The WHO has stated that antibiotic resistance is escalating to perilously high levels globally and that traditional therapies of antimicrobial drugs are futile against infections caused by resistant microorganisms. Novel antimicrobial drugs are therefore required. We report in this study on the inhibitory activity of the 1,4‐naphthoquinone‐2,3‐bis‐sulfides and 1,4‐naphthoquinone sulfides against two bacteria and a fungus to determine their antimicrobial properties. The 1,4‐naphthoquinone sulfides have potent activity with a minimum inhibitory concentration (MIC) of 7.8 μg/mL against Staphylococcus aureus (Gram +ve), an MIC of 23.4 μg/mL against the fungus, Candida albicans, which was better than that of Amphotericin B (MIC = 31.3 μg/mL), and against Escherichia coli (Gram −ve) an MIC of 31.3 μg/mL was obtained. The 1,4‐naphthoquinone had an MIC of 11.7 μg/mL against S. aureus and the 1,4‐naphthohydroquinone also had the same activity against E. coli. Hit, Lead & Candidate Discovery

In this study, we report on the inhibitory activity of synthesized aminonaphthoquinones against two bacterial and one fungal species to determine their antimicrobial properties. A minimum inhibitory concentration (MIC) of 7.8 μg/mL was obtained against the fungus, Candida albicans, which was better than that of Amphotericin B (MIC = 31.25 μg/mL). Escherichia coli (Gram ‐), was inhibited at a MIC of 23.4 μg/mL and Staphylococcus aureus (Gram +) at a MIC of 31.3 μg/mL. The aminonaphthoquinones were also screened against HCT116 colon, PC3 prostate and HepG2 liver cancer cell lines to evaluate their cytostatic effects. They had potent activity (GI50 = 5.87–9.90 μM) which was about three‐6‐fold better than that of parthenolide (GI50 = 25.97 μM) against the prostate cancer cell line. These compounds were generally more selective for cancer cells than for normal human lung fetal fibroblasts (WI‐38).