Labeling of atenolol with radioactive iodine-125 using <Emphasis Type="Italic">N</Emphasis>-bromosuccinimide and hydrogen peroxide as oxidizing agents

An adopted method for the preparation of high radiochemical purity ¹²⁵I-atenolol was investigated. Direct radioiodination of atenolol was carried out using N-bromosuccinamide or hydrogen peroxide as an oxidizing agent. The reaction proceeds well within 30 min at room temperature (25 ± 1 °C) and afforded a radiochemical yield up to 97% as pure as ¹²⁵I-atenolol. Different chromatographic techniques (electrophoresis, TLC and HPLC) were used to determine the radiochemical yield and purity of the labeled product. Biodistribution studies were carried out in normal Albino Swiss mice and the results indicate that ¹²⁵I-atenolol can be used safely as myocardial imaging agent.     

Validated spectrophotometric methods for the simultaneous determination of ciprofloxacin hydrochloride and metronidazole in tablets

A binary mixture of ciprofloxacin hydrochloride (CIP) and metronidazole (MET) was determined by five simple and accurate methods, without prior separation. In the first method, CIP was determined by second derivative spectrophotometric method ((2)D) by measuring the amplitude at 282 nm (zero ordinate value of MET). On the other hand, the determination of MET was based on isosbestic point technique, where the total content of the mixture was determined at 294.5 nm (isosbestic point), then the content of MET could be calculated by subtraction. The second method was first derivative ratio spectrophotometric method ((1)DD) where the total amplitude at 261 and 285 nm and the amplitude at 295.5 nm were selected to simultaneously determine CIP and MET in binary mixture, respectively. The third method was based on dual wavelength analysis, in which two wavelengths were selected, at which the absorbances of the other component were the same. The fourth method depends on using Q-analysis method (absorbance ratio) which involves the formation of Q-absorbance equation using the respective absorptivity values at 294.5 nm (isosbestic point) and 281.5 nm (λ(max) of CIP). The fifth method is partial least-squares (PLS) chemometric technique for determination of CIP and MET. The developed methods were successfully applied to the analysis of CIP and MET in laboratory prepared mixtures and tablets with good recoveries and their validation was carried out following the International Conference on Harmonization (ICH) guidelines. The results obtained were statistically compared with each other showing no significant difference with respect to accuracy and precision.     

Numerical modeling of guided wave interaction with non-axisymmetric cracks in elastic cylinders

A three dimensional (3D) hybrid method combining the classical finite element (FE) method with the semi-analytical finite element (SAFE) technique is developed. This hybrid method is employed to study the interaction of guided waves with non-axisymmetric damages in cylinders. The near field surrounding the damage is analysed with the 3D FE method. The solution is expanded into sums of guided modes on both inlet and outlet cross-sections. Such eigenmode expansions enable separation into ingoing and outgoing waves, i.e., incident, reflected and transmitted waves. Using the SAFE method, elastic guided modes are then computed at the aforementioned cross-sections thus reducing the analysis to two dimensions (2D). The amplitudes of the incident modes are imposed, whereas those of the scattered modes are determined by solving the global system of the 3D hybrid FE-SAFE model. In this paper, a formula is proposed for the calculation of eigenforces and modal power flows from eigendisplacements and SAFE matrices. This has the advantage of simplifying the post-process of load eigenvectors in hybrid FE-SAFE methods. Results obtained for a vertical free-end cylinder are in good agreement with those published in the literature. Moreover, first results of the interaction of the fundamental compressional, flexural and torsional Pochhammer–Chree modes with non-axisymmetric vertical cracks are obtained and discussed. Then, the interactions of the fundamental compressional mode with oblique free-ends and cracks are briefly addressed. The power balance is shown to be satisfied with a good accuracy.     

13C NMR Assignments of Artemisinin,Desoxyartemisinin and Artemether

The ¹³C nmr assignments for all carbons except the methylene groups were made for artemisinin (1), artemether (2) and desoxyartemisinin (3). The assignments were based on chemical shift theory and confirmed by selective band decoupling experiments.     

Synthesis,In Vitro Anti-Microbial Analysis and Molecular Docking Study of Aliphatic Hydrazide-Based Benzene Sulphonamide Derivatives as Potent Inhibitors of α-Glucosidase and Urease

A unique series of sulphonamide derivatives was attempted to be synthesized in this study using a new and effective method. All of the synthesized compounds were verified using several spectroscopic methods, including FTIR, ¹H-NMR, ¹³C-NMR, and HREI-MS, and their binding interactions were studied using molecular docking. The enzymes urease and α-glucosidase were evaluated against each derivative (1–15). When compared to their respective standard drug such as acarbose and thiourea, almost all compounds were shown to have excellent activity. Among the screened series, analogs 5 (IC₅₀ = 3.20 ± 0.40 and 2.10 ± 0.10 µM) and 6 (IC₅₀ = 2.50 ± 0.40 and 5.30 ± 0.20 µM), emerged as potent molecules when compared to the standard drugs acarbose (IC₅₀ = 8.24 ± 0.08 µM) and urease (IC₅₀ = 7.80 ± 0.30). Moreover, an anti-microbial study also demonstrated that analogs 5 and 6 were found with minimum inhibitory concentrations (MICs) in the presence of standard drugs streptomycin and terinafine.     

LC-ESI-MS/MS profiling of alkaloids and antiproliferative activity of Pachypoduim lamerei drake leaves

Abstract

In the present study, evaluation of the antiproliferative activity of Pachypodium lamerei Drake leaves (family Apocyaceae) against human breast cancer cell lines MDA-MB-231 was done for the total methanolic extract, crude alkaloidal mixture and ursolic acid using the MTT colorimetric assay. The methanolic extract showed the strongest antiproliferative activity followed by ursolic acid and crude alkaloidal fraction with an IC₅₀ equal to 6.2, 14.55 and 56.3?µg/ml respectively compared to oleocanthal. It is the first record for the LC/ESI-MS/MS alkaloidal profiling of the leaves of P. lamerei. Seven alkaloids were tentatively identified according to their fragmentation patterns. Four alkaloids were related to the parent indole class and two alkaloids belong to the quinoline class in addition to one steroidal alkaloid with a pregnan nucleus. Phytochemical investigation of the methanolic extract led to the isolation of three triterpenoidal compounds including ursolic acid, 11,12-didehydroursolic acid lactone and ursolic acid lactone.     

Mössbauer, X-ray, electrical and magnetic properties of lithium borosilicate glasses containing iron and manganese Part I. Mössbauer measurements

The effect of the replacement of MnO₂ by Fe₂O₃ on the oxidation states of iron in some lithium borosilicate glasses were studied using Mössbauer spectroscopy. DTA and infrared measurements showed the presence of two glassy phases, one of them containing iron and the other manganese. The Mössbauer spectra were measured at room temperature for all the glass samples. The spectra revealed the presence of Fe ions only in ferric state in both tetrahedral and octahedral coordination. Also, it was observed that the ratio between the number of iron ions in both coordination states has not changed with the increase of MnO₂ content.     

The use of Omega Chrome Black Blue G in chelatometric titrations

Summary The reactions of Omega Chrome Black Blue G with a large number of cations is studied. This study has shown in many cases high sensitivity limits of detection of metals. It also showed that this dye can be used as an indicator for EDTA titrations of zinc, cadmium, manganese and lead. It is also a suitable indicator for the step wise titration of calcium and magnesium in blood serum and water.     

Polarographische Untersuchungen an Solochromviolett RS in Pufferlösungen in Abwesenheit und in Gegenwart oberflächenaktiver Stoffe (SAS)

The polarographic behaviour of solochrome violet RS is investigated in buffer solutions of varying pH in the absence and presence of surfactants (triton 100-X and dodecylbenzene-sulphonate). The reduction proceeds irreversibly along a single wave in acid solutions and two waves in alkaline ones. The electrode reaction corresponds to four electrons in media of pH<2.5 and pH>8.0; in media of pH 4 5.5 two electrons are consumed. In solution of pH 2.5 4 or 5.5–8.0, both reactions contribute in varying magnitudes. The addition ofSAS causes the inhibition of reduction beyond the 2-electrons stage in acid solutions; the polarograms comprise one wave in case ofDBS and two waves of equal height in presence of triton. In alkaline media the polarogram comprises three waves due to the splitting of the main reduction wave. The kinetic parameters of the electrode reaction are also determined.     

Zur Kenntnis des Härtungsprozesses von Phenol-Formaldehyd-Harzen

Zusammenfassung Durch Hydrierung, Abbau und durch Vergleich des Verhaltens linearer Mehrkernverbindungen bei diesen Reaktionen wurde neuerdings experimentell geprüft, ob die annahme, daß gewisse Härtungsprodukte von Phenolalkoholen cyclische Struktur besitzen, zutrifft.