Kinetic Spectrophotometric Analysis and Spectrofluorimetric Analysis of Ciprofloxacin Hydrochloride and Norfloxacin in Pharmaceutical Preparations Using 4‐Chloro‐7‐Nitrobenzo‐2‐Oxa‐1,3‐Diazole (NBD‐Cl)

Simple, reliable, sensitive and accurate kinetic spectrophotometric and spectrofluorimetric methods were proposed for the determination of ciprofloxacin hydrochloride (CPX) and norfloxacin (NRX) in pure form and in pharmaceuticals. The methods are based on coupling the studied drugs with 4‐chloro‐7‐nitrobenzo‐2‐oxa‐1,3‐diazole (NBD‐Cl) in the presence of alkaline borate buffer. Spectrophotometric measurement was achieved by recording the absorbance at 477 nm after a fixed time of 20 and 15 min on a water bath adjusted at 70 ± 1 °C for CPX and NRX, respectively. The same product exhibited emission peaks at 540 nm. The different experimental parameters affecting the development and stability of the color were carefully studied and optimized. The absorbance concentration plots were linear over the ranges 3‐18 and 2.5‐15.0 μg/mL for CPX and NRX, respectively, while the fluorescence concentration plots were linear over the ranges 0.06‐0.36 and 0.05‐0.30 μg/mL for CPX and NRX, respectively. The limit of detection of the kinetic method was about 0.2 μg/mL for both drugs while the fluorescence measurement enabled their detection at a concentration of about 0.012 μg/mL. The proposed methods were successfully applied for the assay of the two drugs in their commercial products. The results obtained were statistically compared with those obtained by reference HPLC and spectrophotometric methods. The stoichiometry of the reaction was determined and the reaction pathway was postulated.     

Structure-based design and synthesis of acyclic and substituted heterocyclic phosphonates linearly linked to thiazolobenzimidazoles as potent hydrophilic antineoplastic agents

As a contribution to our investigations to develop multidisciplinary entities of substituted heterocycle phosphor esters, in this paper, we prepared a series of thiazolobenzimidazoles incorporating phosphor esters of potential anticancer properties. Phosphoryl reagents were applied on E-3-(N,N-dimethylamino)-1-(3-methythiazolo[3,2-a]benzoimidazol-2-yl)prop-2-en-1-one and 1-(3-methylthiazolo[3,2-a]benzimidazol-2-yl)ethanone. The reactions proceeded under mild conditions to give an ensemble of 14 new phosphonates in good yields (68–74%). The stereoselective chemistry was studied by a series of heteronuclear ¹³C[¹H]-nOe experiments. Based on the prediction studies in the early stage using PASS algorithm 14, the synthesized phosphonates were evaluated as antitumor candidates at a dose of 10 µmol/mL against human breast and human colon tumor (4 cultured cell lines each). Three products showed significant antineoplastic potency in relative to the standard drug, adriamycin. Permeability of the lead molecules was determined and the structure–activity relationship (SAR) was discussed to suggest a pro-drug chromophore. Furthermore, there was good coincidence of experimental data of antitumor properties and prediction results.     

Complex Formation Reactions of Promethazine Copper(II) and Various Biologically Relevant Ligands. Synthesis,Equilibrium Constants,Spectroscopic Characterization and Biological Activity

Binary and ternary complexes of copper(II) involving promethazine, N,N-dimethyl-3-(phenothiazin-10-yl)propylamine (Prom) and various biologically relevant ligands containing different functional groups, were investigated. The ligands (L) are dicarboxylic acids, amino acids, amides and DNA constituents. The ternary complexes of amino acids, dicarboxylic acids or amides are formed by simultaneous reactions. The results showed the formation of Cu(Prom)(L) complexes with amino acids and dicarboxylic acids. The effect of chelate ring size of the dicarboxylic acid complexes on their stability constants was examined. Amides form both Cu(Prom)(L) complexes and the corresponding deprotonated species Cu(Prom)(LH₋₁). The ternary complexes of copper(II) with (Prom) and DNA are formed in a stepwise process, whereby binding of copper(II) to (Prom) is followed by ligation of the DNA components. DNA constituents form both 1:1 and 1:2 complexes with Cu(Prom)²⁺. The stability of these ternary complexes was quantitatively compared with their corresponding binary complexes in terms of the parameters Δlog₁₀ K. The values of Δlog₁₀ K indicate that the ternary complexes containing aromatic amino acids were significantly more stable than the complexes containing alkyl- and hydroxyalkyl-substituted amino acids. The concentration distribution of various complex species formed in solution was also evaluated as a function of pH. The solid complexes [Cu(Prom)L)] where L=1,1-cyclobutanedicarboxylic acid (CBDCA), oxalic and malonic acid were isolated and characterized by elemental analysis, infrared, TGA, and magnetic susceptibility measurements. Spectroscopic studies of the complexes revealed that the complexes exhibits square planar coordination with copper(II). The isolated solid complexes have been screened for their antimicrobial activities using the disc diffusion method against some selected bacteria and fungi. The activity data show that the metal complexes are found to have antibacterial and antifungal activity.     

Derivative Spectrophotometric and Colorbmetric Methods for the Determination of Guanoxan Sulphate in Tablets,Urine, and Serum.

Three simple and rapid methods for the determination of guanoxan sulphate in tablets, urine and serum are presented. The first method is based on the direct measurement of the first (¹D) and second (²D) (peak-trough) derivative values at 274–250 nm and 276–260 urn respectively. The other two methods depend on the formation of a charge- transfer chromogen with either tetracyanoethylene (TCNE) and 7,7,8,8- tetracyanoquinodimethane (TCNQ). The absorbance of the color developed at 416 and 840 nm respectively. The first and second derivative (¹D & ²D) values for the charge- transfer products were also measured. The methods were proved to be accurate and reproducible as indicated by relative standard deviation of less than 2%. The proposed methods have been applied to the determination of guanoxan sulphate in tablets, and spiked human urine and serum.     

Effective widths of boson gas confined in a harmonic rotating trap

In this Letter, we evaluate the radial and axial square radii (effective widths) of a rapidly rotating boson gas. The corresponding effective area and the expansion energy are calculated from these effective widths. A modified semiclassical approximation is suggested. This approach provides significant corrections to these quantities, such as finite size effect and indirectly interaction effect. We show that the effective widths still follow a non-rotating temperature dependence. Rotation leads to expansion or shrinking the effective widths through the change of the harmonic frequencies of the confinement trap.     

Design,Regiospecific Green Synthesis,Chemical Computational Analysis,and Antimicrobial Evaluation of Novel Phthalazine Heterocycles

Phthalazines have received considerable attention for their wide antimicrobial activity. Regiospecific nucleophilic attack of 4‐benzylphthalazin‐1‐ol by the 1‐oxo rather than the aza group on different alkyl halides gave novel phthalazine heterocyclic derivatives. Moreover, a variety of nucleosides bonded to electron‐withdrawing groups were synthesized using 4‐benzylphthalazine‐1‐ol. The density functional theory has been used to investigate the electronic structure of the synthesized compounds. All of the synthesized derivatives showed remarkable activity when tested against Gram‐positive and Gram‐negative bacteria, Aspergillus niger, and Candida albicans. The reactivity of these nucleosides was expected to arise from their bonding with the lone pair of N‐atom of the macromolecules of bacteria. These bonding were expected to inhibit the enzyme by forming highly stable complex with lower highest occupied molecular orbital energy. The structures of these synthesized derivatives were established by Fourier transform infrared, ¹H‐NMR, and ¹³C‐NMR spectroscopic evidence.     

Synthesis and chemical reactivity of the novel 3-chloro-3-(4-chlorocoumarin-3-yl)prop-2-enal

Vilsmeier-Haack formylation of 3-acetyl-4-hydroxycoumarin (1) afforded the unexpected 3-chloro-3-(4-chlorocoumarin-3-yl)prop-2-enal (3). Compound 3 reacted with p-toluidine and benzylamine producing Schiff base 4 and enamine 6, respectively. Treatment of compound 3 with hydrazine hydrate produced bis-coumarin 15 which upon treating with hydrazine hydrate afforded bis chromeno[4,3-c]pyrazole derivative 16. Compound 3 reacted with cyanoacetohydrazide under different conditions. Condensation of compound 3 with some heterocyclic amines and 1,2-N,N-binucleophiles was studied. Structures of the new synthesized products were deduced on the basis of their analytical and spectral data.     

Effect of the weak interaction on the in situ radii of condensate boson atoms in one or two-dimensional deep optical lattices

In this letter we suggest a theoretical model to investigate the weak interaction dependence of the in situ radii of condensate boson atoms in a combined harmonic with one or two-dimensional deep optical lattice. The semiclassical approximation is employed to calculate the above mentioned parameters. The calculated results showed that the in situ radii depends crucially on the interatomic interaction. Our results can be extended to investigate the moment of inertia of condensate boson atoms in combined harmonic-optical potential as well as superfluidity nature of synthetically charged boson atoms in combined potential.     

The effect of light on the electrical conduction of pure and doped poly(methyl methacrylate)

Thin films of pure and doped poly(methyl methacrylate) (PMMA) with thicknesses ranging from 0·1 to 0·2 mm were prepared by the casting method. The effect of light on the electrical conduction of these films was studied using a specially designed electrical cell. The results showed that the resistivity of PMMA decreases gradually with increasing exposure time and the effect was found to be reversible. The doped samples showed more stability against the light effect. The current-voltage (I–V) characteristics indicated that the mechanism of conduction of PMMA depends on the presence of localized states or trapping levels arising from lack of order. Some physical parameters such as fermi energy, E_f, trap energy, E_t, density of charge carriers, n₀, ion mobility, μ, as well as the electrical conductivity of the test samples were calculated.     

Herstellung und thermisches Verhalten einiger Polyarylsilane

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