Gallotannin

Gallotannin is a type of hydrolysable tannin, a class of polyphenols. Gallotannins are found in a variety of plants, including the oak family and the sumac family. They are also found in the nutgalls formed by insects on plants of the oak family.

Chemistry

Gallotannins are composed of a central glucose molecule, to which multiple gallic acid molecules are attached. The number of gallic acid molecules can vary, but is typically between three and seven. The gallic acid molecules are attached to the glucose molecule via ester bonds.

Gallotannins are hydrolysable tannins, meaning they can be hydrolyzed into smaller molecules by the action of acid, base, or enzymes. Upon hydrolysis, gallotannins yield glucose and gallic acid.

Biological Activity

Gallotannins have been found to have a variety of biological activities. They have antioxidant properties, and can scavenge free radicals, potentially protecting against oxidative stress. They also have antimicrobial activity, and can inhibit the growth of certain bacteria and fungi.

In addition, gallotannins have been found to have anticancer activity. They can inhibit the growth of cancer cells and induce apoptosis, or programmed cell death. However, more research is needed to fully understand the potential of gallotannins as anticancer agents.

Uses

Gallotannins have been used in tanning leather, due to their ability to cross-link proteins. They have also been used in the production of ink, due to their ability to form dark, permanent colors.

In addition, gallotannins have been used in traditional medicine. For example, they have been used in Ayurvedic medicine to treat diarrhea and dysentery.

See Also

• Tannin
• Hydrolysable tannin
• Gallic acid
• Polyphenol