Uridine compounds in glucuronic acid metabolism. 2. The isolation and structure of ‘uridine-diphosphate-glucuronic acid’

Abstract

Using ethanol fractionation of the barium salts and ion-exchange chromatography, the active liver factor responsible for glucuronide synthesis in liver suspensions was isolated. It is shown to be a nucleotide of uridine 5''-phosphate linked to glucuronic acid 1-phosphate through a pyrophosphate bond, urudine-diphosphate-glucuronic acid (UDP glucuronic acid). It is suggested that the reaction between UDP glucuronic acid and acceptor (ROH) is UDP glu-curonic acid + ROH - UDP + R-O-glucuronic acid. It is sug-gested that the formation of the disaccharide unit, N-acetyl-hexosamine glucuronide by the liver is an essential step in the synthesis of mucopolysaccharides, and the formation of glucuronides by hydroxyl containing aromatic compounds is a diversion rather than an essential function of this enzyme system.