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Molecules (Basel, Switzerland) Sep 2020Red Seaweed "Rhodophyta" are an important group of macroalgae that include approximately 7000 species. They are a rich source of structurally diverse bioactive... (Review)
Review
Red Seaweed "Rhodophyta" are an important group of macroalgae that include approximately 7000 species. They are a rich source of structurally diverse bioactive constituents, including protein, sulfated polysaccharides, pigments, polyunsaturated fatty acids, vitamins, minerals, and phenolic compounds with nutritional, medical, and industrial importance. Polysaccharides are the main components in the cell wall of red algae and represent about 40-50% of the dry weight, which are extensively utilized in industry and pharmaceutical compounds, due to their thickening and gelling properties. The hydrocolloids galactans carrageenans and agars are the main red seaweed cell wall polysaccharides, which had broad-spectrum therapeutic characters. Generally, the chemical contents of seaweed are different according to the algal species, growth stage, environment, and external conditions, e.g., the temperature of the water, light intensity, nutrient concentrations in the ecosystem. Economically, they can be recommended as a substitute source for natural ingredients that contribute to a broad range of bioactivities like cancer therapy, anti-inflammatory agents, and acetylcholinesterase inhibitory. This review touches on the main points of the pharmaceutical applications of red seaweed, as well as the exploitation of their specific compounds and secondary metabolites with vital roles.
Topics: Animals; Anti-Inflammatory Agents; Antineoplastic Agents; Carrageenan; Cholinesterase Inhibitors; Galactans; Humans; Rhodophyta; Seaweed
PubMed: 32992919
DOI: 10.3390/molecules25194411 -
Marine Drugs Jul 2022Various seaweed sulfated polysaccharides have been explored for antimicrobial application. This study aimed to evaluate the antibacterial activity of the native...
Various seaweed sulfated polysaccharides have been explored for antimicrobial application. This study aimed to evaluate the antibacterial activity of the native sulfated galactans (NSG) and depolymerized fractions against the marine pathogenic bacteria and . NSG was hydrolyzed in different concentrations of HO to generate sulfated galactans degraded fractions (SGF). The molecular weight, structural characteristics, and physicochemical parameters of both NSG and SGF were determined. The results revealed that the high molecular weight NSG (228.33 kDa) was significantly degraded to SGFs of 115.76, 3.79, and 3.19 kDa by hydrolysis with 0.4, 2, and 10% HO, respectively. The Fourier transformed spectroscopy (FTIR) and H- and C-Nuclear magnetic resonance (NMR) analyses demonstrated that the polysaccharide chain structure of SGFs was not affected by HO degradation, but alterations were detected at the peak positions of some functional groups. In vitro study showed that SGFs significantly exerted a stronger antibacterial activity against and than NSG, which might be due to the low molecular weight and higher sulfation properties of SGF. SGF disrupted the bacterial cell membrane, resulting in leakage of intracellular biological components, and subsequently, cell death. Taken together, this study provides a basis for the exploitation and utilization of low-molecular-weight sulfated galactans from to prevent and control the shrimp pathogens.
Topics: Anti-Bacterial Agents; Galactans; Gracilaria; Hydrogen Peroxide; Polysaccharides; Rhodophyta; Sulfates; Vibrio; Vibrio parahaemolyticus
PubMed: 35892937
DOI: 10.3390/md20080469 -
Biomolecules Dec 2023Agarophytes are important seaweeds of the Rhodophyta type, which have been highly exploited for industrial use as sources of a widely consumed polysaccharide of agar. In... (Review)
Review
Agarophytes are important seaweeds of the Rhodophyta type, which have been highly exploited for industrial use as sources of a widely consumed polysaccharide of agar. In addition to that, sulfated galactans (SGs) from agarophytes, which consist of various functional sulfate groups, have attracted the attention of scientists in current studies. SGs possess various biological activities, such as anti-tumor, anticoagulant, anti-inflammatory, antioxidant, anti-obesity, anti-diabetic, anti-microbial, anti-diarrhea, and gut microbiota regulation properties. Meanwhile, the taxonomy, ecological factors, i.e., environmental factors, and harvest period, as well as preparation methods, i.e., the pretreatment, extraction, and purification conditions, have been found to influence the chemical compositions and fine structures of SGs, which have, further, been shown to have an impact on their biological activities. However, the gaps in the knowledge of the properties of SGs due to the above complex factors have hindered their industrial application. The aim of this paper is to collect and systematically review the scientific evidence about SGs and, thus, to pave the way for broader and otherwise valuable industrial applications of agarophytes for human enterprise. In the future, this harvested biomass could be sustainably used not only as a source of agar production but also as natural materials in functional food and pharmaceutical industries.
Topics: Humans; Galactans; Sulfates; Agar; Polysaccharides; Anticoagulants
PubMed: 38136616
DOI: 10.3390/biom13121745 -
Nutrients Mar 2022Carob is one of the major food trees for peoples of the Mediterranean basin, but it has also been traditionally used for medicinal purposes. Carob contains many... (Review)
Review
Carob is one of the major food trees for peoples of the Mediterranean basin, but it has also been traditionally used for medicinal purposes. Carob contains many nutrients and active natural products, and D-Pinitol is clearly one of the most important of these. D-Pinitol has been reported in dozens of scientific publications and its very diverse medicinal properties are still being studied. Presently, more than thirty medicinal activities of D-Pinitol have been reported. Among these, many publications have reported the strong activities of D-Pinitol as a natural antidiabetic and insulin regulator, but also as an active anti-Alzheimer, anticancer, antioxidant, and anti-inflammatory, and is also immune- and hepato-protective. In this review, we will present a brief introduction of the nutritional and medicinal importance of Carob, both traditionally and as found by modern research. In the introduction, we will present Carob's major active natural products. The structures of inositols will be presented with a brief literature summary of their medicinal activities, with special attention to those inositols in Carob, as well as D-Pinitol's chemical structure and its medicinal and other properties. D-Pinitol antidiabetic and insulin regulation activities will be extensively presented, including its proposed mechanism of action. Finally, a discussion followed by the conclusions and future vision will summarize this article.
Topics: Biological Products; Fabaceae; Galactans; Hypoglycemic Agents; Inositol; Insulin; Mannans; Plant Gums
PubMed: 35406064
DOI: 10.3390/nu14071453 -
Microbiology Spectrum Jul 2019The mycobacterial cell envelope consists of a typical plasma membrane of lipid and protein surrounded by a complex cell wall composed of carbohydrate and lipid. In... (Review)
Review
The mycobacterial cell envelope consists of a typical plasma membrane of lipid and protein surrounded by a complex cell wall composed of carbohydrate and lipid. In pathogenic species, such as , an outermost "capsule" layer surrounds the cell wall. This wall embraces a fundamental, covalently linked "cell-wall skeleton" composed of peptidoglycan, solidly attached to arabinogalactan, whose penta-saccharide termini are esterified by very-long-chain fatty acids (mycolic acids). These fatty acids form the inner leaflet of an outer membrane, called the mycomembrane, whose outer leaflet consists of a great variety of non-covalently linked lipids and glycolipids. The thickness of the mycomembrane, which is similar to that of the plasma membrane, is surprising in view of the length of mycoloyl residues, suggesting dedicated conformations of these fatty acids. Finally, a periplasmic space also exists in mycobacteria, between the plasma membrane and the peptidoglycan. This article provides a comprehensive overview of this biologically important and structurally unique mycobacterial cell compartment.
Topics: Animals; Cell Membrane; Cell Wall; Fatty Acids; Galactans; Glycolipids; Humans; Mycobacterium tuberculosis; Peptidoglycan; Tuberculosis
PubMed: 31267927
DOI: 10.1128/microbiolspec.GPP3-0027-2018 -
Nature Communications Sep 2023The cell walls of pathogenic and acidophilic bacteria, such as Mycobacterium tuberculosis and Mycobacterium leprae, contain lipoarabinomannan and arabinogalactan. These...
The cell walls of pathogenic and acidophilic bacteria, such as Mycobacterium tuberculosis and Mycobacterium leprae, contain lipoarabinomannan and arabinogalactan. These components are composed of D-arabinose, the enantiomer of the typical L-arabinose found in plants. The unique glycan structures of mycobacteria contribute to their ability to evade mammalian immune responses. In this study, we identified four enzymes (two GH183 endo-D-arabinanases, GH172 exo-α-D-arabinofuranosidase, and GH116 exo-β-D-arabinofuranosidase) from Microbacterium arabinogalactanolyticum. These enzymes completely degraded the complex D-arabinan core structure of lipoarabinomannan and arabinogalactan in a concerted manner. Furthermore, through biochemical characterization using synthetic substrates and X-ray crystallography, we elucidated the mechanisms of substrate recognition and anomer-retaining hydrolysis for the α- and β-D-arabinofuranosidic bonds in both endo- and exo-mode reactions. The discovery of these D-arabinan-degrading enzymes, along with the understanding of their structural basis for substrate specificity, provides valuable resources for investigating the intricate glycan architecture of mycobacterial cell wall polysaccharides and their contribution to pathogenicity.
Topics: Animals; Female; Humans; Galactans; Lipopolysaccharides; Mycobacterium tuberculosis; Endometriosis; Mammals
PubMed: 37726269
DOI: 10.1038/s41467-023-41431-2 -
Carbohydrate Research Apr 2024Profiling of pectic arabinans and galactans by analysis of the released oligosaccharides after backbone cleavage provides information on the complexity of the polymer...
Profiling of pectic arabinans and galactans by analysis of the released oligosaccharides after backbone cleavage provides information on the complexity of the polymer structure. In plants of the family Amaranthaceae, arabinan and galactan substitution with ferulates extends the polysaccharide complexity, changing its chemical properties. Knowledge of the ferulate environment is crucial to understand structure-function-relationships of feruloylated pectins. Here, we present an approach to separate enzymatically generated feruloylated and non-feruloylated arabino- and galactooligosaccharides, followed by deesterification and semiquantitative analysis by HPAEC-PAD using previously reported relative response factors. Application of this approach to sugar beet pectins and insoluble and soluble dietary fiber preparations of amaranth and quinoa suggests that ferulates are preferably incorporated into more complex structures, as nicely demonstrated for feruloylated galactans. Also, ferulate substitution appears to negatively affect enzymatic cleavage by using endo-enzymes. As a consequence, we were able to tentatively identify new feruloylated tri- and tetrasaccharides of galactans isolated from sugar beet pectins.
Topics: Galactans; Pectins; Oligosaccharides; Chromatography; Sugars; Polysaccharides
PubMed: 38537364
DOI: 10.1016/j.carres.2024.109076 -
International Journal of Molecular... Apr 2021Galectins represent β-galactoside-binding proteins with numerous functions. Due to their role in tumor progression, human galectins-1, -3 and -7 (Gal-1, -3 and -7) are...
Galectins represent β-galactoside-binding proteins with numerous functions. Due to their role in tumor progression, human galectins-1, -3 and -7 (Gal-1, -3 and -7) are potential targets for cancer therapy. As plant derived glycans might act as galectin inhibitors, we prepared galactans by partial degradation of plant arabinogalactan-proteins. Besides commercially purchased galectins, we produced Gal-1 and -7 in a cell free system and tested binding capacities of the galectins to the galactans by biolayer-interferometry. Results for commercial and cell-free expressed galectins were comparable confirming functionality of the cell-free produced galectins. Our results revealed that galactans from bind to Gal-1 and -7 with K values of 1-2 µM and to Gal-3 slightly stronger with K values between 0.36 and 0.70 µM depending on the sensor type. Galactans from the seagrass with higher branching of the galactan and higher content of uronic acids showed stronger binding to Gal-3 (0.08-0.28 µM) compared to galactan from . The results contribute to knowledge on interactions between plant polysaccharides and galectins. Arabinogalactan-proteins have been identified as a new source for production of galactans with possible capability to act as galectin inhibitors.
Topics: Cell-Free System; Galactans; Galectin 1; Galectin 3; Galectins; Humans; Neoplasms; Protein Binding; Zosteraceae
PubMed: 33920014
DOI: 10.3390/ijms22084058 -
Marine Drugs Jun 2022Urolithiasis is a common urological disease characterized by the presence of a stone anywhere along the urinary tract. The major component of such stones is calcium...
Urolithiasis is a common urological disease characterized by the presence of a stone anywhere along the urinary tract. The major component of such stones is calcium oxalate, and reactive oxygen species act as an essential mediator of calcium oxalate crystallization. Previous studies have demonstrated the antioxidant and antiurolithiatic activities of sulfated polysaccharides. In this study, native sulfated galactans (N-SGs) with a molecular weight of 217.4 kDa from were modified to obtain lower molecular weight SG (L-SG) and also subjected to sulfation SG (S-SG). The in vitro antioxidant and antiurolithiatic activities of the modified substances and their ability to protect against sodium oxalate-induced renal tubular (HK-2) cell death were investigated. The results revealed that S-SG showed more pronounced antioxidant activities (DPPH and O scavenging activities) than those of other compounds. S-SG exhibited the highest antiurolithiatic activity in terms of nucleation and aggregation, as well as crystal morphology and size. Moreover, S-SG showed improved cell survival and increased anti-apoptotic BCL-2 protein in HK-2 cells treated with sodium oxalate. Our findings highlight the potential application of S-SG in the functional food and pharmaceutical industries.
Topics: Antioxidants; Calcium Oxalate; Cell Death; Galactans; Gracilaria; Oxalic Acid; Sulfates
PubMed: 35736184
DOI: 10.3390/md20060382 -
Microbiology Spectrum Aug 2014The cell wall of Mycobacterium tuberculosis is unique in that it differs significantly from those of both Gram-negative and Gram-positive bacteria. The thick,... (Review)
Review
The cell wall of Mycobacterium tuberculosis is unique in that it differs significantly from those of both Gram-negative and Gram-positive bacteria. The thick, carbohydrate- and lipid-rich cell wall with distinct lipoglycans enables mycobacteria to survive under hostile conditions such as shortage of nutrients and antimicrobial exposure. The key features of this highly complex cell wall are the mycolyl-arabinogalactan-peptidoglycan (mAGP)-based and phosphatidyl-myo-inositol-based macromolecular structures, with the latter possessing potent immunomodulatory properties. These structures are crucial for the growth, viability, and virulence of M. tuberculosis and therefore are often the targets of effective chemotherapeutic agents against tuberculosis. Over the past decade, sophisticated genomic and molecular tools have advanced our understanding of the primary structure and biosynthesis of these macromolecules. The availability of the full genome sequences of various mycobacterial species, including M. tuberculosis, Mycobacterium marinum, and Mycobacterium bovis BCG, have greatly facilitated the identification of large numbers of drug targets and antigens specific to tuberculosis. Techniques to manipulate mycobacteria have also improved extensively; the conditional expression-specialized transduction essentiality test (CESTET) is currently used to determine the essentiality of individual genes. Finally, various biosynthetic assays using either purified proteins or synthetic cell wall acceptors have been developed to study enzyme function. This article focuses on the recent advances in determining the structural details and biosynthesis of arabinogalactan, lipoarabinomannan, and related glycoconjugates.
Topics: Antitubercular Agents; Biosynthetic Pathways; Galactans; Genome, Bacterial; Lipopolysaccharides; Molecular Biology; Mycobacterium
PubMed: 26104198
DOI: 10.1128/microbiolspec.MGM2-0013-2013