Synthesis,structural characterization,in vitro cytotoxicities,and BSA interaction of di-organotin(IV) complexes derived from salicylaldehyde nicotinoyl hydrazone

Two organotin(IV) compounds were synthesized from salicylaldehyde nicotinoyl hydrazone and the corresponding dialkyltin(IV) precursor. Their structures were determined by IR, elemental analysis, NMR, and single crystal X-ray diffraction analysis. Compound 1 exhibits a distorted trigonal bipyramidal geometry around tin, which is coordinated to the Schiff-base ligand in an enolic tridentate fashion. For 2, structural analysis reveals that it is a centro-symmetric trimer, in which the central Sn adopts a six-coordinate octahedral geometry and the other two Sn ions adopt five-coordinate trigonal bipyramidal geometry. In vitro cytotoxicities of the compounds against three human cisplatin-resistant tumor cell lines (A549, HeLa, and MCF-7) were assessed by MTT assay. Further, the interaction of 1 and 2 with bovine serum albumin (BSA) has been explored by the titration method with fluorescence quenching spectra and synchronous ?uorescence spectra. Studies reveal that di-n-butyltin(IV) complex 1 with significant antiproliferative effects in the cells shows stronger BSA interaction.     

Colorimetric and Polarographic Methods of Analysis for Prenalterol Hydrochloride

Abstract

Two proposed methods have been described for the determination of prenalterol hydrochloride in acetate buffer (pH=4.1) as authentic material and in tablets form using a (i) colorimetric method based on reduction of ferric iron by prenalterol hydrochloride and subsequent measurement at 511 nm of the red color obtained by the treatment of the resultant ferrous iron with 1, 10-orthophenanthroline, (ii) a differential pulse polarographic method based on nitrosation with 0.1 M NaNO₂/dil. HC1 and consequent recording of the differential pulse polarogram. The differential polarogram was obtained under constant amplitude pulses of 50 mV (DP 50) superimposed on a linearly increasing DC-voltage ramp. The peak height (h), of the polarogram was measured at the peak potential of -0.2V on the dropping mercury electrode (DME) versus Ag/AgCl reference electrode. The linearity ranges observed are 0.6μgfml to 6.0μg/ml and 2μg/ml to 12μg/ml, respectively. The mean percentage recoveries for an authentic sample are 99.5±1.4 and 100.5±0.7, respectively. When applied to tablets claimed to contain 10 mg each, the mean percentages obtained are 99.7±2.3 and 100.6 ±1.5 respectively.     

高效液相色谱法测定西红柿中克线磷残留量

高效液相色谱法测定西红柿中克线磷残留量包宏,夏民洲,胡兹苓（南京林业大学南京２１００３７）１前言克线磷（ｆｅｎａｍｉｐｈｏｓ）,商品名Ｎｅｍａｃｕｒ,是防治作物根结、孢囊与自由线虫的杀线虫农药￣［１］。对它的残留分析,有气相色谱法和薄层色谱法等￣［２...     

Exact solutions to Landau-Zener problems by evolution operator method

Various analytic approaches have been developed to solve the famous Landau-Zener (LZ) problem. Here, we introduce a time-evolution operator method to investigate such a problem by numerically solving the induced algebraic equations (by Runge-Kutta method). Based on these calculations, transitions between two levels driven by various time-dependent external fields can be simulated in detail, typically near the so-called avoided crossing points. Far from these points, our results reduce to the original Landau-Zener transition (LZT).     

Feedback control design for Rössler and Chen chaotic systems anti-synchronization

The proposed anti-synchronization conditions of coupled chaotic systems are based, in this Letter, on the use of aggregation techniques for the stability study of the error dynamics. The schemes are, successfully, applied to coupled Rössler and Chen chaotic systems making the instantaneous characteristic matrix under the arrow form. Numerical simulations are performed to illustrate the efficiency of the proposed approach.     

Complex formation between imidazole and carboxylate ligands in aqueous solution

We report the results of a potentiometric study on the formation of weak complexes between imidazole (im) and acetate, malonate, and citrate (L), at T=25°C. Formation of protonated species H_j (im)(L), in which j=1 for acetate, j=1, 2 for malonate and j=1, 2, 3 for citrate, was found. The formation of weak complexes between N-ligands and O-ligands may be used to interpret the behavior of these classes of compounds in natural fluid and/or in biological systems, as regards inter-or intra-molecular interactions.