Piperine is a principal bio-active component of pepper. This natural alkaloid is that very element that gives pungency and biting taste to it. The first person to discover the substance was Danish chemist Hans Christian Orsted in 1819. Initially, he extracted it from Piper nigrum (black pepper), later, there were found two other sources of piperine: Piper longum and Piper officinarum. In 1882 it was first synthesized by the combination of piperidine and piperoyl chloride.
The seeds of black pepper contain five to ten percent piperine and are used in its commercial production. These seeds are treated with ethyl acetate or hexane, then the resin is removed by treating the solvent-free residue with potassium hydroxide solution. The last step is to rinse the remaining residue in warm alcohol to get piperine crystals.
Physical and Chemical Properties
This black pepper extract is a yellow crystalline compound the melting point of which is 128 to 130 °C. The chemical structure of piperine is defined as piperoylpiperidine with chemical formula C17H19NO3. It is a very weak base and in the process of acid or alkali hydrolysis breaks down into a volatile basic known as piperidine (C5H11N), and piperic acid (C12H10O4).
The substance is slightly soluble in water, same as other members of the lipid family. It solubility is 40 mg/l. That fact along with certain degree of toxicity for the central nervous and reproductive systems limits its pharmaceutical activity. At the same time, this chemical is highly soluble in alcohol, ether and chloroform.
The alkaloid is highly valued for its remarkably broad spectrum of therapeutic activities. Piperine is able to enhance the bioavailability of different drugs and nutrients, such as rifampicin, sulfadiazine, tetracycline, beta-carotene, selenium, etc. The effect is achieved by slowing down the metabolism of the drug, increasing its absorption or combining both methods.
The latest investigations showed that this alkaloid has the bunch of properties, such as chemopreventive, antioxidant, immunomodulatory, anticarcinogenic, stimulatory, hepatoprotective, antiinflammatory, antimicrobial, and antiulcer. Besides, the scientists have noticed that piperine also shows protective effect against radiation and as though may be prescribed to cancer patients before radiotherapy.