Synthesis and biological effect of lysosome-targeting fluorescent anion transporters with enhanced anionophoric activity

Abstract

Two lysosome-targeting fluorescent anion transporters derived from coumarins, trifluoromethylated arylsquaramides and morpholines were synthesized, and their specificity and efficiency to target and alkalize lysosomes were investigated. They are able to target lysosomes specifically. Compared with the previous analogue without trifluoromethyl substituents, these two conjugates, in particular the one having a 3,5-bis(trifluoromethyl) substituent, exhibit significantly higher ability to facilitate the transport of chloride anions, alkalize lysosomes and reduce the activity of lysosomal Cathepsin B enzyme. The present finding suggests that improving the anionophoric activity of lysosome-targeting fluorescent anion transporters is favorable to the efficiency to alkalize lysosomes and deactivate lysosomal Cathepsin B enzyme.

Keywords: Cathepsin B enzyme; Fluorescent anion transporter; Lysosomal alkalization; Lysosome targeting.