O-sulfate esters of hydroxy amino acids in hydrolyzates of proteoglycans

Abstract

In the preparation of hydrolyzates of proteoglycans for analysis of amino acids, ninhydrin-positive materials other than free amino acids can be generated. Some of these are O-sulfate esters of the hydroxy amino acids and some unknown sulfate derivatives of the hexosamines.The amounts of the O-sulfate esters of the hydroxy amino acids and of the unknown derivatives of the hexosamines can be minimized if the hydrolyzates are evaporated to dryness in a flash evaporator at 45[deg]C.A method is described for the separation and quantitation of the O-sulfate esters of serine, threonine, hydroxyproline, tyrosine, and cysteic acid.