title: Carboxymethylation of (1 → 6)-β-glucan (lasiodiplodan): Preparation, characterization and antioxidant evaluation.
abstract: D-Glucans possess immunomodulatory activities and potential for the development of new therapeutic agents. Biological activities can be enhanced in these biopolymers through chemical derivatization, e.g., carboxymethylation. This work presents the carboxymethylation, characterization and the evaluation of antioxidant activities of the exocellular (1 → 6)-β-D-glucan produced by Lasiodiplodia theobromae MMPI. Thermal analysis indicated that the native and carboxymethylated polysaccharides presented four stages of mass-loss. The first stage occurred at 125°C (loss of water) with two consecutive events of mass loss (200-400°C) attributed to polymer degradation and the fourth stage between 425 and 620°C (final decomposition). Scanning electron microscopy analysis indicated that the gross morphological features of lasiodiplodan were ruptured following carboxymethylation. X-ray diffractometry analysis demonstrated that the native and carboxymethylated polysaccharides presented a non-crystalline structure. Carboxymethylation contributed to improving the polysaccharide's water solubility and antioxidant capacity.
authors.affiliation: Department of Chemistry, Federal Technological University of Paraná, Via do Conhecimento, km 01, Bairro Fraron, CEP: 85503-390 Pato Branco, PR, Brazil.
authors.forename: Francini Y
authors.initials: FY
authors.lastname: Kagimura
authors.affiliation: Department of Chemistry, Federal Technological University of Paraná, Via do Conhecimento, km 01, Bairro Fraron, CEP: 85503-390 Pato Branco, PR, Brazil. Electronic address: mcunha@utfpr.edu.br.
authors.forename: Mário Antônio A
authors.initials: MA
authors.lastname: da Cunha
authors.affiliation: Department of Chemistry, Federal Technological University of Paraná, Via do Conhecimento, km 01, Bairro Fraron, CEP: 85503-390 Pato Branco, PR, Brazil.
authors.forename: Thais V
authors.initials: TV
authors.lastname: Theis
authors.affiliation: Midwestern State University (Graduate Program in Pharmaceutical Sciences), CEDETEG Campus, CEP: 85040-080 Guarapuava, PR, Brazil.
authors.forename: Carlos R M
authors.initials: CR
authors.lastname: Malfatti
authors.affiliation: Biorefining and Biotechnology Consultancy, Rua João Huss 200, Glebe Palanho, CEP: 86050-490 Londrina, PR, Brazil.
authors.forename: Robert F H
authors.initials: RF
authors.lastname: Dekker
authors.affiliation: Department of Chemistry-CCE, Londrina State University, CEP: 86051-990 Londrina, PR, Brazil.
authors.forename: Aneli M
authors.initials: AM
authors.lastname: Barbosa
authors.affiliation: Department of Chemistry, Federal Technological University of Paraná, Via do Conhecimento, km 01, Bairro Fraron, CEP: 85503-390 Pato Branco, PR, Brazil.
authors.forename: Sirlei D
authors.initials: SD
authors.lastname: Teixeira
authors.affiliation: Chemistry Department, Federal University of Paraná, Caixa Postal 19032, CEP: 81.531-980 Curitiba, PR, Brazil.
authors.forename: Kahlil
authors.initials: K
authors.lastname: Salomé
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000378:metabolism; D001203:Ascomycota / Q000737:chemistry* / Q000378:metabolism; D008745:Methylation; D010316:Particle Size; D047071:beta-Glucans / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D047071:beta-Glucans; C064197:beta-1,6-glucan
keywords: Antioxidant capacity; Biopolymers; Exopolysaccharides; β-Glucans