Towards deeper understanding of structure, properties and applications of selected phytochemicals via theoretical routes

Abstract

The present thesis consists of eight chapters. The first chapter describes brief introduction to polyphenols, their classification, and applications in both medicinal and industrial fields. In addition, it offers important computational studies on polyphenols' anti-oxidant, molecular docking, and molecular dynamic simulation properties as well as earlier research on the compounds under consideration. The second chapter goes into further detail on the computational techniques. The third chapter provides in-depth details on the composition, reactivity, and structure of cholesterol and its derivatives. Comparative analysis revealed that coumestrol derivatives have superior anti-oxidant and anti-cancer activities to coumestrol molecule. The structure, stability, and electrical properties of the Zn2+ chelates of the herbacetin molecule are all covered in length in the fourth chapter along with the impact of solvents on metal chelation. In both polar and non-polar solvents, the Zn2+ ion significantly affects the anti-oxidant activity of herbacetin. In the concluding section of this chapter, the anti-AD potential of the herbacetin molecule is investigated using in silico molecular docking studies against AChE2 and BChE targets. The gossypetin molecule's structural and electrical investigation is the main topic of Chapter 5. The UV-filtering capacity and antioxidant potential of gossypetin against reactive oxygen species like •OH, •OOH, and reactive nitrogen species like •NO 2 is also described in this chapter. Chapter 6 focuses on the identification of bioactive components found in the herbs C. hirsutus and R. rosea and their antiviral activity towards COVID 19 major protease 6LU7 with the use of molecular docking and molecular dynamic modeling studies. By using density functional theory (DFT) at the B3LYP/6-31++G(d,p) level of theory, we eventually determine the ideal structures of the molecules from each plant that have the highest binding affinity to the designated target. In chapter 7, the DFT parameters and an important computational tool, Monte Carlo (MC) simulation, are used to compare the anti-corrosive properties of the molecules herbacetin and gossypetin with the well-researched green corrosion inhibitor quercetin. The main findings of the investigations are summarized in Chapter 8, along with some suggestions for future research.