Efficient photo-release of hydrogen sulfide (H2S) from stable water-soluble precursors

Two hydrogen sulfide photo-releasing molecules (photo-HSRMs), 3-hydroxy-2-naphthalene-methanethiol and the corresponding disulfide, have been synthetized, their properties, and photochemical reactivity explored. Both compounds are stable in the neat form and in aqueous solutions in the dark, but release H2S under exposure to UVA and UVB light in good quantum and chemical yields. In the presence of thiols, such as cysteine, glutathione, and mercaptoethanol, the yield of hydrogen sulfide release reaches 90%. The mechanisms of H2S photo-release from these photo-HSRMs is discussed.