Calcium hydroxide
Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca(OH). It is a colorless crystal or white powder and is obtained when calcium oxide (called "lime" or "quicklime") is mixed, or slaked with water. It has many names including hydrated lime, caustic lime, builders' lime, slack lime, cal, or pickling lime. Calcium hydroxide is used in many applications, including food preparation, where it has been identified as E number E526. Limewater is the common name for a saturated solution of calcium hydroxide.
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.