Introduction: Rheumatoid Arthritis [RA] is an autoimmune disease that can cause chronic inflammation
of the joints. Human DiHydroOrotate DeHydrogenase [DHODH] is a clinically validated drug
target for the treatment of Rheumatoid Arthritis. DHODH inhibition results in beneficial immunosuppressant
and anti-proliferative effects.
Materials and Methods: Leflunomide [LEF] and Brequinar Sodium [BREQ], drugs used in the treatment
of RA, suppresses the immune cells responsible for inflammation but has several side-effects, most predominant
being symptomatic liver damage and toxicity. An existing scaffold based on structural analogies
with LEF and BREQ was used to screen out potent inhibitors of DHODH, in ZINC Database using 2D binary
fingerprint. 10 structures similar to the scaffold were shortlisted due to their Tanimoto similarity coefficient.
Selected structures were docked using the tools AutoDock, Ligand fit and iGEMDOCK with target
human DHODH. High scoring compounds having similar interactions as that of scaffold were checked to
evaluate their Drug-Likeliness.
Results: The five shortlisted compounds were then subjected to Molecular Dynamics Simulation studies for
50ns using GROMACS. Measures of structural similarity based on 2D Fingerprint Screening and Molecular
Dynamics Simulation studies can suggest good leads for drug designing. The novelty of this study is
that the workflow used here yields the same results that are at par with the experimental data.
Conclusion: This suggests the use of the 2D fingerprint similarity search in various databases, followed by
multiple docking algorithms and dynamics as a workflow that will lead to finding novel compounds that a
structurally and functionally similar to LEF and BREQ.