Large-scale preparation of the oligosaccharide phosphate fraction of Pichia holstii NRRL Y-2448 phosphomannan for use in the manufacture of PI-88

Mild acid-catalysed hydrolysis of the extracellular phosphomannan of the ye ast Pichia holstii NRRL Y-2448 produces a high-molecular-weight phosphomann an core, a low-molecular-weight oligosaccharide phosphate fraction, and a n eutral oligosaccharide fraction. A method was developed for the large-scale preparation of the oligosaccharide phosphate fraction, consisting predomin antly of the pentasaccharide phosphate, 6-O-PO3H2-alpha -D-Man-(1 --> 3)-al pha -D-Man-(1 --> 3)-alpha -D-Man-(1 --> 3)-alpha -D-Man-(1 --> 2)-D-Man, f or use in the manufacture of the promising new anti-cancer agent, PI-88. Fu rther insights were also gained into the structure of the phosphomannan by HPLC analysis of the time course of the hydrolysis reaction. (C) 2001 Elsev ier Science Ltd. All rights reserved.