title: Structural elucidation and biological studies of a novel exopolysaccaride from Klebsiella pneumoniae PB12.
abstract: An exopolysaccharide (KNPS) of an average molecular weight ∼1.8×10(5) Da was isolated from the culture medium of Klebsiella pneumoniae PB12. Structural characterization of KNPS was carried out using sugar and methylation analysis, Smith degradation and 1D/2D NMR experiments. Sugar analysis showed that the KNPS composed of arabinose, galactose, 3-O-methyl-galctose and glucose in a molar ratio of nearly 4:3:1:1. The proposed repeating unit of the KNPS has a backbone chain consisting of two (1→6)-galactopyranosyl residues, two (1→5)-arabinofuranosyl residues, one (1→6)-glucopyranosyl residue and one (1→3)-arabinopyranosyl residue, out of which one (1→6)-galactopyranosyl residue was branched at O-2 position with a (1→2)-linked-galactopyranosyl residue terminated with non reducing arabinofuranosyl residue and one (1→5)-arabinofuranosyl residue branched at O-3 position with non reducing end 3-O-Me-galactopyranosyl residue. KNPS was found non-toxic toward human lymphocyte up to the dosage of 100 μg/ml. KNPS enhanced malondialdehyde (MDA), reactive oxygen species (ROS), and have the potential to alter the ratio of oxidized glutathione (GSSG) and reduced glutathione (GSH) levels in the cellular system.
authors.affiliation: Department of Microbiology, Vidyasagar University, Midnapore, West Bengal, India; Omics Laboratory, Department of Biotechnology, University of North Bengal, Siliguri, West Bengal, India.
authors.forename: Amit K
authors.initials: AK
authors.lastname: Mandal
authors.affiliation: Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore, West Bengal, India.
authors.forename: Ipsita K
authors.initials: IK
authors.lastname: Sen
authors.affiliation: Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore, West Bengal, India.
authors.forename: Prasenjit
authors.initials: P
authors.lastname: Maity
authors.affiliation: Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore, West Bengal, India.
authors.forename: Sourav
authors.initials: S
authors.lastname: Chattopadhyay
authors.affiliation: Omics Laboratory, Department of Biotechnology, University of North Bengal, Siliguri, West Bengal, India.
authors.forename: Ranadhir
authors.initials: R
authors.lastname: Chakraborty
authors.affiliation: Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore, West Bengal, India.
authors.forename: Somenath
authors.initials: S
authors.lastname: Roy
authors.affiliation: Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore, West Bengal, India. Electronic address: sirajul_1999@yahoo.com.
authors.forename: Syed S
authors.initials: SS
authors.lastname: Islam
mesh_terms: D001089:Arabinose / Q000032:analysis; D002240:Carbohydrate Sequence; D005690:Galactose / Q000032:analysis; D005947:Glucose / Q000032:analysis; D005978:Glutathione / Q000037:antagonists & inhibitors; D019803:Glutathione Disulfide / Q000819:agonists; D006801:Humans; D007711:Klebsiella pneumoniae / Q000737:chemistry / Q000378:metabolism*; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects; D008315:Malondialdehyde / Q000819:agonists; D008756:Methylgalactosides / Q000032:analysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016877:Oxidants / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D061251:Primary Cell Culture; D017382:Reactive Oxygen Species / Q000819:agonists
chemical_list: D008756:Methylgalactosides; D016877:Oxidants; D011135:Polysaccharides, Bacterial; D017382:Reactive Oxygen Species; C031552:methyl beta-galactoside; D008315:Malondialdehyde; D001089:Arabinose; D005978:Glutathione; D005947:Glucose; D019803:Glutathione Disulfide; D005690:Galactose
keywords: Exopolysaccharide; Klebsiella pneumoniae PB12; NMR