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. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TH7-42HXHB0-W4&_user=10&_coverDate=12%2F31%2F1991&_alid=1024789976&_rdoc=8&_fmt=high&_orig=search&_cdi=5275&_docanchor=&view=c&_ct=148&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b667cb359d7d0b0d268d260ac1013a8c Procyanidin dimers and trimers from grape seeds. Jorge M. Ricardo da Silva, Jacques Rigaud, Véronique Cheynier, Annie Cheminat and Michel Moutounet, 1991
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. Synthesis of condensed tannins. Part 9. The condensation sequence of leucocyanidin with (+)-catechin and with the resultant procyanidins. Jan. A. Delcour, Daneel Ferreira and David G. Roux, J. Chem. Soc., Perkin Trans. 1, 1983, pages 1711-1717,