Procyanidin

Epicatechin (EC), one of the building blocks of procyanidins
Cyanidin, the anthocyanidin produced when procyanidin are depolymerized under oxidative conditions

Procyanidins are members of the proanthocyanidin (or condensed tannins) class of flavonoids. They are oligomeric compounds, formed from catechin and epicatechin molecules. They yield cyanidin when depolymerized under oxidative conditions.

See the box below entitled "Types of procyanidins" for links to articles on the various types.