ESR Studies of Firefly<scp>D</scp>-(-)-Luciferin Chemiluminescence in Dimethyl Sulfoxide

Abstract

The primary step of firefly D -(-)-luciferin (Ln) chemiluminescence in the O 2 -bubbled dimethyl sulfoxide (DMSO) dissolving t -BuOK was investigated by the ESR rapid-freezing technique. It was discovered that superoxide anion radical (O 2 - ) is generated and is stably present in the DMSO solution of t -BuOK at room temperature and is consumed on mixing with the solution containing Ln to produce light emission. Thus it was concluded that O 2 - is clearly related to the primary step of Ln chemiluminescence.