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.

Aqueous extraction of pectin from sisal waste.

In this work, sisal waste was used as a source of pectin. Sisal is known worldwide as a source of hard fibres, and Brazil is the largest producer of sisal, producing more than 246,000 tonnes. However, the process of removing the fibres of the sisal leaf generates 95% waste. This study investigated the effect of the liquid/solid ratio (%), time (min), and temperature (°C) on the yield of the pectin obtained from sisal waste by attractive environmentally friendly process. A statistical Box-Behnken design was applied to determine the important effects and interactions of these independent variables on the yield of pectin, the dependent variable. Significant models were obtained. The yield of the extracted pectin ranged from 4.61 to 19.2%. The conditions that produced the highest yield (19.2%) were a temperature of 85 °C, extraction time of 60 min and a liquid/solid ratio of 2%.

Homology modelling of pyrophosphosrylase, enzyme involved in chitin pathway of Moniliophthora perniciosa.

Moniliophthora perniciosa (Sthael) (Singer) Phillips-Mora is the causal agent of witches' broom disease, which can infect Theobroma cacao decreasing the production of cocoa about 60%. M. perniciosa has a set of potential enzymes that can be useful targets for design of new inhibitors. After the release of the aminoacid sequence of pyrophosphorylase of M. perniciosa, a comparative modelling approach was carried out to obtain the 3D structure of this target. This model can be useful to develop new inhibitors against witches' broom disease.

Pectin methylesterase activity and ascorbic acid content from guava fruit, cv. Predilecta, in different phases of development.

The guava pectin methylesterase (PME) specific activity and vitamin C were assayed in samples from different phases of guava fruit development. The PME enzyme from guava was extracted with borate-acetate buffer, 50 mol/l, pH 8.0, in the presence of NaCl 0.3 mol/l. The results showed PME optimum activity at pH 9 and 95 degrees C, and it is a thermostable enzyme. Guava PME retained 96.8% of activity after 300 min in 90 degrees C. Electrophoresis showed that guava PME contained two isoforms, one with 57 kDa molecular mass. The analyses of the different phases of guava maturation showed that ascorbic acid decreases during the maturation process, but PME activity increases with maturation.