoxide are xanthine oxidase, NADPH oxidases and cytochromes P450. 18. It is degraded by xanthine dehydrogenase to 2, 8-dihydroxyadenine ( DHA ). 19. "' Xanthosine "'is a nucleoside derived from xanthine and ribose. 20. The active metabolite of allopurinol is oxypurinol, which is also an inhibitor of xanthine oxidase.
