Original scientific paper
https://doi.org/10.17113/ftb.57.04.19.6264
Sulfonated (1→6)-β-D-Glucan (Lasiodiplodan): Preparation, Characterization and Bioactive Properties
Gabrielle Cristina Calegari
; Chemistry Department, Federal University of Technology – Paraná, Via do Conhecimento, Km 1, 85503-390 Pato Branco, PR, Brazil
Vidiany Aparecida Queiroz Santos
; Chemistry Department, Federal University of Technology – Paraná, Via do Conhecimento, Km 1, 85503-390 Pato Branco, PR, Brazil
Aneli M. Barbosa-Dekker
; Chemistry Department, State University of Londrina, Rod. Celso Garcia Cid, Km 380, 86057-970 Londrina, PR, Brazil
Cleverson Busso
; Bioprocess and Biotechnology Engineering Coordination, Federal University of Technology – Paraná, Rua Cristo Rei, 19, 85902-490 Toledo, PR, Brazil
Robert F. H. Dekker
; Graduate Program in Environmental Engineering, Federal University of Technology – Paraná, Estr. dos Pioneiros, 3131, 86036-370 Londrina, PR, Brazil
Mário Antônio Alves da Cunha
orcid.org/0000-0002-1589-7311
; Chemistry Department, Federal University of Technology – Paraná, Via do Conhecimento, Km 1, 85503-390 Pato Branco, PR, Brazil
Abstract
Sulfonated derivatives of lasiodiplodan (LAS-S) with different degrees of substitution (1.61, 1.42, 1.02 and 0.15) were obtained and characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermal and solubility analyses. Antimicrobial, antioxidant and cytotoxic potential were also assessed. The sulfonation was confirmed by FTIR analysis with specific bands at 1250 cm–1 (S=O, strong asymmetrical stretching vibration) and at 810 cm–1 (C-O-S, symmetrical vibration associated with the C-O-SO3 group) in the sulfonated samples. SEM demonstrated that sulfonation promoted morphological changes on the surface of the biopolymer with heterogeneous fibrillary structures appearing along the surface following chemical modification. LAS-S showed high thermal stability, with mass loss due to oxidation at temperatures close to 460 °C. Sulfonation increased the solubility of LAS, and in addition, increased the antimicrobial activity, especially against Candida albicans (fungicidal) and Salmonella enterica Typhimurium (bacteriostatic). Native lasiodiplodan (LAS-N) showed higher OH˙ removal capacity, while LAS-S had higher ferric ion reducing antioxidant power (FRAP) potential. LAS-N and LAS-S did not demonstrate lethal cytotoxicity against wild and mutant strains of Saccharomyces cerevisiae. Samples with higher degree of substitution (1.42 and 1.61) showed lower potential to induce oxidative stress.
Keywords
sulfonation; fungal exopolysaccharides; microbiocidal activity
Hrčak ID:
233421
URI
Publication date:
27.12.2019.
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