Deferiprone solubility in some non-aqueous mono-solvents at different temperatures: experimental data and thermodynamic modelling

The solubility of deferiprone (DFP) in five organic solvents including ethyl acetate, chloroform, acetonitrile, 1,4-dioxane and dichloromethane was investigated by the flask-shake method under atmospheric pressure at temperatures ranging from 293.15 to 313.15 K. In general, the solubility (mol L^–1) obeyed the following order from high to low in different mono-solvents: dichloromethane > chloroform > acetonitrile > 1,4-dioxane > ethyl acetate. The solubility of DFP in the mono-solvents increased with a rise of temperature. The solubility data were successfully correlated with the van’t Hoff equation. The generated data in this work and the previously published data were used to calculate the thermodynamic parameters of the system using the modified van’t Hoff equation, and the derived thermodynamic properties were correlated using Abraham solvation parameters.     

Fully integrated PDMS/SU-8/quartz microfluidic chip with a novel macroporous poly dimethylsiloxane (PDMS) membrane for isoelectric focusing of proteins using whole-channel imaging detection

A fully integrated polydimethylsiloxane (PDMS)/modified PDMS membrane/SU-8/quartz hybrid chip was developed for protein separation using isoelectric focusing (IEF) mechanism coupled with whole-channel imaging detection (WCID) method. This microfluidic chip integrates three components into one single chip: (i) modified PDMS membranes for separating electrolytes in the reservoirs from the sample in the microchannel and thus reducing pressure disturbance, (ii) SU-8 optical slit to block UV light (below 300?nm) outside the channel aiming to increase detection sensitivity, and (iii) injection and discharge capillaries for continuous operation. Integration of all these components on a single chip is challenging because it requires fabrication techniques for perfect bonding between different materials and is prone to leakage and blockage. This study has addressed all the challenges and presented a fully integrated chip, which is more robust with higher sensitivity than the previously developed IEF chips. This chip was tested by performing protein and pI marker separation. The separation results obtained in this chip were compared with that obtained in commercial cartridges. Side-by-side comparison validated the developed chip and fabrication techniques.     

Group 6 metal carbonyl complexes of 3′H-spiro[indole-3,2′-[1,3]benzothiazole-2(1H)]-one

The spiro-compound 3′H-spiro[indole-3,2′-[1,3]benzothiazole-2(1H)-one (IBTH₂) was synthesized and its structure was determined using spectroscopic techniques (FTIR, ¹H NMR and mass) and X-ray crystallography. This ligand possesses different centers for coordination. Reactions of [M(CO)₆], M = Cr, Mo or W with IBTH₂ in THF under reduced pressure were studied. For chromium a complex with molecular formula [Cr(ITP)₂] was isolated; where ITP is the opened form of the ligand which occurred through C_spiro–S bond, while [Mo(CO)₅(IBTH₂)] and [W(CO)₅(IBTH₂)] were isolated from the reaction of IBTH₂ with molybdenum and tungsten carbonyls, respectively. All complexes were characterized by elemental analysis, IR, mass and ¹H NMR spectroscopy. The biological activity of the ligand and its complexes were studied and compared with the parent compound isatin.     

Hydrophobic modification of nanocellulose and all-cellulose composite films using deep eutectic solvent as a reaction medium

Cellulose - In this work, deep eutectic solvent (DES) based on imidazole and triethylmethylammonium chloride was used as a reaction medium for the esterification of cellulose nanofiber (CNF) and...     

Determination of Sumatriptan and Zolmitriptan in Presence of Their Corresponding Degradation Products by HPTLC Methods

Accurate, sensitive, and precise high performance thin layer chromatographic (HPTLC) methods were developed and validated for the determination of sumatriptan and zolmitriptan in presence of their degradation products. Sumatriptan was separated from its degradation products and analyzed on TLC silica gel 60 F₂₅₄ plates using chloroform–ethyl acetate–methanol–ammonia (4:3:3:0.1, v/v) as a developing system followed by densitometric measurement of the bands at 228 nm. Zolmitriptan was determined using chloroform–ethyl acetate–methanol–ammonia (3:3:3:1, v/v) as a developing system followed by densitometric measurement at 222 nm. The methods were validated over a range of 0.5–4 μg/spot for sumatriptan and 0.5–3 μg/spot for zolmitriptan. The proposed methods were successfully applied for the determination of the studied drugs in bulk powder and in their pharmaceutical formulations.     

In vitro surface biocompatibility of high-content silicon-substituted calcium phosphate ceramics

The present work investigates surface biocompatibility of silicon-substituted calcium phosphate ceramics. Different silicon-substituted calcium phosphate ceramic bodies were prepared from co-precipitated powders by sintering at 1300°C. The in vitro bioactivity of the ceramics was assessed in simulated body fluid (SBF) at 37°C for periods up to 4 weeks. The changes in the surface morphology and composition were determined by scanning electron microscopy (SEM) coupled with electron probe microanalysis and energy dispersive spectrometer (EDX). Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to observe the change in ionic concentration of SBF after removal of the samples. The bioactivity of the ceramics increased with an increasing silicate ion substitution in a systematic way. The surface of ceramics with 2.23% silicon substitution was partially covered with apatite layer after one week, while ceramics with 8.1% silicon substitution were completely covered with apatite in the first week. The porous microstructure of high-concentration Si-substituted ceramics helps the dissolution of surface ions and the leaching process. This allows SBF to reach supersaturation in a short time and accelerate the deposition of apatite layer.      

Preparation, nano purification, quality control and labeling optimization of [64Cu]-5,10,15,20-tetrakis (penta fluoro phenyl) porphyrin complex as a possible imaging agent

Cu-64 was produced via the ⁶⁸Zn (p,αn)⁶⁴Cu nuclear reaction (≈200 mCi, >95 % chemical yield at 180 μA for 1.1 h irradiation, (radionuclidic purity >96 %, copper-67 as impurity) followed by purification with amino functionalized nano magnetic oxide, Fe₃O₄ aiming to remove trace amount of heavy metal ions from aqueous media due to achieve ultra pure [⁶⁴Cu] CuCl₂ for labeling step. [⁶⁴Cu] labeled 5,10,15,20-tetrakis(penta fluoro phenyl) porphyrin ([⁶⁴Cu]-TFPP) was prepared using freshly prepared [⁶⁴Cu] CuCl₂ (Cu-64; T _1/2 = 12.7 h) and 5,10,15,20-tetrakis(penta fluoro phenyl)porphyrin (H₂TFPP) for 60 min at 100 °C under reflux condition (radiochemical purity: >97 % ITLC, >98 % HPLC, specific activity: 14–16 GBq/mmol). Stability of the complex was checked in final formulation and human serum for 24 h. The partition coefficient was calculated for the compound (log P = 0.73). The biodistribution of the labeled compound in vital organs of wild-type rats was studied using scarification studies and PET imaging up in 2 and 4 h after injection. A detailed comparative pharmacokinetic study performed for ⁶⁴Cu cation and [⁶⁴Cu]-TFPP. The complex is mostly washed out from the circulation through kidneys and liver and can be an interesting tumor imaging/targeting agent due to high specific uptake and rapid excretion through the urinary tract.     

New Group 6 metal carbonyl derivatives of 2-(2'(-pyridyl)benzimidazole: synthesis and spectroscopic studies

Reaction of Cr(CO)(6) with 2-(2'-pyridyl)benzimidazole (pbiH) under reduced pressure resulted in the formation of the dinuclear complex [Cr(2)(CO)(6)(pbiH)(2)]. Infra-red (IR) spectroscopy revealed the presence of terminal and bridge Cr-CO bonds. Interaction of M(CO)(6), M=Cr, Mo and W, with pbiH in the presence of 2,2'-bipyridine (bpy) gave the tetracarbonyl complexes [M(CO)(4)(pbiH)].bpy. Spectroscopic studies of the complexes indicated the presence of hydrogen bonding between the bpy nitrogen and the NH group of pbiH. Reactions of M(CO)(6) with pbiH in the presence of PPh(3) gave the tricarbonyl monosubstituted derivatives [M(CO)(3)(PPh(3))(pbiH)]. The spectroscopic studies of the complexes suggested the proposed structures.     

Structural studies of 3-chloro-N-(8′-quinolyl)×benzo[b]thiophene-2-carboxamide

3-Chloro-N-(8′-quinolyl)benzo[b]thiophene-2-carboxamide was synthesized from 3-chlorobenzo[b] thiophene -2-carboxyl chloride and 8-aminoquinoline in the presence of triethylamine. The single crystal X-ray structure determination confirmed the earlier proposed structure and also characterized by ¹HNMR, and Mass spectroscopy. Crystallographic study reveals that the structure crystallizes in monoclinic system, a = 14.878(4) ?, b = 8.4292(15) ?, c = 25.461(7) ?, β = 112.022(18)°, Z = 8, V = 2960.20(12) ?³ with space group C2/c (No. 15). In the structure packing, three kinds of interactions are responsible for the stability of the structure. Infinite two-dimensional stair-like layered chains are formed by relatively strong intermolecular hydrogen bonds [C14—H14...O1]. These parallel chains are connected by several π—π and CH—π interactions, alternatively. There are two such parallel chains with 70.53°, which are in contact by van der Waals interactions.     

Synthesis,characterization and catalytic performance of nanosized iron-cobalt catalysts for light olefins production

Nanosized Fe-Co catalysts were prepared by co-precipitation method and studied for the conversion of synthesis gas to light olefins.In particular,the effects of a range of preparation variables such as Co/Fe molar ratios of the precipitation solution,pH value of precipitate,temperature of precipitation,promoters and loading of optimum promoter on the structure and catalytic performance are investigated.The optimal nano catalyst for light olefins (C2-C4) production was obtained over the catalyst with Co/Fe molar ratio of 3/1 which promoted with 2 wt% K.The results show that the best operational conditions were GHSV=2200 h-1 (H2/CO=2/1) at 260℃ under atmospheric pressure.Characterization of catalysts were carried out using X-ray diffraction (XRD),thermal gravimetric analysis (TGA),differential scanning calorimetry (DSC),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and N2 physisorption measurements such as Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods.