DFT-Based Quantum Mechanical and Molecular Docking Investigation of Synthesized Flavokawain B and Its Derivatives

Flavokawain B (FKB) is a naturally occurring chalcone that exhibits potential anti-cancer properties. Density functional theory (DFT) is a computational simulation approach used to investigate the electronic properties of molecules. Here, we investigated the structural-activity relationship and optoelectronic properties of naturally occurring chalcones; FKB and their derivatives named (E)-3’-(2’-fluorophenyl)-1’-(2’-hydroxy-4and#39;,6and#39;-dimethoxyphenyl)prop-2-en-1-one (KG1), (E)-3and#39;-(2and#39;-chlorophenyl)-1and#39;-(2-hydroxy-4and#39;,6and#39;-dimethoxyphenyl)prop-2-en-1-one (KG2), (E)-3and#39;-(4and#39;-bromophenyl)-1and#39;-(2and#39;-hydroxy-4and#39;,6and#39;-dimethoxyphenyl)prop-2-en-1-one (KG3), (E)-3and#39;-(4and#39;-fluorophenyl)-1and#39;-(2and#39;-hydroxy-4and#39;,6and#39;-dimethoxyphenyl)prop-2-en-1-one (KG4), and (E)-1and#39;-(2and#39;-hydroxy-4and#39;,6and#39;-dimethoxyphenyl)-3and#39;-(3-nitrophenyl)prop-2-en-1-one (KG5) were used for computational approaches. The substituents in the acceptor moiety of derivatives were ortho F (KG1), ortho Cl (KG2), para Br (KG3), meta F (KG4), and meta nitro (KG5), respectively. The findings evaluated that the KG5 molecule showed excellent redshift (406 nm), the lowest excitation of 3.05 eV, lower HOMO of -6.25eV, LUMO of -2.82eV and a lower bandgap of 3.43eV. KG5 has a lower binding energy of 0.38eV, and electron mobility of 0.0206eV leading toward greater charge transference. The finding results showed that the presence of strong electron-withdrawing (KG5) on ring B in the FKB derivatives could make it an active site to attach the different types of proteins, which leads to becoming a potential bioactive compound. FKB and its derivatives were synthesized by our research group. These findings suggested that the KG5 molecule could be the best among all the derivatives and can be used for different biological assays.