Verfahren zur Gewinnung von Heparin

摘要

A material containing a sulphated polysaccharide in an aqueous medium at pH 4 to 10 is treated with a cross-linked copolymer of a mixture of 96-99.9 mole per cent of an aromatic monovinyl hydrocarbon and 4-0.1 mole per cent of an aromatic divinyl hydrocarbon, said copolymer bearing on the aromatic nuclei substituent groups of formula where R1, R2 and R3 are hydrocarbon groups, n is 1 to 4 and Y is an anion, said aqueous medium containing a water-soluble alkali metal, alkaline earth metal or ammonium salt of an acid, in such an amount that at least 50% of the sulphated polysaccharide is bound to the copolymer, and the copolymer bearing the bound sulphated polysaccharide is then separated from the aqueous medium. Specified sulphated polysaccharides are heparin, chitin sulphate, xylon sulphate, chondroitin sulphate and hyaluronic acid sulphate. Preferred copolymers are styrene-divinylbenzene copolymers bearing methylene trimethyl ammonium chloride groups and methylene dimethyl hydroxyethyl ammonium chloride groups, e.g. certain "Dowex" (Registered Trade Mark) quaternary ammonium anion exchange resins. In the extraction of e.g. heparin from hog liver, by treating the lever with aqueous salt solution, the homogenized aqueous extract is, after adjustment of salt content and pH if necessary, stirred with, or passed down a column of, anion exchange resin. After washing the resin, the heparin adsorbed thereon may be removed by elution with an aqueous solution of an alkali metal or ammonium salt of a mineral acid at a concentration of at least 1.9 molar. Alternatively the resin may be eluted with aqueous salt solutions of successively increasing molar concentrations up to at least 1.9 molar. The eluted polysaccharide may be precipitated from aqueous salt solution by addition of an organic solvent, e.g. methanol, ethanol or acetone. The resin may be regenerated by washing with an aqueous or salt solution of concentration at least 3 molar. Heparin may also be stored adsorbed on the resin, i.e. as a quaternary ammonium heparin salt of the above cross-linked copolymers. Specification 654,706 is referred to.