Depolymerization of a fucosylated chondroitin sulfate from Cucumaria japonica: Structure and activity of the product

The regulatory effect of polysaccharides on the gut microbiota and their effect on human health: A review

Polysaccharides with low toxicity and high biological activities are a kind of biological macromolecule. Recently, growing studies have confirmed that polysaccharides could improve obesity, diabetes, tumors, inflammatory bowel disease, hyperlipidemia, diarrhea, and liver-related diseases by changing the intestinal micro-environment. Moreover, polysaccharides could promote human health by regulating gut microbiota, enhancing production of short-chain fatty acids (SCFAs), improving intestinal mucosal barrier, regulating lipid metabolism, and activating specific signaling pathways. Notably, the biological activities of polysaccharides are closely related to their molecular weight, monosaccharide composition, glycosidic bond types, and regulation of gut microbiota. The intestinal microbiota can secrete glycoside hydrolases, lyases, and esterases to break down polysaccharides chains and generate monosaccharides, thereby promoting their absorption and utilization. The degradation of polysaccharides can produce SCFAs, further regulating the proportion of gut microbiota and achieving the effect of preventing and treating various diseases. This review aims to summarize the latest studies: 1) effect of polysaccharides structures on intestinal flora; 2) regulatory effect of polysaccharides on gut microbiota; 3) effects of polysaccharides on gut microbe-mediated diseases; 4) regulation of gut microbiota on polysaccharides metabolism. The findings are expected to provide important information for the development of polysaccharides and the treatment of diseases.

Synthesis and ab initio conformational investigation of a series of model sulfated α-L-iduronopyranosides

Due to the all-axial orientation of the OH-groups in the 1C4 chair conformation considered standard for L-hexapyranosides, including l-iduronopyranoside - a component of many biologically and medically significant sulfated glycans, these monosaccharides can be anticipated to display unusual conformations upon the introduction of bulky and charged substituents. Herein we describe the synthesis of a series of iduronopyranoside derivatives with varying sulfation patterns, which were studied computationally using the DLPNO-MP2 approach and by means of analyzing their chemical shifts to ascertain the effects sulfation has on the conformation of the iduronopyranoside ring.

Sulfated polysaccharides in sea cucumbers and their biological properties: A review

Sea cucumbers contain a wide range of biomolecules, including sulfated polysaccharides (SPs), with immense therapeutic and nutraceutical potential. SPs in sea cucumbers are mainly fucosylated chondroitin sulfate (FCS) and fucan sulfate (FS) which exhibit a series of pharmacological effects, including anticoagulant activity, in several biological systems. FCS is a structurally distinct glycosaminoglycan in the sea cucumber body wall, and its biological properties mainly depend on the degree of sulfation, position of sulfate group, molecular weight, and distribution of branches along the backbone. So far, FCS and FS have been recognized for their antithrombotic, anti-inflammatory, anticancer, antidiabetic, anti-hyperlipidemic, anti-obesity, and antioxidant potential. However, the functions of these SPs are mainly dependent on the species, origins, harvesting season, and extraction methods applied. This review focuses on the SPs of sea cucumbers and how their structural diversities affect various biological activities. In addition, the mechanism of actions of SPs, chemical structures, factors affecting their bioactivities, and their extraction methods are also discussed.

The Discovery of the Fucoidan-Active Endo-1→4-α-L-Fucanase of the GH168 Family, Which Produces Fucoidan Derivatives with Regular Sulfation and Anticoagulant Activity

Sulfated polysaccharides of brown algae, fucoidans, are known for their anticoagulant properties, similar to animal heparin. Their complex and irregular structure is the main bottleneck in standardization and in defining the relationship between their structure and bioactivity. Fucoidan-active enzymes can be effective tools to overcome these problems. In the present work, we identified the gene fwf5 encoding the fucoidan-active endo-fucanase of the GH168 family in the marine bacterium Wenyingzhuangia fucanilytica CZ1127T. The biochemical characteristics of the recombinant fucanase FWf5 were investigated. Fucanase FWf5 was shown to catalyze the endo-type cleavage of the 1→4-O-glycosidic linkages between 2-O-sulfated α-L-fucose residues in fucoidans composed of the alternating 1→3- and 1→4-linked residues of sulfated α-L-fucose. This is the first report on the endo-1→4-α-L-fucanases (EC 3.2.1.212) of the GH168 family. The endo-fucanase FWf5 was used to selectively produce high- and low-molecular-weight fucoidan derivatives containing either regular alternating 2-O- and 2,4-di-O-sulfation or regular 2-O-sulfation. The polymeric 2,4-di-O-sulfated fucoidan derivative was shown to have significantly greater in vitro anticoagulant properties than 2-O-sulfated derivatives. The results have demonstrated a new type specificity among fucanases of the GH168 family and the prospects of using such enzymes to obtain standard fucoidan preparations with regular sulfation and high anticoagulant properties.

Fucosylated Chondroitin Sulfates with Rare Disaccharide Branches from the Sea Cucumbers Psolus peronii and Holothuria nobilis: Structures and Influence on Hematopoiesis

Two fucosylated chondroitin sulfates were isolated from the sea cucumbers Psolus peronii and Holothuria nobilis using a conventional extraction procedure in the presence of papain, followed by anion-exchange chromatography on DEAE-Sephacel. Their composition was characterized in terms of quantitative monosaccharide and sulfate content, and structures were mainly elucidated using 1D- and 2D-NMR spectroscopy. As revealed by the data of the NMR spectra, both polysaccharides along with the usual fucosyl branches contained rare disaccharide branches α-D-GalNAc4S6R-(1→2)-α-L-Fuc3S4R → attached to O-3 of the GlcA of the backbone (R = H or SO3-). The polysaccharides were studied as stimulators of hematopoiesis in vitro using mice bone marrow cells as the model. The studied polysaccharides were shown to be able to directly stimulate the proliferation of various progenitors of myelocytes and megakaryocytes as well as lymphocytes and mesenchymal cells in vitro. Therefore, the new fucosylated chondroitin sulfates can be regarded as prototype structures for the further design of GMP-compatible synthetic analogs for the development of new-generation hematopoiesis stimulators.

Two Molecular Weights Holothurian Glycosaminoglycan and Hematoporphyrin Derivative-Photodynamic Therapy Inhibit Proliferation and Promote Apoptosis of Human Lung Adenocarcinoma Cells

Holothurian glycosaminoglycan (hGAG) is extracted from the body wall of the sea cucumber, and previous studies have shown many unique bioactivities of hGAG, including antitumor, anti-angiogenesis, anti coagulation, anti thrombosis, anti-inflammation, antidiabetic effect, antivirus, and immune regulation. The effects of 3W and 5W molecular weights hGAG with hematoporphyrin derivative-photodynamic therapy (HPD-PDT) on lung cancer were investigated. Human lung adenocarcinoma A549 cells were divided into 6 groups: control group, 3W molecular weight hGAG group, 5W molecular weight hGAG group, HPD-PDT group, 3W molecular weight hGAG + HPD-PDT group, and 5W molecular weight hGAG + HPD-PDT group. Cell morphology was observed under inverted phase contrast microscope. Cell proliferative activity was detected by CCK8 and cell apoptosis was assayed by Hoechst33258 staining and flow cytometry. The results showed that two different molecular weights hGAG could inhibit proliferation, promote apoptosis rates of A549 cells, and enhance the sensitivity of A549 cells to HPD-PDT. The combined use of hGAG and HPD-PDT has synergistic inhibitory effects on A549 cells, and the effects of 3W molecular weight hGAG are better than that of 5W molecular weight hGAG.

Novel and Promising Strategies for Therapy of Post-Transplant Chronic GVHD

Despite the achievements that have increased viability after the transplantation of allogeneic hematopoietic stem cells (aHSCT), chronic graft-versus-host disease (cGVHD) remains the main cause of late complications and post-transplant deaths. At the moment, therapy alternatives demonstrate limited effectiveness in steroid-refractory illness; in addition, we have no reliable data on the mechanism of this condition. The lack of drugs of choice for the treatment of GVHD underscores the significance of the design of new therapies. Improved understanding of the mechanism of chronic GVHD has secured new therapy goals, and organized diagnostic recommendations and the development of medical tests have ensured a general language and routes for studies in this field. These factors, combined with the rapid development of pharmacology, have helped speed up the search of medicines and medical studies regarding chronic GVHD. At present, we can hope for success in curing this formidable complication. This review summarizes the latest clinical developments in new treatments for chronic GVHD.