Structure and Antitumor Activity of the Less-Branched Derivatives of an Alkali-Soluble Glucan Isolated from Omphalia lapidescens: (Studies on Fungal Polysaccharide: XXXVIII1))

Abstract

The structure and antitumor activity of Smith-type degradation products (0L-24 OL-2-11 and OL-2-III) of an alkali-soluble glucan, OL-2, isolated from a crude fungal drug “Leiwan” (Omphalia lapidescens) were investigated. Methylation analysis suggested that OL-2-1 was a (l-> 3)-/?-d-glucan with approximately one branch at every three main chain glucosyl units at each C-6 position; OL-2-II was a (l->3)-/?-D-glucan with approximately one branch at two main chain glucosyl units at each C-6 position, and OL-2-III was a (l->3)-/J-D-glucan with approximately one branch at twenty four main chain glucosyl units at each C-6 position (number of all main chain glucosyl units is on average). OL-2-1 OL-2-II and OL-2-III which were Smith-type degradation products of OL-2, showed potent antitumor activity against the solid form of sarcoma 180 in ICR mice. These results indicated that the degree of fl-linked branching at position 6 was remarkably related to the antitumor activity. © 1992, The Pharmaceutical Society of Japan. All rights reserved.