Carnosic acid is a natural

benzenediol In organic chemistry, dihydroxybenzenes (benzenediols) are organic compounds in which two hydroxyl groups () are substituted onto a benzene ring (). These aromatic compounds are classed as phenols. There are three structural isomers: 1,2-dihydrox ...

abietane Abietane is a diterpene that forms the structural basis for a variety of natural chemical compounds such as abietic acid, carnosic acid, and ferruginol which are collectively known as abietanes or abietane diterpenes. Abietanes are found in the ...

diterpene Diterpenes are a class of chemical compounds composed of four isoprene units, often with the molecular formula C20H32. They are biosynthesized by plants, animals and fungi via the HMG-CoA reductase pathway, with geranylgeranyl pyrophosphate being ...

found in rosemary (''

Rosmarinus officinalis ''Salvia rosmarinus'' (), commonly known as rosemary, is a shrub with fragrant, evergreen, needle-like leaves and white, pink, purple, or blue flowers, native to the Mediterranean region. Until 2017, it was known by the scientific name ''Rosmar ...

'') and common sage (''

Salvia officinalis ''Salvia officinalis'', the common sage or just sage, is a perennial, evergreen subshrub, with woody stems, grayish leaves, and blue to purplish flowers. It is a member of the mint family Lamiaceae and native to the Mediterranean region, tho ...

''). Dried leaves of rosemary and sage contain 1.5 to 2.5% carnosic acid. Carnosic acid and

carnosol Carnosol is a phenolic diterpene found in the herbs rosemary (''Rosmarinus officinalis'') and Mountain desert sage ('' Salvia pachyphylla''). It has been studied in-vitro for anti-cancer effects in various cancer cell types. See also * Carnos ...

, a derivative of the acid, are used as antioxidant

preservative A preservative is a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or by ...

s in food and nonfood products, where they're labelled as "extracts of rosemary" ( E392).

References

{{reflist Phenol antioxidants Diterpenes Phenanthrenes Isopropyl compounds Carboxylic acids Catechols