Poedyer3052

Characterizing polysaccharides with large molecular weights and isomeric heterogeneity with mass spectrometry (MS) is generally difficult. selleck In this work, we demonstrate how coupling size exclusion chromatography (SEC) and high-resolution MS with source-induced dissociation (SID) can be used for the separation and direct structural evaluation of intact polysaccharides. The analytical method was successfully developed using dextran standards up to 3755 kDa. This method was used to separate naturally occurring plant polysaccharides based on size, after which numerous polysaccharide fragments were identified from the resulting MS spectra. The results provided strong evidence for structural diversity, complexity, and heterogeneity among polysaccharides. MS showed superior sensitivity and reliability for the polysaccharides in eluted fractions when compared to a refractive index detector. Putative compositions for the fragments were proposed based on exact mass values. The work demonstrated that SEC-SID-MS is a feasible alternative for obtaining valuable structural information from the analysis of intact polysaccharides.Artemisinin is mainly derived from Artemisia annua L. Since the leaves composition is complex, artemisinin purification faces great challenges. In this work, functional chitosan membranes were fabricated by a one-step hydrolysis method through grafting long-chain alkyl group on the surface of chitosan to increase its hydrophobicity. The as-prepared membranes were used to adsorb wax oil (i.e., the impurity components) in Artemisia annua L. and to avoid co-precipitation of wax oil along with artemisinin using the crystallization technique for purification. Octyl-trimethoxysilane modified chitosan membrane (FCM-C8) showed excellent capability to intensify this purification process. The product purity could reach more than 98 % using one crystallization step under the optimal conditions, and in this case, adsorption capacity of FCM-C8 for wax oil was 478.9 mg/g. In addition, the adsorption kinetics and mechanism of wax oil on FCM-C8 were studied. The membrane can simultaneously adsorb multiple components in wax oil through interactions like electrostatic forces, hydrogen bondings.Inulin (IN), a fructan-type plant polysaccharide, is widely found in nature. The major plant sources of IN include chicory, Jerusalem artichoke, dahlia etc. Studies have found that IN possessed a wide array of biological activities, e.g. as a prebiotic to improve the intestinal microbe environment, regulating blood sugar, regulating blood lipids, antioxidant, anticancer, immune regulation and so on. Currently, IN is widely used in the food and pharmaceutical industries. IN can be used as thickener, fat replacer, sweetener and water retaining agent in the food industry. IN also can be applied in the pharmaceutics as stabilizer, drug carrier, and auxiliary therapeutic agent for certain diseases such as constipation and diabetes. This paper reviews the physiological functions of IN and its applications in the field of pharmaceutics, analyzes its present research status and future research direction. This review will serve as a one-in-all resource for the researchers who are interested to work on IN.Hot water extract from biomass of heterotrophic mutant green alga Parachlorella kessleri HY1 (Chlorellaceae) was deproteinised, and three polysaccharidic fractions were obtained by preparative chromatography. The low-molecular fraction (1.5 × 104g mol-1) was defined mainly as branched O-2-β-xylo-(1→3)-β-galactofuranan where xylose is partially methylated at O-4. Two high-molecular fractions (3.05 × 105 and 9.84 × 104g mol-1) were complex polysaccharides containing α-l-rhamnan and xylogalactofuranan parts in different ratios. The polysaccharides were well soluble in hot water and, upon cooling, tended to self-segregate. Immunomodulatory activities of the obtained fractions were preliminary tested using ELISA, FACS and ImmunoSpot kits. The polysaccharides increased the TNF-α production in melanoma bearing mice with much higher intensity than in healthy mice. This was in agreement with the FACS results on T and B cells indicating their possibly secondary activation by innate immunity cells.Chitosan hydrogels fabricated by covalent crosslinking exhibit tough mechanical properties and chemical stability. In this paper, debranched starch (DBS) is oxidized to dialdehyde debranched starch (DADBS), which is used as a new type of a crosslinking agent to prepare hydrogels. Chitosan hydrogels with excellent properties are prepared by dynamic Schiff-base crosslinking between the aldehyde groups in DADBS and the amino groups in chitosan. Hence, chitosan hydrogels exhibit a rapid gelation ability, with a gelation time of less than 30 s, and their storage modulus increases with the gelation time. By adjusting the molar ratio of the amino group of chitosan to the aldehyde group of DADBS and the reaction temperature, the hydrogels exhibit tunable elasticity and mechanical properties. Notably, scanning electron microscopy revealed the presence of 100-200 nm microgels in the hydrogel network, which could exert a strengthening effect on the mechanical properties of the hydrogels. In addition, chitosan hydrogels exhibit a rapid self-healing ability and remarkable fluorescence properties; also, they can be 3D printed in different shapes. Overall, the DADBS cross-linked chitosan hydrogels demonstrate potential applications in food, medicine, agriculture, and materials.This work concerns the chemical modification of medium molecular weight hyaluronan for ophthalmic applications. The synthesis of amphiphilic HA with dodecanoyl moities was carried out under mild aqueous conditions. Perfect control of the degree of substitution was obtained by varying the molar ratio of activated fatty acid used in the reaction feed. Moreover, the preparation of the derivatives was optimized to achieve the desired degree of substitution (DS = 9.0 ± 0.2 %). The prepared hyaluronan derivatives were water-soluble and exhibited self-associating properties (amphiphilicity). The structure of the prepared derivatives was elucidated by NMR spectroscopy, rheology, turbidity, SEC-MALLS, and gas chromatography (GC). The hydrophobic moieties increase the solution viscosity by physical crosslinking. Low concentration of HAC12 is needed to prepare highly viscous solutions with potential use for ophthalmic applications. Amphiphilic HA kept the biocompatibility of hyaluronan. The degree of substitution and Mw of the amphiphilic HA controls the sterilization by filtration.