Variations of pH as an additional tool in the analysis of crowded NMR spectra of fucosylated chondroitin sulfates

Chemical substances and their activities in sea cucumber Apostichopus japonicus: A review

Apostichopus japonicus, also known as Stichopus japonicus, with medicinal and food homologous figures, is a globally recognized precious ingredient with extremely high nutritional value. There is no relevant review available through literature search, so this article selects the research articles through the keywords "sea cucumber" and "Apostichopus japonicus (Stichopus japonicus)" in six professional databases, such as Wiley, PubMed, ScienceDirect, ACS, Springer, and Web of Science, from 2000 to the present, summarizing the extraction, isolation, and purification methods for the four major categories (polysaccharides, proteins and peptides, saponins, and other components) of the A. japonicus chemical substances and 10 effective biological activities of A. japonicus. Included are anticoagulation, anticancer/antitumor activities, hematopoiesis, regulation of gut microbiota, and immune regulatory activities that correspond to traditional efficacy. Literature support is provided for the development of medicines and functional foods and related aspects that play a leading role in future directions.

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.

Nanostructures assembly and the property of polysaccharide extracted from Tremella Fuciformis fruiting body

Polysaccharides from fungi are good free radical scavengers. However, there are no enzymes digesting these polysaccharides in the human body, which limits the use of fungal polysaccharides. Therefore, it is of great significance to study the preparation methods of fungal polysaccharides to improve the utilization rate of fungal polysaccharides. In this paper, the acidic polysaccharide of Tremella fuciformis was extracted by boiling and precipitated by ethanol. The total sugar content obtained by freeze-drying after ion exchange chromatography purification was 93.6%. It is mainly composed of mannose, glucuronic acid, xylose and fucose. According to the peak area, the mass ratio of the substance is about 6.8:1:1.5:0.6, which indicates that TFP is a polysaccharide with mannose as its main chain and glucuronic acid, fucose and xylose as well as a small amount of glucose as the branch chain. Molecular weight is 1.86 × 10⁶ Da. The existence of glucuronic acid endows polysaccharides with negative charge in aqueous solution and can be assembled into nanostructures with chitosan. By measuring the swelling property in aqueous, it shows the TFP separated from Tremella fuciformis fruits is suitable for drug controlled release.

Structural characterization and rheological properties of a pectin with anti-constipation activity from the roots of Arctium lappa L

A new pectin (ALP-2) was extracted from the roots of Arctium lappa L. with the molecular weight of 1.84 × 10⁶ Da. ALP-2 was composed of rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, xylose and arabinose. Results of NMR revealed that the dominant linkage types of ALP-2 were →4-α-GalpA-6-OMe-(1→, →2-α-Rha-(1→, →5-α-Araf-(1→ and →3,6-β-Galp-(1→. The ELISA results indicated ALP-2 was a typical pectin with HG chain and RG-I chain. The rheological experiments showed that ALP-2 fluid exhibited shear thinning behavior. The viscosity of ALP-2 was mainly affected by concentration, temperature, and pH. The ALP-2 fluid with elastic properties at high frequencies could be used as a thickener in the food industry. Moreover, ALP-2 with the dosages of 200 mg/kg and 400 mg/kg exhibited strong anti-constipation activity in vivo. ALP-2 treated groups could improve small intestinal movement rate and increase the weight of feces significantly in constipation mice. Therefore, ALP-2 could be considered as the active component for functional food or therapeutic agent in constipation therapy.

New insight on the structural diversity of holothurian fucosylated chondroitin sulfates

Fucosylated chondroitin sulfates (FCS) are unique glycosaminoglycans isolated from body walls of sea cucumbers (holothuria). These biopolymers are composed of a chondroitin core [→4)-β-D-GlcA-(1→3)-β-D-GalNAc-(1→]n bearing fucosyl branches and sulfate groups. Structural variations of FCS are species specific and depend on type, amount and position of branches, as well as on degree and pattern of sulfation of a backbone and branches. A wide spectrum of biological properties was determined for these polysaccharides including anticoagulant, antithrombotic, antitumor, anti-inflammatory activities. Structural features of FCS influence significantly on their biological effect. In this review recent data about structural variations within holothurian FCS are summarized. The NMR data of the key building blocks are presented, which may be used for the analysis of new FCS.

Structural characterization and antitumor effects of fucoidans from brown algae Kjellmaniella crassifolia farmed in northern China

Brown alga-derived fucoidan has been proven to have a variety of bioactivities. To explore the antitumor effect of fucoidan, Kjellmaniella crassifolia (farmed in Dalian, China)was enzymatically digested to obtain the crude extract (F), which was further separated into three fractions (F1, F2 and F3). The monosaccharide composition and structural characteristics of the isolated fractions were determined using high-performance liquid chromatography (HPLC), Fourier-transform infrared spectroscopy (FTIR) and 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. F1 is an acetylated galactofucan, and F2 consists of fucose, galactose, mannose and glucuronic acid. F3 has two components, an acetylated galactofucan and a pure sulfated fucan. F, F1 and F2 showed limited cytotoxicity against murine hepatocarcinoma Hca-F cells in vitro. Oral administration of F at a dose of 450 mg/kg d significantly inhibited lump growth in Hca-F-inoculated mice and led to upregulated FAS expression in tumor tissues compared to that of the control. F1 and F2 did not show competitive antineoplastic efficacy, as did the crude extract. Crude fucoidan could be a promising antitumor adjuvant. The origin of its efficacy may be the small molecules, such as phenols that attached to native fucoidan. This theory needs to be further confirmed.

Structural elucidation of fucosylated chondroitin sulfates from sea cucumber using FTICR-MS/MS

Fucosylated chondroitin sulfates are complex polysaccharides extracted from sea cucumber. They have been extensively studied for their anticoagulant properties and have been implicated in other biological activities. While nuclear magnetic resonance spectroscopy has been used to extensively characterize fucosylated chondroitin sulfate oligomers, we herein report the first detailed mass characterization of fucosylated chondroitin sulfate using high-resolution Fourier transform ion cyclotron resonance mass spectrometry. The two species of fucosylated chondroitin sulfates considered for this work include Pearsonothuria graeffei (FCS-Pg) and Isostichopus badionotus (FCS-Ib). Fucosylated chondroitin sulfate oligosaccharides were prepared by N-deacetylation-deaminative cleavage of the two fucosylated chondroitin sulfates and purified by repeated gel filtration. Accurate mass measurements obtained from electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry measurements confirmed the oligomeric nature of these two fucosylated chondroitin sulfate oligosaccharides with each trisaccharide repeating unit averaging four sulfates per trisaccharide. Collision-induced dissociation of efficiently deprotonated molecular ions through Na/H+ exchange proved useful in providing structurally relevant glycosidic and cross-ring product ions, capable of assigning the sulfate modifications on the fucosylated chondroitin sulfate oligomers. Careful examination of the tandem mass spectrometry of both species deferring in the positions of sulfate groups on the fucose residue (FCS-Pg-3,4- OS) and (FCS-Ib-2,4- OS) revealed cross-ring products 0,2Aαf and 2,4X2αf which were diagnostic for (FCS-Pg-3,4- OS) and 0,2X2αf diagnostic for (FCS-Ib-2,4- OS). Mass spectrometry and tandem mass spectrometry data acquired for both species varying in oligomer length (dp3-dp15) are presented.