Catechol-type tannin

Catechol-type tannin is a specific type of tannin, a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds. They are widely distributed in many species of plants, where they play a role in protection from predation, and perhaps also as pesticides, and in plant growth regulation.

Chemical Structure

Catechol-type tannins are characterized by their catechol (benzene-1,2-diol) subunits. These subunits are derived from the shikimate pathway in plants, which is responsible for the biosynthesis of aromatic amino acids. The basic building block of catechol-type tannins is the flavan-3-ol unit, which can be polymerized to form larger structures.

Occurrence and Role in Plants

Catechol-type tannins are found in a wide variety of plant species, including many types of fruits, nuts, and seeds, as well as in the bark and leaves of many trees. They are particularly abundant in the tea plant (Camellia sinensis), where they contribute to the astringency and bitterness of the brewed beverage.

In plants, catechol-type tannins serve several important functions. They can deter herbivory by making the plant material less palatable or nutritious to animals. They also have antimicrobial properties, which can help protect the plant from pathogens. Additionally, they may play a role in plant growth regulation, although this is not fully understood.

Health Effects

Catechol-type tannins have been studied for their potential health benefits in humans. They have antioxidant properties, which means they can help neutralize harmful free radicals in the body. Some research suggests that they may also have anti-inflammatory, anti-cancer, and heart health benefits. However, more research is needed to fully understand these effects and their implications for human health.

See Also

• Tannin
• Catechol
• Polyphenol
• Tea