Chemical Methodologies

Published by eJournalPlus

Online ISSN: 2588-4344

Articles


Scheme 1. The condensation of 2-naphthol with 3-nitrobenzaldehyde and thioacetamide
The synthesis of 1-thioamidoalkyl-2-naphthols catalyzed by [TMBSED][OMs]2 at 70 °C under solvent-free conditions
Comparison of the results of the reaction of 2-naphthol with 3-nitrobenzaldehyde and thioacetamide using our method with those obtained by the reported methods
N,N,N',N'-Tetramethyl-N,N'-bis(sulfo)ethane-1,2- Diaminium Mesylate ‎as a Highly Effective and Dual-functional Catalyst for the Synthesis of 1-Thioamidoalkyl-2-naphthols
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June 2020

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100 Reads

Navid Irannejad-Gheshlaghchaei

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Fig. 4. Plot of predicted RT obtained by L-M ANN against the experimental values (a) calibration and prediction sets of molecules and (b) for validation set 
Approach to Chemometrics Models by Artificial Neural Network for Structure: First Applications for Estimation Retention Time of Doping Agent

October 2017

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42 Reads

A quantitative structure–retention relationship (QSRR), was developed using the genetic algorithm-partial least square (GA-PLS), Kernel partial least square (GA-KPLS) and Levenberg-Marquardt artificial neural network (L-M ANN) approach for the prediction of the retention time (RT) of doping agents in urine. These retention times are obtained by ultra-high-pressure liquid chromatography–quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS). A suitable set of the molecular descriptors was calculated and the important descriptors were selected with the aid of the GA-PLS and GA-KPLS. By comparing the results, GA-KPLS descriptors are selected for L-M ANN. Finally a model with a low prediction error and a good correlation coefficient was obtained by L-M ANN. This model was used for the prediction of the RT values of some of doping agents which were not used in the modeling procedure. This is the first research on the QSRR of doping agents against the RT using the GA-PLS, GA-KPLS and L-M ANN model.

Study of Quantitative Structure-Activity Relationship (QSAR) of Diarylaniline Analogues as in Vitro Anti-HIV-1 Agents in Pharmaceutical Interest

October 2017

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133 Reads

A study of quantitative structure-activity relationship (QSAR) is applied to a set of 24 molecules derived from diarylaniline to predict the anti-HIV-1 biological activity of the test compounds and find a correlation between the different physic-chemical parameters (descriptors) of these compounds and its biological activity, using principal components analysis (PCA), multiple linear regression (MLR), multiple non-linear regression (MNLR) and the artificial neural network (ANN). We accordingly proposed a quantitative model (non-linear and linear QSAR models), and we interpreted the activity of the compounds relying on the multivariate statistical analysis. The topological descriptors were computed with ACD/ChemSketch and ChemBioOffice14.0 programs. A correlation was found between the experimental activity and those obtained by MLR and MNLR such as (Rtrain = 0.886 ; R2train = 0.786) and (Rtrain = 0.925 ; R2train = 0.857) for the training set compounds, and (RMLR-test = 0.6) and (RMNLR-test = 0.7) for a randomly chosen test set of compounds, this result could be improved with ANN such as (R = 0.916 and R2 = 0.84) with an architecture ANN (6-1-1). To evaluate the performance of the neural network and the validity of our choice of descriptors selected by MLR and trained by MNLR and ANN, we used cross-validation method (CV) including (R = 0.903 and R2 = 0.815) with the procedure leave-one-out (LOO). The results showed that the MLR and MNLR have served to predict activities, but when compared with the results given by a 6-1-1 ANN model. We realized that the predictions fulfilled by the latter model were more effective than the other models. The statistical results indicated that this model is statistically significant and showing a very good stability towards the data variation in leave-one-out (LOO) cross validation.

Fig1: Epoxidation of Norbornen 
Epoxidation of Norbornene in the Presence of Oxidizing Agents

June 2017

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532 Reads

Part1: epoxidation of norbornen and norbornadien in the presence of dimethyloxirane as reagent oxidant has been investigated. Part 2: A general procedure for the epoxidation of norbornen using hydrogen peroxide as the oxidant in the presence of ruthenium trichloride has been investigated. norbornene gave the epoxides at room temperature in good to excellent yield. And epoxy norbornene identified by H-NMR,FT-IR,13C-NMR method spectroscopics.

Figure 1. The theoretical geometric structure of the studied molecules. 
Figure 2. The density of states (DOS) graphs of the studied molecules. 
Scheme 1. The molecular structure of the studied silicon analogs of cyclobutadiene. 
Prediction of the Structural and Spectral Properties and Reactivity of the Silicon Analogs of Cyclobutadiene C4-nSinH4 (n=0-4) by Density Functional Theory Computations

October 2017

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82 Reads

In recent years, it has been noted that the silicon analogs of compounds have more pharmaceutical applications because of their more lipophilicity properties. The present research paper studies the structural and spectral properties and reactivity of the silicon analogs of cyclobutadiene compound. The study was done based on the quantum-mechanical computations. All studied compounds were optimized by B3LYP/6-311++G(d,p) basis set of theory. The IR computations showed no imaginary frequency for all molecules. So, the accuracy of computational methods was proved. This study indicates the silicon analogs have more benefits based on the structural and stability properties than the carbon analog.






Silica Boron Sulfonic Acid as a New and Efficient Catalyst for the Green Synthesis of Quinoxaline Derivatives at Room Temperature

June 2017

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119 Reads

A simple, highly efficient and green procedure for the condensation of aryl and alkyl 1,2-diamines with α-diketones in the presence of catalytic amount of silica boron sulfonic acid (SBSA) at room temperature is described. By Using this method, quinoxaline derivatives as biologically interesting compounds are produced in high to excellent yields and short reaction times.

Synthesis and Characterization of Novel Composite-Based Phthalocyanine Used as Efficient Photocatalyst for the Degradation of Methyl Orange

June 2017

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830 Reads

In this study, Copper-tetraaminophthalocyanine (CuTAP) supported on polyvinylcholoride by reflux condition was synthesized and characterized using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and UV-vis spectroscopy. The results showed that the photocatalytic degradation of methyl orange was performed in mild conditions at ambient pressure and temperature under visible light. The synthesized catalyst could be readily separated from the catalytic system by centrifuging and loss of activity was negligible when the catalyst was recovered in four consecutive cycles. The effect of operational various factors such as catalyst amount, initial dye concentration and contact time on degradation of methyl orange were investigated. Optimization results showed that maximum degradation of methyl orange efficiency 98.6 % was achieved at the optimum conditions.

Chemical Methodologies Synthesis, Characterization and Antimicrobial Activity of Cu(II), Pt(IV) and Au(III) Complexes with 2,6-bis(((1-decyl-1H-1,2,3- triazole-4-yl)methoxy)methyl)pyridine

December 2022

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37 Reads

In this work, 2,6-bis(((1-decyl-1H-1,2,3-triazole-4- yl)methoxy)methyl)pyridine was prepared by click reactions between 2,6-bis((prop-2-yn-1-yloxy) methyl) pyridine and 1-azidodecane catalyzed by cuprous ion, then used as ligand in complexation reaction with some metal ions [Cu(II), Pt(IV) , and Au(III)]. The prepared ligand chelates N2O2 with copper (II) and Gold (III), as well as N3O2 with Platinum (IV). Characterized by [Flame-AAS, C.H.N. analysis, 1H�13C-NMR, Mass Spectroscopy, UV/Vis, FT-IR, conductivity, and magnetic susceptibility] were used to describe these compounds in the solid-state. The L-Cu and L-Au complexes have square planer geometry, while the L�Pt complex has octahedral geometry. The biological behaviors as antibacterial (against Staphylococcus aureus, and Escherichia coli) and antifungal (against candida albicaus) of the prepared ligand with its complexes were tested in different concentrations (10, 50, 200) ppm after incubation at 37ºC for 24h.The results showed that the performance of the prepared compounds was better in resisting and inhibiting the growth of tested bacteria and fungi at high concentrations and that the gold complex was more synergetic effective than others.

Figure 2. Correlation graphics of theoretical chemical shift values of 1H and 13C NMR of the title compound. 
Figure 5. Calculated DOS plots of the title compound (using the B3LYP/6-311++G**). 
Figure 6. Molecular electrostatic potential (MEP) map of the title compound calculated using the B3LYP/6311++G** level. 
Table 7 .
Molecular structure, NMR, FMO, MEP and NBO analysis of ethyl-(Z)-3-phenyl-2-(5-phenyl-2H-1,2,3,4-tetraazol-2-yl)- 2-propenoate Based on HF and DFT Calculations

August 2017

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455 Reads

In the present work, for the first time the quantum calculations of Ethyl-(Z)-3-phenyl-2-(5-phenyl-2H-1,2,3,4-tetraazol-2-yl)-2- propenoate are evaluated using the HF and B3LYP methods with 6-311++G** basis set. The geometry of the title compound was optimized by B3LYP/6-311++G** level of theory. The theoretical 1H and 13C NMR chemical shift values of the title compound are calculated and compared with the experimental results. The computed data are in good agreement with the experimental data. Frontier molecular orbitals (FMOs), molecular electrostatic potential (MEP), energy gap between HOMO and LUMO, electronic properties, thermodynamic parameters, natural charges distribution (NBO charges) and NBO analysis were investigated and discussed by theoretical calculations.

Synthesis of New 1,2,4-Triazole Derivatives with Expected Biological Activities

November 2021

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135 Reads

To further study novel N-aceyl, N-thiourea and imidazole derivatives were synthesized. We used a multi-step reaction protocol that began with symmetrical 4-amino- 1,2,4-Triazole [I]. The synthesized compounds were characterized on the spectroscopic data and their physical properties. Also, we studied the anti-bacterial activity of the prepared compounds against three types of bacteria: Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa, some of which showed best antibacterial activity comparable with Ampicillin, as standard antibiotic. Furthermore, the cytotoxic effect of various concentrations of the prepared compounds [II] and [VI] was investigated against MCF-7 (human breast carcinoma cells), Hep G2 (human liver cancer cell line) and WRL-68 (human hepatic cell line), revealing a moderate activity at 400 μl/ml, which had no effect on the growth of normal WRL-68 cells, and confirmed the safety of using this type of molecules in medications.

Scheme 1: Synthesis of the target compounds (I)-(IV)a,b
Anti-bacterial /anti-fungal activities of synthesized compounds
Design, Synthesis, and Biological Activity of New Thiazolidine-4- One Derived from Symmetrical 4-Amino-1,2,4-Triazole

January 2023

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202 Reads

Thiazolidine-4-one derivatives (IV)a,b containing 1,2,4-triazole rings linked to 3,4,5-trihydroxyphenyl moiety were designed, synthesized, and biologically evaluated for the antibacterial/antifungal activities. These derivatives (IV)a,b were achieved from many sequence reactions. A multistep reaction protocol was used that began with the first step involving a new and very fast one-pot solventless greener microwave-assisted method of synthesis galloyl hydrazide (I) from gallic acid and hydrazine hydrate. The galloyl hydrazide (I) was used as the starting material for synthesizing new 5,5'-(4-amino-4H-1,2,4-triazole-3,5-diyl) bis (benzene- 1,2,3-triol) (II) via a reflux cyclization process of galloyl hydrazide in DMSO. On the other hand, new Schiff base (III)a,b was prepared via condensation reaction of the symmetrical 4-amino-1,2,4-triazole compound (II) and substituted aromatic aldehyde in ethanol. Finally, the treatment of Schiff bases (III)a,b was done with thioglycolic acid in refluxing dioxin by using zinc chloride (II) to afford the target thiazolidine- 4-one derivatives (IV)a,b. The structure identification of the new compounds (I-IVa,b) was elucidated by FT-IR,1H-NMR, and 13C-NMR. The new synthetic derivatives were subjected to antibacterial/ antifungal activity by using two types of Gram-positive and Gram-negative bacteria also test it against Candida albicans as a fungi sample.

Conformational Analysis of 2-halo-1,3,2-dioxaphosphinanes: A Density Functional Theory (DFT) Investigation

October 2019

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6 Reads

This research aimed at evaluating the stability of the 2-halo-1,3,2- dioxaphosphinanes conformers at the LC-BLYP/aug-cc-pVTZ level of theory. The estimation of the total energy and the dipole moments of the axial and equatorial conformations were first done for the aforementioned molecules. Intermediate states of the transformations of the axial to equatorial conformer were determined. In the basis of the calculations, the axial conformer was found to be more stable than the equatorial conformer in these molecules. Transition states of these transformations were studied, as well. IN addition, the energetic and thermodynamics parameters of these transformations were investigated. Change of the P=O bond distances were illustrated with endo and exo-anomeric effects. The comparison of the P-O bond distances indicated the shorter bonds in the axial conformer compared to the equatorial conformer. These changes attributed to a dominant LP (2)O  σ* (P-X) negative hyperconjugation interaction between a pair of non-bonded electrons on oxygen and the adjacent P-X bond in axial conformer. The partitioning of the total electronic energy E(tot) into Lewis E(L) and non-Lewis E(NL) parts was performed using the concept of the natural bond orbital (NBO) analysis. Then, the natural coulomb electrostatic (NCE) potential energies, total energies into Lewis components, and total steric exchange energies were estimated. Calculations revealed that axial conformer was more stable than the equatorial conformer in the studied molecules. In addition, the barrier energy values of the transformations of axialboatequatorial conformers enhanced with decreasing the electronegativity of halogen.

A Probe into Hydrolysis of Nitrile Moiety in 2-Amino-1-methyl-4-oxo-1,4-dihydroquinoline-3-carbonitrile

October 2020

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129 Reads

2-Amino-1-methyl-4-oxo-1,4-dihydroquinoline-3-carbonitrile 2 was prepared by the reaction of N-methylisatoic anhydride 1 with malononitrile via the ring-opening/ring closure pathway. The treatment of this compound with concentrated sulfuric acid at 100 °C gave a mixture of 2-amino-1-methyl-4- oxo-1,4-dihydroquinoline-3-carboxamide 3 and 2-amino-1-methyl-4-oxo-1,4- dihydroquinoline-3-carboxylic acid 4. The NMR analysis showed that the ratio of compound 3 to 4 in the mixture was one to two (1:2). When the later reaction was performed in the presence of NaOH in refluxing H2O:EtOH, the compounds 3 and 4 were not formed, but instead, ring cleavage occurred to give compound 2-(methylamino) benzoic acid 5 in high yield. Density functional theory (DFT) calculations at the M06-2X/6-311+G(d,p) level of theory was also used to compute the 1H NMR chemical shifts of the compounds 3 and 4. Good agreement between the DFT-calculated 1H NMR chemical shifts and corresponding experimental values confirmed the suitability of the optimized geometries for these compounds. Characteristics of the bonding interactions were explored using the atoms in molecules (AIM) analysis.

Figure 1: Some first members of Circumcoronene Series of Benzenoid Hk (k≥1) [29-33].
Figure 2. The Ring-cuts of Circumcoronene series of Benzenoid Hk (k≥1) [29-33]. 
On Topological Indices of Circumcoronene Series of Benzenoid [142]

January 2018

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480 Reads

Let G be a connected graph with vertex and edge sets V (G) and E(G), respectively. The first Zagreb index M1(G) was originally defined as as the sum of the squares of the degrees of all vertices of G Recently, we know a new version of the first Zagreb index as the Multiplicative Zagreb Eccentricity index that introduced by Nilanjan De and ε(u) is the largest distance between u and any other vertex v of G. In this paper we compute this new topological index of famous molecular graph “Circumcoronene Series of Benzenoid Hk”. Keywords: Molecular Graph; Circumcoronene series of Benzenoid; Topological index; Multiplicative Zagreb Eccentricity index.

CHEMM-2202-1437 (Galley Proof)

April 2022

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69 Reads

The aim of the study was to produce a Polyvinyl chloride-based membrane containing a polymer imprinted with a valproic acid molecule which was directly coated on a graphite electrode to determine the amount of valproic acid in aqueous samples. With the dispersion of molecularly imprinted polymer particles in dioctyl phthalate plasticizer as a solvent mediator, this potentiometric sensor was designed and after that it was embedded in a polyvinyl chloride matrix. The designed electrode showed a near-Nernstian slope of 54.1 ± 1 mV decade-1 in the concentration range of 10-6-10-2 M and a detection limit of 10-6 M with a response time of about 40 seconds for valproic acid and can be used for 2 months without divergence changing the potential. The fabricated electrode, in the pH range among 3.5-8.5, indicates the good sensitivity to valproic acid relative to the other ions. Finally, this electrode can be used as an indicator electrode in determining the concentration of valproic acid in valproic acid tablets

A New Continuous Flow Injection Analysis Method Coupled with NAG-ADF-300-2 Analyzer for Promethazine-HCl by Cadmium Iodide as a Precipitating Reagent

October 2021

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99 Reads

A highly accurate, simple, sensitive turbidimetric method was introduced for the determination of promethazine-HCl using a homemade NAG-ADF-300-2 system with continuous flow injection analysis system. This method is based on reaction between promethazine-HCl and cadmium iodide (CdI2) in the presence of ammonium acetate to obtain a white precipitate for the ion-pair complex. Turbidity was measured via the attenuation of incident light by precipitated at 0-180°. Optimum parameters were studied to increase the sensitivity for newly developed methodology of promethazine-HCl-cadmium iodide system. The linear dynamic range for the instrument response vs. concentration of promethazine-HCL-was 0.25-25 mmol. L-1 for cell A and 0.1-20 mmol.L-1 for cell B, and limit of quantitative (S/N=10) 360.5574 µg /sample for cell A and 275.5830 µg /sample for cell B respectively with correlation coefficient (r) 0.9961 for cell no. 1 (cell A) and 0.9966 for cell no.2 (cell B); RSD % was lower than 0.6%. A comparison was made between the newly developed method with UV-Spectrophotometric and turbidimetric method as a classical method by using the standard addition method via the use of t-test at 95% confidence level. In addition, F-test was utilized to predict which of the methods was more precise than other method. The comparison of data revealed that long distance chasing photometer (NAG-ADF-300-2) is the choice with excellent extended detection, wide application and more sensitivity.

Determination of Fuconazole Using Flow Injection Analysis and Turbidity Measurement by a Homemade NAG-4SX3-3D Analyzer

July 2022

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60 Reads

The research work exemplifies a sensitive, rapid, and simple procedure for measuring fluconazole using turbidity-continuous flow injection analysis for the generation of white precipitate via the reaction of fluconazole with phosphotungestic acid, and detecting the attenuation of incident light caused by light colliding with the precipitate surface grain using the NAG-4SX3-3D analyzer to determine turbidity (0-180 ͦ). The linear range extended from 0.01-18 mmol.L-1 for fluconazole measurements were considerably lower than 0.5 RSD % for the repetition (n=6) for the concentration chosen (2, 13 mmol.L-1), with limit of detection=7.5342 ng/sample from the gradual dilution over the lowest concentration on the calibration graph , linear dynamic range (r = 0.9989), (correlation coefficient), percentage linearity (R 2 percent = 99.79) traditional approaches (UV-spectrophotometric at λmax=260 nm with linear range (0.001-1) mmol.L-1 , r=0.9987, R 2 =0.9973, R 2 %=99.73, and turbidimetric method with linear range (0.01-17) mmol.L-1 , r= 0.9869, R 2 =0.9740, R 2 %= 97.40 were compared with the suggested strategy. In comparison to the typical reference method's 10 mm irradiation, it was discovered, in addition to the technique's developed sensitivity and the use of minimal chemicals, that this approach is characterized by a dynamic system, which avoids precipitated particle setting during measurements. The results indicated that the developed method has a wide range of concentration with a high linearity and sensitivity. Furthermore, the continuous dilution in CFIA allows for the management of high or low concentrations, for a wider range of applications. The devised approach is believed to be the most acceptable for fluconazole molecule determination in pure and pharmaceutical formulations when compared with the reference methods. The method used in this research work is a pioneered developed approach and proved its success in determination of fluconazole in pure and pharmaceutical formulations.

A Pioneered Homemade NAG-4SX3-3D Analyzer Coupled with Continuous Flow Injection Analysis New Approach for The On- Line Turbidimetric Measurements of Metronidazole in Pure and Pharmaceutical Formulations
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  • Full-text available

September 2023

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363 Reads

The detection of metronidazole (MTZ) in pure and pharmaceutical formulations is now possible with a newly developed analytical technique based on turbidimetric measurement (from 0 to 180 degrees) utilizing a NAG-4SX3-3D analyzer. The technique relied on the fact that phosphotungstic acid and metronidazole would precipitate white in an acidic medium, indicating the presence of an ion pair molecule. In order to measure turbidity, we used the attenuation of light after it collided with precipitated particles on surfaces with angles ranging from 0 to 180 degrees. We looked into both chemical and physical parameters. With a linear dynamic from 0.05 to 20 mmol.L-1, metronidazole has a correlation coefficient value ® of 0.9993. From the step-wise dilution for the least concentration in the linear dynamic range of the calibration graph with an RSD percent lower than 0.5 percent, we find that the detection limit for 3, 35 mmol.L-1 (n = 8) metronidazole is 29.953 ng/sample. Four medicinal items have been successfully identified using this method. Standard addition and a t-test were used to compare the newly developed method of analysis to the tried-and-true methods (the HANNA equipment for turbidity measurement and the UV-spectrophotometric method). The researchers found no significant difference between the three methods at the 95% confidence level.

Entry 1): white solid, yield, 90%, 1 H NMR
Effect of the catalyst dosage on the synthesis of naphthoxazine-3-one derivatives
Effect of microwave power on the synthesis of naphthoxazine-3-one derivatives
Microwave Assisted Solvent-free Synthesis of 1-phenyl-1, 2-dihydro-3H-naphtho[1, 2-e][1, 3]oxazin-3-one Catalyzed by FeCl3

October 2019

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175 Reads

Three-component coupling of 2-naphthol, aldehydes, and urea has been accomplished in the presence of FeCl3 under microwave irradiation and solvent-free conditions to afford the corresponding synthesis of 1-phenyl-1, 2-dihydro-3H-naphtho[1,2-e][1,3]oxazin-3-onederivatives in excellent yields. It is a promising catalyst for the microwave-assisted reaction providing high product yield in a short period.

Table 1 . optimization of amount of catalyst in synthesis of 2-amino-4H-chromene
Table 2 . optimization of solvent in synthesis of 2-amino-4H-chromene
Table 3 . synthesis of 2-amino-4H-chromene using MOF-5 as catalyst
Chemical Methodologies Original Synthesis of 2-Amino-4H-chromene Derivatives under Solvent-Free Condition Using MOF-5

November 2018

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514 Reads

MOF-5 has been employed as a powerful catalyst for the preparation of 2-amino-4H-chromene. A wide variety of aromatic aldehydes was condensed with malononitrile and 2-naphthol under mild and solvent-free conditions in the presence of the trace amount of catalyst. A variety of 2-amino-4H-chromene can be obtained in good to excellent yield up to 95% in relatively short time reaction and easy workup. KEYWORDS MOF-5 Metal organic framework Solvent-Free 2-Amino-4H-chromenes Graphical Abstract Synthesis of 2-Amino-4H-chromene Derivatives… P a g e | 252

Figure 1. Ketones investigated
Cyclodehydration and Baker-Venkataraman rearrangement methodologies for the preparation of fluorinated 4H-chromones

May 2020

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107 Reads

Trifluoromethylated and ring-fluorinated 4H-chromones have been prepared via cyclodehydration and via the Baker-Venkataraman rearrangement. The cyclodehydration of 4,4,4-trifluoro-1-(1-naphthol-2-yl)-1,3-butanedione was performed under a variety of base promoted and acid catalyzed processes enroute to 2-trifluoromethyl--naphthochromone. Using microwave irradiative, sonication and conventional processes, selected o-hydroxyaromatic ketones underwent single-pot, based promoted Baker-Venkataraman rearrangements with trifluoroacetic anhydride to give trifluoromethylated 4H-chromones in yields ranging from 50-82%. Microwave irradiation conditions allowed for yields ranging from 50-80%, which compare favorably to yields achieved via conventional methods (60-82%) as well as reducing reaction times by 55% compared to conventional refluxing conditions.

Chemical Methodologies Characterization of Catalyst: Comparison of BrØnsted and Lewis Acidic Power in Boron Sulfonic Acid as a Heterogeneous Catalyst in Green Synthesis of Quinoxaline Derivatives

September 2018

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104 Reads

A simple, highly efficient and green procedure for the condensation of aryl and alkyl 1,2-diamines with α-diketones in the presence of catalytic amount of boron sulfonic acid (BSA) and silica trimethyl borat (STMB) and silica triisopropyl borate (STIPB), as two novel heterogeneous Lewis acid catalysts at room temperature, is described. In this method, we proved that the BrØnsted acidic power of boron sulfonic acid (BSA) is more important than its Lewis acidity. Using this method, quinoxaline derivatives as biologically interesting compounds are produced in high to excellent yields.

Static and Dynamic Study of Novel 4-Formyl-N-Hexadecyl-N,N- Dimethylbenzenaminium Bromide Synthesized as a Corrosion Inhibitor Use in Petroleum Wells Acidizing Process

January 2023

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38 Reads

7 This study showcases the innovative synthesis of 4-formyl-N-hexadecyl-N,N-dimethylbenzenaminium bromide (FHDB) using a reaction of 1-Bromohexadecane and 4-di methyl amino benzaldehyde. The compound was then characterized through various techniques such as FT-IR, 1 H-NMR, and 13 C-NMR, along with physical property measurements. Thereafter, the synthesized FHDB was tested for its corrosion inhibition properties on C-steel in 6M HCl, with a focus on kinetics and thermodynamics using potentiodynamic polarization (PDP). The surface changes of the C-steel were observed through Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The study revealed that FHDB exhibited strong inhibitory properties against corrosion in 6M hydrochloric acid solutions, with an adsorption pattern on the steel surface in agreement with Langmuir adsorption isotherm. The results, which include corrosion and electrochemical testing data, demonstrate that the experimental corrosion inhibitors are typically practically equal between the fluid flow study (dynamic simulations) and the static study, which is attributable to the FHDB chemical structure. K E Y W O R D S FHDB Corrosion inhibition C-Steel 6M HCl Potentiostatic polarization Langmuir adsorption isotherm Dynamic autoclave

Figure 1. Schematic representation of the cell used for measurement of the transport of aromatic compounds [16]. 
Figure 2. Plot of concentration Cp of aniline in permeate vs. time t of the permeation measurement before and after treatment with Prussian blue (Fe III HCF III ) 
Figure 7. Permeation rates of phenol and a variety of charged aromatic compounds (10 mmol.L-1 ) across calix8/PVA membrane. 
Selective Transport of Aromatic Compounds across Parchment Supported Prussian blue Membrane

April 2018

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114 Reads

The study of permeation of Aromatic compounds across parchment-supported membrane treated with Prussian blue is presented. The skin layer of the metal hexacyanoferrate membrane consists of a network structure could be selectively used with defined pore size in the nanometer range to permeate molecules with different size molecules. In order to demonstrate a possible sieving of molecules, we have investigated the permeation of a variety of aromatic compounds such as aniline (An), phenol (Ph), and naphthalene (Np). For these neutral compounds, a size-selective transport was found. Size lead to a separation factor α(An/Ph) of 1.5 and α(An/Np) of 4 respectively. Finally, it is demonstrated that purely inorganic membrane of Prussian Blue (PB) can be prepared upon adsorption of ferric ion and hexacyanoferrate on porous support.

Effect of Lithium Salts on the Optical Properties of Poly Acrylonitrile/Poly Methyl Methacrylate Blends

June 2022

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66 Reads

Polymer blends from Poly Acrylonitrile/Poly Methyl Methacrylate (PAN/PMMA) with different blend ratios (80/20,75/25,70/30,65/35, and 60/40) wt% undoped and doped with various lithium (Li) salts (LiCO3, Li2SO4H2O, and LiCl) at 20 wt %. Different techniques were employed to investigate the composition and optical properties of the prepared blend samples undoped and doped with Lithium salts like FT-IR and UV-Visible spectroscopies. The optical properties analysis declared that the energy gap increased from (4.0 eV to 4.20 eV) by increasing of PMMA ratio from 20 to 40 wt %. In contrast, the energy gap reduced and shifted toward the low energy side by adding lithium salts; the minimum energy gap value was 2 eV obtained from 65 % PAN and 35 % PMMA doped with Li2CO3. The optical constants were determined and plotted as a function of wavelength in the range (of 100-1100) nm. The general results showed that the optical constants (n, εr, and εi) for undoped blends increased with the PMMA ratio from 20 to 35 wt%. In contrast, all-optical constants were grown with the addition of lithium salts.

Acid Activation of Iraqi Bentonite Clay and Studying its Structural, Dielectric and Electrical Behavior at Various Temperatures

March 2022

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137 Reads

Iraqi calcium bentonite was activated via acidification in order to be studied in terms of structural and electrical properties. The elemental analysis of treated bentonite was determined by using X-ray fluorescence while the unit crystal structure was studied through X-ray diffraction which shows disappearance of some fundamental reflections due to the treatment processes. The surface morphology, on the other hand, has been studied thoroughly by Scanning Electron microscopy SEM and Atomic Force Microscope AFM which shows some fragments of montmorillonite sheets. Furthermore, the electrical properties, of bentonite have studied including; the dielectric permittivities, conductivity, tangent loss factor, and impedance with range of frequency (0.1-1000 KHz) at different temperatures.

Toxicity of Callosobruchus maculatus exposed to the plant oils using the fumigation bioassay
Chemical Composition and Insecticidal Activities of Mentha Longifolia and Mentha Mozaffarianii Essential Oils against Callosobruchus Maculatus

August 2021

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77 Reads

Essential oils from two species of Mentha genus, (Mentha longifolia L. and Mentha mozaffarianii Jamzad), from the mint family Lamiaceae that grow in Iran were isolated and analyzed by GC and GC-MS and their insecticidal and repellent activities were investigated against adult cowpea beetles. Mortality rates increased with increasing of the time of exposure and concentration, where M. mozaffarianii oil showed more potent toxicity. Using the topical application, LD50s values of M. mozaffarianii and M. longifolia oils at 96 h after exposure against adults were 22.7 and 39.4 μg/adult, respectively. In the fumigant test, LC50s at 96 h after exposure was between 38.5 and 55.4 µL/L air against adults, respectively. The results demonstrated that no concentration-dependent effect was observed in the test of the repellent effect and M. longifolia oil was most repellent to C. maculatus adults at 10 µl/l air (29.00%) while M. mozaffarianii oil's repellency was 9% at a lower concentration of 5 µl/l air. The main chemical components of the M. longifolia oil were Pulegone (48.67%), Menthone (14.31%), 1, 8-Cineole (9.37%) and Camphor (6.60%) while the major constituents of oil of the M. mozaffarianii were Piperitone (23.59%), Linalool (14.44%), 1, 8-Cineole (11.77%) and Piperitenone oxide (9.39%).

Chemical Methodologies Gas Chromatography-Mass spectrum and Infra-Red spectral analysis of Fixed Oil from Sudanese Adansonia digitata Seeds

January 2021

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247 Reads

The recent trend of using natural products from the plants, either as pure constituents or as standardised extracts, provides many opportunities for novel drugs, precisely the wild edible plants. The Adansonia digitata is considered one of the most important therapeutic and nutritional wild edible plants because of bioactive compounds existing in the seed oil; therefore, this study investigated the petroleum ether and methanol seed oil extracts via using two analytical methods [GC-MS, and FTIR spectrometer]. The seed oil was extracted by using Soxhlet apparatus. The GC-MS analysis of A. digitata seed oil showed thirty-five compounds. About twenty-four of them showed peak Area > 1%, The major compounds were eight, they showed peak area% (2.6%-1508%), namely Hexadecanoic acid, methyl ester, 9-Octadecenoic acid, methyl ester, (E), 9, 17-Octadecadienal, (Z), 9, 12-Octadecadienoic acid (Z, Z)-, methyl ester, Diethyl malonic acid, monochloride, hexadecyl ester, Malonic acid, 4-heptyl propyl ester, 9-Octadecenal, and (Z), 13-Tetradecen-1-ol acetate, while the FTIR spectrum showed functional groups for alcohols, phenols, alkanes, alkenes, carbonyls and Carboxylic acids and aromatic compounds in the petroleum ether and methanol extracts with different absorbance bands and their correspondences. The GC-MS and FTIR analysis showed the availability of bioactive compounds in the plant extracts, and these ingredients may be responsible of pharmaceutical value of the A. digitata plant. K E Y

ANOVA analysis and post hoc test for parameters of G1, G2, C groups
Correlation of Serum Adiponectin and C-reactive protein with Other Biochemical Parameters in Iraqi Pregnant Women

January 2022

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53 Reads

Adiponectin has anti-inflammatory, insulin-sensitizing and anti-atherogenic properties, while C-reactive protein (CRP) is a systemic inflammation marker. This study was conducted to investigate the relation between adiponectin and CRP with glycemic, lipid profile, liver enzymes, and blood pressure parameters in gestation. Ninety pregnant women were divided into three groups including: Thirty pregnant women in their first trimester (G1 group), another thirty pregnant women in their third trimester (G2 group) and thirty non-pregnant women (C or control group). All subjects had been fasting for ten hours before blood samples were drawn. The concentrations of serum adiponectin, serum CRP, fasting plasma glucose, serum insulin, glycated hemoglobin, alanine amine-transferase, aspartate amine-transferase, and blood pressure parameters were assessed. The results showed that serum adiponectin significantly decreased in gestation in G1 group (p<0.01) and non-significantly in G2 group in comparison to the C group. CRP continuously increased from G1 to G2 groups (p<0.01) in comparison to C group. In G1 group, there was a significant increase in fasting serum insulin. The homeostasis model assessment of insulin resistance (HOMA2-IR), systolic blood pressure and alanine amine-transferase significantly increased (p<0.05) in G1 group compared with C group. The homeostasis model assessment for β cell function (HOMA2-β) and diastolic blood pressure significantly increased (p<0.01) in G1 group in comparison with C group. In G2 group, BMI, BF %, FSI, HOMA2-β, HOMA2-IR, systolic, diastolic blood pressure, and lipid parameters were significantly increased (p<0.01) in comparison to C group, while aspartate amine-transferase significantly changed (p<0.05) when compared with C group. This study showed that the early decrease in serum adiponectin and its late correlation with high density lipoprotein might be an adaption mechanism to protect maternal system against high triglycerides level in third trimester. K E Y

Removal of Methylene Blue from Aqueous Solutions using Nano-Magnetic Adsorbent Based on Zinc-Doped Cobalt Ferrite

January 2020

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352 Reads

In this study, Zn-substituted cobalt ferrite nanoparticles (CoFe1.9Zn0.1O4, CFZ) were successfully synthesized via a combined EDTA-citrate sol-gel process. The synthesized CoFe1.9Zn0.1O4 nanoparticles were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), point zero charge (pHpzc) and scanning electron microscopy (SEM). The adsorption experiments of methylene blue (MB) onto CFZ surface were conducted in batch mode. The experiments were conducted under different conditions (contact time, adsorbent dosage, initial pH solution, solution temperature and initial dye concentration). The experimental data were better fitted to pseudo-second-order (PSO) kinetic model (R2=0.9990). In addition, Langmuir isotherm (R2=0.9906) was the best model to describe the experimental adsorption data. The maximum adsorbed amount of MB (qmax) per unit mass of adsorbent was about 27.79 mg/g. The adsorption thermodynamics (i.e., ΔG°, ΔH°, ΔS°) revealed that the proposed adsorption process is feasible, spontaneous and exothermic in nature. The obtained results suggest that CFZ is a promising material used as an adsorbent for very toxic pollutants from aqueous solutions.

Adsorption and Photocatalytic Degradation of Crystal Violet Dye under Sunlight Irradiation Using Natural and Modified Clays by Zinc Oxide

June 2022

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445 Reads

A ZnO-supported natural volcanic Algerian clay (ZnO/CNA) was synthesized through an impregnation method to prepare a photocatalytic adsorbent integrated. The discoloration of crystal violet dye (CV) from an aqueous solution was carried out using natural and modified clays via zinc oxide by adsorption and photocatalytic degradation. The materials were characterized through X-ray fluorescence spectrometer (XRF), Scanning electronic microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The effects of diverse experimental parameters on the adsorption process efficiency were investigated. The photocatalysis process of CV was executed by the ZnO/CNA material under sunlight irradiation. The characterization results informed that ZnO nanoparticles were well dispersed on the clay surface (CNA). The adsorption experiments were well clarified via the kinetic model of pseudo-second-order and isotherm model of Langmuir with correlation coefficients (R2 > 0.99). Moreover, thermodynamic data showed that CV adsorption was endothermic, spontaneous, and physical. The adsorption capacity of CV was high utilizing ZnO/CNA material and gives 74.63 mg/g by the Langmuir equation. The photodegradation kinetics followed pseudo-1st order approximate the model of Langmuir-Hinshelwood. The discoloration efficiency with the ZnO/CNA (∼ 92%) was higher compared with the CNA (67%), clearly suggesting promoting effect of ZnO. K E Y

Figure 3: EDXS test for bolox before sintering
Figure 4: EDXS test for bolox after sintering
Results data of XRD before sintering
Chemical Methodologies Synthesis of Advanced ZTA for Orthopedic Application by Sol-Gel Method

September 2022

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65 Reads

The demand for ceramic products for orthopedic applications is increasing due to the lowest rate of wear. A fourth-generation ceramic (BIOLOX delta; CeramTec.) consists of 82 wt. % Al2O3, 17 wt. % (1.3 Yttria Stabilized ZrO2), 0.5 wt. % strontium oxide, and 0.5 wt. % chromium oxide. It has good mechanical properties compared to the other generations of ceramics (BIOLOX forte and pure alumina), which may increase the range of movement and decrease the rate of dislocation. This ceramic composite (delta) has a smaller grain size (0.6 μm) than previous alumina composites (1.8 μm). So, this paper tries to obtain the smallest grain size on the scale of nanometers to improve biolox properties and good distribution for its components. By the sol-gel method, the BIOLOX delta was prepared from the gel precursor and sintering at 1100 °C for 2 h in the oven. The heat-up rate was 5 °C/min. As-obtained particles were characterized before and after sintering temperature using X-Ray Diffraction (XRD), Energy Dispersive X-Ray Analysis (EDX), and Scanning Electron Microscopy (SEM). The dried powder which was obtained consists of phases, γ-Al2O3, θ-Al2O3, and δ-Al2O3, while ZrO2 is found as (t + m) ZrO2 after calcination and the obtained average grain size was (10.94 nm).

Figure 1. (a) Chromatogram obtained by gel filtration chromatography; (b) Chromatogram obtained by HIC
Figure 3. Comparison of Purification Results with Different Methods; a): Comparison of protein levels with three purification methods; b): Comparison chart and purity efficiency with three purification methods
Optimization of Streptokinase Mutant Protein Purification Method using Affinity Chromatography Technique

July 2020

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84 Reads

Protein purification has always been one of the most critical and challenging stages of drug-protein production. Streptokinase as the most common cost-effective fibrinolytic drug is no exception. In this research study, the mutated streptokinase producing clone (SK263cyc) to which the histidine tag was grown in TY2x medium, and SDS-PAGE assessed protein expression after induction of protein expression. Three different methods did protein purification. In the first one, metal, ion affinity chromatography (IMAC) technique was used. In the second solution, first, by filtration with ammonium sulfate, the purification was carried out, and then by affinity purification, chromatography continued. In the third solution, hydrophobic chromatography was utilized to purify the streptokinase protein. The purity of the ophthalmic purity was 93.2%, and the purity of hydrophobic purity was found to be 90.4%, whereas the combination of pre-treatment with ammonium sulfate and the purity of the ophthalmic method did not achieve more than 88%. The results of this study revealed that, the IMAC method is more suitable as a final method at the process of streptokinase purification than the other two approaches.

Micellar Properties of a Foam Extinguishing Agent Based on Fluorocarbon Non-Ionic and Hydrocarbon Cationic Surfactants in a Mixed System

May 2022

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120 Reads

Fluorocarbon surfactant containing perfluorinated is the key component in aqueous film-forming foam extinguishing agent (AFFF), although its environmental concern is becoming more evident. In order to reduce the amount of this fluorinated surfactant while maintaining the micellar and surface properties, mixed systems based on fluorocarbon non-ionic and hydrocarbon cationic surfactants have received more attention with the aim of decreasing the environmental hazard of perfluorinated surfactants. The micellar properties, surface activity, and synergistic behavior of mixture systems of non-ionic fluorocarbon surfactant (undecafluoro-n-pentyl-decaoxyethylene ether (C5F11EO10)) and three cationic surfactants with different alkyl chain (n-alkyltrimethylammonium bromides: 10 (DTAB), 14 (TTAB) and 16 (CTAB)) are investigated. The effect of cationic chain length on physicochemical and thermodynamic properties are evaluated. Results obtained highlight a remarkable effect of reduction of the critical micellar concentration (CMC) with an increase in length of the chain; this effect is due to high the increase of hydrophobicity with the increase of the chain length. Furthermore, mixed system (C10TAB-C5F11EO10) has optimal synergy for minimizing surface tension. Also, the case of mixed micelles solutions rich on C5F11EO10, CMC has less steric hindrance among hydrocarbons and fluorocarbons, which are more or less similar to carbon chains. Finally, the C5F11EO10 suggests a synergy of CMC reduction with intermediate activity between C16TAB-C5F11EO10 and the C10TAB-C5F11EO10. Mixed systems (Foam) containing short-chain fluorotelomers tend to promote fewer toxic alternatives.

Figure 3: Three-dimensional view of compounds 7a-8b from 9A-12A into the binding cavity of 1ad4, 2D view by Discovery studio of compounds 7a-8b from 9B-12B for 1ad4 (dihydropteroate synthetized of S. aureus)
Summary of protein used for molecular docking by MVD
Antimicrobial test of some prepared compounds 7, 8 (a, b)
Molecular Docking against bacterial Strains
Molecular Docking against Fungal Strains Molecular Docking against Fungal Strains A. flavus C. albican
As Antimicrobial Agents: Synthesis, Structural Characterization and Molecular Docking Studies of Barbituric Acid Derivatives from Phenobarbital

December 2021

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86 Reads

Despite phenobarbital having been used in various medical fields as hypnotics, anxiolytics, and anticonvulsants, it also contains active functional groups that can form dyes, polymers, antimicrobial, and anti-antioxidants agents. A series of barbituric acid derivatives containing 1,2,3,4-tetrazoline moiety were synthesized from phenobarbital. Phenobarbital as raw starting material was reacted with acrylonitrile compound to give diacetonitrile derivative, this compound was treated in two ways, urea and thiourea to form barbituric acid derivatives containing oxadiazole and thiadiazole ring respectively. The Schiff bases derivatives were synthesized from reacting the latter compounds with three aromatic aldehydes. In the final step, the barbituric acid derivatives containing 1,2,3,4-tetrazoline moiety were prepared by cycloaddition reaction between different Schiff bases derivatives and sodium azide. The synthesized compounds were characterized using melting point, 13C-NMR, 1H-NMR and FTIR techniques. The compounds were also tested against two kinds of bacteria and two kinds of fungi. Most of the prepared derivatives revealed a high and clear effect against different types of bacteria and fungi. Molecular docking of final barbituric acid derivatives were investigated using Molegro Virtual Docker (MVD).

Isolation and Characterization of Fatty Acid Derivatives from the Stem Barks of Albizia Amara (Fabaceae), Sudanese Medicinal Plant

July 2020

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113 Reads

In this work, four fatty acid derivatives including, methyl tritriacont-17-en-1-oate 1, (9Z, 12Z)-ethyl octadeca-9,12-dienoate 2, stearic acid 3, and 21-acetyl tetracosanoic acid 4 were isolated from acetone extract of the stem barks of Albizia amara by chromatographic separation [TLC and CC]. The structures of the isolated compounds were established on the basis of extensive spectroscopic studies including 1D, 2D-NM, and MS analysis, and compared with literature. Compound 1, 2 and 3 were reported first time from the Albizia genus and compound 4 was a new phytoconstituent isolated for the first time from plant sources.

Figure 1. The three-domain structure of HSA. The protein secondary structure is shown in different colors (N and C-termini are marked as N and C, respectively)
Figure 3. The binding sites of doxorubicin-HSA with the ligplus software
Figure 4. The-binding sites of goxorubicin-HSA with the pymol software
Chemical Methodologies Study of Interaction of Human Serum Albumin with Doxorubicin (Anti-Cancer Drug) by Docking Simulation

January 2018

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121 Reads

Human serum albumin (HSA) is one of the main endogenous vehicles for biodistribution of molecules by blood plasma. Association constants and thermodynamic parameters for the interaction of HSA with doxorubicin were studied by docking. Docking study suggests that doxorubicin is able to interact with HSA by means of hydrogen bond with one arginine residue, whereas the hydroxyl group is inserted in a hydrophobic pocket. The estimated of Gibbs free energies (ΔG°) is equal to-9.1 kcal/mol for the best model. The negative values of ΔG° indicate a spontaneous process. The association constant value (Ka ≈ 8×10 3 L.mol −1) is favorable for its efficient biodistribution by blood plasma. KEYWORDS Human serum albumin Doxorubicin Docking Thermodynamic parameters Study of Interaction of Human Serum Albumin … P a g e | 355 Graphical Abstract Introduction

Chemical Methodologies Thermostable Polarizing Film on the Basis of Poly (vinyl alcohol) and New Dichroic Synthesized Azo Dye for Optical Applications: Theoretical and Experimental Investigations A R T I C L E I N F O RM A TI ON A B S T R A CT

December 2017

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3,549 Reads

Quantum-chemical calculations using the Density Functional Theory (DFT) approach for structural analysis of the new dichroic mono azo dye: Sodium (E)-5-((4-carboxylatophenyl)diazenyl)-2-hydroxybenzoate (S) (trans isomer) was carried out using B3LYP methods with 6-311+G* basis set. After calculations, the new mono azo dye was synthesized. UV, FT-IR and 1H NMR spectra of the compound S are reported. The electronic spectrum of the mono azo dye S was also carried out in the water solution. Interpretation of absorption strips in UV region of spectrum was also reported. On the basis of the polyvinyl alcohol (PVA) and the new dichroic synthesized azo dye thermostable polarizer film absorbing in the UV region of spectrum (λmax=388 nm) with effect of polarization (PE) in the absorption maximum 97% was developed. The main spectral-polarization parameters (transmittance, optical density) of stretched PVA-films were measured and discussed. It was also established that oriented colored PVA-films is phenomenon of anisotropy of thermal conductivity. Thermal conductivity in the direction of orientation is higher than in the direction perpendicular to the orientations. The developed thermostable polarizer film was used in polarizing microscopes, circular polarizers, magnetometers, spectropolarimeters and electrical signals sensors.

Chemical Methodologies A Simple Spectrophotometric Method for the Determination of Famotidine via Reaction with Alizarin Red S

January 2022

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122 Reads

A simple, quick, and sensitive spectrophotometric method was proposed to determine famotidine (FAMT) in its pure form and pharmaceutical preparation (tablet). The method involves the reaction of FAMT with alizarin red S to produce a stable, water-soluble red complex with the maximum absorption signal at 528 nm, Beer's law is followed for standard FAMT solutions in the range of 6.0-80 µg/mL with a negative deviation at concentrations higher than 80 µg/mL. The method is sensitive. The molar absorptivity and Sandell᾽s sensitivity index values are 3.3 × 10 4 l/mol.cm and 0.0109 µg /cm 2 respectively. Two approaches were applied to determine the amount of FAMT in its pharmaceutical formulation (famosam tablets), the one depending on a regression equation and the second on the standard addition method. The results were obtained with sufficient precision and accuracy, with negligible effects from excipient interference. K E Y W O R D S Alizarin red S Famotidine Famosam tablets



The Activity of Alkyl Groups in Morpholinium Cation on Chemical Reactivity, and Biological Properties of Morpholinium Tetrafluroborate Ionic Liquid Using the DFT Method

October 2019

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494 Reads

The physical properties, chemical and biological properties are evaluated through the Density Functional Theory (DFT) of molecular mechanics. The difference between Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) is starting from -5.91 to 6.15, which means that chemical reactions change the same for all anions. The biological activity of predictions given by QSAR calculation is forecasted where the PIC50 of all ionic liquids is near or less than -4.00, as a result, these are considered as the highly bioactive ionic liquids. To identify these molecules, computational data is used to determine the vibrational and electronic spectrum.

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