Piperine is an alkaloid extracted from the plant, Piper nigrum. Responsible for the pungency of black pepper, it is used in food flavorings as a spice, in fragrances, as an insecticide, and as an animal pest repellent. Piperine also inhibits CYP2J2.
It has been used in some forms of traditional medicine. It can be acutely toxic if swallowed in high doses. or ethanol. The amount of piperine varies from 1–2% in long pepper, to 5–10% in commercial white and black peppers.
Piperine can also be prepared by treating the solvent-free residue from a concentrated alcoholic extract of black pepper with a solution of potassium hydroxide to remove resin (said to contain chavicine, an isomer of piperine).
Chemical synthesis
Piperine has been synthesized by the reaction of piperonoyl chloride with piperidine.
- The last step is catalyzed by piperine synthase (piperoyl-CoA:piperidine piperoyl transferase). As suggested by its systematic name, it converts piperoyl-CoA and piperidine into piperine.
- Piperoyl-CoA is made by piperoyl-CoA ligase from piperic acid, which is in turn made from feruperic acid by CYP719A37.
- Feruperic acid is presumably made from ferulic acid. Piperine is presumably made from lysine.
In addition to piperine synthase PipBAHD2, there is an orthologous enzyme with broader substract specificity in Piper nigrum with gene symbol PipBAHD1, called a "piperamide synthase". This other enzyme is responsible for the many piperamide compounds (see ) besides piperine found in black pepper. Both enzymes are BAHD acyltransferases.
History
Piperine was discovered in 1819 by Hans Christian Ørsted, who isolated it from the fruits of Piper nigrum, the source plant of both black and white pepper. Piperine was also found in Piper longum and Piper officinarum (Miq.) C. DC. (=Piper retrofractum Vahl), two species called "long pepper".
Uses
Piperine gives black pepper its pungency properties, making it favorable in food flavorings as a spice and in fragrances.