**3. Methodology**

## *3.1.* Databases Used

The search for MSPs in this study was conducted using SciFinder (https://www.cas. org/solutions/cas-scifinder-discovery-platform/cas-scifinder, accessed on 15 May 2021), Scopus (https://www.scopus.com), Web of Science (https://login.webofknowledge.com), Google Scholar, and DNP (Dictionary of Natural Products) databases. The keywords "antiviral", "SARS CoV-2", marine-derived", and "COVID-19" were paired with "sulphated polysaccharide" to obtain published records up until 2021.
