cinnamate

Cinnamate is a general term for salts and esters derived from cinnamic acid, also known as trans-3-phenyl-2-propenoic acid. In organic nomenclature, cinnamates have the formula C6H5-CH=CH-COO-R for esters, where R is an alkyl or aryl group, and the cinnamate anion refers to the deprotonated acid (C6H5-CH=CH-COO−).

Natural occurrence and preparation: Cinnamic acid occurs in trace amounts in some plant essential oils and is a product of the phenylpropanoid biosynthetic pathway. Cinnamate esters are prepared by esterification of cinnamic acid with alcohols or via reactions of cinnamoyl chlorides. The cinnamate anion forms salts with metals such as sodium or potassium.

Characteristics and uses: The cinnamate family features an unsaturated conjugated system that influences aroma and reactivity. A number of cinnamate esters, including methyl cinnamate and ethyl cinnamate, are prized for their fruity, spicy, or vanilla-like notes and are widely used as flavor and fragrance ingredients. Some cinnamate derivatives are employed as ultraviolet (UV) absorbers in cosmetics; for example, ethylhexyl methoxycinnamate (octinoxate) is a common UVB filter in sunscreens. Other cinnamates serve as intermediates in organic synthesis or as components in polymer and material science.

Safety and regulation: Cinnamate esters generally show low acute toxicity but can cause skin irritation or sensitization in some individuals. Regulatory status varies by region, particularly for cinnamate-based UV filters, with some jurisdictions imposing restrictions due to environmental or safety considerations.