AP39 (Item No. 17100) is a compound used to increase the levels of hydrogen sulfide (H2S) within mitochondria.{28632} It consists of a mitochondria-targeting motif (triphenylphosphonium) coupled to an H2S-donating moiety (dithiolethione) by an aliphatic linker. AP219 is a control compound for AP39, containing the triphenylphosphonium scaffold but lacking the H2S-releasing portion.{28632}