title: Procyanidin B3
text: # Procyanidin B3
  
  Procyanidin B3 is a B type proanthocyanidin. Procyanidin B3 is a catechin dimer (catechin-(4α→8)-catechin).
  
  ## Natural occurrences
  
  It can be found in red wine, in barley, in beer, in peach or in Jatropha macrantha, the Huanarpo Macho.
  
  ## Health effects
  
  It has been identified as a hair-growth stimulant.
  
  ## 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, B6) the all-trans-[4,8:4,8]- and [4,8:4,6]-tri-[(+)-catechins] (procyanidin C2 and isomer).
  
  