Marine Natural Products against Coronaviruses

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

Deadline for manuscript submissions: closed (31 July 2022) | Viewed by 79178

Special Issue Editor


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Special Issue Information

Dear Colleagues,

Coronaviruses are a large group of enveloped viruses with a positive-sense single-stranded RNA genome and a nucleocapsid of helical symmetry. This group includes various human respiratory diseases: some common colds, Middle East Respiratory Syndrome (MERS), Severe Acute Respiratory Syndrome (SARS) and the recently appeared COVID-19. Marine Drugs, as the leading journal in reporting marine natural products and their biological/pharmacological/therapeutical applications, would like to provide a publication platform on this topic. Thus, scientists in the marine field are invited to present original and advanced research outcomes about marine natural products with potential efficacy against coronavirus. We welcome both research articles and comprehensive reviews.

Prof. Orazio Taglialatela-Scafati
Guest Editor

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Published Papers (13 papers)

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Editorial

Jump to: Research, Review

2 pages, 306 KiB  
Editorial
New Hopes for Drugs against COVID-19 Come from the Sea
by Orazio Taglialatela-Scafati
Mar. Drugs 2021, 19(2), 104; https://doi.org/10.3390/md19020104 - 11 Feb 2021
Cited by 14 | Viewed by 4584
Abstract
The latest chapter of the historic battle of humans against pathogenic microbes is the severe acute respiratory syndrome (SARS)-like coronavirus-2 (SARS-CoV-2), responsible for COVID-19, a respiratory disease declared a global pandemic by the WHO on March 11, 2020 [...] Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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Research

Jump to: Editorial, Review

16 pages, 2200 KiB  
Article
Anti-SARS-CoV-2 Activity of Polysaccharides Extracted from Halymenia floresii and Solieria chordalis (Rhodophyta)
by Clément Jousselin, Hugo Pliego-Cortés, Alexia Damour, Magali Garcia, Charles Bodet, Daniel Robledo, Nathalie Bourgougnon and Nicolas Lévêque
Mar. Drugs 2023, 21(6), 348; https://doi.org/10.3390/md21060348 - 6 Jun 2023
Cited by 4 | Viewed by 2620
Abstract
Even after hundreds of clinical trials, the search for new antivirals to treat COVID-19 is still relevant. Carrageenans are seaweed sulfated polysaccharides displaying antiviral activity against a wide range of respiratory viruses. The objective of this work was to study the antiviral properties [...] Read more.
Even after hundreds of clinical trials, the search for new antivirals to treat COVID-19 is still relevant. Carrageenans are seaweed sulfated polysaccharides displaying antiviral activity against a wide range of respiratory viruses. The objective of this work was to study the antiviral properties of Halymenia floresii and Solieria chordalis carrageenans against SARS-CoV-2. Six polysaccharide fractions obtained from H. floresii and S. chordalis by Enzyme-Assisted Extraction (EAE) or Hot Water Extraction (HWE) were tested. The effect of carrageenan on viral replication was assessed during infection of human airway epithelial cells with a clinical strain of SARS-CoV-2. The addition of carrageenans at different times of the infection helped to determine their mechanism of antiviral action. The four polysaccharide fractions isolated from H. floresii displayed antiviral properties while the S. chordalis fractions did not. EAE-purified fractions caused a stronger reduction in viral RNA concentration. Their antiviral action is likely related to an inhibition of the virus attachment to the cell surface. This study confirms that carrageenans could be used as first-line treatment in the respiratory mucosa to inhibit the infection and transmission of SARS-CoV-2. Low production costs, low cytotoxicity, and a broad spectrum of antiviral properties constitute the main strengths of these natural molecules. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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13 pages, 1832 KiB  
Article
Evaluation of Antiviral Effect against SARS-CoV-2 Propagation by Crude Polysaccharides from Seaweed and Abalone Viscera In Vitro
by Sang-Min Kang, Dongseob Tark, Byeong-Min Song, Gun-Hee Lee, Ju-Hee Yang, Hee-Jeong Han and Sung-Kun Yim
Mar. Drugs 2022, 20(5), 296; https://doi.org/10.3390/md20050296 - 27 Apr 2022
Cited by 8 | Viewed by 3196
Abstract
Crude polysaccharides, extracted from two seaweed species (Hizikia fusiforme and Sargassum horneri) and Haliotis discus hannai (abalone) viscera, were evaluated for their inhibitory effect against SARS-CoV-2 propagation. Plaque titration revealed that these crude polysaccharides efficiently inhibited SARS-CoV-2 propagation with IC50 [...] Read more.
Crude polysaccharides, extracted from two seaweed species (Hizikia fusiforme and Sargassum horneri) and Haliotis discus hannai (abalone) viscera, were evaluated for their inhibitory effect against SARS-CoV-2 propagation. Plaque titration revealed that these crude polysaccharides efficiently inhibited SARS-CoV-2 propagation with IC50 values ranging from 0.35 to 4.37 μg/mL. The crude polysaccharide of H. fusiforme showed the strongest antiviral effect, with IC50 of 0.35 μg/mL, followed by S. horneri and abalone viscera with IC50 of 0.56 and 4.37 μg/mL, respectively. In addition, immunofluorescence assay, western blot, and quantitative RT-PCR analysis verified that these polysaccharides could inhibit SARS-CoV-2 replication. In Vero E6 cells, treatment with these crude polysaccharides before or after viral infection strongly inhibited the expression level of SARS-CoV-2 spikes, nucleocapsid proteins, and RNA copies of RNA-dependent RNA-polymerase and nucleocapsid. These results show that these crude marine polysaccharides effectively inhibit SARS-CoV-2 propagation by interference with viral entry. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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45 pages, 12098 KiB  
Article
In Silico Evaluation of Antifungal Compounds from Marine Sponges against COVID-19-Associated Mucormycosis
by Omkar Pokharkar, Hariharan Lakshmanan, Grigory Zyryanov and Mikhail Tsurkan
Mar. Drugs 2022, 20(3), 215; https://doi.org/10.3390/md20030215 - 20 Mar 2022
Cited by 22 | Viewed by 6443
Abstract
The world is already facing the devastating effects of the SARS-CoV-2 pandemic. A disseminated mucormycosis epidemic emerged to worsen this situation, causing havoc, especially in India. This research aimed to perform a multitargeted docking study of marine-sponge-origin bioactive compounds against mucormycosis. Information on [...] Read more.
The world is already facing the devastating effects of the SARS-CoV-2 pandemic. A disseminated mucormycosis epidemic emerged to worsen this situation, causing havoc, especially in India. This research aimed to perform a multitargeted docking study of marine-sponge-origin bioactive compounds against mucormycosis. Information on proven drug targets and marine sponge compounds was obtained via a literature search. A total of seven different targets were selected. Thirty-five compounds were chosen using the PASS online program. For homology modeling and molecular docking, FASTA sequences and 3D structures for protein targets were retrieved from NCBI and PDB databases. Autodock Vina in PyRx 0.8 was used for docking studies. Further, molecular dynamics simulations were performed using the IMODS server for top-ranked docked complexes. Moreover, the drug-like properties and toxicity analyses were performed using Lipinski parameters in Swiss-ADME, OSIRIS, ProTox-II, pkCSM, and StopTox servers. The results indicated that naamine D, latrunculin A and S, (+)-curcudiol, (+)-curcuphenol, aurantoside I, and hyrtimomine A had the highest binding affinity values of −8.8, −8.6, −9.8, −11.4, −8.0, −11.4, and −9.0 kcal/mol, respectively. In sum, all MNPs included in this study are good candidates against mucormycosis. (+)-curcudiol and (+)-curcuphenol are promising compounds due to their broad-spectrum target inhibition potential. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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8 pages, 530 KiB  
Communication
Griffithsin and Carrageenan Combination Results in Antiviral Synergy against SARS-CoV-1 and 2 in a Pseudoviral Model
by Sahar Alsaidi, Nadjet Cornejal, Oneil Mahoney, Claudia Melo, Neeharika Verma, Thierry Bonnaire, Theresa Chang, Barry R. O’Keefe, James Sailer, Thomas M. Zydowsky, Natalia Teleshova and José A. Fernández Romero
Mar. Drugs 2021, 19(8), 418; https://doi.org/10.3390/md19080418 - 26 Jul 2021
Cited by 33 | Viewed by 7114
Abstract
Over 182 million confirmed cases of COVID-19 and more than 4 million deaths have been reported to date around the world. It is essential to identify broad-spectrum antiviral agents that may prevent or treat infections by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [...] Read more.
Over 182 million confirmed cases of COVID-19 and more than 4 million deaths have been reported to date around the world. It is essential to identify broad-spectrum antiviral agents that may prevent or treat infections by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) but also by other coronaviruses that may jump the species barrier in the future. We evaluated the antiviral selectivity of griffithsin and sulfated and non-sulfated polysaccharides against SARS-CoV-1 and SARS-CoV-2 using a cytotoxicity assay and a cell-based pseudoviral model. The half-maximal cytotoxic concentration (CC50) and half-maximal effective concentration (EC50) were determined for each compound, using a dose-response-inhibition analysis on GraphPad Prism v9.0.2 software (San Diego, CA, USA). The therapeutic index (TI = CC50/EC50) was calculated for each compound. The potential synergistic, additive, or antagonistic effect of different compound combinations was determined by CalcuSyn v1 software (Biosoft, Cambridge, UK), which estimated the combination index (CI) values. Iota and lambda carrageenan showed the most potent antiviral activity (EC50 between 3.2 and 7.5 µg/mL). Carrageenan and griffithsin combinations exhibited synergistic activity (EC50 between 0.2 and 3.8 µg/mL; combination index <1), including against recent SARS-CoV-2 mutations. The griffithsin and carrageenan combination is a promising candidate to prevent or treat infections by SARS-CoV-1 and SARS-CoV-2. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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17 pages, 3655 KiB  
Article
Dieckol and Its Derivatives as Potential Inhibitors of SARS-CoV-2 Spike Protein (UK Strain: VUI 202012/01): A Computational Study
by Mohammad Aatif, Ghazala Muteeb, Abdulrahman Alsultan, Adil Alshoaibi and Bachir Yahia Khelif
Mar. Drugs 2021, 19(5), 242; https://doi.org/10.3390/md19050242 - 25 Apr 2021
Cited by 25 | Viewed by 3663
Abstract
The high risk of morbidity and mortality associated with SARS-CoV-2 has accelerated the development of many potential vaccines. However, these vaccines are designed against SARS-CoV-2 isolated in Wuhan, China, and thereby may not be effective against other SARS-CoV-2 variants such as the United [...] Read more.
The high risk of morbidity and mortality associated with SARS-CoV-2 has accelerated the development of many potential vaccines. However, these vaccines are designed against SARS-CoV-2 isolated in Wuhan, China, and thereby may not be effective against other SARS-CoV-2 variants such as the United Kingdom variant (VUI-202012/01). The UK SARS-CoV-2 variant possesses D614G mutation in the Spike protein, which impart it a high rate of infection. Therefore, newer strategies are warranted to design novel vaccines and drug candidates specifically designed against the mutated forms of SARS-CoV-2. One such strategy is to target ACE2 (angiotensin-converting enzyme2)–Spike protein RBD (receptor binding domain) interaction. Here, we generated a homology model of Spike protein RBD of SARS-CoV-2 UK strain and screened a marine seaweed database employing different computational approaches. On the basis of high-throughput virtual screening, standard precision, and extra precision molecular docking, we identified BE011 (Dieckol) as the most potent compounds against RBD. However, Dieckol did not display drug-like properties, and thus different derivatives of it were generated in silico and evaluated for binding potential and drug-like properties. One Dieckol derivative (DK07) displayed good binding affinity for RBD along with acceptable physicochemical, pharmacokinetic, drug-likeness, and ADMET properties. Analysis of the RBD–DK07 interaction suggested the formation of hydrogen bonds, electrostatic interactions, and hydrophobic interactions with key residues mediating the ACE2–RBD interaction. Molecular dynamics simulation confirmed the stability of the RBD–DK07 complex. Free energy calculations suggested the primary role of electrostatic and Van der Waals’ interaction in stabilizing the RBD–DK07 complex. Thus, DK07 may be developed as a potential inhibitor of the RBD–ACE2 interaction. However, these results warrant further validation by in vitro and in vivo studies. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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14 pages, 1204 KiB  
Article
Inhibition of SARS-CoV-2 Virus Entry by the Crude Polysaccharides of Seaweeds and Abalone Viscera In Vitro
by Sung-Kun Yim, Kian Kim, Inhee Kim, SangHo Chun, TaeHwan Oh, Jin-Ung Kim, Jungwon Kim, WooHuk Jung, Hosang Moon, Bosung Ku and Kyoojin Jung
Mar. Drugs 2021, 19(4), 219; https://doi.org/10.3390/md19040219 - 15 Apr 2021
Cited by 50 | Viewed by 6109
Abstract
Much attention is being devoted to the potential of marine sulfated polysaccharides as antiviral agents in preventing COVID-19. In this study, sulfated fucoidan and crude polysaccharides, extracted from six seaweed species (Undaria pinnatifida sporophyll, Laminaria japonica, Hizikia fusiforme, Sargassum horneri, Codium fragile, Porphyra [...] Read more.
Much attention is being devoted to the potential of marine sulfated polysaccharides as antiviral agents in preventing COVID-19. In this study, sulfated fucoidan and crude polysaccharides, extracted from six seaweed species (Undaria pinnatifida sporophyll, Laminaria japonica, Hizikia fusiforme, Sargassum horneri, Codium fragile, Porphyra tenera) and Haliotis discus hannai (abalone viscera), were screened for their inhibitory activity against SARS-CoV-2 virus entry. Most of them showed significant antiviral activities at an IC50 of 12~289 μg/mL against SARS-CoV-2 pseudovirus in HEK293/ACE2, except for P. tenera (IC50 > 1000 μg/mL). The crude polysaccharide of S. horneri showed the strongest antiviral activity, with an IC50 of 12 μg/mL, to prevent COVID-19 entry, and abalone viscera and H. fusiforme could also inhibit SARS-CoV-2 infection with an IC50 of 33 μg/mL and 47 μg/mL, respectively. The common properties of these crude polysaccharides, which have strong antiviral activity, are high molecular weight (>800 kDa), high total carbohydrate (62.7~99.1%), high fucose content (37.3~66.2%), and highly branched polysaccharides. These results indicated that the crude polysaccharides from seaweeds and abalone viscera can effectively inhibit SARS-CoV-2 entry. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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19 pages, 4357 KiB  
Article
Caged Dexamethasone/Quercetin Nanoparticles, Formed of the Morphogenetic Active Inorganic Polyphosphate, are Strong Inducers of MUC5AC
by Meik Neufurth, Xiaohong Wang, Shunfeng Wang, Heinz C. Schröder and Werner E. G. Müller
Mar. Drugs 2021, 19(2), 64; https://doi.org/10.3390/md19020064 - 27 Jan 2021
Cited by 14 | Viewed by 3684
Abstract
Inorganic polyphosphate (polyP) is a widely distributed polymer found from bacteria to animals, including marine species. This polymer exhibits morphogenetic as well as antiviral activity and releases metabolic energy after enzymatic hydrolysis also in human cells. In the pathogenesis of the coronavirus disease [...] Read more.
Inorganic polyphosphate (polyP) is a widely distributed polymer found from bacteria to animals, including marine species. This polymer exhibits morphogenetic as well as antiviral activity and releases metabolic energy after enzymatic hydrolysis also in human cells. In the pathogenesis of the coronavirus disease 2019 (COVID-19), the platelets are at the frontline of this syndrome. Platelets release a set of molecules, among them polyP. In addition, the production of airway mucus, the first line of body defense, is impaired in those patients. Therefore, in this study, amorphous nanoparticles of the magnesium salt of polyP (Mg-polyP-NP), matching the size of the coronavirus SARS-CoV-2, were prepared and loaded with the secondary plant metabolite quercetin or with dexamethasone to study their effects on the respiratory epithelium using human alveolar basal epithelial A549 cells as a model. The results revealed that both compounds embedded into the polyP nanoparticles significantly increased the steady-state-expression of the MUC5AC gene. This mucin species is the major mucus glycoprotein present in the secreted gel-forming mucus. The level of gene expression caused by quercetin or with dexamethasone, if caged into polyP NP, is significantly higher compared to the individual drugs alone. Both quercetin and dexamethasone did not impair the growth-supporting effect of polyP on A549 cells even at concentrations of quercetin which are cytotoxic for the cells. A possible mechanism of the effects of the two drugs together with polyP on mucin expression is proposed based on the scavenging of free oxygen species and the generation of ADP/ATP from the polyP, which is needed for the organization of the protective mucin-based mucus layer. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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21 pages, 3314 KiB  
Article
Morphogenetic (Mucin Expression) as Well as Potential Anti-Corona Viral Activity of the Marine Secondary Metabolite Polyphosphate on A549 Cells
by Werner E. G. Müller, Meik Neufurth, Shunfeng Wang, Rongwei Tan, Heinz C. Schröder and Xiaohong Wang
Mar. Drugs 2020, 18(12), 639; https://doi.org/10.3390/md18120639 - 14 Dec 2020
Cited by 25 | Viewed by 4015
Abstract
The mucus layer of the nasopharynx and bronchial epithelium has a barrier function against inhaled pathogens such as the coronavirus SARS-CoV-2. We recently found that inorganic polyphosphate (polyP), a physiological, metabolic energy (ATP)-providing polymer released from blood platelets, blocks the binding of the [...] Read more.
The mucus layer of the nasopharynx and bronchial epithelium has a barrier function against inhaled pathogens such as the coronavirus SARS-CoV-2. We recently found that inorganic polyphosphate (polyP), a physiological, metabolic energy (ATP)-providing polymer released from blood platelets, blocks the binding of the receptor binding domain (RBD) to the cellular ACE2 receptor in vitro. PolyP is a marine natural product and is abundantly present in marine bacteria. Now, we have approached the in vivo situation by studying the effect of polyP on the human alveolar basal epithelial A549 cells in a mucus-like mucin environment. These cells express mucins as well as the ectoenzymes alkaline phosphatase (ALP) and adenylate kinase (ADK), which are involved in the extracellular production of ATP from polyP. Mucin, integrated into a collagen-based hydrogel, stimulated cell growth and attachment. The addition of polyP to the hydrogel significantly increased cell attachment and also the expression of the membrane-tethered mucin MUC1 and the secreted mucin MUC5AC. The increased synthesis of MUC1 was also confirmed by immunostaining. This morphogenetic effect of polyP was associated with a rise in extracellular ATP level. We conclude that the nontoxic and non-immunogenic polymer polyP could possibly also exert a protective effect against SARS-CoV-2-cell attachment; first, by stimulating the innate antiviral response by strengthening the mucin barrier with its antimicrobial proteins, and second, by inhibiting virus attachment to the cells, as deduced from the reduction in the strength of binding between the viral RBD and the cellular ACE2 receptor. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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19 pages, 6128 KiB  
Article
Putative Inhibitors of SARS-CoV-2 Main Protease from A Library of Marine Natural Products: A Virtual Screening and Molecular Modeling Study
by Davide Gentile, Vincenzo Patamia, Angela Scala, Maria Teresa Sciortino, Anna Piperno and Antonio Rescifina
Mar. Drugs 2020, 18(4), 225; https://doi.org/10.3390/md18040225 - 23 Apr 2020
Cited by 258 | Viewed by 16294
Abstract
The current emergency due to the worldwide spread of the COVID-19 caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a great concern for global public health. Already in the past, the outbreak of severe acute respiratory syndrome (SARS) in [...] Read more.
The current emergency due to the worldwide spread of the COVID-19 caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a great concern for global public health. Already in the past, the outbreak of severe acute respiratory syndrome (SARS) in 2003 and Middle Eastern respiratory syndrome (MERS) in 2012 demonstrates the potential of coronaviruses to cross-species borders and further underlines the importance of identifying new-targeted drugs. An ideal antiviral agent should target essential proteins involved in the lifecycle of SARS-CoV. Currently, some HIV protease inhibitors (i.e., Lopinavir) are proposed for the treatment of COVID-19, although their effectiveness has not yet been assessed. The main protease (Mpro) provides a highly validated pharmacological target for the discovery and design of inhibitors. We identified potent Mpro inhibitors employing computational techniques that entail the screening of a Marine Natural Product (MNP) library. MNP library was screened by a hyphenated pharmacophore model, and molecular docking approaches. Molecular dynamics and re-docking further confirmed the results obtained by structure-based techniques and allowed this study to highlight some crucial aspects. Seventeen potential SARS-CoV-2 Mpro inhibitors have been identified among the natural substances of marine origin. As these compounds were extensively validated by a consensus approach and by molecular dynamics, the likelihood that at least one of these compounds could be bioactive is excellent. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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Review

Jump to: Editorial, Research

7 pages, 203 KiB  
Review
Fucoidan and Lung Function: Value in Viral Infection
by J. Helen Fitton, Ah Young Park, Samuel S. Karpiniec and Damien N. Stringer
Mar. Drugs 2021, 19(1), 4; https://doi.org/10.3390/md19010004 - 24 Dec 2020
Cited by 30 | Viewed by 6512
Abstract
Compromised lung function is a feature of both infection driven and non-infective pathologies. Viral infections—including the current pandemic strain SARS-CoV-2—that affect lung function can cause both acute and long-term chronic damage. SARS-CoV-2 infection suppresses innate immunity and promotes an inflammatory response. Targeting these [...] Read more.
Compromised lung function is a feature of both infection driven and non-infective pathologies. Viral infections—including the current pandemic strain SARS-CoV-2—that affect lung function can cause both acute and long-term chronic damage. SARS-CoV-2 infection suppresses innate immunity and promotes an inflammatory response. Targeting these aspects of SARS-CoV-2 is important as the pandemic affects greater proportions of the population. In clinical and animal studies, fucoidans have been shown to increase innate immunity and decrease inflammation. In addition, dietary fucoidan has been shown to attenuate pulmonary damage in a model of acute viral infection. Direct inhibition of SARS-CoV-2 in vitro has been described, but is not universal. This short review summarizes the current research on fucoidan with regard to viral lung infections and lung damage. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
27 pages, 12995 KiB  
Review
Bioactivity Potential of Marine Natural Products from Scleractinia-Associated Microbes and In Silico Anti-SARS-COV-2 Evaluation
by Eman Maher Zahran, Amgad Albohy, Amira Khalil, Alyaa Hatem Ibrahim, Heba Ali Ahmed, Ebaa M. El-Hossary, Gerhard Bringmann and Usama Ramadan Abdelmohsen
Mar. Drugs 2020, 18(12), 645; https://doi.org/10.3390/md18120645 - 16 Dec 2020
Cited by 33 | Viewed by 5827
Abstract
Marine organisms and their associated microbes are rich in diverse chemical leads. With the development of marine biotechnology, a considerable number of research activities are focused on marine bacteria and fungi-derived bioactive compounds. Marine bacteria and fungi are ranked on the top of [...] Read more.
Marine organisms and their associated microbes are rich in diverse chemical leads. With the development of marine biotechnology, a considerable number of research activities are focused on marine bacteria and fungi-derived bioactive compounds. Marine bacteria and fungi are ranked on the top of the hierarchy of all organisms, as they are responsible for producing a wide range of bioactive secondary metabolites with possible pharmaceutical applications. Thus, they have the potential to provide future drugs against challenging diseases, such as cancer, a range of viral diseases, malaria, and inflammation. This review aims at describing the literature on secondary metabolites that have been obtained from Scleractinian-associated organisms including bacteria, fungi, and zooxanthellae, with full coverage of the period from 1982 to 2020, as well as illustrating their biological activities and structure activity relationship (SAR). Moreover, all these compounds were filtered based on ADME analysis to determine their physicochemical properties, and 15 compounds were selected. The selected compounds were virtually investigated for potential inhibition for SARS-CoV-2 targets using molecular docking studies. Promising potential results against SARS-CoV-2 RNA dependent RNA polymerase (RdRp) and methyltransferase (nsp16) are presented. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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25 pages, 8068 KiB  
Review
Man-Specific, GalNAc/T/Tn-Specific and Neu5Ac-Specific Seaweed Lectins as Glycan Probes for the SARS-CoV-2 (COVID-19) Coronavirus
by Annick Barre, Els J.M. Van Damme, Mathias Simplicien, Hervé Benoist and Pierre Rougé
Mar. Drugs 2020, 18(11), 543; https://doi.org/10.3390/md18110543 - 29 Oct 2020
Cited by 18 | Viewed by 5229
Abstract
Seaweed lectins, especially high-mannose-specific lectins from red algae, have been identified as potential antiviral agents that are capable of blocking the replication of various enveloped viruses like influenza virus, herpes virus, and HIV-1 in vitro. Their antiviral activity depends on the recognition of [...] Read more.
Seaweed lectins, especially high-mannose-specific lectins from red algae, have been identified as potential antiviral agents that are capable of blocking the replication of various enveloped viruses like influenza virus, herpes virus, and HIV-1 in vitro. Their antiviral activity depends on the recognition of glycoprotein receptors on the surface of sensitive host cells—in particular, hemagglutinin for influenza virus or gp120 for HIV-1, which in turn triggers fusion events, allowing the entry of the viral genome into the cells and its subsequent replication. The diversity of glycans present on the S-glycoproteins forming the spikes covering the SARS-CoV-2 envelope, essentially complex type N-glycans and high-mannose type N-glycans, suggests that high-mannose-specific seaweed lectins are particularly well adapted as glycan probes for coronaviruses. This review presents a detailed study of the carbohydrate-binding specificity of high-mannose-specific seaweed lectins, demonstrating their potential to be used as specific glycan probes for coronaviruses, as well as the biomedical interest for both the detection and immobilization of SARS-CoV-2 to avoid shedding of the virus into the environment. The use of these seaweed lectins as replication blockers for SARS-CoV-2 is also discussed. Full article
(This article belongs to the Special Issue Marine Natural Products against Coronaviruses)
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