Synthesis of a Fluorescence Labeled Spin Trap and Its ESR Study

Abstract

Free radicals play a key role in physiological and pathological processes including aging and cancer development. To understand the biological role of free radicals,it is of critical importance to develop highly sensitive techniques for the detection and quantitation of free radicals being produced. Among the numbers of techniques used for the detection of free radicals,electron spin resonance( ESR)-spin trapping technique,owing to its relative higher specificity,is believed to be an indispensable method for the detection of free radicals in biological systems. However,the ESR-spin trapping technique was limited becauseit has the relative low sensitivity and it's hard to achieve real-time detection of free radicals in living cells. Considering that the fluorescence probes for labeling and tracking subcellular structures in living cells are easily available,a new spin trap conjugated with fluorescence moiety( DanPPN) was synthesized and characterized. The ESR study showed that the DanPPN could be used for the detection of superoxide anion,oxygen and carbon-centered radicals. Moreover,it was observed that the fluorescence intensity of DanPPN was decreased with the increase of the concentration of AIBN. The results suggested that the new spin trap may have a potential use for the detection of free radicals in biological systems.