Design, synthesis and biological evaluation of marine naphthoquinone-naphthol derivatives as potential anticancer agents

1’-Hydroxy-4’,8,8’-trimethoxy-[2,2’-binaphthalene]-1,4-dione (compound <b>5</b>), a secondary metabolite recently discovered in marine fungi, demonstrates promising cytotoxic and anticancer potential. However, knowledge regarding the anticancer activities and biological mechanisms of its derivatives remains limited. Herein, a series of novel naphthoquinone-naphthol derivatives were designed, synthesised, and evaluated for their anticancer activity against cancer cells of different origins. Among these, Compound <b>13</b>, featuring an oxopropyl group at the <i>ortho</i>-position of quinone group, exhibited the most potent inhibitory effects on HCT116, PC9, and A549 cells, with IC₅₀ values decreasing from 5.27 to 1.18 μM (4.5-fold increase), 6.98 to 0.57 μM (12-fold increase), and 5.88 to 2.25 μM (2.6-fold increase), respectively, compared to compound <b>5</b>. Further mechanistic studies revealed that compound <b>13</b> significantly induced cell apoptosis by increasing the expression levels of cleaved caspase-3 and reducing Bcl-2 proteins through downregulating the EGFR/PI3K/Akt signalling pathway, leading to the inhibition of proliferation in HCT116 and PC9 cells. The present findings suggest this novel naphthoquinone-naphthol derivative may hold potential as an anticancer therapeutic lead.