LIGHT EMISSION ACCOMPANIES OXYGEN UPTAKE DURING THE PEROXIDATIVE METABOLISM OF TETRACYCLINES

Abstract— Tetracycline molecules offer several sites for peroxidative metabolism of the type known to lead to oxygen consumption and electronic cxcitation. Accordingly, when tetracycline and chlortetracycline were exposed to horseradish peroxidase in the presence of hydrogen peroxide, oxygen was taken up and light emission was observed. The overall quantum yield ofchemiluminescencc is on the order of 10 ⁶, but that of chemiexcitation may be orders of magnitude higher as suggested by studies of sensitized emission. Given the widespread distribution of peroxidases, the formalion of highly reactive metabolites of tetracycline may have biological importance.