Hydrogen sulfide (H2S) is a critical signaling molecule that regulates many physiological and/or pathological processes. Modulation of H2S levels could have potential therapeutic value. In this work, we report the rational design, synthesis, and biological evaluation of a class of phosphonamidothioate-based H2S-releasing agents (i.e., H2S donors). A novel pH-dependent intramolecular cyclization was employed to promote H2S release from the donors. These water-soluble compounds showed slow, controllable, and pH-sensitive production of H2S in aqueous solutions. The donors also showed significant cytoprotective effects in cellular models of oxidative damage. Most importantly, the donors were found to exhibit potent cardioprotective effects in an in vivo murine model of myocardial ischemia-reperfusion (MI/R) injury through a H2S-related mechanism.

Hydrogen sulfide (H2S), known as an important cellular signaling molecule, plays critical roles in many physiological and/or pathological processes. Modulation of H2S levels could have tremendous therapeutic value. However, the study on H2S has been hindered due to the lack of controllable H2S releasing agents which could mimic the slow and moderate H2S release in vivo. In this work we report the design, synthesis and biological evaluation of a new class of controllable H2S donors. Twenty five donors were prepared and tested. Their structures were based on a perthiol template, which was suggested to involve in H2S biosynthesis. H2S release mechanism from these donors was studied and proved to be thiol-dependent. We also developed a series of cell-based assays to access their H2S related activities. H9c2 cardiac myocytes were used in these experiments. We tested lead donors’ cytotoxicity and confirmed their H2S production in cells. Finally we demonstrated that selected donors showed potent protective effects in an in vivo murine model of myocardial ischemia-reperfusion injury, through a H2S related mechanism.

A sulfane sulfur mediated benzodithiolone formation was developed. Based on this reaction, two fluorescent probes (SSP1 and SSP2) for the detection of sulfane sulfur species (persulfide, polysulfide, and elemental sulfur) were prepared and evaluated. The probes showed high selectivity and sensitivity to sulfane sulfurs. Moreover, SSP2 was successfully applied for bioimaging sulfane sulfurs in living cells.

The design, synthesis, properties, and cell imaging applications of a series of pyridine-disulfide based fluorescent probes (WSP1, WSP2, WSP3, WSP4 and WSP5) for hydrogen sulfide detection are reported. The strategy is based on the dual-nucleophilicity of hydrogen sulfide. A hydrogen sulfide mediated tandem nucleophilic substitution-cyclization reaction is used to release the fluorophores and turn on the fluorescence. The probes showed high sensitivity and selectivity for hydrogen sulfide over other reactive sulfur species including cysteine and glutathione.

Hydrogen sulfide (H2S) and hydrogen polysulfides (H2Sn, n > 1) are endogenous regulators of many physiological processes. In order to better understand the symbiotic relationship and cellular cross-talk between H2S and H2Sn, it is highly desirable to develop single fluorescent probes which enable dual-channel discrimination between H2S and H2Sn. Herein we report the rational design, synthesis, and evaluation of the first dual-detection fluorescent probe DDP-1 that can visualize H2S and H2Sn with different fluorescence signals. The probe showed high selectivity and sensitivity to H2S and H2Sn in aqueous media and in cells.