The interactions between MBE bioactive constituents and 19 pesticides with HSA and PPARg were investigated using molecular docking. In the case of MBE, the binding energies and binding modes of MBE bioactive constituents were compared. Relatively suitable binding energies were observed and 4-methoxy honokiol showed most negative binding energy (-36.43 kJ mol -1 ). In addition, magnolol and honokiol as two primary active constituents of MBE were subjected to a 14 ns Molecular Dynamics (MD) simulation to further validate the docking results. The interaction between 19 pesticides and HSA were also studied using molecular docking. For more investigation in interactions, dichlorvos, chlorfenvinphos, and deltamethrin were selected and studied by UV absorption and fluorescence spectra. The binding constants of them with HSA were calculated that equal to (3.62±0.01) ×10 3 , (8.08 ± 0.02) ×10 5 and (7.33±0.03) ×10 8 M ?1 , respectively. These pesticides can quench the intrinsic fluorescence of HSA by static quenching and non-radiative energy transferring. Molecular docking studies revealed these pesticides can bind to site 1 of HSA. In addition, 14 ns MD simulation was performed and results suggested that the binding of ligands could cause somewhat changes in tertiary structures of HSA. In the next section of this thesis, the interactions between PPAR? and its six known antagonists were investigated using computational methods. The binding energies evaluated by molecular docking varied between ?22.59 and ?35.15 kJmol ??1 . Analysis of the RMSF of backbone atoms shows that H3 of PPAR? has a higher mobility in the absence of antagonists and moderate conformational changes were observed in the presence of ligands. Finally, the interaction energies between antagonists and each PPAR? residues involved in the interactions were studied by QM/MM calculations. These calculations reveal that antagonists with different structures show different interaction energies with the same residue of PPAR?. Therefore, it can be concluded that the key residues vary depending on the structure of the ligand, which binds to PPAR?. To halt the buildup of carbon dioxide, the main greenhouse gas, the development of an alternative energy source to fossil fuels becomes more and more important. Hydrogen (H 2 ) has the potential to meet the requirements as a clean non-fossil fuel in the future, if it can be produced using our primary source of energy, the sun, and stored and traorted safely. In the second part of this thesis, CrTiO 2 nanotubes was fabricated using in-situ anodizing. The Nobel metals such as Ag, Au, Pd, Pt, Ni and Ru were used to modifying the surface of CrTiO 2 . The newphotocatalyst has been characterized by SEM, EDX, XRD, and Uv-Vis spectra.The photoelectrochemical activities of them were evaluated by LSV, CA, and OCP mesurments. All of them improved photo current density. Pd, Au, and Pt show an anodic peak that belong to photo oxidation of Ethylen glycol. Finally, water spiliting were performed, in the presence of light and at 0.6 V vs. Ag/AgCl, for all of the new photocatalysts and the H 2 evaluated were measured. Pt3, Ni2, Au6, Ru1, pd6, and Ag4 have more H2 evalution among their families which correspond to 1.08, 0.9, 0.84, 0.7, 0.64, and 0.52 mlh -1 .