Identification and validation of potent inhibitor of Escherichia coli DHFR from MMV pathogen box.

The present study is conducted to find the solution of rising antimicrobial resistance (AMR) in Escherichia coli which is a pathogen responsible for fatal systemic infections in human and animals. The enzyme dihydrofolate reductase (DHFR) is found in all organisms. In this study DHFR of E. coli (ec-DHFR) and human DHFR (h-DHFR) is targeted by novel chemical entities (NCE) from the Pathogen box of Medicines for Malaria Venture, Switzerland (MMV) using molecular modelling. The in-silico studies were further validated by in-vitro assays. The virtual screening of 400 MMV compounds was conducted using PyRx standard tool followed by manual docking of selected compounds by Autodock vina and Ligplot program. The in-silico studies showed good binding energy and strong hydrogen bond in docking of MMV675968 with ec-DHFR and no hydrogen bond with h-DHFR. This was further validated by the Molecular dynamic studies that revealed high binding free energy in ec-DHFR and in-vitro assays that produced good synergy in combination study of MMV675968 with last line (meropenem) and last resort (colistin) antibiotics. The extensive MD simulation and energetic analysis thus concludes that MMV675968 targets ec-DHFR. The combination studies were conducted with MMV675968 and FDA approved drugs against a panel of multidrug resistant Escherichia coli isolates. The synergistic results obtained in combination studies concluded that in-vitro data is consistent with in-silico data and that MMV675968 is a potential lead for future process of antimicrobial drug development against the multidrug resistance E. coli.Communicated by Ramaswamy H. Sarma.

Identification and validation of potent Mycobacterial proteasome inhibitor from Enamine library.

As a consequence of present status of tuberculosis (TB) it is the obligation to develop novel targets and potential drugs so that rate of drug resistant TB can be declined. Mycobacterium proteasome is considered to be significant target for the purpose of drug designing as it is responsible for resisting the effect of NO (nitric oxide) immune system defence mechanism against the bacterial cells. Small compounds library from Enamine database has already been tested using virtual screening and molecular docking studies. Further a reanalysis with two picked out significant compounds Z1020863610, Z106766984 was carried out using molecular dynamic simulation studies and in vitro validations (in vitro susceptibility assay, enzyme inhibition assay and MTT assay). In silico outcome that two inhibiters were interacting at the active site pocket of receptor with high stability, was found to be very consistent with in vitro results. So it was conferred that compounds (Z1020863610, Z106766984) are potential lead for future process of drug development (in vivo testing and clinical trials).Communicated by Ramaswamy H. Sarma.