Production of benzazepine derivatives via four-component reaction of isatins: study of antioxidant activity.

In current research, benzazepine derivative is synthesized via a new process of four-component reaction of isatin or its derivatives, α-haloketones, activated acetylenic compounds, isoquinoline and potassium fluoride/clinoptilolite nanoparticles (KF/CP NPs) in acidic solution of H2O2 in water at room temperature. Also, antioxidation property of some prepared benzazepines is investigated by employing trapping diphenyl-picrylhydrazine (DPPH) radical and ability of ferric reduction experiment. Among investigated compounds, compounds 5c have good results relative to BHT and TBHQ as standard antioxidant. Also, the Gram-positive and Gram-negative bacteria disk diffusion research is used for the confirmation of antimicrobial power of some prepared benzazepines. The achieved outcomes of disk diffusion experiment showed that these compounds avoided the growth of bacteria. Our procedure has a few benefits relative to reported method such as good rate of reaction, product with high efficiency, simple removal of catalyst from mixture of reaction. In the yield of the product, KF/clinoptilolite nanoparticles show a satisfactory recyclable activity.

Immobilized TiO2 nanoparticles on carbon nanotubes: an efficient heterogeneous catalyst for the synthesis of chromeno[b]pyridine derivatives under ultrasonic irradiation.

A new protocol for the synthesis of chromeno[b]pyridine derivatives is described via a three-component reaction of 4-aminocoumarin, aromatic aldehydes and malononitrile catalyzed by TiO2 nanoparticles immobilized on carbon nanotubes (TiO2-CNTs) as an efficient heterogeneous catalyst under ultrasonic irradiation in water. The sustainable and economic benefits of the protocol are the high yields of products, short reaction time, simple work-up procedure, and use of a non-toxic and reusable catalyst.

Quantification of Meloxicam in Human Plasma Using Ionic Liquid-Based Ultrasound-Assisted In Situ Solvent Formation Microextraction Followed by High-Performance Liquid Chromatography.

A robust extraction method against the variations of sample ionic strength viz. ionic liquid-based ultrasound-assisted in situ solvent formation microextraction (IL-UA-ISFME) was coupled for the first time with high-performance liquid chromatography-ultraviolet detection (HPLC-UV), and successfully used as a more sustainable approach for the determination of meloxicam (MEL) in human plasma. Herein, a hydrophobic IL (1-butyl-3-methylimidazolium hexafluorophosphate) was formed by adding a hydrophilic IL (1-butyl-3-methylimidazolium tetrafluoroborate) to aqueous sample solution containing an ion-exchange reagent (sodium hexafluorophosphate). The target analyte was transferred into the IL medium while the extraction solvent was completely dispersed into the sample using ultrasonic irradiation and then, the settled enriched phase was injected to HPLC. Firstly, main factors affecting the microextraction performance were evaluated and optimized. The linearity was in the range of 5-1,500 ng mL-1 with regression coefficient corresponding to 0.997. Limits of detection (LOD; signal-to-noise ratio (S/N) = 3) and quantification (LOQ, S/N = 10) were 1 and 5 ng mL-1, respectively. An acceptable recovery range of 82.1-93.6% and satisfactory intra-assay (3.6-4.8%, n = 6) and inter-assay (3.3-5.1%, n = 9) precision as well as remarkable sample clean up exhibited good efficiency of the method. The freeze-thaw stability study was performed for samples and standard solutions. To study the applicability of the proposed method, it was employed for the determination of MEL in human plasma after oral administration of the drug and some pharmacokinetic data were achieved. The technique proved to be accurate and reliable for the screening intentions.

Synthesis and Antinociception Activities of Some Novel Derivatives of Phencyclidine with Substituted Aminobenzothiazoles.

BACKGROUND: Phencyclidine (PCP) as well as the analogues has indicated several pharmacological behaviors like analgesic, anticonvulsant, antianxiety, antidepressant depending on the dose and species examined. They interact with some neurotransmitter systems in the central nervous system like particular affinity for PCP sites in NMDA receptors or dopamine uptake blocking or both. OBJECTIVE: Due to analgesic properties of aminobenzothiazoles family, piperidine ring of PCP was replaced with electron-donating and electron-withdrawing substituted aminobenzothiazoles (1-4) for obtaining new analogues (II-V) with more analgesic activities. METHODS: Synthesis of new compounds (II-V) and measuring the acute and chronic pain properties of them were carried out through applying tail immersion &formalin tests on mice and the outcomes compared with control & PCP groups at dosage of 10 mg/kg. RESULTS: III & V with substituted methoxy and methyl-aminobenzothiazoles indicated better activity to lessen acute and chronic (thermal and chemical) pains compared with unsubstituted & phencyclidine animal groups. CONCLUSION: Methoxy and methyl-aminobenzothiazole derivatives" of phencyclidine revealed more analgesic activities compared with other groups which may concern to close affinity for DA uptake blocking as well as NMDA receptors in this family.

Ionic liquid phase microextraction combined with fluorescence spectrometry for preconcentration and quantitation of carvedilol in pharmaceutical preparations and biological media.

BACKGROUND: Carvedilol belongs to a group of medicines termed non-selective beta-adrenergic blocking agents. In the presented approach, a practical and environmentally friendly microextraction method based on the application of ionic liquids (ILs) was followed by fluorescence spectrometry for trace determination of carvedilol in pharmaceutical and biological media. METHODS: A rapid and simple ionic liquid phase microextraction was utilized for preconcentration and extraction of carvedilol. A hydrophobic ionic liquid (IL) was applied as a microextraction solvent. In order to disperse the IL through the aqueous media and extract the analyte of interest, IL was injected into the sample solution and a proper temperature was applied and then for aggregating the IL-phase, the sample was cooled in an ice water-bath. The aqueous media was centrifuged and IL-phase collected at the bottom of the test tube was introduced to the micro-cell of spectrofluorimeter, in order to determine the concentration of the enriched analyte. RESULTS: Main parameters affecting the accuracy and precision of the proposed approach were investigated and optimized values were obtained. A linear response range of 10-250 µg I(-1) and a limit of detection (LOD) of 1.7 µg I(-1) were obtained. CONCLUSION: Finally, the presented method was utilized for trace determination of carvedilol in commercial pharmaceutical preparations and biological media.

Removal of Co(II), Cu(II) and Pb(II) ions by polymer based 2-hydroxyethyl methacrylate: thermodynamics and desorption studies.

Removal thermodynamics and desorption studies of some heavy metal ions such as Co(II), Cu(II) and Pb(II) by polymeric surfaces such as poly 2-hydroxyethyl methacrylate (PHEMA) and copolymer 2-hydroxyethyl methacrylate with monomer methyl methacrylate P(MMA-HEMA) as adsorbent surfaces from aqueous single solution were investigated with respect to the changes in pH of solution, adsorbent composition, contact time and temperature in the individual aqueous solution. The linear correlation coefficients of Langmuir and Freundlich isotherms were obtained and the results revealed that the Langmuir isotherm fitted the experiment results better than Freundlich isotherm. Using the Langmuir model equation, the monolayer removal capacity of PHEMA surface was found to be 0.7388, 0.8396 and 3.0367 mg/g for Co(II), Cu(ΙΙ) and Pb(II) ions and removal capacity of P(MMA-HEMA) was found to be 28.8442, 31.1526 and 31.4465 mg/g for Co(II), Cu(ΙΙ) and Pb(II) ions, respectively. Changes in the standard Gibbs free energy (ΔG0), standard enthalpy (ΔH0) and standard entropy (ΔS0) showed that the removals of mentioned ions onto PHEMA and P(MMA-HEMA) are spontaneous and exothermic at 293-323 K. The maximum desorption efficiency was 75.26% for Pb(II) using 0.100 M HNO3, 70.10% for Cu(II) using 0.100 M HCl, 59.20% for 0.100 M HCl 63.67% Co(II).

Microwave-assisted solvent-free synthesis of Bis(dihydropyrimidinone)benzenes and evaluation of their cytotoxic activity.

An effective one-pot synthesis of bis(dihydropyrimidinonoe)benzenes using chlorotrimethylsilane (TMSCl) through Biginelli condensation reaction of terephthalic aldehyde, 1,3-dicarbonyl compounds and (thio)urea or guanidine under microwave irradiation conditions is described. Excellent yields of the products and simple work-up are attractive features of this green protocol. Then, the cytotoxic activities of these compounds were evaluated on five different human cancerous cell lines (Raji, HeLa, LS-180, SKOV-3 and MCF7). Their cytotoxic study indicated that they possessed a weak to moderate activity. Furthermore, the higher activity of compound 4b bearing sulfur in C2 position of pyrimidinone ring showed the importance of this site for cytotoxic activity of these compounds.

Electrochemical synthesis of 4-(dihydroxyphenylthio)-2H-chromen-2-one derivatives.

The 4-(dihydroxyphenylthio)-2H-chromen-2-one derivatives have been synthesized by direct electrochemical oxidation of catechols in the presence of 4-mercaptocoumarin as a nucleophile in water/acetonitrile (50/50) solution, in a one-pot process, at carbon rod electrode, in an undivided cell and in constant current conditions, through an EC mechanism. The products are characterized by spectra data. Besides, the difference in electrochemical oxidation of catechol in the presence of 4-hydroxycoumarin and 4-mercaptocoumarin explained by computational structure, natural bond orbital (NBO) analysis and density functional theory (DFT: B3LYP/6-31G*//B3LYP/6-31G*) based methods, using the GAUSSIAN 98 package of programs.