This section is from the book "A Text-Book Of Pharmacology, Therapeutics And Materia Medica", by T. Lauder Brunton. Also available from Amazon: A text-book of pharmacology, therapeutics and materia medica.
Composition. - Piperine, resin, and volatile oil. Piperine is a crystalline principle, almost neutral, tasteless, inodorous, and insoluble in water, and is isomeric with morphine. The resin possesses the pungent taste of the drug, and gives the oil its aromatic smell.