Pro-anthocyanidins can be differentiated into B-type or A-type depending on their interflavanic linkages.
A-type pro-anthocyanidins containing double interflavanyl linkages (for example, procyanidin A2: epicatechin (2b→7,4b→8)-epicatechin) compared to B-type pro-anthocyanidins that have a single interflavanyl bond, typically between C4→C8 (for example procyanidin B2: epicatechin–(4b→8)-epicatechin.
The most common A-type compounds are A1 and A2. A-type pro-anthocyanidins were found in only three fruits (cranberry, avocado and plum), one nut (peanut), and two spices (cinnamon and curry).
Study shows that cinnamon, which contains a series of unique trimeric and tetrameric procyanidins with A-type linkages, significantly decreased plasma levels of triglycerides and total and LDL cholesterol, when administered (1–6 g=day) just for 20 days.
Pro-anthocyanidins found in cranberry juice with A-type linkages prevented adhesion of uropathogenic P-fimbriated E. coli suggesting they may help to maintain a healthy urinary tract.
A-type pro-anthocyanidins
