The Structure Of Biologically Active Molecules And The Interaction Theory Study

There are three parts in this paper: the first part is to make use of density functional theory to study the structure and electronic properties of the resveratrol, naringenin and apigenin molecules and to explain their antioxidant activities which are extracted from the Chinese traditional medicines; the second part is to research the mechanism of uracil molecular recognition membrane and theophyline molecular recognition membrane by using density functional theory too; the third part is to investigate the binding modes between the Epidermal growth factor receptor(EGFR) and its inhibitors, and the binding modes between the α -Glucosidase(AglA) and its amino-sugar inhibitor.The first part: The density function theory (DFT) is applied to study the conformations of trans-resveratrol and cis-resveratrol. Based on calculation results, in terms of the energy of abstracting H atom from hydroxybenzene, HOMO and LUMO, total spin density and unpaired electron distribution of resveratrols and their free radicals, we get to know the main active part of cis-resveratrol in scavenging free radicals is C4'-hydroxyl group too, the same with trans-resveratrol. The double bond between Cα and Cβ in the molecule plays an important role in their activity from comparison between trans-resveratrol, cis-resveratrol and α,β-dihydro-3,5,4'-trihydroxystilbene. The similar study is done to naringenin and apigenin molecules. Their steady structures are obtained and activity center are affirmed by computation and deduction.The second part: The interaction mechanism between uracil and its molecularly imprinted membrane, which is composed of acrylonitrile and methylacrylic acid, has been investigated by DFT method. Four possible complexes that there are hydrogen bonds between uracil and the membrane molecules are considered and their complete geometry optimizations are performed. A normal-mode analysis of the vibrations of the four complexes was carried out and compared with the experimental values. At last, the primary form of interaction is concluded based on the binding energy and vibrational spectrum. The similar study is done to the interaction of theophyline and its molecularly imprinted membrane.The third part: A series of various reported EGFR inhibitors are selected. Theconformation searches are performed to these inhibitors and the different methods of conformation searches such as systematise search, molecular dynamics and boltzman jump method, are adopted for different molecule based on their structure. The lower energy and varied conformations are combined to one sd file, then the docking between the Epidermal growth factor receptor (EGFR: 1M17) and inhibitors are performed by using the Ligandfit in the Cerius2, and then the docking modes are analyzed. The rule of this kind docking is induced. The similar study is done to investigate the docking modes between a -Glycosidase(10BB), and two different new docking modes are obtained.