Synthesis,Characterization And Biological Activities Of Arenetelluronic Di-and Triorganotin(?)Esters

The organotin derivatives have attracted more and more attention based on their structural diversity and wide application in catalysts,functional materials,antimold agents and plastic stabilizers,etc.Especially,the organotin derivatives show well biological activity in anti-cancer and anti-bacterial areas.Therefore,to synthesize organotin compounds with novel structure and high biological activity has become one of the hot research topics now.The telluric acid exhibits multiple hydroxyl groups,which could be an excellent electon donor and could combine with tin atom in various forms to form compounds with special structures and unique properties.On the other hand,tellurium compounds possess significant effects in terms of anti-oxidation,anti-bacterial,anti-tumor properties and so forth.Based on the above considerations,we carried out our research on arenetelluronic organotin esters,we designed and synthesized some new kinds of arenetelluronic acid diorganotin and triorganotin esters.The main works we've done are listed as follows:1.Four halogenated phenyltelluronic acid ligands had been designed and synthesized,and their reactions with trialkyltin chlorides were studied.We obtained eight novel triorganotin complexes and characterized them by X-ray single crystal diffraction,elemental analysis,FT-Infrared spectra,NMR(¹H,¹³C,¹¹⁹Sn)spectroscopy,etc.The results show that the complexes exhibit two kinds of structures with single and double tellurium cores,all the structure of tin atoms is all four-coordinated distorted tetrahedral structure.The central tellurium atoms still maintain hexa-coordinated,display slightly distorted octahedral configuration.During the reactions,four oxygen atoms on each arenetelluronic acid molecule are coordinated with Sn atoms or bridged with another Te atom.In addition,we have found that the molar ratio of the reactants and the solvent systems are significant factors,which could govern the process of the reactions.The reaction with same raw materials but different solvents and raw material ratios can yield two different structures,one is monomer with a single tellurium core,and the other one is dimer with a ditellurium core.In the crystals of the complexes,various weak intermolecular interactions exist in all of them.Nevertheless,through weak intermolecular interactions,they can form various infinite and sophisticated network supramolecular structures.2.Four halogenated phenyltelluronic acid ligands had been designed and synthesized,using the synthesized ligands to react with diorganotin dichlorides,ten new arenetelluronic diorganotin esters were obtained.After we characterized these complexes,we found that all the oxygen atoms belonging to the ligands participated in the reactions.There's an eight-membered ring structure of a tetra-tin core and a double tellurium core formed in the center of all the complexes.The center ring of arenetelluronic acid itself is almost orthogonally run through the eight-membered ring.The tellurium atoms of the arenetelluronic diorganotin esters are also hexa-coordinated and display octahedron geometries,but the tin atoms display a five-coordinated triangular double-pyramid configuration in two different environments.Similar to trialkyltin derivatives,there are weak intermolecular interactions such as C-H···F and CH···?in the complexes,which make the crystals of the complexes form a variety of one-or two-dimensional supramolecular structures.In addition,we found that under certain conditions,arenetelluronic diorganotin esters would combine solvent molecules to form solvates through hydrogen bonding,which further diversified their structures.3.Preliminary in vitro cytostatic activity tests were performed on the synthesized complexes.The results show that most of the arenetelluronic organotin derivatives possess significant inhibitory effects on He La and Hep G-2 cell lines.The relationship between activity and structures show obvious laws.For example,triorganotin complexes tend to be better than corresponding diorganotin complexes,and derivatives with ample substituted halogen atoms are always better than the corresponding unsubstituted phenyltelluronic organotin derivatives.To further confirm the cytostatic activity of the complexes,we also assessed the morphologic alteration and apoptosis using fluorescence microscopy and flow cytometry.The results show that the complexes inhibit their activity by increasing early apoptotic population rather than late apoptosis or necrosis.4.Fluorescence quenching spectroscopy studies were performed on the interactions of the synthesized complexes with bovine serum albumin(BSA).The results show that most of the complexes have the effects of fluorescence quenching on BSA.The fluorescence intensity drops regularly with increasing concentrations of complexes.The experimental data show that all the complexes could quench the intrinsic fluorescence of BSA in a static quenching way.The number of binding sites n between the complexes and BSA is around1,which means there's a single binding site between complexes and BSA.At the same time,we tested the synchronous fluorescence spectrum of the interactions between the complexes and BSA.Our study showed that the presence of the complexes cause the micro-environments around tryptophan residues disturbed,the polarity of the tyrosine residues changed.The synchronous fluorescence spectroscopic data confirmed that the presence of these complexes caused the microenvironmental and the conformational changes in BSA.In short,we synthesized different kinds of arenetelluronic acid ligands,and reacted with alkyltin chlorides under different conditions to try to synthesize complexes with special structures and properties.An in-depth study of the relationship between synthetic conditions and product structures,biological activities,structure-activity of these complexes will allow us to understand organotin complexes more clearly and deeply.In the future work,we will further study and discuss such kind of complexes,and explore their potential application values.