FACTORS INFLUENCING CONJUGATION OF PHENOLIC COMPOUNDS WITH THE ɛ-AMINO GROUP

Factors influencing the conjugation potency of eugenol (E), isoeugenol (IE), methyl isoeugenol (MIE), and acetyl isoeugenol (AIE) with [l-14C]ɛ-aminocaproic acid are investigated. The conjugation reaction for IE is accelerated in the presence of H2O2-peroxidase and inhibited under anaerobic conditions by nitrogen gas flow. An oxidation reaction is found to be necessary for the conjugation of IE with ɛ-aminocaproic acid. Immediately after mixing the phenolic compounds with [1-14C]ɛ-aminocaproic acid and H2O2-peroxidase, the main conjugates are 7.7% for IE, 2.1% for E, 0.7% for AIE, and 0.2% for MIE. IE, which is a potent sensitizer in vivo, produces the greatest amount of conjugates while MIE, which is negative in vivo, produces almost no conjugates. AIE and E, both mild sensitizers in vivo, produce less conjugates than IE.