Kinetic observation of rapid electron transfer between thymine and thymidine anion radicals and caffeic acid. A pulse radiolysis study

Utilizing pulse radiolysis and kinetic spectrophotometric monitoring techniques, rapid electron transfer reaction from thymine and thymidine anion radicals to caffeic acid was observed respectively. Anion radicals of caffeic acid with absorption maximum at 360 nm have been generated via foregoing electron transfer reaction with rate constant of 1 x 109 mol-1Ls-1. Accordingly the subsequent protonation of thymine anion radicals should be prevented by the electrophilic protector. These kinetic demonstrations have provided direct evidence of charge transfer protection mechanism