An all-atom Refined Force Field for Osthol
Osthol is a medical molecule isolated from the fruit of Cnidium monnieri as a cytotoxic principle. A new all-atom model, based on the Amber force field, is presented in this work for simulating the structural and dynamic properties of a class of osthols, 7-Methoxy-8(3-methyl-2-butenyl). The quantum mechanics (QM) calculation was performed to optimize the molecular geometry parameters by the Gaussian03 software, with its initial crystal structure data. The atom charges were determined by using a 6-31G* basis set and fitting restrained electrostatic potential (RESP). The fitting of vibrational frequency data by TINKER package was used for the optimization of the bond and angle parameters in force field. The parameters of torsions were obtained by fitting the torsion energy profiles with QM and Molecular mechanics (MM) depending on dihedral angles. To validate our force field, extensive comparison between molecular dynamics simulations by MD44 package and experimental data for the density, vaporization enthalpy were investigated and a good consistence was observed. Finally, the space distribution functions for water and osthol were analyzed by molecular dynamic simulation, and a possible mechanism of aqueous solubility was proposed, based on the microscopic structures of the binary mixture.
Osthol force field quantum mechanics simulation molecular dynamics
Yuxiao Yang Xuan Peng Jinsong Zhao
Lab for Intelligent Process Systems Engineering,College of Information Science and Technology,Beijing University of Chemical Technology,Beijing 100029,PR China
国际会议
西安
英文
2007-08-15（万方平台首次上网日期，不代表论文的发表时间）