Structure-activity relationships of alloxan-like compounds derived from uric acid.

The diabetogenic activity of a range of alloxan-like compounds derived from uric acid has been investigated. The classes of derivatives were: 5-substituted-isouric acids; 4,5-disubstituted-4, 5-dihydrouric acids; 5-substituted-pseudouric acids; salts of dehydro-uramil hydrate; salts of dehydro-isouramil hydrate; alloxan derivatives. Compounds were tested by intravenous injection into rats and diabetogenic activity assessed by production of persistent hyperglycaemia and glycosuria. The only essential structural feature common to all active compounds was the presence of a quinonoid pyrimidine system or its hydrated equivalent. The presence of the five-membered ring of uric acid (or an opened form thereof) did not abolish and in some compounds enhanced diabetogenic activity.