Optimization of TopoIV Potency, ADMET Properties, and hERG Inhibition of 5-Amino-1,3-dioxane-Linked Novel Bacterial Topoisomerase Inhibitors: Identification of a Lead with In Vivo Efficacy against MRSA
Lu, Y; Vibhute, S; Li, L; Okumu, A; Ratigan, SC; Nolan, S; Papa, JL; Mann, CA; English, A; Chen, A; Seffernick, JT; Koci, B; Duncan, LR; Roth, B; Cummings, JE; Slayden, RA; Lindert, S; Mcelroy, CA; Wozniak, DJ; Yalowich, J; Mitton-Fry, MJ
Novel bacterial topoisomerase inhibitors (NBTIs) are among the most promising new antibiotics in preclinical/clinical development. We previously reported dioxane-linked NBTIs with potent antistaphylococcal activity and reduced hERG inhibition, a key safety liability. Herein, polarity-focused optimization enabled the delineation of clear structure-property relationships for both microsomal metabolic stability and hERG inhibition, resulting in the identification of lead compound 79. This molecule demonstrates potent antibacterial activity against diverse Gram-positive pathogens, inhibition of both DNA gyrase and topoisomerase IV, a low frequency of resistance, a favorable in vitro cardiovascular safety profile, and in vivo efficacy in a murine model of methicillin-resistant Staphylococcus aureus infection.