Regular monoterpenes and sesquiterpenes (essential oils)

Abstract

Monoterpenes resulting from the combination of two and sesquiterpenes from three branched, unsaturated C5 units (isoprene) represent a large class of natural products with a wide range of biological activities. They include unsaturated hydrocarbons and their oxidation products as alcohol, aldehydes, ketones, and rarely ethers. Volatile compounds are constituents of essential oils that are accumulated by numerous plants in special structures in the tissue. Besides the conspicuous aromatic properties, a wide range of biological activities has been documented allowing a wide field of applications. In an ecological context, mono- and sesquiterpenes play an important role in the relations between organisms, for example, as attractants of pollinators or deterrents of herbivores. On a large-scale, monoterpene emissions from vegetation in nature can have ecosystem-wide influences. The further investigation and documentation of this high biodiversity and its sustainable use remains a promising task. This requires the further development of analytical and production techniques and the exact definition and characterization of the plant sources.