Hetero-bimetallic transition metal-substituted Krebs-type polyoxometalate with N-chelating ligand as anticancer agents

A novel hetero-bimetallic transition metal(Sb^(Ⅴ)/Mn^(Ⅱ))-substituted Krebs-type polyoxometalate(POM)with N-chelating ligand H_(4)Na_(4)[Mn_(4)(H_(2)O)_(4)(trz)_(2)(SbO_(2))_(2)(SbW_(9)O_(33))_(2)]-20H_(2)O(Sb_(2)Mn_(2))(1)(trz=1,2,4-triazole)built from trilacunary Keggin POM unitα-B-[SbW_(9)O_(33)]^(9-){SbW_(9)]has been synthesized and characterized by single-crystal/powder X-ray diffraction and a wide range of analytical methods,including powder X-ray diffraction,Fourier transform infrared spectroscopy,Raman,ultraviolet-visible spectroscopy,electrospray ionization-mass spectroscopy,and thermogravimetric analysis.To further investigate the antitumor activity of the(Sb_(2)Mn_(2))(1)in human gastric cancer Human Gastric Adenocarcinoma Cells and Human Gastric Cancer Cell lines,in vitro cytotoxicity assay and flow cytometry analysis was performed.The results indicated that the IC_(50) values of(Sb_(2)Mn_(2))(1)on Human Gastric Adenocarcinoma(AGS)and Human Gastric Cancer(BGC-823)Cell Lines were 1.86±0.05μmol·L^(-1) and 14.61±0.55μmol·L^(-1),respectively.(Sb_(2)Mn_(2))(1)also exhibited high cytotoxicity on Human Gastric Cancer Cells and could induce cell apoptosis by inhibiting S and G_(2)/M cell cycles.Therefore,the result not only shows that this new POM-based inorganic-organic hybrid compound has high selectivity and low toxicity,but also provides an effective method for the development of potential transition metal-substituted POMs based antitumor drugs.

Conformational Properties of Comb-shaped Polyelectrolytes with Negatively Charged Backbone and Neutral Side Chains Studied by a Generic Coarse-grained Bead-and-Spring Model

A generic coarse-grained bead-and-spring model,mapped onto comb-shaped polycarboxylate-based(PCE)superplasticizers,is developed and studied by Langevin molecular dynamics simulations with implicit solvent and explicit counterions.The agreement on the radius of gyration of the PCEs with experiments shows that our model can be useful in studying the equilibrium sizes of PCEs in solution.The effects of ionic strength,side-chain number,and side-chain length on the conformational behavior of PCEs in solution are explored.Single-chain equilibrium properties,including the radius of gyration,end-to-end distance and persistenee length of the polymer backbone,shape-asphericity parameter,and the mean span dimension,are determined.It is found that with the increase of ionic strength,the equilibrium sizes of the polymers decrease only slightly,and a linear dependenew of the persistence length of backbone on the Debye screening length is found,in good agreement with the theory developed by Dobrynin.Increasing side-chain numbers and/or side-chain lengths increases not only the equilibrium sizes(radius of gyration and mean span)of the polymer as a whole,but also the persistence length of the backbone due to excluded volume interactions.