Chemical Insights into the Antiviral Mechanisms of Marine Sulfated Polysaccharides: An In-Silico Screening and Molecular Docking Study
et al., Biointerface Research in Applied Chemistry, doi:10.33263/BRIAC155.071, Oct 2025
In silico study showing potential antiviral benefits with marine sulfated polysaccharides, specifically carrageenan, against SARS-CoV-2. Authors used molecular docking to screen compounds against the human ACE2 receptor, Spike protein RBD, and Mpro. Kappa-carrageenan showed the strongest binding affinity (-9.3 kcal/mol) with ACE2, suggesting inhibition of viral entry. Authors also noted strong Mpro binding, potentially hindering replication. All compounds complied with Lipinski’s Rule of Five, indicating favorable drug-likeness and oral bioavailability comparable to or exceeding the control drugs remdesivir and nafamostat.
18 preclinical studies support the efficacy of iota-carrageenan for COVID-19:
1.
Krylova et al., Carrageenans and the Carrageenan-Echinochrome Complex as Anti-SARS-CoV-2 Agents, International Journal of Molecular Sciences, doi:10.3390/ijms26136175.
2.
Rohilla et al., Algae Polysaccharides (Carrageenan and Alginate)—A Treasure-Trove of Antiviral Compounds: An In Silico Approach to Identify Potential Candidates for Inhibition of S1-RBD Spike Protein of SARS-CoV-2, Stresses, doi:10.3390/stresses3030039.
3.
Thet, H., The potential of carrageenan for the drug discovery of COVID-19 via molecular docking with angiotensin-converting enzyme 2 (ACE2) and the main protease (Mpro) of SARS-CoV-2, Journal of Bioinformatics and Genomics, doi:10.18454/jbg.2022.18.2.001.
4.
Alsaidi et al., Griffithsin and Carrageenan Combination Results in Antiviral Synergy against SARS-CoV-1 and 2 in a Pseudoviral Model, Marine Drugs, doi:10.3390/md19080418.
5.
Sattari et al., Repositioning Therapeutics for COVID-19: Virtual Screening of the Potent Synthetic and Natural Compounds as SARS-CoV-2 3CLpro Inhibitors, Research Square, doi:10.21203/rs.3.rs-37994/v1.
6.
Hoffmann et al., Controlling the Sulfation Density of Glycosaminoglycan Glycopolymer Mimetics Enables High Antiviral Activity against SARS-CoV-2 and Reduces Anticoagulant Activity, Biomacromolecules, doi:10.1021/acs.biomac.5c00576.
7.
Yathindranath et al., Lipid Nanoparticle-Based Inhibitors for SARS-CoV-2 Host Cell Infection, International Journal of Nanomedicine, doi:10.2147/IJN.S448005.
8.
Setz et al., Iota-Carrageenan Inhibits Replication of the SARS-CoV-2 Variants of Concern Omicron BA.1, BA.2 and BA.5, Nutraceuticals, doi:10.3390/nutraceuticals3030025.
9.
Meister et al., Virucidal activity of nasal sprays against severe acute respiratory syndrome coronavirus-2, Journal of Hospital Infection, doi:10.1016/j.jhin.2021.10.019.
10.
Bovard et al., Iota-carrageenan extracted from red algae is a potent inhibitor of SARS-CoV-2 infection in reconstituted human airway epithelia, Biochemistry and Biophysics Reports, doi:10.1016/j.bbrep.2021.101187.
11.
Fröba et al., Iota-Carrageenan Inhibits Replication of SARS-CoV-2 and the Respective Variants of Concern Alpha, Beta, Gamma and Delta, International Journal of Molecular Sciences, doi:10.3390/ijms222413202.
12.
Varese et al., Iota-carrageenan prevents the replication of SARS-CoV-2 on an in vitro respiratory epithelium model, bioRxiv, doi:10.1101/2021.04.27.441512.
13.
Morokutti-Kurz et al., Iota-carrageenan neutralizes SARS-CoV-2 and inhibits viral replication in vitro, PLoS ONE, doi:10.1371/journal.pone.0237480.
14.
Song et al., Inhibitory activities of marine sulfated polysaccharides against SARS-CoV-2, Food & Function, doi:10.1039/D0FO02017F.
Herida et al., 8 Oct 2025, peer-reviewed.
In silico studies are an important part of preclinical research, however results may be very different in vivo.
DOI record:
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"DOI": "10.33263/briac155.071",
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"URL": "http://dx.doi.org/10.33263/BRIAC155.071",
"abstract": "<jats:p>In recent years, several viral diseases have emerged suddenly, leading to widespread infection and fatalities. SARS-CoV-2, which appeared in late 2019, mutates frequently, and current vaccines have limited effectiveness in fully preventing SARS-CoV-2 infections. As a result, natural antiviral medicines have gained attention, particularly sulfated polysaccharides from seaweeds, which are promising sources of bioactive compounds for antiviral activity and immune support. This study screened the types of sulfated polysaccharides, such as carrageenan, fucoidan, and ulvan, using computational analysis to evaluate their antiviral potential against SARS-CoV-2. Molecular docking was conducted to examine potential interactions with human ACE2, SARS-CoV-2's RBD, and main protease. The results of molecular docking analysis showed that kappa carrageenan exhibited better docking scores of -9.3 kcal/mol with ACE2 and -8.1 kcal/mol with spike protein-RBD. Meanwhile, carrageenan showed a better docking score of -7.6 kcal/mol with the main protease. The prediction of drug compounds based on RO5 indicates that all bioactive test compounds have the potential to be used as therapeutic agents. It is concluded that the sulfated polysaccharides derived from red seaweed, namely carrageenan and its derivatives, exhibit greater potential in demonstrating antiviral activity against SARS-CoV-2 compared to fucoidan and ulvan.</jats:p>",
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"title": "Chemical Insights into the Antiviral Mechanisms of Marine Sulfated Polysaccharides: An In-Silico Screening and Molecular Docking Study",
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