title: Free radical-induced chitosan depolymerized products protect calf thymus DNA from oxidative damage.
abstract: Low molecular weight chitosan (LMWC) and chitooligosaccharides (COs), obtained by persulfate-induced depolymerization of chitosan showed scavenging of OH. and O2.- radicals and offered protection against calf thymus DNA damage. Over 85% inhibition of free radicals and DNA protection were observed. LMWC (0.05 micromol) showed a strong inhibitory activity compared to COs (3.6 micromol). Further, LMWC showed calf thymus DNA condensation reversibly giving stability, as evident from CD, TEM and melting curves (Tm). A fluorescence study suggests the binding of LMWC in the minor groove, forming H-bonds to the backbone phosphates without distorting the double helix structure.
authors.affiliation: Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Mysore 570 020, India.
authors.forename: Keelara V
authors.initials: KV
authors.lastname: Harish Prashanth
authors.forename: Shylaja M
authors.initials: SM
authors.lastname: Dharmesh
authors.forename: Kosagi S
authors.initials: KS
authors.lastname: Jagannatha Rao
authors.forename: Rudrapatnam N
authors.initials: RN
authors.lastname: Tharanathan
mesh_terms: D000818:Animals; D002417:Cattle; D048271:Chitosan / Q000737:chemistry / Q000378:metabolism*; D002942:Circular Dichroism; D004247:DNA / Q000378:metabolism*; D004249:DNA Damage / Q000187:drug effects*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000378:metabolism; D005609:Free Radicals / Q000737:chemistry / Q000378:metabolism; D006878:Hydroxides / Q000737:chemistry / Q000378:metabolism; D008970:Molecular Weight; D044366:Transition Temperature
chemical_list: D016166:Free Radical Scavengers; D005609:Free Radicals; D006878:Hydroxides; D004247:DNA; D048271:Chitosan; C427203:calf thymus DNA; C031356:hydroxide ion