5-Nitroso-8-quinolinol is a chemically unique HDAC inhibitor that harbors a different Zn2+ chelation motif compared to SAHA. As an antitumor agent, 10 μM 5-nitroso-8-quinolinol can induce oxidative stress contributing to apoptosis and differentiation in MCF-7 breast cancer cells. Additionally, 5-nitroso-8-quinolinol inhibits T. gondii tachyzoite propagation in human fibroblasts with an EC50 value of 80 nM and inhibits P. falciparum growth in human red blood cells with an EC50 value of 1.3 μM.