An alternative procedure for the cleavage of the xilose serine linkage in heparin

C. MARTINI BECHECH; A. FERNÁNDEZ CIRELLI

REVISTA LATINOAMERICANA DE QUIMICA

Universidad Autónoma de México

Lugar: México; Año: 1986 vol. 17 p. 15 - 19

0370-5943

Glycosaminoglycans from mammalian tissues occur in their native state as proteoglycans. Heparin, well know for its anticoagulant and antithrombotic propierties has the structure of a sulfated glycosaminoglycan consisting of alternating hexuronic acid (D-glucoronic or L-iduronic) and 2-amino-2-deoxy-D-glucose (D-glucosamine) residues. The polysaccharide-protein linkage region in heparin chains consists of a sequence of D-glucoronic acid and three neutral sugars, two D-galactoses and one D-xylose, this latter linked to a serine residue. This O-glycosidic linkage to serine can be easily cleaved under alkaline conditions through a B-elimination reaction to release the polysaccharide chain. Sodium hydroxide in concentrations ranging from 0.1 to 0.5 M. at 4ºC for varius periods of time, followed by neutralization and decationization, are the generally adopted experimental conditions. We now report on the use of triethylamine to catalyze the B-elimination reaction. Organic bases have the advantage that they can be easily eliminated from the mixture by extraction with appropiate solvents.