Tannins: Natural plant-derived polyhydroxy phenolic compounds with potential for biotechnological and biomedical applications

The difference between Tannin and Tannic Acid is that the term Tannin is used to name the group of organic compounds whereas Tannic acid is a type of tannin.
Members of the group of Tannins - all of them polyhydroxyphenolic compounds – are present in leaves and other nutrient-rich parts of a huge number of Angiosperm plants. In nature, Tannins play a significant role in the protection of the plants against herbivores. Tannins inactivate enzymes in the digestive tract of the herbivores, with respective consequences: the herbivores may die of starvation.
A well-known example for a technological application of Tannins is the process of leather production. Complex formation with collagen the denaturation of proteins - here in the animal skin - by the polyhydroxyphenol components of Tannin is their major function. Various biomedical applications are known, such as application of Tannins due to their adstringent property, production of tannate salts, antihistamines and antitussive drugs.
Recently, it was discovered that Tannic acid suppresses the virus SARS-CIY-2 as a dual inhibitor of the main viral protease and the cellular TMPRSS 2 protein, with the consequence that the virus cannot infect human cells.