Novel aspects of tannins - Renewed concepts and structure-activity relationships

摘要

The concept of tannins has been changed recently by an understanding of their structural diversity and newly-found pharmacological activities. Tannins of most notable recent interest are hydrolyzable tannin oligomers comprising macrocyclic oligomers with highly structure-specific antitumor activity, and hydrolyzable tannins in various oxidative stages with structure-activity relationships of their antioxidative activities. Caffetannins and labiatetannins, which have increased structural variety, can be included among the tannins. The presence of a galloyl group at flavan O-3 remarkably enhances the activity. [References: 60]