Eco‐friendly ionic liquid assisted capillary electrophoresis and α‐acid glycoprotein‐assisted liquid chromatography for simultaneous determination of anticancer drugs in human fluids

In the current work, two eco‐friendly analytical methods based on capillary electrophoresis (CE) and reversed phase liquid chromatography (RPLC) were developed for simultaneous determination of the most commonly used anticancer drugs for Hodgkin's disease: methotrexate (MTX), vinblastine, chlorambucil and dacarbazine. A background electrolyte (BGE) of 12.5 mmol/L phosphate buffer at pH 7.4 and 0.1 µmol/L 1‐butyl‐3‐methyl imidazolium bromide (BMImBr) ionic liquid (IL) was used for CE measurements at 250 nm detection wavelength, 20 kV applied voltage and 25 °C. The rinsing protocol was significantly improved to reduce the adsorption of IL on the interior surface of capillary. Moreover, RPLC method was developed on α‐1‐acid glycoprotein (AGP) column. Mobile phase was 10 mmol/L phosphate buffer at pH 6.0 (100% v/v) and flow rate at 0.1 mL/min. As AGP is a chiral column, it was successfully separated l ‐MTX from its enantiomer impurity d ‐MTX. Good linearity of quantitative analysis was achieved with coefficients of determinations (r²) >0.995. The stability of drugs measurements was investigated with adequate recoveries up to 24 h storage time under ambient temperature. The limits of detection were <50 and 90 ng/mL by CE and RPLC, respectively. The using of short‐chain IL as an additive in BGE achieved 600‐fold sensitivity enhancement compared with conventional Capillary Zone Electrophoresis (CZE). Therefore, for the first time, the proposed methods were successfully applied to determine simultaneously the analytes in human plasma and urine samples at clinically relevant concentrations with fast and simple pretreatments. Developed IL‐assisted CE and RPLC methods were also applied to measure MTX levels in patients’ samples over time. Copyright © 2014 John Wiley & Sons, Ltd.     

Syntheses of Novel Isopenam and Isocephem Antibiotics. Preparation of a retinamido derivative of a highly strained β-lactam as potent anticancer agent

Syntheses of the cis-configurated isopenam 9 (Scheme 1), isocephem 14 (Scheme 2), and isocephem 19 (Scheme 3) are described. The key step in the preparation of 14 and 19 involved a Pummerer-type rearrangement of the corresponding sulfoxides 12 and 18 . These β-lactams were found to possess biological activity against several pathogenic microorganisms in vitro. The electronic activation of the lactam moiety of 19 remarkably enhanced its biological activity. A retinoic moiety was attached to 19 via an amino linker. The resultant retinamido-β-lactam 21 showed significant cytostatic activity in tracheal organ cultures obtained from vitamin-A-deficient hamsters.     

Biological Effect,Aquation, and Kinetics of Oxidation of Bis(2‐aminobenzothiazole)dichlorocobalt(II) Complex by Periodate in Aqueous Acidic Medium

The biological effect, aquation, and kinetics of oxidation of bis(2‐aminobenzothiazole)dichlorocobalt(II) complex by periodate in aqueous acidic solutions were studied. The complex exhibited a broad resistance toward the studied pathogens. The average value of the aquation constant was calculated spectrophotometrically as 2.55 × 10^?5 mol² dm^?6. Kinetics of the oxidation reaction showed first‐order dependence on each reactant concentration and increased by increasing pH over the 3.80–4.80 range, 35–50°C, and decreased by increasing the ionic strength over the 0.1–0.5 mol dm^?3 range. The polymerization of acrylonitrile was taken as an evidence for an inner‐sphere mechanism through the formation of free radical intermediates of Co(III) complexes, which were slowly converted to the final Co(III)products.     

Forced Convection Heat Transfer on a Flat Plate Embedded in Porous Media for Power-Law Fluids

The effect of the presence of an isotropic solid matrix on the forced convection heat transfer rate from a flat plate to power-law non- Newtonian fluid-saturated porous medium, has been investigated. Numerical results are presented for the distribution of velocity and temperature profiles within the boundary layer. The effects of the flow index, first-order and second-order resistance on the velocity, and temperature profiles are discussed. The missing wall values of the velocity and thermal functions are tabulated.     

On the wave propagation in isotropic fractal media

In this paper, we explore the wave propagation phenomenon in three-dimensional (3D) isotropic fractal media through analytical and computational means. We present the governing scalar wave equation, perform its eigenvalue decomposition, and discuss its corresponding modal solutions. The homogenization through which this fractal wave equation is derived makes its mathematical analysis and consequently the formulation of exact solutions possible if treated in the spherical coordinate system. From the computational perspective, we consider the finite element method and derive the corresponding weak formulation which can be implemented in the numerical scheme. The Newmark time-marching method solves the resulting elastodynamic system and captures the transient response. Two solvers capable of handling problems of arbitrary initial and boundary conditions for arbitrary domains are developed. They are validated in space and time, with particular problems considered on spherical shell domains. The first solver is elementary; it handles problems of purely radial dependence, effectively, 1D. However, the second one deals with general advanced 3D problems of arbitrary spatial dependence.     

饱和纳米流体多孔介质中竖直嵌入板上边界层的非Newton流

在层流条件下,对饱和多孔介质中的竖直板,研究幂指数型非Newton流的自由对流热交换.非Newton纳米流体服从幂指数型的数学模型,模型综合考虑了Brown运动和热泳的影响.通过相似变换,将问题的偏微分控制方程组,转化为常微分方程组,得到了常微分方程组的数值解.数值解依赖于幂指数n,Lewis数Le,浮力比Nr,Brown运动参数Nb,以及热泳参数Nt.在n和Le的不同取值下,研究并讨论了对相关流体性质参数的影响和简化的Nusselt数.     

Recent advances in capillary electrophoretic migration techniques for pharmaceutical analysis (2013–2015)

This review updates and follows‐up a previous review by highlighting recent advancements regarding capillary electromigration methodologies and applications in pharmaceutical analysis. General approaches such as quality by design as well as sample injection methods and detection sensitivity are discussed. The separation and analysis of drug‐related substances, chiral CE, and chiral CE‐MS in addition to the determination of physicochemical constants are addressed. The advantages of applying affinity capillary electrophoresis in studying receptor–ligand interactions are highlighted. Finally, current aspects related to the analysis of biopharmaceuticals are reviewed. The present review covers the literature between January 2013 and December 2015.     

Synthesis,Antiviral, and Antimicrobial Activity of N‐ and S‐Alkylated Phthalazine Derivatives

A series of N‐alkylphthalazinone were synthesized by the reaction of phthalazin‐1(2H)‐one derivatives 1a , 1b , 1c with alkylating agents namely, propargyl, allyl bromide, epichlorohydrin, 1,3‐dichloro‐2‐propanol, 4‐bromobutylacetate, and 1‐(bromomethoxy)ethyl acetate to give the corresponding N‐alkylphthalazinone 2a , 2b , 2c , 3a , 3b , 3c , 5a , 5b , 5c , 6a , 6b , 6c , 7a , 7b , 7c , and 9a , 9b , 9c . Alkylation of phthalazin‐1(2H)‐thione to give a series from S‐alkylphthalazine 12 , 13 , 14 and thioglycosides 15 and 17 was performed. Deprotection of compounds 7a , 7b , 7c , 9a , 9b , 9c , 15 , and 17 resulted in the formation of the corresponding products 8a , 8b , 8c , 10a , 10b , 10c , 16 , and 18 . The structure of newly synthesized compounds was assigned by IR, ¹H, ¹³C NMR, and elemental analysis. Some of these compounds were screened for antiviral and antimicrobial activity.     

The Syntheses of Purine and Pyrimidine Secoribo-nucleosides: Acyclo-uridine Derivative of Cyclophosphamide

The synthesis of secoribo-nucleoside analogues is described. Compounds 4 and 5 possess interesting antiviral effects in vitro. A procedure is also developed for the conversion of acyclo-uridine nucleoside 7 to a novel derivative of cyclophosphamide 8 .