Modification and application of polysaccharide from traditional Chinese medicine such as Dendrobium officinale.
Huang Shiyu,Chen Fang,Cheng Hao,Huang Gangliang
International journal of biological macromolecules
Polysaccharides have various biological activities, such as antioxidant, anti-tumor, antiviral, anti-aging, anti-inflammatory, anti-radiation, hypoglycemic and lipid lowering, immune regulation, etc. Although many polysaccharides have been proved to have various biological activities, in the research process, it has been found that more polysaccharides in nature do not have biological activities or have low activities, and some polysaccharides have poor activities due to lack of certain groups. While others are due to polysaccharide with too large molecular weight, because its molecular weight is too large to smoothly enter cells and thus cannot exert its activity. For the former, we need to adopt molecular grafting modification. This kind of modification method is mainly chemical modification method, which increases the functional groups and molecular weight of various polysaccharides to improve their biological activity. For the latter, we need to adopt molecular degradation modification, which includes biodegradation, physical degradation, chemical degradation and other means to improve the solubility of polysaccharide in water phase by reducing its molecular weight, thus improving its activity. This article mainly introduces polysaccharide structure modification methods that have been widely used in recent years.
10.1016/j.ijbiomac.2020.04.141
Recent advances in polysaccharide bio-based flocculants.
Salehizadeh Hossein,Yan Ning,Farnood Ramin
Biotechnology advances
Natural polysaccharides, derived from biomass feedstocks, marine resources, and microorganisms, have been attracting considerable attention as benign and environmentally friendly substitutes for synthetic polymeric products. Besides many other applications, these biopolymers are rapidly emerging as viable alternatives to harmful synthetic flocculating agents for the removal of contaminants from water and wastewater. In recent years, a great deal of effort has been devoted to improve the production and performance of polysaccharide bio-based flocculants. In this review, current trends in preparation and chemical modification of polysaccharide bio-based flocculants and their flocculation performance are discussed. Aspects including mechanisms of flocculation, biosynthesis, classification, purification and characterization, chemical modification, the effect of physicochemical factors on flocculating activity, and recent applications of polysaccharide bio-based flocculants are summarized and presented.
10.1016/j.biotechadv.2017.10.002
Chitosan Hydrogels and Bionanocomposites Formed through the Mineralization and Regulated Charging.
Chemical record (New York, N.Y.)
The account presents survey of our systematic studies on chitosan. Only this polysaccharide bears cationic charges, possesses antimicrobial activity and wound healing ability that make it highly appropriate for using in medicine, biomedical engineering, cosmetics, food, packaging. However, its application meets with severe limitation. Chitosan belongs to polysaccharides that do not jellify solutions. Main approaches are based on the chemical modifications and cross-linking, but these treatments impairs therewith the biocompatibility and biological activity of chitosan. We have developed approaches in which monolithic hydrogels are fabricated via the mineralization of polysaccharide by method of green sol-gel chemistry and via the formation of polyelectrolyte complex with oppositely charged counterparts in the regime of its charging by means of regulated acidification. The latter approach was also extended for the preparation of chitosan bionanocomposites and films with nanoparticles.
10.1002/tcr.201800049
Composition and Charge Compensation in Chitosan/Gum Arabic Complex Coacervates in Dependence on pH and Salt Concentration.
Biomacromolecules
In this study, complex coacervates of the biopolyelectrolytes chitosan and gum arabic were investigated with respect to their composition and charge compensation depending on the pH and salt concentration. Individual polyelectrolyte yields were deduced from thermogravimetric analysis and chitosan quantification via enzymatic hydrolysis/HPLC-ELSD. The polyelectrolyte mass ratio in the complex coacervate is found to remain approximately constant irrespective of the pH, despite the latter's effect on the polyelectrolyte charge ratio. Two regimes are identified, including either chitosan charges in excess (at pH < 6.0) or gum arabic charges in excess (at pH > 6.0). The amount of extrinsic charge compensation in the complex coacervates is discussed in detail. We show for the first time that the doping level, a quantity traditionally used to describe salt-induced changes of the charge compensation in polyelectrolyte complexes, is also suitable for the description of pH-induced extrinsic charge compensation in such systems.
10.1021/acs.biomac.2c01255
Theoretical study of structures and charge distributions of 2-, 3- and 6-hydroxypropyl-β-cyclodextrin with different degrees of substitution.
Journal of biomolecular structure & dynamics
Hydroxypropyl-β-cyclodextrin (HPβCD) is a derivative of cyclodextrin extensively used in the pharmaceutical industry, since it improves the solubility of drugs, and widens their oral bioavailability and safety profile. Theoretical studies about HPβCD configurations are important so as to simulate by molecular mechanics and dynamics, the complex formation and enantiomeric separations of these cyclodextrins with other molecules. Twelve structures and charge distributions of 2-, 3- and 6-hydroxypropyl-β-cyclodextrin (2-, 3-, 6-HPβCD) with different degrees of substitution were obtained using methods. The atomic positions of glucose units, dihedral angles of hydroxypropyl groups (HPs), radius of gyration, and H-bonds formed were analysed in the structures. The 3-HPβCD configurations showed the greatest variations in their atomic positions, their HPs groups being slightly rotated towards the interior of the rim of cyclodextrin and hence narrowing its opening. The structures of 2-HPβCD are the least influenced by the degree of substitution and include fewer H-bonds. Different values for the partial atomic charges for each glucose unit in a molecule were obtained, as well as for all HPβCD configurations. This result, consequence of the methods used, is a new contribution that can be important to simulate processes in which small energy differences decisively influence the results. The electric potential due to the charge distribution of HPβCDs was calculated inside and outside the cavity. It was found that the changes at each position were mainly due to atomic configurations, since the differences in partial atomic charges are one or two orders of magnitude smaller than in atomic positions.Communicated by Ramaswamy H. Sarma.
10.1080/07391102.2022.2155700
Impact of ultrafiltration membrane material on Peptide separation from a snow crab byproduct hydrolysate by electrodialysis with ultrafiltration membranes.
Doyen Alain,Beaulieu Lucie,Saucier Linda,Pouliot Yves,Bazinet Laurent
Journal of agricultural and food chemistry
Electrodialysis with ultrafiltration membrane (EDUF) is a technology based on the separation of molecules according to their charge and molecular mass. Some works have already successfully demonstrated the recovery of bioactive peptide fractions. However, the impact of ultrafiltration membrane (UFM) material, used in the EDUF system, on the peptide migration has never been studied. Consequently, the objectives of this work were (1) to evaluate the effect of two different UFM materials on the selective separation of peptides from a snow crab byproduct hydrolysate by electrodialysis with ultrafiltration membranes and (2) to determine the effect of UFM material on their potential fouling by peptides. It appeared that, after 6 h of EDUF separation using polyether sulfone (PES) and cellulose acetate (CA) UFM, peptides with low molecular weights ranging from 300 to 700 Da represented the most abundant population in the KCl1 (compartment located near the anode for the recovery of anionic/acid peptide fractions) and KCl2 (compartment located near the cathode for the recovery of cationic/basic peptide fractions) permeates. Peptides with molecular weights ranging from 700 to 900 Da did not migrate during the EDUF treatment. Moreover, only CA UFM allowed the recovery of high molecular weight molecules (900-20000 Da) in both KCl compartments. Peptides desorbed from PES and CA UFM after 6 h of EDUF separation had low molecular weights and belonged mainly to the 600-700 Da molecular weight range. These peptides represented a low proportion of the peptides initially present in the snow crab byproduct hydrolysate with individual molecular weight range proportions from 1.52 ± 0.31 to 10.2 ± 2.32%.
10.1021/jf103739m
Extraction, structure, pharmacological activities and drug carrier applications of Angelica sinensis polysaccharide.
Nai Jijuan,Zhang Chao,Shao Huili,Li Bingqian,Li Huan,Gao Lei,Dai Mengmeng,Zhu Liqiao,Sheng Huagang
International journal of biological macromolecules
Angelica sinensis polysaccharide (ASP) is one of the main active components of Angelica sinensis (AS) that is widely used in traditional Chinese medicine. ASP is water-soluble polysaccharides, and it is mainly composed of glucose (Glc), galactose (Gal), arabinose (Ara), rhamnose (Rha), fucose (Fuc), xylose (Xyl) and galacturonic acid (GalUA). The extraction methods of ASP include hot water extraction and ultrasonic wave extraction, and different extraction methods can affect the yield of ASP. ASP has a variety of pharmacological activities, including hematopoietic activity, promoting immunity, antitumor, anti-inflammatory, antioxidant, anti-aging, anti-virus, liver protection, and so on. As a kind of natural polysaccharide, ASP has potential application as drug carriers. This review provides a comprehensive summary of the latest extraction and purification methods of ASP, the strategies used for monosaccharide compositional analysis plus polysaccharide structural characterization, pharmacological activities and drug carrier applications, and it can provide a basis for further study on ASP.
10.1016/j.ijbiomac.2021.05.213