Chikungunya virus (CHIKV) is a re-emerging disease caused by an alphavirus of the Togaviridae family. Since its first description in 1952, the disease has spread worldwide, affecting populations in both tropical and temperate countries. To date, there is no licensed vaccine or specific pharmacological treatment. Therefore, there is an increasing urgency in developing new antiviral drugs capable of specifically inhibiting viral replication. In the present work, we report the synthesis and antiviral activity evaluation of nineteen naphthoquinone derivatives, containing a sulfonamide or sulfonate group. Cell viability assays indicated a low toxic potential for all tested compounds and inhibitory assays against CHIKV identified five compounds with potent activity. The compounds were also evaluated for their virucidal potential, and the results demonstrated that compound 11a exhibited a virucidal effect higher than 70% in the treatment with 20 µM. Furthermore, in silico studies were performed to predict the antiviral drug targets.

The cariogenic processes are mainly caused by the bacterium Streptococcus mutans (S. mutans) and consist of the demineralization of the tooth that occurs when the acid production overcomes the natural repair or if a problem occurs in the last one. In this work, we performed the synthesis of twenty-one 1,4-naphthoquinones tethered to 1,2,3-1H-triazoles (8a-8k and 9a-9j), antibacterial evaluation against the S. mutans in vitro and the acute toxicity of the better ones in vivo. We observed strong inhibition results in the disc diffusion test ranging, the halos of inhibitions, from 18.66 (± 0.57) to 29 (± 2.64) mm, and good values in the minimum inhibitory concentration (5 to 50 μg), for the compounds 9e, 9h, 9i and 9j. Furthermore, they do not have a cytotoxic effect at the concentrations tested. Besides that, in the in vivo test, they show some slight alteration in the histopathological analyses and the biochemistry. Thus, we found four potential candidates to become instruments for the treatment of cavities.