ABSTRACT
Combination of FDA approved drugs may be more effective in biological activities by targeting different protein mechanism at a same time and less toxic. A combination of 5-Fluorouracil and tamoxifen may cause a synergistic effect and induce cancer cell death and more effective against corona virus. In this study, constructed 5-Fluorouracil with tamoxifen structure was optimized through DFT/B3LYP approach with the basis set 6-311 G. Theoretical, ultraviolet-visible spectrum was calculated, and electronic transitions were examined. The energy gap between HOMO and LUMO was used to study the combined structure's structural stability and reactivity and the computed energy gap (Delta E) was 4.3023825 eV. The Mulliken charge distribution was assessed and the atomic charges were calculated. The molecular docking simulation was performed with breast cancer and SARS-CoV-19 target proteins. The docking scores showed that the complex compound's binding affinity was higher, that confirms better synergistic effect of 5-Fluorouracil and tamoxifen. The complex compound's maximum binding affinity was -8.0 Kcal/mol against caspase 6 and -8.1 Kcal/mol against furin, that showed inhibitory potential against cancer and corona virus. The pharmacokinetic properties and toxicity of the complex structure was studied, and the results showed the safety profile of the complex lead compound and can be utilized as an effective anticancer and antiviral drug.