Research On Electronic Structure And Structure-Activity Correlationship Of Polyoxometalates In Antitumor Activity

Many factors, such as changing counterion, substituting central atom, varyingconfiguration, being protonated with different nurnber of protons and so on, mayinflunce clectronic stnJctures and antitumor activities of polyoxometalates. TOunderstand which is the key one and to build a correlationship between electronicstructures of polyoxometalates and their antitumor activities, Density FunctionalTheory with Discrete Variational Method(DFT-DVM) was employed at first tocaIcuIate systematicaIIy the eIectronic structures of poIyoxometalates in aniiturnoractivity, which own the configurations of Lindqvist type and Anderson tyPe. ThenPolyoxometalate (NH,Pr').[Mo,O,.j and several of its possible single-electronreduced forms were also stUdied in the same WayResults of Variance Analysis, F-test and other methods showed us that there isno remarkable difference among the electtonic smictures of POlyoxometalates withdifferefit conterions or protonated with different number of protons. But it doesinflunce the electronic structUre notably to replace central atom of polyoxometalate.Based on the conc1usion that changing counterion does not influenceremarkably the electronic structure of polyoxometalate, an experimental result thatthe polyoxomolybdate structure of Mo7O24 framework is aPparently of criticalsignificance fOr the antitumor action was expIained reasonabIyA theory proof, which sustains the only redox mechanism for the anhaoraIactivity of polyoxometalates proposed by Yamase, was gotten frOm the resuIts ofcalculating [Mo,O,.]& and several of its possible single-electron reduced fOrms.Meanwhile, an idea, which disagrees with that of Dr Yamase, was fallen wiunn ourcongnizance that it is not any other molybdenurn atom in anion [Mo:O,.]& bllt thecentral molybdenum atom that will be reduced when the anion gets an electron inthe process of killing tumor cells according to more than enough proofs gained fromthe calculations.By improving on the calculating method of Vertex Valence for Atom with natelectronic charges of atoms in polyoxometalate from DFT-DVM calculations, andconsidering the "central atom effect in polyoxometalate" with a weighted coefficientwhile calculating Molecular Connectivity, a new model named as WeightedQuantum Topological Index (WQTI) was set up by us.The correlationship between electronic structures of polyoxometalates based onDFT-DVM and antitumor activities of polyoxometalates could be expressedcorrectly by WQTI. The antitumor activities of a series of polyoxometalates wereprognosticated according to the WQTI. At the same time, such a conclusion couldL. ..dched that central atom and conflgurations of polyoxometalates are two mainelements to influnce their antitumor activities, howeveT, central atom is moreimportant.