Polymers with Dithiobenzoate End Groups Constitutively Release Hydrogen Sulfide upon Exposure to Cysteine and Homocysteine.

Dithioesters are well-established as efficient reversible addition-fragmentation chain transfer (RAFT) agents. More recently, certain small molecule dithioesters have been reported to release the biological signaling molecule hydrogen sulfide (HS) upon exposure to cysteine. Herein, we examine the propensity of polymers synthesized using RAFT with a dithioester chain transfer agent to release HS via reaction of cysteine with constitutive dithioester end-groups. Homocysteine-triggered release of HS from these materials is also observed, with evidence suggesting that the mechanism is analogous to the reaction with cysteine.