Chemical synthesis of phosphatidylinositol mannoside glycans from Mycobacterium tuberculosis

The efficient synthesis of phosphatidylinositol mono- to hexa-mannoside (PIM1 to PIM6) is reported. The invention relates to these phosphatidylinositol mono- to hexa-mannosides carrying a linker and a reactive functional group, e.g. the sulfhydryl group, a protein, a fluorescent probe, or a solid phase. The invention further relates to vaccines comprising the PIMs linked to a carrier protein or an antigen

The Influence of H2O2 on The Photocatalytic Pretreatment of Cellulose for 5-Hydroxymethyl Furfural (5-HMF) Production

Photocatalysis has been widely known as a simple green technology to be applied in the synthesis and degradation process of organic molecules. An application of photocatalysis in a biomass pretreatment for a 5-hydroxymethylfurfural (5-HMF) production was investigated in this study. The results have revealed that photocatalysis, applied during pretreatment, facilitates the breakdown of cellulose. The presence of oxidizing agent (H2O2) in the ratios to cellulose of 11:1, 18:1, and 37:1 mol.mol-1 has been investigated for its effect on the production of 5-HMF. The optimum conditions obtained for the pretreatment process was the presence of H2O2 at 37:1 mol.mol-1, which was followed by the process of evaporation of the remaining H2O2 after pretreatment. The 5-HMF yield from the hydrolysis process involving pretreatment was 13.07%, while the yield from the process without pretreatment was 9.79%. The application of the pretreatment has succeeded in increasing the 5-HMF yield by 25.09%. The progress in the pretreatment was also marked by the presence of the carboxyl groups in the pretreated samples which were observed by the Fourier Transforms Infrared spectroscopy (FTIR). Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Identification of bacteria and yeast communities in a Thai sugary kefir by Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) analyses

AbstractThe microbial diversity of Thai sugary kefir was identified for the first time by Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) analysis. The V3 regions of 16S bacterial rDNA and 18S rDNA of yeasts in both kefir grains and kefir fermentates were analyzed. Acetic acid bacteria Gluconobacter japonicus and Bacillus cereus were identified with 99% similarity to the GenBank database. Other bacteria species, including Lactobacillus rhamnosus, were also identified with less than 97% similarity. Two yeast species, namely Saccharomyces cerevisiae, Candida ethanolica, were identified with 99% similarity to the GenBank database. Sugary kefir grains and fermentates have higher diversity of bacteria communities than yeast communities. In comparison with the microorganisms found in sugary kefir cultured in different parts of the world, Lactobacillus paracasei, Lactobacillus rhamnosus, Bacillus cereus, and Saccharomyces cerevisiae were the common species also found in a Thai kefir. This study is the first time to find the yeast Candida ethanolica in sugary kefir. Morphology of sugary kefir grains revealed that bacteria and yeasts spread throughout the grains. Yeast communities are located on the outer portion of kefir grains and the bacterial communities are located on the inner portion of kefir grains

Conversion of konjac powder into glucomannan-oligosaccharides, mannose, and glucose by hydrolysis facilitated by microwave heating and HCl catalyst

AbstractThe reaction conditions to hydrolyze konjac powder (KP) were investigated by using a combination of microwave radiation heating and HCl as a catalyst to explore the possibility of glucomannan-oligosaccharides, mannose, and glucose extractions from the polysaccharides of KP. Selective reaction conditions to produce glucomannan-oligosaccharides, mannose, and glucose were determined. The highest yield for glucomannan-oligosaccharides production, at 19.2%, was achieved under the reaction conditions of 110°C, 15 min, 2 M HCl and 10:1 (mL/g) ratio of reaction volume to KP mass. The highest yield for both mannose and glucose production, at 35.8% and 30.2%, respectively, was achieved under the reaction conditions of 110°C, 15 min, 1.2 M HCl and    10:1 (mL/g) ratio of reaction volume to KP mass. Only a small amount of 5-HMF at 0.3% was formed and a low level of UV absorbance (284 nm) of hydrolyzed products (HP) at 1.7 was found under these conditions. The combination of microwave radiation (MCR) heating and HCl effectively hydrolyzed konjac powder selectively into glucomannan-oligosaccharides and/or monosaccharides in a relatively short reaction time

Effect of purified soluble polysaccharides extracted from gray oyster mushroom [Pleurotus sajor-caju (Fr.) Sing.] on 3t3-L1 adipocytes

Functional mushroom polysaccharides have been known to the Asian traditional medicine for many years. The anti-obesity activity of mushroom polysaccharides has been illustrated both in vivo and in vitro. However, the effect of pure polysaccharides on isolated fat cells has not been demonstrated. In this study, we used hot water and ammonium oxalate to extract polysaccharides from gray oyster mushroom [Pleurotus sajor-caju (Fr.) Sing.] and subsequently purified with enzymatic digestion, solvent extraction and ion-exchange chromatography. One of the fractions, 7S1-1, has the highest yield and purity and contains polysaccharides with the molecular weight around 500 kDa. In addition, Fourier transformed infrared spectroscopy (FTIR) and monosaccharide composition analyses showed that this 7S1-1 sample contains mostly β-glucan and some mannan. We find that the 7S1-1 fraction does not affect the total amount of triglycerides in the 3T3-L1 adipocytes but promotes a release of glycerol of the fat cells, suggesting that the fraction does not inhibit adipogenesis but stimulates lipolysis. Laminarin, a small β-glucan, confers similar results to the 7S1-1 sample, but it could not stimulate lipolysis as well as the 7S1-1 sample. Therefore, these results suggest a potential anti-obesity activity of the mushroom polysaccharides

Influence of Ethanol as a Co-Solvent in Cyclodextrin Inclusion Complexation: A Molecular Dynamics Study

Molecular dynamics (MD) simulations were used to investigate the dynamics and host-guest interactions of the inclusion complexes between a potent anti-HIV agent, UC781, and three different types of cyclodextrins (CDs) including βCD, 2,6-dimethyl-βCD (MβCD), and 2-hydroxypropyl-βCD (HPβCD) in aqueous solution with ethanol (EtOH) as a co-solvent. The MD simulation results revealed that EtOH as the co-solvent and the type of cyclodextrin affected the inclusion complex formation. From this study, UC781/MβCD provided the most stable inclusion complex. The competition for the cavity of βCD between UC781 and EtOH and the ensuing occupation of βCD cavities by EtOH resulted in a weaker interaction between βCD and UC781. In HPβCD, a supramolecular complex of UC781−HPβCD−EtOH was formed. The EtOH could easily fill the residual void space of the interior of unoccupied HPβCD due to the movement of UC781. In MβCD, the strong hydrogen bond interactions between the UC781 amide group and the secondary hydroxyl groups of MβCD significantly stabilized the inclusion complex in the presence of EtOH