Procyanidin B6 Explained

Procyanidin B6 is a B type proanthocyanidin.

Procyanidin B6 is a catechin-(4α→6)-catechin dimer. It can be found in grape seeds^[1] and in beer.^[2]

Chemical synthesis

Molar equivalents of synthetic (2R,3S,4R or S)-leucocyanidin and (+)-catechin condense with exceptional rapidity at pH 5 under ambient conditions to give the all-trans-[4,8]- and [4,6]-bi-[(+)-catechins] (procyanidins B3 and B6) the all-trans-[4,8:4,8]- and [4,8:4,6]-tri-[(+)-catechins] (procyanidin C2 and isomer).^[3]

Notes and References

1. Procyanidin dimers and trimers from grape seeds . 10.1016/S0031-9422(00)95213-0 . Phytochemistry . January 1991 . 30 . 4 . 1259–1264 . Rigaud . Jacques . Cheynier . Véronique . Cheminat . Annie . Moutounet . Michel . 1991PChem..30.1259R . Ricardo Da Silva . Jorge M. .
2. http://www.agr.kuleuven.ac.be/lmt/labolmc/DOCS/Delcour.htm Structure elucidation of proanthocyanidins: Direct synthesis and isolation from Pilsener beer. Jan Delcour, 1985
3. 10.1039/P19830001711 . Synthesis of condensed tannins. Part 9. The condensation sequence of leucocyanidin with (+)-catechin and with the resultant procyanidins . 1983 . Delcour . Jan. A. . Ferreira . Daneel . Roux . David G. . Journal of the Chemical Society, Perkin Transactions 1 . 1711-1717 .