Structure-aided optimization of non-nucleoside M. tuberculosis thymidylate kinase inhibitors
Mycobacterium tuberculosis thymidylate kinase (MtTMPK) has emerged as an attractive target for rational drug design. We recently investigated new families of non-nucleoside MtTMPK inhibitors in an effort to diversify MtTMPK inhibitor chemical space. We here report a new series of MtTMPK inhibitors by combining the Topliss scheme with rational drug design approaches, fueled by two co-crystal structures of MtTMPK in complex with developed inhibitors. These efforts furnished the most potent MtTMPK inhibitors in our assay, with two analogues displaying low micromolar MIC values against H37Rv Mtb. Prepared inhibitors address new sub-sites in the MtTMPK nucleotide binding pocket, thereby offering new insights into its druggability. We studied the role of efflux pumps as well as the impact of cell wall permeabilizers for selected compounds to potentially provide an explanation for the lack of correlation between potent enzyme inhibition and whole-cell activity.
Song, Lijun,Merceron, Romain,Hulpia, Fabian,Lucía, Ainhoa,Gracia, Bego?a,Jian, Yanlin,Risseeuw, Martijn D.P.,Verstraelen, Toon,Cos, Paul,Aínsa, José A.,Boshoff, Helena I.,Munier-Lehmann, Hélène,Savvides, Savvas N.,Van Calenbergh, Serge
(2021/08/27)
Cinnamonitrile adjuvants restore susceptibility to β-lactams against methicillin-resistant staphylococcus aureus
β-Lactams are used routinely to treat Staphylococcus aureus infections. However, the emergence of methicillin-resistant S. aureus (MRSA) renders them clinically precarious. We describe a class of cinnamonitrile adjuvants that restore the activity of oxacillin (a penicillin member of the β-lactams) against MRSA. The lead adjuvants were tested against six important strains of MRSA, one vancomycin-intermediate S. aureus (VISA) strain, and one linezolid-resistant S. aureus strain. Five compounds out of 84 total compounds showed broad potentiation. At 8 μM (E)-3-(5-(3,4-dichlorobenzyl)-2-(trifluoromethoxy)phenyl)-2-(methylsulfonyl)acrylonitrile (26) potentiated oxacillin with a >4000-fold reduction of its MIC (from 256 to 0.06 mg·L-1). This class of adjuvants holds promise for reversal of the resistance phenotype of MRSA.