ocimene

Ocimene refers to a group of monoterpene hydrocarbons with the molecular formula C10H16. The term typically denotes the two main isomers, alpha-ocimene and beta-ocimene; a gamma form is sometimes included among ocimenes. All ocimenes are acyclic, unsaturated hydrocarbons that contribute to the characteristic scents of many plants and flowers.

Natural occurrence and occurrence in essential oils: Ocimene is found in a wide range of essential oils, including those from basil, mint, parsley, dill, and orchids. It is also present in some cannabis essential oils and can appear in fragrances and flavor formulations.

Chemical characteristics and isomerism: Alpha- and beta-ocimene differ in the arrangement around their double bonds and exist as multiple geometric isomers (cis/trans). These structural variations influence their scent notes, which are commonly described as sweet, herbaceous, or citrus-like. As volatile organic compounds, ocimenes readily evaporate from plant tissues.

Biological and ecological roles: In plants, ocimenes are emitted in response to wounding or herbivore attack and function as semiochemicals. They can attract natural enemies of pests and may participate in plant-plant communication, helping neighboring plants prepare defenses.

Industrial and practical applications: Ocimenes are used as fragrance ingredients in cosmetics, perfumery, and some foods and beverages. They are typically obtained by steam distillation or fractional distillation of plant essential oils, and can also be synthesized for commercial use.

Safety and regulation: Ocimene is generally used within established fragrance and flavor guidelines. Some individuals may experience sensitivity or allergic reactions at certain concentrations. As with many essential oil constituents, exposure should follow regulatory and labeling recommendations.