cineol

Cineol, or 1,8-cineole, also known as eucalyptol, is a monoterpene oxide with the molecular formula C10H18O. It is a colorless, volatile liquid with a characteristic eucalyptus- and mint-like aroma and is a major constituent of eucalyptus oil. It occurs in various other essential oils, including rosemary, bay laurel, and tea tree.

Source and production: Cineol is produced naturally by several plant species as part of their essential oils. Commercially, it is obtained by steam distillation and purification of plant material such as Eucalyptus globulus oil.

Chemistry and properties: Cineol is a cyclic ether (a monoterpene oxide). It typically exists as enantiomeric forms, and natural oils may show enantiomeric excess. It boils at about 176 C and is poorly soluble in water but soluble in alcohol and most organic solvents.

Uses: It is used as a fragrance and flavoring agent, and in pharmaceuticals as an expectorant and decongestant. In traditional and modern medicine, it is valued for potential anti-inflammatory and antimicrobial effects; it is common in inhalants, cough syrups, and various topical formulations.

Safety: Cineol is generally regarded as safe at low concentrations for flavorings and cosmetics, but higher doses can irritate mucous membranes and skin and may be toxic if ingested. It should be used in accordance with regulatory guidelines and packaged warnings for consumer products.