Transient photochemistry of naphazoline in a protein environment

Abstract

The photoreactivity of naphazoline (NP), 2-(1-naphthylmethyl)imidazoline, in the presence of bovine serum albumin (BSA) is investigated. The protein microenvironment affects markedly the efficiency of the photochemical deactivation pathways of the NP transient intermediates photogenerated upon laser excitation. The triplet state of the drug associates with BSA and its lifetime increases by more than one order of magnitude. Hydrated electrons and nitrogen-centered radicals formed in the NP photolysis react efficiently with protein sites, behaving as sources of reductive and oxidative protein damage, respectively. NP photoinduced protein structural modification is also observed.