## 4 Conclusions  
The key role of FAS-I in the survival and growth of mycobacterium makes it an attractive drug target. Only the pyrazinamide analogs have been reported as competitive inhibitors of FAS-I for NADPH binding. Therefore, in pursuit of finding potential inhibitors against FAS-I, we carried out structure-based virtual screening, focusing on the NADPH binding site of the enoyl reductase domain. Subsequently, molecular dynamics simulations were done to assess the stability of predicted binding poses and to perform MM/PBSA-based binding free energy. Based upon the predicted binding free energy values and stability of the compounds in the binding pocket, the compounds BTB14738, RH00608, SPB02705, and CD01000 have been proposed as putative hits. The calculated binding free energy indicates significant binding of the selected compounds. The proposed compounds can serve as pioneer inhibitors against Mtb FAS-I, which could pave the way for the development of a novel treatment for TB.  
The following are available online at [[https://www.mdpi.com/article/10.3390/app11156977/s1](https://www.mdpi.com/article/10.3390/app11156977/s1)]([https://www.mdpi.com/article/10.3390/app11156977/s1](https://www.mdpi.com/article/10.3390/app11156977/s1)), Figure S1: 2D interaction plots for selected protein-ligand complexes. Figure S2: The r.m.s.d plots shown for FMN molecule and protein backbone atoms.  
Conceptualization, W.L.; formal analysis, N.S.; investigation, N.S.; resources, W.L.; data curation, N.S.; writing--original draft preparation, N.S.; writing--review and editing, S.-Q.M. and W.L.; visualization, S.-Q.M.; supervision, W.L.; funding acquisition, W.L. All authors have read and agreed to the published version of the manuscript.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Compound Code** & \begin{tabular}{c} **Van der Waals** \\ **Energy** \\ \end{tabular} & \begin{tabular}{c} **Electrostatic** \\ **Energy** \\ \end{tabular} & \begin{tabular}{c} **Polar Solvation** \\ **Energy** \\ \end{tabular} & \
\begin{tabular}{c} **SASA Energy** \\ \end{tabular} &
\begin{tabular}{c} **Binding Free** \\ **Energy** \\ \end{tabular} \\ \hline BTB14738 & \(-165.92\pm 11.998\) & \(-33.77\pm 6.45\) & \(146.82\pm 13.80\) & \(-19.39\pm 0.97\) & \(-72.27\pm 12.63\) \\ \hline RH00608 & \(-219.005\pm 10.53\) & \(-14.61\pm 6.551\) & \(190.10\pm 10.54\) & \(-24.55\pm 1.22\) & \(-68.06\pm 11.80\) \\ \hline SPB02705 & \(-183.88\pm 16.99\) & \(-2.59\pm 10.16\) & \(145.40\pm 21.44\) & \(-22.50\pm 1.59\) & \(-63.57\pm 12.22\) \\ \hline CD01000 & \(-201.98\pm 15.30\) & \(-35.31\pm 9.28\) & \(209.04\pm 20.93\) & \(-23.04\pm 1.60\) & \(-51.28\pm 13.74\) \\ \hline \hline \end{tabular}
\end{table}
Table 3: The MM/PBSA results for the selected putative hits. All energies are in unit of KJ/mol.  
**Funding:** This research was funded by Natural Science Foundation of Guangdong Province, China (Grant No. 2020A1515010984) and the Start-up Grant for Young Scientists (860-000002110384), Shenzhen University. The APC was funded by the Start-up Grant for Young Scientists (860-000002110384).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The data presented in this study are available in the article and supplementary material.  
**Conflicts of Interest:** The authors declare no conflict of interest.