Abstract:

Procyanidins, also known as condensed tannins, are naturally occurring flavan-3-ols, present widely in the plant
kingdom. This review compiles the recent reports on the chemical composition, biological activities, absorption, metabolism
and toxicology of procyanidins in China and abroad. The chemical structures of procyanidins are classified according to
polymerization degree combined with structure units, connection mode, configuration and substituents, with figures to
illustrate each type. This paper summarizes the current knowledge on biological activities, such as antioxidant activity,
cardiovascular disease prevention and inhibition of cancer, hypertension, hyperlipidemia, diabetes, etc. Meanwhile, this
review elucidates the absorption and metabolism of procyanidins, including Caco-2 cell model and in vivo metabolic studies.
At last, toxicological studies show that procyanidins are safe. Based on the latest studies worldwide, procyanidins are
considered as natural food-derived antioxidants with strong antioxidant activity and low toxicity.

Key words: procyanidins, chemical structure, biological activity, absorption, metabolism, toxicology