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]

References

  1. ^ Procyanidin dimers and trimers from grape seeds. Jorge M. Ricardo da Silva, Jacques Rigaud, Véronique Cheynier, Annie Cheminat and Michel Moutounet, 1991[dead link]
  2. ^ Structure elucidation of proanthocyanidins: Direct synthesis and isolation from Pilsener beer. Jan Delcour, 1985 Archived 2011-07-06 at the Wayback Machine
  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, doi:10.1039/P19830001711