MD/QM/CSM method for extracting representative conformation of beta-CD subject-object system

Abstract

The invention discloses an MD / QM / CSM method for extracting representative conformation of a beta-CD subject-object system. The method comprises the following steps: (1) calculating a topological structure and RESP charges of a host molecule; (2) calculating topological structures and RESP charges of guest molecules; (3) constructing an initial conformation of a subject-object compound; (4) screening dominant conformations of the host-guest compound, the host molecules and the guest molecules; (5) carrying out ECD calculation on the dominant conformation of the subject-object compound, and comparing with an ICD experiment to determine the accuracy of the screening structure; (6) calculating inclusion free energy of dominant conformations of the subject-guest compound, the subject molecules and the guest molecules by adopting a QM / CSM method, and performing linear correlation analysis on a calculated value and an experimental value. According to the method, the representative conformation of the subject-guest compound system can be accurately extracted, an accurate structural model is provided for calculation of the inclusion free energy, meanwhile, the inclusion free energy and the solvent effect in vacuum are calculated, calculation of the inclusion free energy of the subject-guest system is more perfect, and guidance is provided for experiments.

Description

technical field [0001] The invention belongs to the theoretical calculation field of a supramolecular host-guest system, and relates to an MD / QM / CSM method for extracting a representative conformation of a β-CD host-guest system. Background technique [0002] N-methylcarbamate insecticides are widely used in agriculture to eliminate various pests that may damage crops and improve the quality of agricultural products. However, its use poses a threat to human health, so simple, rapid and sensitive methods are needed to quantify the residues of this pesticide. Since the addition of such pesticide molecules in an organic medium has a strong fluorescent signal, adding such pesticide molecules to a β-cyclodextrin (β-CD) medium can quickly determine its content when determining its residue. [0003] β-CD and its derivatives have the property of "hydrophobic on the inside and hydrophilic on the outside", and can be included with different guest molecules to improve the solubility a...

AI Technical Summary

Problems solved by technology

They found that the DFT method has a high linear correlation with the experimental value, but the root mean square error is large; for the PM6-DH2X method, the root mean square error between the calculated value and the experimental value is smaller than the DFT method, but for different subjects and objects The ordering of the relative stability of the complexes is wrong; when using MD-WHAM for calculation, the root mean square error of the calculated value and the experimental value is the smallest, but the relative stability of different host-guest complexes cannot be correctly ordered (Journalof Computational Chemistry, 2012, 33(29):2310-2317)

Images