OXYGEN REQUIREMENT FOR NEAR‐UV MEDIATED CYTOXICITY OF α‐TERTHIENYL TO <i>ESCHERICHIA COLI</i> AND <i>SACCHAROMYCES CEREVISIAE</i>

Abstract

Abstract— The photosensitizing activity of α‐terthienyl, a naturally occurring compound from Tagetes has been studied. Fluence‐response curves for the effect of α‐terthienyl and near‐UV radiation on Escherichia coli have been prepared. Photosensitization of E. coli was enhanced in aerobic as compared to anaerobic conditions and exogenous superoxide dismutase had a slight protective effect. Sodium azide, a quencher of 1 O 2 , protected yeast cells from photosensitization with α‐terthienyl. The available evidence suggests that α‐terthienyl acts as a photodynamic sensitizer in vivo.