Design and synthesis of imidazole and triazole pyrazoles as Mycobacterium tuberculosis CYP121A1 inhibitors

Safaa Kishk, Kirsty Mclean, Sakshi Sood, Darren Smith, Jack Evans, Mohamed Helal, Mohamed Gomaa, Ismail Salama, Samia Mostafa, Luiz Pedro de Carvalho, Colin Levy, Andrew Munro, Claire Simons

Research output: Contribution to journalArticlepeer-review


The emergence of untreatable drug-resistant strains of Mycobacterium tuberculosis is a major public health problem worldwide, and the identification of new efficient treatments is urgently needed. Mycobacterium tuberculosis cytochrome P450 CYP121A1 is a promising drug target for the treatment of tuberculosis owing to its essential role in mycobacterial growth. Using a rational approach, which includes molecular modelling studies, three series of azole pyrazole derivatives were designed through two synthetic pathways. The synthesized compounds were biologically evaluated for their inhibitory activity towards M. tuberculosis and their protein binding affinity (KD). Series 3 biarylpyrazole imidazole derivatives were the most effective with the isobutyl (10 f) and tert-butyl (10 g) compounds displaying optimal activity (MIC 1.562 μg/mL, KD 0.22 μM (10 f) and 4.81 μM (10 g)). The spectroscopic data showed that all the synthesised compounds produced a type II red shift of the heme Soret band indicating either direct binding to heme iron or (where less extensive Soret shifts are observed) putative indirect binding via an interstitial water molecule. Evaluation of biological and physicochemical properties identified the following as requirements for activity: LogP >4, H-bond acceptors/H-bond donors 4/0, number of rotatable bonds 5-6, molecular volume >340 Å3, topological polar surface area <40 Å2.
Original languageEnglish
Article numberdoi: 10.1002/open.201900227
Pages (from-to)995-1011
Number of pages17
Issue number7
Early online date23 Jul 2019
Publication statusPublished - 2019


  • cytochrome P450
  • CYP121A1
  • Mycobacterium tuberculosis
  • enzyme inhibitors
  • heme protein
  • enzyme assays

Research Beacons, Institutes and Platforms

  • Biotechnology
  • Manchester Energy
  • Manchester Institute of Biotechnology


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