Nanaomycin A is the first selective DNMT3B inhibitor with an IC50 of 500 nM. Nanaomycin A, a quinone antibiotics, reactivates silenced tumor suppressor genes in human cancer cells. Nanaomycin A inhibits in vitro growth of the human malaria parasite Plasmodium falciparum with an IC80 value of 33.1 nM.