ß(1,3) ß(1,6) glucogalactan from Rhizopus microsporus var. oligosporus: extraction, characterization, antioxidant and α-amylase inhibitory activities.

In this study, the Box-Behnken experimental planning was used to optimize the extraction of polysaccharides from the cell wall of Rhizopus microspore var. oligosporus, with analysis of the quantitative effects of parameters pH, temperature and extraction time for polysaccharide yield. The optimal conditions for extraction were determined by the regression equation and evaluation of the response surface graphs, which indicated: pH 13, temperature of 120ºC and time of 60 min, with maximum yield around 18.5%. Fourier transform infrared spectroscopy analysis indicated typical polysaccharide signals. Nuclear magnetic resonance spectroscopy and monosaccharide analysis indicated a ß(1,3) ß(1,6) glucogalactan. The polysaccharide exhibited an average molecular weight of 120 kDa and a polymerization degree of 741. Antioxidant assays in vitro revealed the potential of polysaccharide in elimination of ABTS+ radical and hydroxyl radicals. EC50 values for free radical elimination were 7.69 and 17.8 mg/mL, for ABTS+ and hydroxyls, respectively. The polysaccharides showed potential for α-amylase inhibition with an EC50 of 1.66 mg/mL. The results suggest that ß(1,3) ß(1,6) glucogalactan from Rhizopus microsporus var. oligosporus can be used in biotechnological applications.

The extraction and characterisation of a polysaccharide from Moniliophthora perniciosa CCMB 0257.

The alpha-D-glucans are worldwide acknowledged as powerful immune system stimulants found in several sources; however, the fungal-derived sources appear to respond with higher activity. The present study has investigated polysaccharide production in Moniliophthora perniciosa. The dry biomass was subjected to thermal treatment in alkaline solution after fermentation. The biopolymers dissolved in this solution were precipitated after three volumes of absolute ethanol were added to the supernatant. The pure polysaccharide MPS1 was obtained through molecular exclusion chromatography using the Sephacryl S-200 column. The HPLC-RI analysis showed that MPS1 was a glucose homopolysaccharide. Nuclear magnetic resonance (NMR) spectra indicated the α-form as the anomeric carbon configuration in glucose residue. The structure of the polysaccharide was further confirmed as (1→4)-α-D-glucan through the chemical shift of C4. The molecular weight of MPS1 was 31.0 kDa.

Extraction optimization and antinociceptive activity of (1→3)-ß-d-glucan from Rhodotorulamucilaginosa.

ß-d-glucans are polymers of d-glucose monomers found in the cell walls of many bacteria, plants, fungi and yeasts. A variety of ß-d-glucans differing in structures have been isolated from various sources and their biological activity to be regulated by various structural factors, such as the primary structure, molecular weight, solubility, and conformation. This study investigated the effect of extraction time and temperature on the yield of ß-d-glucan produced by Rhodotorulamucilaginosa. A statistical Doehlert design was applied to determine the important effects and interactions of these independent variables on the yield of ß-d-glucan, the dependent variable. Significant models were obtained. The best yield was of 25% obtained after 128min of extraction in a temperature of 72°C. The polysaccharides were characterized as (1⟶3)-ß-d-glucan by methods spectroscopic (FT-IR, (1)HNMR and (13)CNMR). In addition, the antinociceptive effect was evaluated using different experimental tests (acetic acid-induced writhing test, formalin test and tail immersion test). The (1⟶3)-ß-d-glucan showed a potent peripheral antinociceptive effect, possibly by the inhibition of inflammatory mediators.