OXIDATION OF INDOLE-3-ACETIC ACID BY SONICATED NEUTROPHILS. PITFALLS IN CORRELATING EPR SIGNALS AND CHEMILUMINESCENCE

Abstract –The oxidation-peroxidation of indole-3-acetic acid by sonicated neutrophils, unlike the horseradish peroxidase-catalyzed process, features not only the skatole radical, but also a tertiary carbon-centered radical in the electron paramagnetic resonance (EPR) spectrum. Moreover, emission occurs only in the red.
From the present and earlier data it is concluded that the observation of the skatole radical does not necessarily indicate its involvement in the ¹Δ_gO₂ generating process. Also unlikely is a correlation between the tertiary carbon-centered radical and red emission.
Our results indicate that in general great care must be taken in attempting to correlate EPR signals with chemi-luminescence and with oxygen consumption.