Acidic exopolysaccharide from Penicillium allahabadense

Abstract

Penicillium allahabadense grown statically in liquid medium formed an extracellular polysaccharide which was collected by precipitation with ethanol (fraction A). The mycelium mat retained a considerable amount of polysaccharide extractable with water, which did not precipitate with ethanol but precipitated with FeCl3 (fraction B). Both fractions were formed mainly by glucose and malonic acid. Their optical rotation values and infrared spectra indicated β configuration. From fraction A was obtained the polysaccharide in the acid form (fraction C), whose equivalent weight is 425, and the demalonylated polysaccharide (fraction D). The main linkage type among glucose residues in the demalonylated polysaccharide, determined after Smith degradation, was 1 → 6. The main component obtained by methylation analysis was 2,3,4-tri-O-methyl-glucitol.