Calixarene Drug deleivery invistegation of Calixarene compounds with conection by histidine L and D stereochemistry

Abstract

In this research, Quantum-mechanical calculations were performed at the HF method with the 6-31+G*basis set and at the B3LYP method with the 6-31+G* basis set in the gas phase and five solvents such as water, DMSO, methanol, ethanol and dichloromethane at six temperatures. According to these theoretical results of IR, we extracted thermo chemical parameters such as enthalpy (∆H Kcal/mol), Gibbs free energy (∆G Kcal/mol) and entropy (∆S cal/molK). Important relationship have been found between solvent effect and structure of Calixarens with histidine L and D stereochemistry. Also, nuclear shielding parameters of Calixarene, such as chemical shift isotropic value (σ_iso) and the anisotropy shielding (σ_aniso, ∆σ), have been taken into account using GIAO method at the HF method with the 6-31+G* basis set and at the B3LYP method with the 6-31+G* basis set in the gas phase and in different solvents such as water, DMSO, methanol, ethanol and dichloromethane. The results were revealed that the NMR chemical shielding parameters are strongly affected by inducing different solvent media. According to these theoretical results,it can be drastically concluded that the dielectric permittivity of the solvent is a key factor that determines the chemical behavior of Calixarene with histidine L and D stereochemistry in solution. Also the natural bond orbital (NBO) analysis has been performed at the six levels in the gas phase and different solvent media which show some important atomic and structural features.