Structural elucidation and bioactivity of a novel exopolysaccharide from endophytic Fusarium solani SD5

A bioactive exopolysaccharide [EPS (PS-I)], having M-w similar to 1.87 x 10(5) Da was produced by submerged culture of an endophytic fungus Fusarium solani SD5. Structural elucidation of the EPS (PS-I) was carried out by a series of experiments. Result indicates the presence of terminal alpha-L-rhamnopyranosyl, (1 -> 2)-alpha-L-rhamnopyranosyl, (1 -> 4)-beta-D-galactopyranosyl, (1 -> 4.6)-beta-D-galactopyranosyl moieties in a molar ratio of nearly 1:1:3:1. TEM image showed fibril structure of the EPS with a diameter of approximately 1 nm. Melting point range of the EPS was found 172-178 degrees C. The isolated PS-I exhibit in vitro anti inflammatory and anti allergic activity. EPS (1000 mu g/ml) protects 55% erythrocytes from hypotonic solution induced membrane lysis. Compound 48/80 induced mast cell degranulation was also protected by 56% with 100 mu g/ml EPS. (C) 2012 Elsevier Ltd. All rights reserved.