Enzymatic preparation of heparin disaccharides as building blocks in glycosaminoglycan synthesis

Pharmaceutical heparin and heparan sulfate, isolated from a side-stream of a commercial heparin manufacturing process, have been enzymatically depolymerized with heparin lyases obtained from Flavobacterium heparinun. Heparin afforded a trisulfated disaccharide product that was recovered from the reaction mixture using gel permeation chromatography. Heparan sulfate afforded unsulfated disaccharide that was conveniently recovered from the product mixture by ion exchange chromatography. Both disaccharides were obtained in gram amounts at 90% or higher purity. Both enzymatically prepared disaccharides were chemically protected to prepare building blocks required for the future chemical synthesis of therapeutically valuable heparin oligosaccharides.