Isolation, Purification and Synthesis of Procyanidin B2 and Uses Thereof

A method for synthesizing procyanidin B2 comprising the steps of:

• a) acetylation of an epicatechin to form a 5,7,3′,4′,3″-penta-O-acetyl-epicatechin;
• b) reacting the 5,7,3′,4′,3″-penta-O-acetyl-epicatechin with between about 4.0 and about 4.2 equivalents of benzylchloride for between about 24 hours and about 72 hours in the presence of water to form a reaction mixture comprising a 5,7,3′,4′-tetra-O-benzylepicatechin;
• c) combining the reaction mixture with hydrochloric acid to form purified 5,7,3′,4′-tetra-O-benzylepicatechin, wherein the hydrochloric acid is between about 0.01 M and about 3 M, and between about −10° C. and about +10° C.;
• d) coupling an ethylene glycol with a first portion of the purified 5,7,3′,4′-tetra-O-benzylepicatechin to form a 5,7,3′,4′-tetra-O-benzyl 4-(2-hydroxyethoxy)epicatechin;
• e) dimerizing a second portion of the 5,7,3′,4′-tetra-O-benzylepicatechin with the 5,7,3′,4′-tetra-O-benzyl 4-(2-hydroxyethoxy)epicatechin to form a 5,7,3′,4′-tetra-O-benzylepicatechin-4β→8-5,7,3′,4′-tetra-O-benzylepicatechin;
• f) crystallizing the 5,7,3′,4′-tetra-O-benzylepicatechin-4β→8-5,7,3′,4′-tetra-O-benzylepicatechin;
• g) isolating the 5,7,3′,4′-tetra-O-benzylepicatechin-4β→8-5,7,3′,4′-tetra-O-benzylepicatechin using column chromatography;
• and
• h) deprotecting the 5,7,3′,4′-tetra-O-benzylepicatechin-4β→8-5,7,3′,4′-tetra-O-benzylepicatechin to form procyanidin B2.