Abstract
Ample evidence suggests that H&sub2;S is an important biological mediator, produced by endogenous enzymes and microbiota. So far, several techniques including colorimetric methods, electrochemical analysis and sulfide precipitation have been developed for H&sub2;S detection. These methods provide sensitive detection, however, they are destructive for tissues and require tedious sequences of preparation steps for the analyzed samples. Here, we report synthesis of a new fluorescent probe for H&sub2;S detection, 4-methyl-2-oxo-2H-chromen-7-yl 5-azidopentanoate (1). The design of 1 is based on combination of two strategies for H&sub2;S detection, i.e., reduction of an azido group to an amine in the presence of H&sub2;S and intramolecular lactamization. Finally, we measured salivary H&sub2;S concentration in healthy, 18⁻40-year-old volunteers immediately after obtaining specimens. The newly developed self-immolative coumarin-based fluorescence probe (C15H15N&sub3;O&sub4;) showed high sensitivity to H&sub2;S detection in both sodium phosphate buffer at physiological pH and in saliva. Salivary H&sub2;S concentration in healthy volunteers was within a range of 1.641⁻7.124 μM.