This study reports on the one-step, green, catalyst-free synthesis of new naphthoquinone-polyphenols through an innovative method using the multicomponent domino Mannich-Michael reaction in the lawsone. After optimized condition reactions, twelve novel naphthoquinone polyphenols were synthesized with good yields. The polyphenols were tested on four cancer cell lines (HCT116, PC3, HL60, and SNB19), in which the best results showed antiproliferative activity with IC50 of 25.83-47.95 μM. Additionally, we used the CRAC assay to quantify the antioxidant capacity of each compound and determined a hierarchy based on the Trolox equivalent values.

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The Cover Feature represents the Antioxidant – “Antiox” – like an eccentric figure, because of its quality of donating what is yours, and personifies the naphthoquinone polyphenols in the paper. The “Thief” is the free radical and the “Female figure” describes atoms with all the electrons and healthy cells. In the action, the antioxidant offers an electron to the frightened thief, preventing him from stealing the woman′s bag full of electrons, who holds it tightly. The crowd of passersby, all with electrons overhead, represents other atoms. In the background, fragments of the reaction developed are shown. Cover design by Lucas Cavalcanti – Laboratório de Design Institucional – Sead/Ufes. More information can be found in the Research Article by S. J. Greco et al.