Piperine

Piperine, along with its isomer chavicine, is the alkaloid responsible for the pungency of black pepper and long pepper. It has been used in some forms of traditional medicine. Piperine, along with its isomer chavicine, is the alkaloid responsible for the pungency of black pepper and long pepper. It has been used in some forms of traditional medicine. Piperine is extracted from black pepper using dichloromethane. Aqueous hydrotropes can be used in the extraction to result in high yield and selectivity. The amount of piperine varies from 1–2% in long pepper, to 5–10% in commercial white and black peppers. Further, it may be prepared by treating the solvent-free residue from an alcoholic extract of black pepper, with a solution of potassium hydroxide to remove resin (said to contain chavicine, an isomer of piperine) and solution of the washed, insoluble residue in warm alcohol, from which the alkaloid crystallises on cooling. Piperine yields salts only with strong acids. The platinichloride B4·H2PtCl6 forms orange-red needles ('B' denotes one mole of the alkaloid base in this and the following formulae). Iodine in potassium iodide added to an alcoholic solution of the base in the presence of a little hydrochloric acid gives a characteristic periodide, B2·HI·I2, crystallising in steel-blue needles, melting point 145 °C. 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'. A component of pungency by piperine results from activation of the heat- and acidity-sensing TRPV ion channels, TRPV1 and TRPA1, on nociceptors, the pain-sensing nerve cells. Piperine is under preliminary research for its potential to affect bioavailability of other compounds in food and dietary supplements, such as a possible effect on the bioavailability of curcumin.