DFT, Wave Function and SAR Analyses of Fexinidazole: A Drug for Sleeping Sickness

Fexinidazole is a newly authorized drug employed for the treatment of sleeping sickness in South Africa. The characteristics of drug molecule in the gaseous form were calculated using Gaussian 16W software, employing the DFT/B3LYP/6-311++G(d,p) level of theory. The absence of imaginary frequency indicates the full convergence and optimization. Mulliken charge analysis was carried out. The ESP elucidates the suitability of the nitro group for electrophilic assault and FMO demonstrates that it is an electron donor. The NLO investigation reveals that it is a good NLO candidate and the NBO studies reveals that it is highly stable. The NCI interaction demonstrates that it exhibits van der Waals and steric repulsion forces. IFCT, STM and aromaticity determinations were performed. The S0 → S3 and S4 are having charge transfer (CT) type of excitation as per the HEI investigation. The SAR activity was examined using 5UFG protein, leading to the identification of two promising molecules.