Evaluation of the biological potentials of carboxymethylated beta-glucans

Abstract

The exopolysaccharides (EPS) produced by the fungus Lasiodiplodia theobromae have interesting pharmacological applications, among which the modulation of the immune system stands out, including also the antioxidant, antitumor, antimicrobial and anticoagulant activities. However, in order for these carbohydrates to be better administered to human beings and for them to have greater biological potential, they must be derivatized through organic synthesis resulting in their higher water solubility. In this project, beta-glucans of L. theobromae will be obtained by means of submerged fermentation and their fractions, linear and branched, will be separated from the crude by freezing/thawing. The carboxymethylation of these beta-glucans will be performed for both the crude fraction and the linear and branched fractions. The carboxymethylated products, obtained from extracts and fractions, will be analyzed by Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FT-IR). The effects of carboxymethylation on anticoagulant activity will be evaluated by the tests on Activated Partial Thromboplastin Time (aPTT) and Thrombin Time (TT). The evaluation of the antioxidant potential will be done by determining the sequestering power of DPPH radicals. The antitproliferative potential against MCF-7 (breast cancer), NCI-H460 (lung) and U-251 (glioma CNS) cell lines will also be tested, and at last the determination of MIC (Minimal Inhibitory Concentration) against microorganisms such as Candida albicans (ATCC10231) Enterococcus faecium (ATCCT 5079), Enterococcus hirae (ATCC 10541), Escherichia coli (ATCC 11775), Salmonella choleraesuis (ATCC 10708), Staphylococcus aureus (ATCC 6538) and Pseudomonas aeruginosa (ATCC 13388). (AU)