We report the design, synthesis and application of a directly photocontrollable hydrogen sulfide (H₂S) donor, which releases H₂S proportionally to the intensity and duration of photoirradiation. Photocontrolled H₂S release from this donor was also demonstrated in bovine serum. This H₂S donor should be suitable for use in various biological systems.

Nitric oxide (NO) has been known as a gaseous chemical mediator, which modulates several physiological functions. Spatial and temporal control of NO release facilitates further study and medical application of NO. Herein, we report design and synthesis of a novel NO donor, NO-Rosa. NO-Rosa has a rosamine moiety, which absorbs yellowish green light. Upon irradiation with yellowish green light (530–590 nm), NO is released from NO-Rosa, presumably via photoinduced electron transfer from the N-nitrosoaminophenol moiety to the rosamine moiety. NO release from NO-Rosa was detected by ESR spin trapping and a NO fluorescent probe. Cellular NO release control was achieved in HEK293 cells using a NO fluorescent probe, DAF-FM DA. Furthermore, temporally controlled NO-induced vasodilation was demonstrated by treatment of a rat aortic strip with NO-Rosaex vivo and irradiation by yellowish green light. NO-Rosa is expected to be utilized for further study of NO-related physiological functions, utilizing its ability of spatiotemporal release of NO as a photocontrollable compound with harmless yellowish-green light.

We synthesized hetero-Diels–Alder cycloadducts from acyl nitroso derivatives and 9,10-dimethylanthracene, to be photo-inducible HNO-releasing agents and found that introduction of conjugated nitroaromatic groups effectively enhanced the responsiveness of HNO release to UV-A irradiation; we confirmed photoinduced HNO formation by EPR and GCMS analysis.