Abstract
A number of synthetic hydroxy-xanthones related to isolates from the plant genus Swertia (family Gentianaceae) were prepared and their antiviral activity assessed against human coronavirus OC43. Overall, the results of the initial screening of the test compounds in BHK-21 cell lines show promising biological activity, with a significant reduction in viral infectivity (p ≤ 0.05). In general, the addition of functionality around the xanthone core increases the biological activity of the compounds compared to xanthone itself. More detailed studies are needed to determine mechanism of action, but favourable property predictions make them interesting lead compounds for further development as potential treatments for coronavirus infections.