Ellagitannin

**Semantic type:** Organic Chemical

**Definition:** A class of polyphenols that are formed by the oxidative linkage of galloyl groups to the pentahydroxy gallic acid ester of glucose where the galloyl groups are linked through C-C bonds. Ellagitannins have diverse effects including anti-oxidant, anti-proliferative, anti-viral, and anti-microbial activities.