Structural investigation of an antibacterial polysaccharide from Streptomyces virginia H03

Abstract

The chemical structure of a polysaccharide from the broth of cultured Streptomyces Virginia H03 was investigated. There might be 1→2 and 1→4 and no 1→6 glycosidic linkages in the polysaccharide according to periodate oxidation and Smith degradation. Four fragments including 2,3,4,6-Me4-Man, 2,3,6-Me3-Gal, 2,4,6-Me3-Glc, and 3,6-Me2-Man were found in the methylated polysaccharide. Furthermore, the polysaccharide has a β-Glc(1→4)- α-Man(1→4)-α-Gal(1→3)-linked backbone and a branch at the C-2 position of (1→2)-linked mannose residues as determined by the method of nuclear magnetic resonance (NMR) spectroscopy. The assumed structure of the polysaccharide is [→3)-β-Glc(1→4)-α-Man (1→4)-α-Gal(1→]n. 2 ↑ α-Man(1 Additionally, the polysaccharide has a wide antibiogram and was found to be most effective against Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli. © 2010 Verlag der Zeitschrift für Naturforschung, Tübingen.