Piperine, possibly along with its isomer chavicine,
Preparation
Extraction
Due to its poor solubility in water, piperine is typically extracted from
black pepper by using organic solvents like
dichloromethane 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 action of piperonoyl chloride on
piperidine.
Biosynthesis
The biosynthesis of piperine is only partially known.
-
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
Reactions
Piperine forms salts only with strong acids. The platinichloride B
4·H
2PtCl
6 forms orange-red needles ("B" denotes one mole of the alkaloid base in this and the following formula).
Iodine in
potassium iodide added to an alcoholic solution of the base in the presence of a little hydrochloric acid gives a characteristic periodide, B
2·HI·I
2, crystallizing in steel-blue needles with
melting point 145 °C.
Piperine can be hydrolyzed by an alkali into piperidine and piperic acid.
In light, especially ultraviolet light, piperine is changed into its isomers chavicine, isochavicine and isopiperine, which are tasteless.
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 is widely used in the supplements industry for its effect on enhancing absorption and bioavailability of other compounds such as
curcumin,
,
ashwaganda, amino acids, vitamins and several minerals including selenium. It has been reported to inhibit several enzymes that participate in xenobiotic metabolism, including CYP3A4,
P-gp,
UDP-glucose 6-dehydrogenase, and glucuronosyltransferase.
The last two activities (inhibition of
glucuronidation) are most relevant for curcumin.
See also
