Piperine is a piperidine alkaloid from the group of acid amide alkaloids with the molecular formula: C17H19NO3. Piperine is the most important ingredient of black pepper (Piper nigrum), one of the most commonly used spices, and gives it its pungency. Piperine is found in all types of pepper. Its concentration is particularly high in black pepper, at around 4.6 to 9.7 percent. Piperine is also found in white pepper, long pepper and 0.4% in cubeb pepper. However, the pungency of piperine is nowhere near as pronounced as that of capsaicin, which is found in chilies. The pungency of piperine is linked to the trans-trans position of the two double bonds (see figure). Under the influence of light, isomers of piperine are formed whose pungency is lost.