ricinoleic

Ricinoleic, more precisely ricinoleic acid, is an 18-carbon monounsaturated hydroxy fatty acid, with the chemical name 12-hydroxy-9-octadecenoic acid. It is the principal component of castor oil, typically comprising about 85–95% of the oil. The molecule features a hydroxyl group on carbon 12 and a cis double bond at carbon 9, classifying it as an omega-9 hydroxy fatty acid.

Occurrence and biosynthesis include its prominence in seeds of Ricinus communis (castor plant). Ricinoleic acid is produced in seed lipids by the enzymatic hydroxylation of oleic acid during castor seed oil biosynthesis and is largely incorporated into triacylglycerols, making castor oil unusually rich in this fatty acid.

Chemical properties of ricinoleic acid derive from its hydroxyl group, which increases polarity relative to many other fatty acids. This functional group enables the formation of various esters and derivatives. As a renewable chemical, it serves as a versatile building block for hydroxy fatty acid derivatives used in industry, including polyurethanes, lubricants, plasticizers, coatings, and surfactants.

Uses and applications encompass industrial and consumer contexts. Castor oil and its derivatives are employed in lubricants and plasticizers, as well as in coatings and cosmetics. In medicine, castor oil has long been used as a laxative; the laxative effect is attributed to ricinoleic acid released in the gut after triglyceride hydrolysis, which irritates the intestinal mucosa and stimulates peristalsis.

Safety notes distinguish ricinoleic acid from the castor bean toxin ricin. The toxin ricin is a separate protein found in seeds and is not part of ricinoleic acid. Processing castor oil to remove toxins is essential; ricinoleic acid itself is not the toxin.