Homocapsaicin

Homocapsaicin is a capsaicinoid and analog and congener of capsaicin in chili peppers (Capsicum). Like capsaicin it is an irritant. Homocapsaicin accounts for about 1% of the total capsaicinoids mixture and has about half the pungency of capsaicin. Pure homocapsaicin is a lipophilic colorless odorless crystalline to waxy compound. On the Scoville scale it has 8 600 000 SHU (Scoville heat units). Homocapsaicin isolated from chili pepper has been found in two isomeric forms, both with a carbon-carbon double bond at the 6 position (numbered from the amide carbon) on the 10-carbon acyl chain. One isomer has an additional carbon, a methyl group, at the 8 position and the other has a methyl group at the 9 position. Homocapsaicin (6-ene-8-methyl) is the more abundant isomer. Homocapsaicin with the double bond at the 7 position has never been found in nature, though its structure is widely reported on the Internet and, unfortunately, even in the scientific literature. Details of the misidentification have been published. (Note: the structure to the right is incorrect and has not yet been edited.)