Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is a toxin that is the main active component of chili peppers and gives them their "spicy" or "hot" taste. It is a potent irritant for mammals, including humans, for which it produces a sensation of burning in any tissue with which it comes into contact. Capsaicin and several related amides (capsaicinoids) are produced as secondary metabolites by chili peppers, likely as deterrents against eating by mammals and against the growth of fungi. Pure capsaicin is a hydrophobic, colorless, highly pungent crystalline solid.