Vegetable tannins - Lessons of a phytochemical lifetime

Vegetable tannins are complex polyphenolic metabolites of plants based upon two principal structural themes - oligomeric flavan-3-ols (proanthocyanidins) and poly-3,4,5-trihydroxyaroyl esters (gallotannins and ellagitannins). The remarkable progress made in the last fifty years in the understanding of their chemistry and biochemistry is reviewed.