Carnosic acid is a natural benzenediol

Benzenediol

Benzenediols or dihydroxybenzenes are organic chemical compounds in which two hydroxyl groups are substituted onto a benzene ring. These aromatic compounds are classed as phenols, and more specifically as polyphenols...

 abietane

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....

 diterpene

Diterpene

Diterpenes are a type of terpenes composed of four isoprene units. They derive from geranylgeranyl pyrophosphate. Diterpenes form the basis for biologically important compounds such as retinol, retinal, and phytol...

 found in rosemary (Rosmarinus officinalis) and common sage (Salvia officinalis). Dried leaves of rosemary or sage contain 1.5 to 2.5% carnosic acid.

Carnosic acid has medicinal properties, is a potent antioxidant and protects skin cells against UV-A radiation (photoprotection

Photoprotection

Photoprotection is a group of mechanisms that nature has developed to minimize the damage that the human body suffers when exposed to UV radiation...

). Studies in animals have also found a protection against carcinogens

Chemoprotective agent

In the treatment of cancer, chemoprotective agents are drugs which protect healthy tissue from the toxic effects of anticancer drugs.- External links :* entry in the public domain NCI Dictionary of Cancer Terms...

.

Carnosic acid is used as a preservative or antioxidant in food and nonfood products (e.g. toothpaste, mouthwash and chewing gum -in which it has an antimicrobial effect on the microbes responsible for bad breath- or skin care products).