Objective: The molecular interactions between ursolic acid and cucurbitacin E with the eight
potential Mtb target proteins were investigated with the objective of finding drug-like inhibitors.
Background: Mycobacterium tuberculosis (Mtb), an obligate human pathogen causes tuberculosis
and is one of the major causes of death worldwide. A few combinations of drugs are currently
accessible for treating TB patients, but these are inadequate to tackle worldwide TB cases.
Methods: Avogadro v.1.2.0 and Openbabel v.2.4.1 were used for creating file formats required for
docking analysis. Molecular docking was performed with eight different proteins essential for Mtb
metabolism and survival. AutoDock v.4.2 and AutoDock vina v.1.1.2 were used for docking and
Gromacs 5.1.4 was used for simulation studies.
Results: Among the two ligands used in this research, cucurbitacin E showed a better docking
score relative to the drugs presently available for all the target proteins. Rifampicin showed the
best binding affinity (among known inhibitors) i.e. -10.8 kcal/mol with C terminal caspase
recruitment domain. Moreover, ursolic acid and cucurbitacin E showed uniform binding score
(above -7.5 kcal/mol) with all the target proteins, acknowledged its availability as a potential multitarget drug.
Conclusion: Ursolic acid can be useful in the creation of novel, multi-targeted and effective antiTB medicines since it showed stable structure with FabH.