ESR EVIDENCE FOR THE OXIDATIVE CLEAVAGE OF GENTISIC ACID IN BASIC AQUEOUS-SOLUTION

The oxidative cleavage of 2,5-dihydroxybenzoic acid (gentisic acid), p resumably into maleylpyruvate in basic aqueous solution has been shown by ESR spectra of semiquinonic radicals bearing a methylenic group. O ne of these radicals has been unambiguously attributed to 2,4,5-trihyd roxyphenylacetic acid semiquinonic radical. The formation of an hydrox ylated homogentisic acid from gentisic acid (a metabolite of aspirin) is of particular importance in the treatment of alkaptonuria and relat ed inflammatory arthritis.