1) Chemical irritant 2) Derived from ginger 
Gingerol, or sometimes [6]-gingerol, is the active constituent of fresh ginger. Chemically, gingerol is a relative of capsaicin and piperine, the compounds which give chilli peppers and black pepper their respective spicyness. It is normally found as a pungent yellow oil, but also can form a low-melting crystalline solid. Cooking ginger transforms...
[n] - derived from ginger