Iron(II) hydroxide
Iron(II) hydroxide or ferrous hydroxide is an inorganic compound with the formula Fe(OH). It is produced when iron(II) salts, from a compound such as iron(II) sulfate, are treated with hydroxide ions. Iron(II) hydroxide is a white solid, but even traces of oxygen impart a greenish tinge. The air-oxidized solid is sometimes known as "green rust".
Bisulfide
At physiological pH, hydrogen sulfide is usually fully ionized to bisulfide (HS) so in biochemical settings, "hydrogen sulfide" is often used to mean, bisulfide or hydrosulfide. Hydrosulfide has been identified as the third gasotransmitter along with nitric oxide and carbon monoxide. Its specific role and direct interaction with signaling molecules is the subject of ongoing research.