Model compounds for (6–4) photolyases: a comparative flavin induced cleavage study of oxetanes and thietanes

Abstract

Thietanes were used in the past as mimics for an unstable oxetane intermediate formed during the repair of mutagenic (6–4) lesions. The thietane derivatives were found to be not repaired, raising the question of how well thietanes are cleaved by single electron donation compared to oxetanes. We have prepared two flavin-containing oxetane and thietane model compounds for the (6–4) photolyase catalyzed repair process and we show that both are efficiently cleaved by a reduced and deprotonated flavin. Thietanes are therefore excellent models. The lack of their repair can be attributed to lack of binding.