Determination of blood glucose parameter from human blood serum by using a quartz crystal microbalance sensor coated with phthalocyanines compounds

Determining the blood glucose level is important for the prevention and treatment of diabetes mellitus. We developed a sensor system using Quartz Crystal Microbalance (QCM) to determine the blood glucose level from human blood serum. This study consists of two experimental stages: artificial glucose/pure water solution tests and human blood serum tests. In the first stage of the study, the QCM sensor with the highest performance was identified using artificial glucose solution concentrations. In the second stage of the study, human blood serum measurements were performed using QCM to determine blood glucose levels. QCM sensors were coated with phthalocyanines (Pcs) by jet spray method. The blood glucose values of 96 volunteers, which ranged from 71 mg/dL to 329 mg/dL, were recorded. As a result of the study, human glucose values were determined with an average error of 3.25%.     

Recent progress on coumarin scaffold-based anti-microbial agents (Part III)

The biological, therapeutic, and medicinal properties of coumarins (chromen-2-ones), and its analogs have triggered enormous studies aimed toward growing synthetic routes to these heterocyclic compounds. This review presents a systematic and comprehensive survey of the method of preparation, the chemical reactivity, and the anti-microbial properties associated with this system.     

Studies on Quinolinedione: Synthesis,Reactions, and Applications

In this account we present the rapidly expanding bibliography of published research concerning the progress in the area of quioline-2,4-dione chemistry, including synthetic strategies.     

Pictet-Spengler reactions of Tryptamine and tryptophan with cycloalkanones and ketonicMannich bases

APictet-Spengler reaction of Tryptamine (1) with cyclopentanone under physiological conditions gave 3-(cyclopentylideneaminoethyl)indole (3), which was cyclized to the 1-spirocyclic 1,2,3,4-tetrahydro-2-carboline (4). Treatment of (±)-tryptophan with cyclopentanone and cyclohexanone in acidic medium afforded the spirocyclic systems5 and6, respectively. ThePictet-Spengler reaction was extended further using ketonic bis-Mannich bases, to give compounds7 and8. The possibility of using other types of ketonic bases was investigated.

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DiePictet-Spengler-Reaktion von Tryptamin and Tryptophan mit Cycloalkanonen und Keto-Mannich-Basen

Zusammenfassung DiePictet-Spengler-Reaktion von Tryptamin (1) mit Cyclopentanonen ergab unter physiologischen Bedingungen 30(Cyclopentylidenaminoethyl)indole (3), die zu den spirocyclischen Tetrahydro-2-carbolinen4 cyclisiert wurden. Die Behandlung von (±)-Tryptophan mit Cyclopentanon oder Cyclohexanon in saurem Milieu ergab die spirocyclischen Systeme5 oder6. DiePictet-Spengler-Reaktion wurde auch auf Keto-Bis-Mannich-Basen zur Synthese der Verbindungstypen7 und8 ausgeweitet. Die Möglichkeiten zur Nutzung anderer Keto-Basen wurde untersucht.

     

A qualocation method for parabolic partial differential equations

In this paper a qualocation method is analysed for parabolicpartial differential equations in one space dimension. Thismethod may be described as a discrete H¹-Galerkin method inwhich the discretization is achieved by approximating the integralsby a composite Gauss quadrature rule. An O (h^4-i) rate of convergencein the W^i.p norm for i = 0, 1 and 1 p is derived for a semidiscretescheme without any quasi-uniformity assumption on the finiteelement mesh. Further, an optimal error estimate in the H² normis also proved. Finally, the linearized backward Euler methodand extrapolated Crank-Nicolson scheme are examined and analysed.     

Sensitive determination of hydrazine using poly(phenolphthalein), Au nanoparticles and multiwalled carbon nanotubes modified glassy carbon electrode

This study reports a detailed analysis of an electrode material containing poly(phenolphthalein), carbon nanotubes and gold nanoparticles which shows superior catalytic effect towards to hydrazine oxidation in Britton–Robinson buffer (pH 10.0). Glassy carbon electrode was modified by electropolymerization of phenolphthalein (PP) monomer (poly(PP)/GCE) and the multiwalled carbon nanotubes (MWCNTs) was dropped on the surface. This modified surface was electrodeposited with gold nanoparticles (AuNPs/CNT/poly(PP)/GCE). The fabricated electrode was analysed the determination of hydrazine using cyclic voltammetry, linear sweep voltammetry and amperometry. The peak potential of hydrazine oxidation on bare GCE, poly(PP)/GCE, CNT/GCE, CNT/poly(PP)/GCE, and AuNPs/CNT/poly(PP)/GCE were observed at 596 mV, 342 mV, 320 mV, 313 mV, and 27 mV, respectively. A shift in the overpotential to more negative direction and an enhancement in the peak current indicated that the AuNPs/CNT/poly(PP)/GC electrode presented an efficient electrocatalytic activity toward oxidation of hydrazine. Modified electrodes were characterized with High-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Amperometric current responses in the low hydrazine concentration range of 0.25–13 µM at the AuNPs/CNT/poly(PP)/GCE. The limit of detection (LOD) value was obtained to be 0.083 µM. A modified electrode was applied to naturel samples for hydrazine determination.     

Synthesis and Antimicrobial Evaluation of Novel Polyfused Heterocycles‐Based Quinolone

Syntheses of some new heterocyclic compounds incorporating quinolone moieties were achieved via reaction of 4‐hydroxy‐7‐methoxyquinolin‐2(1H)‐one ( 1 ) or 3‐bromo‐4‐hydroxy‐7‐methoxyquinolin‐2(1H)‐one ( 2 ) with binucleophilic reagents. The newly synthesized compounds were characterized by elemental analyses and spectral data (IR, ¹H‐NMR and mass spectra). The newly synthesized compounds were screened for their antibacterial activity against Gram‐positive bacteria (Bacillus thuringiensis) and Gram‐negative bacteria (Escherichia coli). The results showed clearly that compounds 1 and 3 are the more potent antibacterial agents against E. coli, compounds 4 , 5 , 6 and 8 , 9 , 10 , 11 , 12 , 13 exhibited moderate activities against E. coli strain, and compounds 7 and 11 exhibited weak activities compared with Gentamicin as a well known standard drug.     

Synthesis of Some New Fused and Binary 1,3,4‐Thiadiazoles as Potential Antitumor and Antioxidant Agents

Annulations of 2‐amino‐1,3,4‐thiadiazole ( 1 ) with α,β‐unsaturated carbonyl compounds 2 , 5 , and 9 afforded thiadiazolo[3,2‐a]pyrimidin 3 , benzamide 7 , and bis‐pyrazole derivative 11 . Cyclization of benzamide 7 with POCl₃ gave binary imidazole derivative 8 . Moreover, alkylation of 1 with 2‐bromo‐1‐(2H‐chromen‐3‐yl) ethanone ( 9 ) followed by cyclization gave imidazo[2,1‐b]‐1,3,4‐thiadiazole derivative 15 . Multicomponent reaction of 1 with heterocyclic and/or aromatic aldehyde and thioglycolic acid afforded the corresponding thiazolidinones 17 and 19 . Finally, a one‐pot synthesis of 1 with isatin and thiosemicarbazide furnished the spirotriazole 20 . The newly synthesized compounds were evaluated as antitumor agents.     

Vistas in the field of 1,3-oxathiolan-5-ones: Synthesis and chemical reactivity

This review covers many reports of the applications of multicomponent domino reactions (MDRs) in the synthesis of novel stereocontrolled mercapto-heterocycles from the 1972 up to the end of 2016. The reported approaches were employed for modifications of the oxathiolanone core for new construction of a mercapto-heterocycles scaffold from mercaptoacetyl transfer agent with various reagents.