Special Issue "Marine Glycoconjugates: Trends and Perspectives"

A special issue of Marine Drugs (ISSN 1660-3397).

Deadline for manuscript submissions: closed (20 November 2019) | Viewed by 35632

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Special Issue Editors

Dr. Vladimir I. Kalinin
E-Mail Website
Guest Editor
G.B. Elyakov Pacific Institute of Bioorganic Chemistry of the Far East Branch of the Russian Academy of Sciences, Pr. 100-letya Vladivostoka 159, 690022 Vladivostok, Russia
Interests: marine natural product chemistry; secondary metabolites; sea cucumber triterpene glycosides; biological activities; evolution of biosynthesis; chemotaxonomy
Special Issues, Collections and Topics in MDPI journals
Prof. Dr. Valentin A. Stonik
E-Mail Website
Guest Editor
G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159 Prospect 100-let Vladivostoku, Vladivostok 690022, Russia
Interests: marine natural product chemistry; glycosides; glycoconjugates; steroids; terpenoids; uncommon glycolipids; other marine metabolites; structures; bioactivities; chemistry; biochemistry; cell biology; pharmacology
Special Issues, Collections and Topics in MDPI journals
Dr. Natalia V. Ivanchina
E-Mail Website
Guest Editor
G.B. Elyakov Pacific Institute of Bioorganic Chemistry of the Far East Branch of the Russian Academy of Sciences, Pr. 100-letya Vladivostoka 159, 690022 Vladivostok, Russia
Interests: marine natural product chemistry; secondary metabolites; starfish polar steroids and lipids; biological activities; metabolomics; biosynthesis
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Glycoconjugates, biomolecules in which carbohydrate moieties are attached by a covalent bond to any aglycone, play very significant role in biological systems. Glycoproteins, peptidoglycans, lipopolyshaccharides and other biopolymer glycoconjugates are responsible for cellular interactions, including cell–cell recognition and the binding of cells to intercellular matrix, as well as they carry out other signal, antigenic and transport functions, participate in the formation of receptors and other important membrane and blood constituents. Low molecular weight glycoconjugates, such as triterpene and steroidal glycosides, glycolipids, phenolic glycosides are also well known as molecules having important internal and exterior functions for their organism-producers such as protection against predators, competition for space, food resources, etc. Diverse glycoconjugates provide very wide spectrum of biological activities including defensive, cytotoxic, antitumor, immunomodulatory, and antioxidant properties. Semi-synthetic conjugates of biologically active low molecular weight substances and carbohydrates possess better transport properties because of increased solubility. Water environment requires high solubility for signal or anti-predatory exometabolites of marine organism. All these peculiarities explain very wide diversity of glycoconjugates of marine origin. The main goal of this Special Issue “Marine Glycoconjugates: Trends and Perspectives” is to provide a convenient platform for discussion of all possible scientific aspects concerning low molecular weight and biopolymer glycoconjugates of marine origin, their isolation and chemical structures, taxonomical distribution, methods of analysis, biological activities, biosynthesis and evolution, biological roles and chemical syntheses including the obtaining of semi-synthetic derivatives of biological active natural products.

Dr. Vladimir I. Kalinin
Prof. Dr. Valentin A. Stonik
Dr. Natalia V. Ivanchina
Guest Editors

Manuscript Submission Information

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Keywords

  • marine glycoconjugates
  • triterpene glycosides
  • steroidal glycosides
  • glycolipids
  • lipopolysaccharides
  • biological activities
  • biosynthesis
  • biological role
  • marine invertebrates
  • echinoderms
  • sponges
  • starfish
  • sea cucumbers
  • marine fungi
  • bacteria
  • algae

Published Papers (14 papers)

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Editorial

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Editorial
Marine Glycoconjugates: Trends and Perspectives
Mar. Drugs 2020, 18(2), 120; https://doi.org/10.3390/md18020120 - 18 Feb 2020
Viewed by 1624
Abstract
Glycoconjugates play significant roles in biological systems and are used in medicine, for example as vaccines [...] Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)

Research

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Article
Glycosaminoglycan from Apostichopus japonicus Improves Glucose Metabolism in the Liver of Insulin Resistant Mice
Mar. Drugs 2020, 18(1), 1; https://doi.org/10.3390/md18010001 - 18 Dec 2019
Cited by 25 | Viewed by 1935
Abstract
Holothurian glycosaminoglycan isolated from Apostichopus japonicus (named AHG) can suppress hepatic glucose production in insulin resistant hepatocytes, but its effects on glucose metabolism in vivo are unknown. The present study was conducted to investigate the effects of AHG on hyperglycemia in the liver [...] Read more.
Holothurian glycosaminoglycan isolated from Apostichopus japonicus (named AHG) can suppress hepatic glucose production in insulin resistant hepatocytes, but its effects on glucose metabolism in vivo are unknown. The present study was conducted to investigate the effects of AHG on hyperglycemia in the liver of insulin resistant mice induced by a high-fat diet (HFD) for 12 weeks. The results demonstrated that AHG supplementation apparently reduced body weight, blood glucose level, and serum insulin content in a dose-dependent manner in HFD-fed mice. The protein levels and gene expression of gluconeogenesis rate-limiting enzymes G6Pase and PEPCK were remarkedly suppressed in the insulin resistant liver. In addition, although the total expression of IRS1, Akt, and AMPK in the insulin resistant liver was not affected by AHG supplementation, the phosphorylation of IRS1, Akt, and AMPK were clearly elevated by AHG treatment. These results suggest that AHG could be a promising natural marine product for the development of an antihyperglycemic agent. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Article
Structures and Bioactivities of Psolusosides B1, B2, J, K, L, M, N, O, P, and Q from the Sea Cucumber Psolus fabricii. The First Finding of Tetrasulfated Marine Low Molecular Weight Metabolites
Mar. Drugs 2019, 17(11), 631; https://doi.org/10.3390/md17110631 - 06 Nov 2019
Cited by 12 | Viewed by 1682
Abstract
Ten new di-, tri- and tetrasulfated triterpene glycosides, psolusosides B1 (1), B2 (2), J (3), K (4), L (5), M (6), N (7), O (8), [...] Read more.
Ten new di-, tri- and tetrasulfated triterpene glycosides, psolusosides B1 (1), B2 (2), J (3), K (4), L (5), M (6), N (7), O (8), P (9), and Q (10), were isolated from the sea cucumber Psolus fabricii collected in the Sea of Okhotsk near the Kurile Islands. Structures of these glycosides were established by two-dimensional (2D) NMR spectroscopy and HR-ESI mass-spectrometry. It is particularly interesting that highly polar compounds 9 and 10 contain four sulfate groups in their carbohydrate moieties, including two sulfates in the same terminal glucose residue. Glycoside 2 has an unusual non-holostane aglycone with 18(16)-lactone and a unique 7,8-epoxy fragment. Cytotoxic activities of compounds 110 against several mouse cell lines such as Ehrlich ascites carcinoma cells, neuroblastoma Neuro 2A, normal epithelial JB-6 cells, and erythrocytes were quite different depending both on structural peculiarities of these glycosides and the type of cells subjected to their actions. Psolusoside L (5), pentaoside, with three sulfate groups at C-6 of two glucose and one 3-O-methylglucose residue and holostane aglycone, is the most active compound in the series. The presence of a sulfate group at C-2 of the terminal glucose residue attached to C-4 of the first (xylose) residue significantly decreases activities of the corresponding glycosides. Psolusosides of group B (1, 2, and known psolusoside B) are inactive in all tests due to the presence of non-holostane aglycones and tetrasaccharide-branched sugar chains sulfated by C-2 of Glc4. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Article
Virescenosides from the Holothurian-Associated Fungus Acremonium striatisporum Kmm 4401
Mar. Drugs 2019, 17(11), 616; https://doi.org/10.3390/md17110616 - 29 Oct 2019
Cited by 7 | Viewed by 1758
Abstract
Ten new diterpene glycosides virescenosides Z9-Z18 (110) together with three known analogues (1113) and aglycon of virescenoside A (14) were isolated from the marine-derived fungus Acremonium striatisporum KMM 4401. These [...] Read more.
Ten new diterpene glycosides virescenosides Z9-Z18 (110) together with three known analogues (1113) and aglycon of virescenoside A (14) were isolated from the marine-derived fungus Acremonium striatisporum KMM 4401. These compounds were obtained by cultivating fungus on wort agar medium with the addition of potassium bromide. Structures of the isolated metabolites were established based on spectroscopic methods. The effects of some isolated glycosides and aglycons 1518 on urease activity and regulation of Reactive Oxygen Species (ROS) and Nitric Oxide (NO) production in macrophages stimulated with lipopolysaccharide (LPC) were evaluated. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Article
The Distribution of Asterosaponins, Polyhydroxysteroids and Related Glycosides in Different Body Components of the Far Eastern Starfish Lethasterias fusca
Mar. Drugs 2019, 17(9), 523; https://doi.org/10.3390/md17090523 - 06 Sep 2019
Cited by 7 | Viewed by 1888
Abstract
Glycoconjugated and other polar steroids of starfish have unique chemical structures and show a broad spectrum of biological activities. However, their biological functions remain not well established. Possible biological roles of these metabolites might be indicated by the studies on their distribution in [...] Read more.
Glycoconjugated and other polar steroids of starfish have unique chemical structures and show a broad spectrum of biological activities. However, their biological functions remain not well established. Possible biological roles of these metabolites might be indicated by the studies on their distribution in the organism–producer. In order to investigate the localization of polar steroids in body components of the Far Eastern starfish Lethasterias fusca, chemical constituents of body walls, gonads, stomach, pyloric caeca, and coelomic fluid were studied by nanoflow liquid chromatography/mass spectrometry with captive spray ionization (nLC/CSI–QTOF–MS). It has been shown that the levels of polar steroids in the studied body components are qualitatively and quantitatively different. Generally, the obtained data confirmed earlier made assumptions about the digestive function of polyhydroxysteroids and protective role of asterosaponins. The highest level of polar steroids was found in the stomach. Asterosaponins were found in all body components, the main portion of free polyhydroxysteroids and related glycosides were located in the pyloric caeca. In addition, a great inter-individual variability was found in the content of most polar steroids, which may be associated with the peculiarities in their individual physiologic status. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Article
Structural and Serological Studies of the O6-Related Antigen of Aeromonas veronii bv. sobria Strain K557 Isolated from Cyprinus carpio on a Polish Fish Farm, which Contains l-perosamine (4-amino-4,6-dideoxy-l-mannose), a Unique Sugar Characteristic for Aeromonas Serogroup O6
Mar. Drugs 2019, 17(7), 399; https://doi.org/10.3390/md17070399 - 05 Jul 2019
Cited by 8 | Viewed by 2445
Abstract
Amongst Aeromonas spp. strains that are pathogenic to fish in Polish aquacultures, serogroup O6 was one of the five most commonly identified immunotypes especially among carp isolates. Here, we report immunochemical studies of the lipopolysaccharide (LPS) including the O-specific polysaccharide (O-antigen) of A. [...] Read more.
Amongst Aeromonas spp. strains that are pathogenic to fish in Polish aquacultures, serogroup O6 was one of the five most commonly identified immunotypes especially among carp isolates. Here, we report immunochemical studies of the lipopolysaccharide (LPS) including the O-specific polysaccharide (O-antigen) of A. veronii bv. sobria strain K557, serogroup O6, isolated from a common carp during an outbreak of motile aeromonad septicemia (MAS) on a Polish fish farm. The O-polysaccharide was obtained by mild acid degradation of the LPS and studied by chemical analyses, mass spectrometry, and 1H and 13C NMR spectroscopy. It was revealed that the O-antigen was composed of two O-polysaccharides, both containing a unique sugar 4-amino-4,6-dideoxy-l-mannose (N-acetyl-l-perosamine, l-Rhap4NAc). The following structures of the O-polysaccharides (O-PS 1 and O-PS 2) were established: O-PS 1: →2)-α-l-Rhap4NAc-(1→; O-PS 2: →2)-α-l-Rhap4NAc-(1→3)-α-l-Rhap4NAc-(1→3)-α-l-Rhap4NAc-(1→. Western blotting and an enzyme-linked immunosorbent assay (ELISA) showed that the cross-reactivity between the LPS of A. veronii bv. sobria K557 and the A. hydrophila JCM 3968 O6 antiserum, and vice versa, is caused by the occurrence of common α-l-Rhap4NAc-(1→2)-α-l-Rhap4NAc and α-l-Rhap4NAc-(1→3)-α-l-Rhap4NAc disaccharides, whereas an additional →4)-α-d-GalpNAc-associated epitope defines the specificity of the O6 reference antiserum. Investigations of the serological and structural similarities and differences in the O-antigens provide knowledge of the immunospecificity of Aeromonas bacteria and are relevant in epidemiological studies and for the elucidation of the routes of transmission and relationships with pathogenicity. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Article
Oncolytic Vaccinia Virus Expressing Aphrocallistes vastus Lectin as a Cancer Therapeutic Agent
Mar. Drugs 2019, 17(6), 363; https://doi.org/10.3390/md17060363 - 19 Jun 2019
Cited by 10 | Viewed by 2534
Abstract
Lectins display a variety of biological functions including insecticidal, antimicrobial, as well as antitumor activities. In this report, a gene encoding Aphrocallistes vastus lectin (AVL), a C-type lectin, was inserted into an oncolytic vaccinia virus vector (oncoVV) to form a recombinant virus oncoVV-AVL, [...] Read more.
Lectins display a variety of biological functions including insecticidal, antimicrobial, as well as antitumor activities. In this report, a gene encoding Aphrocallistes vastus lectin (AVL), a C-type lectin, was inserted into an oncolytic vaccinia virus vector (oncoVV) to form a recombinant virus oncoVV-AVL, which showed significant in vitro antiproliferative activity in a variety of cancer cell lines. Further investigations revealed that oncoVV-AVL replicated faster than oncoVV significantly in cancer cells. Intracellular signaling elements including NF-κB2, NIK, as well as ERK were determined to be altered by oncoVV-AVL. Virus replication upregulated by AVL was completely dependent on ERK activity. Furthermore, in vivo studies showed that oncoVV-AVL elicited significant antitumor effect in colorectal cancer and liver cancer mouse models. Our study might provide insights into a novel way of the utilization of marine lectin AVL in oncolytic viral therapies. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Article
Structures and Bioactivities of Six New Triterpene Glycosides, Psolusosides E, F, G, H, H1, and I and the Corrected Structure of Psolusoside B from the Sea Cucumber Psolus fabricii
Mar. Drugs 2019, 17(6), 358; https://doi.org/10.3390/md17060358 - 14 Jun 2019
Cited by 14 | Viewed by 2217
Abstract
Seven sulfated triterpene glycosides, psolusosides B (1), E (2), F (3), G (4), H (5), H1 (6), and I (7), along with earlier known psolusoside A and colochiroside [...] Read more.
Seven sulfated triterpene glycosides, psolusosides B (1), E (2), F (3), G (4), H (5), H1 (6), and I (7), along with earlier known psolusoside A and colochiroside D have been isolated from the sea cucumber Psolus fabricii collected in the Sea of Okhotsk. Herein, the structure of psolusoside B (1), elucidated by us in 1989 as a monosulfated tetraoside, has been revised with application of modern NMR and particularly MS data and proved to be a disulfated tetraoside. The structures of other glycosides were elucidated by 2D NMR spectroscopy and HR-ESI mass-spectrometry. Psolusosides E (2), F (3), and G (4) contain holostane aglycones identical to each other and differ in their sugar compositions and the quantity and position of sulfate groups in linear tetrasaccharide carbohydrate moieties. Psolusosides H (5) and H1 (6) are characterized by an unusual sulfated trisaccharide carbohydrate moiety with the glucose as the second sugar unit. Psolusoside I (7) has an unprecedented branched tetrasaccharide disulfated carbohydrate moiety with the xylose unit in the second position of the chain. The cytotoxic activities of the compounds 27 against several mouse cell lines—ascite form of Ehrlich carcinoma, neuroblastoma Neuro 2A, normal epithelial JB-6 cells, and erythrocytes—were quite different, at that hemolytic effects of the tested compounds were higher than their cytotoxicity against other cells, especially against the ascites of Ehrlich carcinoma. Interestingly, psolusoside G (4) was not cytotoxic against normal JB-6 cells but demonstrated high activity against Neuro 2A cells. The cytotoxic activity against human colorectal adenocarcinoma HT-29 cells and the influence on the colony formation and growth of HT-29 cells of compounds 13, 57 and psolusoside A was checked. The highest inhibitory activities were demonstrated by psolusosides E (2) and F (3). Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Article
Functional Characterization of OXYL, A SghC1qDC LacNAc-specific Lectin from The Crinoid Feather Star Anneissia Japonica
Mar. Drugs 2019, 17(2), 136; https://doi.org/10.3390/md17020136 - 25 Feb 2019
Cited by 7 | Viewed by 4087
Abstract
We identified a lectin (carbohydrate-binding protein) belonging to the complement 1q(C1q) family in the feather star Anneissia japonica (a crinoid pertaining to the phylum Echinodermata). The combination of Edman degradation and bioinformatics sequence analysis characterized the primary structure of this novel lectin, named [...] Read more.
We identified a lectin (carbohydrate-binding protein) belonging to the complement 1q(C1q) family in the feather star Anneissia japonica (a crinoid pertaining to the phylum Echinodermata). The combination of Edman degradation and bioinformatics sequence analysis characterized the primary structure of this novel lectin, named OXYL, as a secreted 158 amino acid-long globular head (sgh)C1q domain containing (C1qDC) protein. Comparative genomics analyses revealed that OXYL pertains to a family of intronless genes found with several paralogous copies in different crinoid species. Immunohistochemistry assays identified the tissues surrounding coelomic cavities and the arms as the main sites of production of OXYL. Glycan array confirmed that this lectin could quantitatively bind to type-2 N-acetyllactosamine (LacNAc: Galβ1-4GlcNAc), but not to type-1 LacNAc (Galβ1-3GlcNAc). Although OXYL displayed agglutinating activity towards Pseudomonas aeruginosa, it had no effect on bacterial growth. On the other hand, it showed a significant anti-biofilm activity. We provide evidence that OXYL can adhere to the surface of human cancer cell lines BT-474, MCF-7, and T47D, with no cytotoxic effect. In BT-474 cells, OXYL led to a moderate activation of the p38 kinase in the MAPK signaling pathway, without affecting the activity of caspase-3. Bacterial agglutination, anti-biofilm activity, cell adhesion, and p38 activation were all suppressed by co-presence of LacNAc. This is the first report on a type-2 LacNAc-specific lectin characterized by a C1q structural fold. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Article
The Marine Dinoflagellate Alexandrium minutum Activates a Mitophagic Pathway in Human Lung Cancer Cells
Mar. Drugs 2018, 16(12), 502; https://doi.org/10.3390/md16120502 - 12 Dec 2018
Cited by 12 | Viewed by 2511
Abstract
Marine dinoflagellates are a valuable source of bioactive molecules. Many species produce cytotoxic compounds and some of these compounds have also been investigated for their anticancer potential. Here, we report the first investigation of the toxic dinoflagellate Alexandrium minutum as source of water-soluble [...] Read more.
Marine dinoflagellates are a valuable source of bioactive molecules. Many species produce cytotoxic compounds and some of these compounds have also been investigated for their anticancer potential. Here, we report the first investigation of the toxic dinoflagellate Alexandrium minutum as source of water-soluble compounds with antiproliferative activity against human lung cancer cells. A multi-step enrichment of the phenol–water extract yielded a bioactive fraction with specific antiproliferative effect (IC50 = 0.4 µg·mL−1) against the human lung adenocarcinoma cells (A549 cell line). Preliminary characterization of this material suggested the presence of glycoprotein with molecular weight above 20 kDa. Interestingly, this fraction did not exhibit any cytotoxicity against human normal lung fibroblasts (WI38). Differential gene expression analysis in A549 cancer cells suggested that the active fraction induces specific cell death, triggered by mitochondrial autophagy (mitophagy). In agreement with the cell viability results, gene expression data also showed that no mitophagic event was activated in normal cells WI38. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Article
Fatty Acid Composition and Thermotropic Behavior of Glycolipids and Other Membrane Lipids of Ulva lactuca (Chlorophyta) Inhabiting Different Climatic Zones
Mar. Drugs 2018, 16(12), 494; https://doi.org/10.3390/md16120494 - 07 Dec 2018
Cited by 15 | Viewed by 2948
Abstract
Increasing global temperatures are expected to increase the risk of extinction of various species due to acceleration in the pace of shifting climate zones. Nevertheless, there is no information on the physicochemical properties of membrane lipids that enable the adaptation of the algae [...] Read more.
Increasing global temperatures are expected to increase the risk of extinction of various species due to acceleration in the pace of shifting climate zones. Nevertheless, there is no information on the physicochemical properties of membrane lipids that enable the adaptation of the algae to different climatic zones. The present work aimed to compare fatty acid composition and thermal transitions of membrane lipids from green macroalgae Ulva lactuca harvested in the Sea of Japan and the Adriatic Sea in summer. U. lactuca inhabiting the Adriatic Sea had bleached parts of thalli which were completely devoid of chloroplast glycolipids. The adaptation to a warmer climatic zone was also accompanied by a significant decrease in the ratio between unsaturated and saturated fatty acids (UFA/SFA) of membrane lipids, especially in bleached thalli. Hence, bleaching of algae is probably associated with the significant decrease of the UFA/SFA ratio in glycolipids. The decreasing ratio of n-3/n-6 polyunsaturated fatty acids (PUFAs) was observed in extra-plastidial lipids and only in the major glycolipid, non-lamellar monogalactosyldiacylglycerol. The opposite thermotropic behavior of non-lamellar and lamellar glycolipids can contribute to maintenance of the highly dynamic structure of thylakoid membranes of algae in response to the increasing temperatures of climatic zones. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Article
In Vitro Anticancer and Proapoptotic Activities of Steroidal Glycosides from the Starfish Anthenea aspera
Mar. Drugs 2018, 16(11), 420; https://doi.org/10.3390/md16110420 - 01 Nov 2018
Cited by 9 | Viewed by 2436
Abstract
New marine glycoconjugates—the steroidal glycosides designated as anthenosides V–X (13)—and the seven previously known anthenosides E (4), G (5), J (6), K (7), S1 (8), S4 (9), [...] Read more.
New marine glycoconjugates—the steroidal glycosides designated as anthenosides V–X (13)—and the seven previously known anthenosides E (4), G (5), J (6), K (7), S1 (8), S4 (9), and S6 (10) were isolated from the extract of the tropical starfish Anthenea aspera. The structures of 13 were elucidated by extensive NMR and ESIMS techniques. Glycoside 1 contains a rare 5α-cholest-8(14)-ene-3α,7β,16α-hydroxysteroidal nucleus. Compounds 2 and 3 were isolated as inseparable mixtures of epimers. All investigated compounds (110) at nontoxic concentrations inhibited colony formation of human melanoma RPMI-7951, breast cancer T-47D, and colorectal carcinoma HT-29 cells to a variable degree. The mixture of 6 and 7 possessed significant anticancer activity and induced apoptosis of HT-29 cells. The molecular mechanism of the proapoptotic action of this mixture was shown to be associated with the regulation of anti- and proapoptotic protein expression followed by the activation of initiator and effector caspases. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Review

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Review
Antitumor Potential of Marine and Freshwater Lectins
Mar. Drugs 2020, 18(1), 11; https://doi.org/10.3390/md18010011 - 21 Dec 2019
Cited by 15 | Viewed by 3758
Abstract
Often, even the most effective antineoplastic drugs currently used in clinic do not efficiently allow complete healing due to the related toxicity. The reason for the toxicity lies in the lack of selectivity for cancer cells of the vast majority of anticancer agents. [...] Read more.
Often, even the most effective antineoplastic drugs currently used in clinic do not efficiently allow complete healing due to the related toxicity. The reason for the toxicity lies in the lack of selectivity for cancer cells of the vast majority of anticancer agents. Thus, the need for new potent anticancer compounds characterized by a better toxicological profile is compelling. Lectins belong to a particular class of non-immunogenic glycoproteins and have the characteristics to selectively bind specific sugar sequences on the surface of cells. This property is exploited to exclusively bind cancer cells and exert antitumor activity through the induction of different forms of regulated cell death and the inhibition of cancer cell proliferation. Thanks to the extraordinary biodiversity, marine environments represent a unique source of active natural compounds with anticancer potential. Several marine and freshwater organisms, ranging from the simplest alga to the most complex vertebrate, are amazingly enriched in these proteins. Remarkably, all studies gathered in this review show the impressive anticancer effect of each studied marine lectin combined with irrelevant toxicity in vitro and in vivo and pave the way to design clinical trials to assess the real antineoplastic potential of these promising proteins. It provides a concise and precise description of the experimental results, their interpretation as well as the experimental conclusions that can be drawn. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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Review
Sterol and Sphingoid Glycoconjugates from Microalgae
Mar. Drugs 2018, 16(12), 514; https://doi.org/10.3390/md16120514 - 17 Dec 2018
Cited by 23 | Viewed by 3329
Abstract
Microalgae are well known as primary producers in the hydrosphere. As sources of natural products, microalgae are attracting major attention due to the potential of their practical applications as valuable food constituents, raw material for biofuels, drug candidates, and components of drug delivery [...] Read more.
Microalgae are well known as primary producers in the hydrosphere. As sources of natural products, microalgae are attracting major attention due to the potential of their practical applications as valuable food constituents, raw material for biofuels, drug candidates, and components of drug delivery systems. This paper presents a short review of a low-molecular-weight steroid and sphingolipid glycoconjugates, with an analysis of the literature on their structures, functions, and bioactivities. The discussed data on sterols and the corresponding glycoconjugates not only demonstrate their structural diversity and properties, but also allow for a better understanding of steroid biogenesis in some echinoderms, mollusks, and other invertebrates which receive these substances from food and possibly from their microalgal symbionts. In another part of this review, the structures and biological functions of sphingolipid glycoconjugates are discussed. Their role in limiting microalgal blooms as a result of viral infections is emphasized. Full article
(This article belongs to the Special Issue Marine Glycoconjugates: Trends and Perspectives)
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