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  • 更新日期:2018-09-09
  • Keto-enol tautomerism in new silatranes Schiff bases tailed with different substituted salicylic aldehyde
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-09-08
    Alexandra Bargan, Mirela Fernanda Zaltariov, Angelica Vlad, Ana-Maria-Corina Dumitriu, Alina Soroceanu, Ana-Maria Macsim, Mihaela Dascalu, Cristian Dragos Varganici, Maria Cazacu, Sergiu Shova
  • Characterization of Agar-CMC/Ag-MMT nanocomposite and evaluation of antibacterial and mechanical properties for packaging applications
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-09-06
    Dipak Makwana, Johanna Castaño, Rajesh S Somani, Hari C Bajaj
  • Intraspecific chemical variability of the Essential Oils of Moroccan endemic Origanum elongatum L. (Lamiaceae) from its whole natural habitats
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-09-01
    Mohamed Bakha, Noureddine El Mtili, Nathalie Machon, Kaoutar Aboukhalid, Fatima Zahra Amchra, Abdelkarim Khiraoui, Marc Gibernau, Félix Tomi, Chaouki Al Faiz
  • 更新日期:2018-09-03
  • Adsorbent materials based on a geopolymer paste for dye removal from aqueous solutions
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-09-01
    Ali Maleki, Masita Mohammad, Zeynab Emdadi, Nilofar Asim, Mojtaba Azizi, Javad Safaei
  • Preparation, Characterization and Evaluation of Chitosan Biguanidine Hydrochloride as a Novel Antiscalant during Membrane Desalination Process
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-30
    Yasmine A. Maher, Mohamed E.A. Ali, Hend E. Salama, Magdy W. Sabaa

    Scale deposition is considered as one of the most critical problems leading to permeate flux decline and deterioration of membrane surface in reverse osmosis (RO) desalination plants. This study aims to preparation of novel high effective scale inhibitor, chitosan biguanidine hydrochloride (CG), to inhibit the precipitation of calcium sulfate and carbonate onto the membrane surface. The modification of Chitosan by the guanidine group was to enhance its solubility in water, because chitosan as it is dissolves only in moderately acidic solutions. CG was synthesized and characterized by FTIR, 13C NMR and 1H NMR. The inhibition efficiency of our antiscalant was evaluated against CaSO4 and CaCO3 solutions at both static (induction time) and real application tests (cross-flow unit for 6 hours). CG showed a good performance as scale inhibitor for CaSO4 and CaCO3 at about 10 and 15 mg. L-1 with flux decline of 2.6 and 5% in feed water, respectively. In addition, the induction time of precipitation of CaSO4 increased from 3 to 15 min with the addition of CG. SEM analysis at different magnifications for Cs and CG proved that CG strongly affects the morphology of the precipitated calcium sulfate and calcium carbonate leading to distortion of crystals.

  • Mechanistic roles of substitutional Fe dopants on catalytic acetylene-sensing process of flame-made SnO2 nanoparticles
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-31
    Jirasak Sukunta, Anurat Wisitsoraat, Adisorn Tuantranont, Sukon Phanichphant, Chaikarn Liewhiran
  • High Pressure Study Of Nitrogen Doped Carbon Nanotubes Using Raman Spectroscopy And Synchrotron X-ray Diffraction
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-31
    Weiguang Shi, Hao Liu, Zhaohui Dong, Zhongying Mi, Sean Shieh, Sun Xueliang, Xiaoyang Liu
  • Biodiesel Production Evaluating the Use and Reuse of Magnetic Nanocatalysts Ni0.5Zn0.5Fe2O4
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-31
    J. Dantas, E. Leal, D.R. Cornejo, A.C.F.M. Costa
  • 更新日期:2018-08-28
  • Synthesis and application of a triazine derivative containing boron as flame retardant in epoxy resins
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-27
    Shanshan Chen, Lianghui Ai, Tie Zhang, Ping Liu, Weishi Liu, Yonghong Pan, Dongfa Liu
  • Paper flower-derived porous carbons with high-capacitance by chemical and physical activation for sustainable applications
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-27
    Pitchaimani Veerakumar, Thandavarayan Maiyalagan, Balasubramaniam Gnana Sundara Raj, Kuppuswamy Guruprasad, Zhongqing Jiang, King-Chuen Lin
  • The effect of polyethylene glycols on the interaction and stability of AOT/water/isooctane microemulsions
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-16
    Dashuang Fan, Zhiguo Hao, Peizhu Zheng, Jihua Zhao, Weiguo Shen
  • Improved Corrosion Resistance of Mild Steel in Acidic Solution by Hydrazone Derivatives: An Experimental and Computational Study
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-16
    Hassane Lgaz, Ill-Min Chung, Mustafa R. Albayati, Abdelkarim Chaouiki, Rachid Salghi, Shaaban K. Mohamed
  • Chemical Composition and Biological Activities of the Aqueous Fraction of Parkinsonea aculeata L. Growing in Saudi Arabia
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-15
    Wafaa H.B. Hassan, Sahar Abdelaziz, Hanan M. Al Yousef
  • 更新日期:2018-08-15
  • A completely green approach to the synthesis of dendritic silver nanostructures starting from white grape pomace as a potential nanofactory
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-14
    Katya Carbone, Mariano Paliotta, Laura Micheli, Claudia Mazzuca, Ilaria Cacciotti, Francesca Nocente, Alessandra Ciampa, Maria Teresa Dell'Abate
  • Synergistic interface between Co3O4 and MgAl2O4 in CO2 assisted continuous vapour phase oxidative dehydrogenation of ethylbenzene to styrene monomer
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-09
    Venkata Rao Madduluri, Peddinti Nagaiah, Challa Prathap, K. Vasikarappa, Ajmeera Nagu, Burri David Raju, Kamaraju Seetha Rama Rao
  • Amorphous content on the photocatalytic performance of micrometer-sized tungsten trioxide particles
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-07
    Asep Bayu Dani Nandiyanto, Rosi Oktiani, Risti Ragadhita, Ajeng Sukmafitri, Rena Zaen
  • Functionalized electrospun carbon nanofibers for removal of cationic dye
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-04
    Badr M. Thamer, Hany El-Hamshary, Salem S. Al-Deyab, Mohamed H. El-Newehy
  • Quantitative screening of parabens in Ready-to-eat foodstuffs available in the Saudi market using high performance liquid chromatography with photodiode array detection
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-08-02
    Hadir M. Maher, Nourah Z. Alzoman, Munira Abdulaziz Almeshal, Hawazin Abdullah Alotaibi, Njoud Naif Alotaibi, Hessa Al-Showiman
  • Mesoporous cobalt phosphate electrocatalyst prepared using liquid crystal template for methanol oxidation reaction in alkaline solution
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-29
    Merfat S. Al-Sharif, Prabhakarn Arunachalam, Twaha Abiti, Mabrook S. Amer, Matar Al-Shalwi, Mohamed A. Ghanem

    A crystalline mesoporous cobalt phosphate (meso-CoPi) electrocatalyst is prepared using liquid crystal template of non-ionic surfactant of Brij®78. The physicochemical investigations of the electrocatalyst executed by surface area analyzer, XRD, transmission electron microscope submits creation of a mesoporous crystalline nanostructured of meso-CoPi with a surface area of 124 m2g-1. This is an 10-fold greatness superior than that for bulk-CoPi particles produced without surfactant template. The meso-CoPi electrocatalyst comprises of metallic cobalt layered with a cobalt-oxo/hydroxo-phosphate layer which facilitates the electro-oxidation of methanol at modest overpotential of < 1.2 V vs RHE in alkaline solution. The methanol oxidation activity of the meso-CoPi catalyst shows more than 20-fold current increase at 1.4 VRHE in comparison to bulk-CoPi counterpart which due to the enhancement of the electroactive specific surface area. Liquid crystal template chemical approach provides a reproducible stage to synthesize mesoporous metal phosphates with improved electrocatalytic activities.

  • Comparative studies of sunlight mediated green synthesis of silver nanoparaticles from Azadirachta indica leaf extract and its antibacterial effect on Xanthomonas oryzae pv oryzae
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-29
    Mounil Mankad, Ghanshyam Patil, Dimpy Patel, Parthvi Patel, Armi Patel

    Biogenic synthesis of silver nanoparticle (AgNPs) has attracted worldwide attention as it is cheap and non-toxic. Therefore, in present study sunlight mediated silver nanoparticle was synthesized from Azadirachta indica A. Juss (Neem) leaf extract. Various combinations i.e., reducing agent (5, 10, 15 and 20 ml leaf extract), substrate concentration (1mM AgNO3) and sunlight durations (5, 10, 15 and 20 minutes) were assessed for their ability to synthesized stabilized AgNPs. Leaf extract provide both reducing and capping agent, while sunlight served as catalyst for the synthesis process. The green synthesized AgNPs were characterized using change in color due to Surface Plasmon Resonance further analyzed by UV-visible spectroscopy, dynamic light scattering for size, polydispersity index and zeta potential for stability studies and Fourier Transform Infrared Spectroscopy (FT-IR). The smallest size of synthesized AgNPs was 67.94±0.72 nm synthesized using to 20ml of reducing agent (leaf extract) and 5 minute of sunlight exposure. Antibacterial activity of synthesized silver nanoparticle was examined against plant pathogen Xanthomonas oryzae pv. oryzae (Xoo) and showed a good antimicrobial activity compared to 200 mg/l of streptocycline.

  • Tuning the morphological structure, light absorption, and photocatalytic activity of Bi2WO6 and Bi2WO6-BiOCl through cerium doping
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-29
    Mirabbos Hojamberdiev, Zuhra Kadirova, Ehsan Zahedi, Diego Onna, María Claudia Marchi, Gangqiang Zhu, Nobuhiro Matsushita, Masashi Hasegawa, Sara Aldabe Bilmes, Kiyoshi Okada
  • Preparation of nanoparticulate TiO2 containing nanocrystalline phases of Anatase and Brookite by electrochemical dissolution of remelted Titanium Components
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-29
    D. Ortega-Díaz, D. Fernández, S. Sepúlveda, R.R. Lindeke, J.J. Pérez-Bueno, E. Peláez-Abellán, J. Manríquez
  • Acylhydrazidate-based porous coordination polymers and reversible I2 adsorption properties
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-25
    Yan-Ning Wang, Rong-Yan Wang, Qing-Feng Yang, Jie-Hui Yu
  • Economical, environmental friendly synthesis, characterization for the production of zeolitic imidazolate framework-8 (ZIF-8) nanoparticles with enhanced CO2 adsorption
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-23
    Imran Ullah Khan, Mohd Hafiz Dzarfan Othman, Asim Jilani, A.F. Ismail, Haslenda Hashim, Juhana Jaafar, Mukhlis A. Rahman, Ghani Ur Rehman

    Zeolitic imidazole framework 8 (ZIF-8) nanoparticles were successfully synthesized in an aqueous solution at the ambient condition with a relatively low molar ratio of zinc salt and an organic ligand, Zn+2/Hmim (1: 8). ZIF-8 has remarkable thermal and chemical stability, tunable microporous structure, and a great potential for absorption, adsorption, and separation. Various physicochemical characterization techniques like X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), attenuated total reflected infrared spectroscopy (ATR-IR), thermogravimetric analysis (TGA), and surface area with pore textural properties by micromeritics gas adsorption equipment were performed to investigate the effect of base type additive triethylamine (TEA) on the morphology, crystallinity, yield, particle and crystal size, thermal stability and microporosity of ZIF-8 nanoparticles. The total quantity of basic sites and carbon dioxide (CO2) desorption aptitude was also calculated using CO2 temperature-programmed desorption (CO2-TPD) system. The pure ZIF-8 nanoparticles of 177 nm were formed at TEA/total mole ratio of 0.002. Furthermore, the size of ZIF-8 nanoparticles was decreased to 77 nm with increasing TEA/total mole ratio up to 0.004. The structures, particle sizes and textural properties of ammonia modified ZIF-8 particle can easily be tailored by the amount of aqueous ammonium hydroxide solution. The smallest ZIF-8 nanoparticles obtained were 75 nm after ammonia modification which shows excellent thermal stability and improved microporosity. The ZIF-8 basicity and uptakes of CO2 improved with TEA and ammonia modification which followed the order: A25ml–Z4 > Z4 > Z3 > Z5 > Z2 > A50ml–Z4. The proposed economical and efficient synthesis method has great potential for large-scale production of ZIF-8.

  • Hydrothermal synthesis, structural characterization and photocatalytic properties of β -Ag2MoO4 microcrystals: correlation between experimental and theoretical data
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-20
    Giancarlo da Silva Sousa, Francisco Xavier Nobre, Edgar Alves Araújo Júnior, Julio Ricardo Sambrano, Anderson dos Reis Albuquerque, Rosane dos Santos Bindá, Paulo Rogério da Costa Couceiro, Walter Ricardo Brito, Laécio Santos Cavalcante, Maria Rita de Morais Chaves Santos, José Milton Elias de Matos

    In this paper, we report about hydrothermal synthesis, structural characterization and photocatalytic properties of beta-silver molybdate ( β -Ag2MoO4) microcrystals obtained at different temperatures (100, 120, 140 and 160 °C) for 2h. These crystals were characterized structurally using X−ray diffraction (XRD), X-ray fluorescence, Rietveld refinement, micro−Raman (m−Raman) and Fourier-transform infrared (FT-IR) spectroscopies. Experimental and theoretical band gap values were correlated by ultraviolet−visible (UV−Vis) diffuse reflectance spectroscopy and periodic first-principles calculations in the framework of density functional theory (DFT) with the B3LYP-D3 hybrid functional. The crystals morphology was observed through field-emission scanning electron microscopy (FE-SEM) images. The photocatalytic properties of these crystals were investigated for degradation of rhodamine B (RhB) dye under UV−light. XRD patterns and Rietveld refinement data indicate that all crystals exhibit a spinel-type cubic structure with space group (Fd 3 _ m) formed by tetrahedral [MoO4] clusters and distorted octahedral [AgO6] clusters. m−Raman spectra exhibited five Raman-active modes in a range from 50 to 1,000 cm-1, while FT-IR spectra have three infrared active modes in a range from 400 to 1,100 cm-1. The experimental results from Raman and IR modes are in reasonable agreement with theoretically calculated results. Experimental UV−Vis spectra indicate a decrease in optical band gap (Egap = 3.35 eV to 3.32 eV) with the temperature rise. The calculated band structure revealed an indirect optical band gap (Egap) of approximately 3.94 eV. Moreover, theoretical calculations based on density of states and electron density maps were employed to understand the polarization phenomenon induced by structural defects in the β -Ag2MoO4 microcrystals. FE-SEM images revealed that the increase of processing temperatures promotes a change in shape of microcrystals from potatoes-like to coral-like. Finally, photocatalytic measures to degradation of the RhB dye resulted in the best catalytic performance for β -Ag2MoO4 microcrystals synthesized at temperatures of 120 and 140 °C, corresponding to 97.3% and 96.8% in the photodegradation of RhB dye under UV–light up to 2h. The stability of the β-Ag2MoO4 was investigated by reusing, resulting in f 97.2, 93.9 and 78.8% degradation of the RhB dye for the first, second and third cycle, respectively.

  • Fabrication of virus metal hybrid nanomaterials: An ideal reference for bio semiconductor
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-20
    Raja Muthuramalingam Thangavelu, Rajendran Ganapathy, Pandian Ramasamy, Kathiravan Krishnan

    Recently, Nanotechnology has made easier utilizing plant pathogens as a potential nanomaterial in biomedical applications. In this research work, we have exploited a devastating plant pathogenic virus of Squash leaf curl China virus (SLCCNV), as a nano-bio template (32 nm) to fabricate the gold and silver nanomaterials. This is achieved through the direct exposure of SLCCNV to gold chloride (HAuCll4) and silver nitrate (AgNO3) precursors at sunlight, resulted into SLCCNV-metallic-hybrid nanomaterials which are synthesized quick (∼5 min) and eco-friendly. However, virus hybrid nanomaterials are fabricated through the nucleation and growth of metal precursors over the pH-activated capsid of SLCCNV. Under the controlled fabrication process, it produced a highly arrayed virus-metallic-hybrid nanomaterial at nanoscale size limit. Its properties are thoroughly studied through spectroscopic techniques (UV–Vis, DLS, Raman) and electron microscopy (HRTEM & FESEM). In a follow-up study of cytotoxicity assay, the virus and its fabricated nanomaterials show better biocompatibility features even at high concentrations. Finally, the electrical conductivities of virus-metallic-hybrid nanomaterials (Au & Ag) are determined by simple “lab on a chip” system and Keithley's pico-ammeter. The result of electrical conductivity measurement revealed that hybrid nanomaterials have greater electrical conductive properties within the band-gap of semi-conductive materials. It is truly remarkable that a plant virus associated metal nanomaterials can be efficiently used as bio-semi-conductors which are the ideal one for biomedical applications.

  • Degradability and Biocompatibility of Magnesium-MAO: the Consistency and Contradiction Between in-vitro and in-vivo Outcomes
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-20
    Haitao Xu, Tu Hu, Manle Wang, Yuxin Zheng, Hui Qin, Huiliang Cao, Zhiquan An

    Magnesium-based metals are promising for biomedical use for its biodegradation characteristic. However, its rapid degradation in physiological environment impedes its application. Oxides coating is a widely-used form of surface modification to improve the corrosion resistance of biomaterials. In this study, we systematically compared two oxides coatings, steam oxidation (SO) and micro-arc oxidation (MAO), in controlling degradation and improving the biocompatibility of pure magnesium in vitro and in vivo. The addition of both coatings was found to reduce the degradation rate of magnesium in vitro at the early stage, but the corrosion behavior became severe with longer immersion time in all the groups. Unfortunately, all the coated and uncoated materials were found undermining the adhesion and proliferation of MC3T3-E1 cells in vitro, even at the first day of culture. In terms of in-vivo circumstance, the Mg-MAO group showed satisfying biocompatibility compared with pure Mg and Mg-SO, as is evidenced by radiographic results and histological analysis. Little corrosion was found, and more newly formed bone was observed in the animal model. These data suggest that the characteristic of in-vivo circumstance have considerable impacts on the degradation and bone integration process.

  • Cordierite honeycomb monoliths coated with Al(III)/ZrO2 as an efficient and reusable catalyst for the Knoevenagel condensation: A faster kinetics
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-20
    S.R. Pratap, S.Z.M. Shamshuddin, N. Thimmaraju, M. Shyamsundar

    Al(III)/ZrO2 with 5–25 wt% Al(III) was coated on honeycomb monoliths by dip & dry technique and were also prepared in their powder forms for the purpose of comparison. These prepared catalysts were characterized for their total acidity, crystallinity, and morphology. The catalytic activity of Al(III)/ZrO2 was examined in 3 different modes of heating, i.e., conventional, ultrasonic, and microwave. The effect of calcination temperature of the catalyst, poisoning of acid sites of the catalyst by adsorbing pyridine adsorption on the physico-chemical properties and the catalytic activity was also studied. The results indicated that the microwave heating mode shows highest catalytic activity when compared to either ultrasonic or conventional modes. The honeycomb form of the catalysts shows almost 1.2 fold time increase in their catalytic activity when compared to their powder forms. Pre-adsorption studies disclose that the Knoevenagel condensation reaction obeys the Langmuir-Hinshelwood type which involves chemisorptions of both of the reactants. A faster kinetic study confirms that monolithic catalysts [15Z-A (CHM)] possess the least energy of activation (35.6 kJ/mol) while their powder forms analogs [15Z-A (PFM)] posses highest activation energy (59.2 kJ/mol) correspondingly with a shorter reaction time indicating that monolithic catalysts are highly efficient compared to their powder forms. Reusability tests pertaining to both calcined and uncalcined catalysts authenticates that calcination enhances catalytic activity with the augmentation of catalytically active sites.

  • Synthesis of low-molecular-weight poly-α-olefins using silicon-bridged zirconocene catalyst for lubricant basestock
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-20
    Huaiqi Shao, Ruofei Wang, Hui Li, Xiaoyan Guo, Tao Jiang

    The oily oligomers with low-molecular-weight, medium kinematic viscosity and high viscosity index are yielded through oligomerizations of higher α-olefins (1-hexene, 1-octene, 1-decene, 1-dodecene and 1-tetradecene) and co-oligomerization of 1-decene with 1-butene in the presence of the silicon-bridged Ph2Si(Cp)(9-Flu)ZrCl2 catalyst and the methylaluminoxane co-catalyst. The oligomerization activity is affected by the bulkiness and lateral size of monomer, and the viscosity of oligomer obtained. Through adding of 1-butene to 1-decene, the oligomerization activity is decreased, but viscosity index of oligomer obviously is increased. The highest co-oligomerization activity of 1-decene with 1-butene is presented at the temperature of 60 °C and Al/Zr molar ratio of 300. 1H and 13C NMR spectroscopy reveal that four types of vinylidene are existed in oligomers and the major olefinic bonds are internal disubstituted vinylidene, which are produced through 2,1-misinsertion and β-hydride elimination, or 2,1-misinsertion and rearrangement followed by β-hydride elimination. The chain termination of oligomerization of α-olefins favors chain transfer to the co-catalyst to produce saturated end group. The oligomerization pathways are summarized.

  • Investigation on the g-C3N4 encapsulated ZnO nanorods heterojunction coupled with GO for effective photocatalytic activity under visible light irradiation
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-21
    N. Kumaresan, M. Maria Angelin Sinthiya, M. Praveen Kumar, S. Ravichandran, R. Ramesh Babu, K. Sethurman, K. Ramamurthi

    The present work reports on a novel ternary nanocomposite of ZnO rods encapsulated by graphitic like carbon nitride (g-C3N4) and coupled with graphene oxide (GO) prepared by ultrasonication assisted hydrothermal method which provides enhanced photocatalytic activity and stability. Field emission scanning electron microscopy analysis showed that the surface morphology of ZnO, g-C3N4 (prepared by heating method) and the GO contains nanorods structures, sheet like structures and sheets with porous structures respectively. Formation of rod like structures of ZnO and thin sheet like structures of g-C3N4 were observed from transmission electron microscopy analysis. Transmission electron microscopy analysis of g-C3N4 (6 wt.%)/ZnO nanocomposites showed that ZnO nanorods are encapsulated by the thin sheets of g-C3N4 and g-C3N4(6 wt.%)/ZnO/GO (30 mg) ternary nanocomposites contains porous structures of GO. The optical band gap of ZnO nanoparticles was shifted from 3.08 eV to 2.85 eV for g-C3N4(6 wt.%)/ZnO/GO(30 mg) ternary nanocomposites. Under visible light irradiation the ZnO nanorods and g-C3N4 (6 wt.%)/ZnO showed photodegradation efficiency of ∼21% and 90% respectively for 120 min whereas g-C3N4 (6 wt.%)/ZnO/GO(30 mg) showed about 99% photodegradation efficiency in a time period of 14 min. The recycle process carried out for g-C3N4(6 wt.%)/ZnO/GO(30 mg) composites up to five cycles showed 91.5% of photodegradation in the fifth cycle for a time period of 14 min. Total Organic Carbon (TOC) analysis shows removal of carbon content 83% of carbon content in 28 min. The Gas Chromatography-Mass Spectroscopy analysis shows the intermediate products of 1,2 benzenedicarboxylic acid and phthalic acid during the RhB dye photodegradation process. The radical trapping experiment reveals that the photo-induced holes (h+) are one of the main reactive species involved in the degradation of the RhB.

  • Physiochemical properties of TiO2 nanoparticle loaded APTES-functionalized MWCNTs composites and their photocatalytic activity with kinetic study
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-19
    Amirah Ahmad, Mohd Hasmizam Razali, Mazidah Mamat, Karimah Kassim, Khairul Anuar Mat Amin

    In this study, functionalized-MWCNTs with 3-aminopropyltriethoxysilane (APTES) loaded titania nanoparticles (MWCNTs-APTES-TiO2) were prepared to investigate their physicochemical properties and photocatalytic activity for methyl orange (MO) degradation. The TiO2 nanoparticles, functionalized-MNCNT and composite powders were characterized by XRD, raman, and TEM. The results obtained proved that titania (TiO2) nanoparticles was successfully loaded on APTES-MWCNTs. For application, MWCNTs-APTES-TiO2 composites were used as photocatalyst for degradation of methyl orange (MO) in aqueous solution under UV light irradiation and the result shows that 87% MO was degraded after 180 min. Kinetic analysis indicated that photocatalytic degradation of MO solution by MWCNTs-APTES-TiO2 obeyed second-order kinetic model (R2 > 0.95), supported by half-life equations and graph. Because of the presence of carbon nanotubes accelerated the degradation of methyl orange due to inhibition of electron-hole recombination, the formation of additional hydroxyl radicals and functional groups of the latter had an inhibitory effect on the degradation of methyl orange. This study suggested the MWCNTs-APTES-TiO2 nanocomposite has considerable potential as environmental photocatalyst due to higher degradation rate as compared to bare TiO2.

  • Determination of carbamates in soils by liquid chromatography coupled with on-line postcolumn UV irradiation and chemiluminescence detection
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-18
    José A. Murillo Pulgarín, Luisa F. García Bermejo, Armando Carrasquero Durán

    In this study, high performance liquid chromatography (HPLC) coupled with a simple and fast sample pre-treatment based on the use of the UV-irradiation in a simple continuous flow system for the chemiluminescent quantification of pesticide carbamates in soils was developed and validated. HPLC was used to separate thiodicarb, bendiocarb and carbaryl in soil extracts. The eluates emerging from the column tail were mixed with an alkaline solution of Co2+ in EDTA and irradiated with UV light to induce photolysis of the carbamates, in order to obtain free radicals and other reactive species capable of oxidizing luminol and producing photoinduced chemiluminescence (PICL) as a result. Measurements of CL intensity were plotted as a function of time to obtain chromatographic peaks. Under the optimum operating conditions for the combined HPLC-PICL system, CL peak areas were linearly related to analyte concentrations. The limit of detection were 0.05 mg L-1 for thiodicarb, 0.09 mg L-1 for bendiocarb and 0.17 mg L-1 for carbaryl. A simple extraction procedure using 98% methanol as solvent ensured complete dissolution of the analytes in spiked soils with recoveries from 87 to 120 %. The proposed method is a simple, fast, accurate choice for quantifying the target pesticides in soils.

  • Sodium hyroxyethylcellulose adipate: An efficient and reusable sorbent for cadmium uptake from spiked high-hardness ground water
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-17
    Muhammad Ajaz Hussain, Shahana Zaman, Azhar Abbas, Muhammad Nawaz Tahir, Muhammad Amin, Syed Zajif Hussain, Irshad Hussain

    Herein, we report on the evaluation of chemically modified hyrdroxyethylcellulose for its sorption efficacy to uptake Cd(II) from spiked high-hardness ground water (GW) and aqueous solution (DW). Hyrdroxyethylcellulose was chemically modified using adipic anhydride in the presence of DMAP as a catalyst under homogeneous reaction conditions. Hyrdroxyethylcellulose adipate (HEC-Adip) obtained was then converted to its sodium salt as HEC-Adip-Na after treating with NaHCO3. Structures were thoroughly characterized using FTIR, SEM, EDS and solid-state CP/MAS 13C NMR. The surface charge and morphology of the sorbent was determined using pHZPC (pH of zero point charge). The sorption data fitted well to Langmuir isotherm and pseudo-second order kinetic model. Maximum sorption capacity of Cd(II) was calculated to be 114.94 mg g–1 and 112.35 mg g-1 from DW and GW, respectively. Thermodynamic parameters, i.e., ΔH°, ΔS° and ΔG°, were also calculated and showed negative values indicating spontaneous and exothermic nature of sorption process. In addition, the synthesized sorbent is more suitable for repeated use because it shows negligible decrease in its sorption capacity for the uptake of Cd(II) from aqueous solution after five regeneration cycles.

  • Design, synthesis, molecular properties and in vitro antioxidant and antibacterial potential of novel enantiopure isoxazolidine derivatives
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-03
    Siwar Ghannay, Sana Bakari, Moncef Msaddek, Sébastien Vidal, Adel Kadri, Kaïss Aouadi

    A novel series of enantiopure isoxazolidines have been synthesized in good yields and with high stereoselectivity by 1,3-dipolar cycloaddition between a (–)-menthone-derived nitrone as a glycine equivalent and various terminal alkenes. The structures and the stereochemistry of the obtained cycloadducts have been determined by spectroscopic methods. Almost all the compounds were predicted to exhibit various degrees of antioxidant and antibacterial potentiality. Finally, the drug likeness and bioactivity were calculated using Molinspiration software. The results indicated that all compounds are in accordance with Lipinski’s rule of five showing good drug likeness and bioactivity score for drug targets with no violations.

  • Tailored surface silica nanoparticles for blood-brain barrier penetration: Preparation and in vivo investigation
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-05
    B.I. Tamba, V. Streinu, G. Foltea, A.N. Neagu, G. Dodi, M. Zlei, A. Tijani, C. Stefanescu

    Surface modified fluorescent silica nanoparticle derivatives (Ru@SNPs), namely, glucose (Glu) and glucose-poly (ethylene glycol) methyl ether amine (Glu-PEG) coated SNPs were designed and tested for their ability to penetrate the blood-brain barrier (BBB) in mice brain. The new obtained nanoparticles were characterized by field emission scanning electron microscope (FE-SEM), dynamic light scattering (DLS) and Fourier transform infrared (FTIR-ATR) analysis. The BBB penetration and distribution of tailored SNPs in mice brain were examined using confocal laser scanning microscopy (CLSM), flow cytometer (FACS) and transmission electron microscopy (TEM). The promising results obtained by in vivo experiments, point out that silica nanoparticle derivatives are an efficient permeable delivery vehicle that are able to cross the BBB and reach the brain tissues via specific and non-specific mechanisms. These findings will enrich the knowledge to rationally engineer multifunctional nanoparticles, and bring new insights into BBB permeability.

  • In vitro and in vivo characterization of mineralized hydroxyapatite/polycaprolactone-graphene oxide based bioactive multifunctional coating on Ti alloy for bone implant applications
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-05
    Nagaraj Murugan, Chandran Murugan, Ashok K. Sundramoorthy

    Hydroxyapatite (HAP) is a form of naturally occurring calcium apatite present in bone and tooth enamel. It is an important biomaterial with diverse biomedical applications such as a surface coating for metallic orthopedic implants. Synthesized pristine HAP has poor mechanical properties, inferior wear resistance and has limits for directly used in bone tissue engineering applications. To address these limitations, we synthesized a suitable orthopedic implant hybrid material (M-HAP/PCL/GO) by using positively charged calcium ions of mineralized HAP (M-HAP) combined with Polycaprolactone-negatively charged graphene oxide (PCL-GO). The successfully synthesized M-HAP/PCL/GO composite was comprehensively characterized by Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The micro-hardness technique was used to determine the mechanical strength of M-HAP (315 ± 4 Hv), M-HAP/GO (370 ± 3 Hv) and M-HAP/PCL/GO (455 ± 5 Hv). M-HAP/PCL/GO was also tested for its anti-bactericidal impact against Staphylococcus aureus and Escherichia coli. MG63 osteoblast cells cultured on the M-HAP/PCL/GO composite (10 mg/mL) coated sample, displayed outstanding viability after 3 and 5 days of incubation at pH 7.4, which indicated that the composite is suitable material for bone implants and induces the cell proliferation. It was also tested in vivo in Wistar rats and was observably beneficial bone formation within 28 days post-implant operation. These tests proved that the M-HAP/PCL/GO composite can be considered as a prospective candidate for future bone implant applications.

  • A novel and convenient oxidation-controlled procedure for the synthesis of oxazolines from TosMIC and aldehydes in water – Anti biofilm activity
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-05
    Rajan Abraham, Periakaruppan Prakash, Karthikeyan Mahendran, Murugappan Ramanathan

    A new convenient procedure for the synthesis of oxazolines from tosylmethyl isocyanide (TosMIC) and aldehydes using imidazole as an efficient catalyst has been reported. The synthesized oxazolines were able to be protected from the oxidation by using just water both as a good solvent and anti oxidant. All the synthesized compounds show good anti biofilm activity against Staphylococcus epidermidis.

  • Ag2O nanoparticles/MnCO3, –MnO2 or –Mn2O3/highly reduced graphene oxide composites as an efficient and recyclable oxidation catalyst
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-05
    Mohamed E. Assal, Mohammed Rafi Shaik, Mufsir Kuniyil, Mujeeb Khan, Abdulrahman Al-Warthan, Abdulrahman Ibrahim Alharthi, Ravi Varala, Mohammed Rafiq H. Siddiqui, Syed Farooq Adil

    Silver oxide nanoparticles doped manganese (IV) oxide along with varying percentages of highly reduced graphene oxide (HRG) [Ag2O(1%)–MnO2/(X%)HRG] nanocomposites were fabricated through a simple co-precipitation method followed by calcination at 400 °C. The as-prepared nanocomposite upon calcination at 300 °C and 500 °C temperatures, yields the manganese carbonate (MnCO3) and manganese (III) oxide (Mn2O3) composites i.e. Ag2O(1%)–MnCO3/(X%)HRG and Ag2O(1%)–Mn2O3/(X%)HRG, correspondingly. The structural composition of the prepared nanocomposites has confirmed by several characterization techniques. The nanocomposites have successfully utilized as a catalyst for liquid-phase oxidation of aromatic alcohols in presence of O2 as a green oxidant under alkali-free conditions. In addition, a comparative study was performed to assess the activity of the manganese carbonates and manganese oxides for aerial oxidation of benzyl alcohol into benzaldehyde as a model reaction. Effects of various parameters have thoroughly examined in detail and the Ag2O(1%)–MnO2/(5%)HRG catalyst exhibited the highest activity in the aerial oxidation of benzyl alcohol to benzaldehyde with a 100% conversion and >99% selectivity in a remarkably short reaction time (35 min) than the undoped precursor i.e. Ag2O(1%)–MnO2. The presence of HRG dopant greatly enhanced the catalytic performance of Ag2O–MnO2 nanocatalysts could be attributed to the presence of carbon vacancies and topological defects as well as oxygen carrying functionalities on the HRG surface and increase in the surface area. The as-prepared catalyst could be efficiently recycled and reused up to five times without a discernible drop in its catalytic performance and the product selectivity remained unchanged. The prepared catalyst i.e. Ag2O(1%)–MnO2/(5%)HRG was employed as oxidation catalyst for a series of various substituted benzylic and aliphatic alcohols into their respective aldehydes and yielded complete conversion with excellent product selectivity with no further oxidation to acids.

  • Aloe-vera flower shaped rutile TiO2 for selective hydrogenation of nitroaromatics under direct sunlight irradiation
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-10
    Satnam Singh, Roopchand Prajapat, Rayees Ahmad Rather, Bonamali Pal

    This study reveals the fabrication of a sunlight receptive flower shaped rutile TiO2 microstructure (F-TiO2) for the selective photoreduction of nitroaromatics. The crystalline F-TiO2 possesses small band gap (∼2.8 eV) and large specific surface area (193 m2g−1). Moreover, the F-TiO2 exhibited higher relaxation time (120 µs) for the electron-hole pairs due to its brilliant multi dimensional morphology that enables shorter diffusion path and multiple scattering of active sites. The experimental results revealed the superior photocatalytic activity of the F-TiO2 microstructure in contrast to active P25 and rutile TiO2 (obtained from thermally treated P25 at 800 °C for 4 h) for the reduction of nitrobenzene, m-dinitrobenzene and 2,2-dinitrobiphenyl in 50% aqueous isopropanol (hole scavenger) to aniline (42–72%), m-nitroaniline (37–42%), m-phenylenediamine (88–100%) and benzo[c]cinnoline (80–94%) respectively under UV and direct sunlight irradiation. The quantitative estimation of byproducts like acetone and hydrogen (H2) produced from iso-propanol oxidation and water splitting during instant reduction of nitroaromatics to aromatic amines is well correlated and explained on the basis of its beneficial surface structural and electronic properties.

  • Analysis of amphetaminic drug compounds in urine by headspace-dielectric barrier discharge ionization-mass spectrometry
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-11
    Ahsan Habib, Aklima Nargis, Lei Bi, Peng Zhao, Wen Luhong

    Rapid detection of trace level amphetaminic drug compounds in urine is essential to monitor consumption of these abuse drugs by athletes. In this work, the amphetaminic drug compounds were spiked in human urine and analyzed using headspace - dielectric barrier discharge (DBD) ionization-mass spectrometry method. In the headspace method, the urine spiked drug compound was treated with alkali solution, thus the free base amphetaminic molecules were released into the gas phase. The gaseous molecules were then ionized by the DBD ion source placed in front of the mass spectrometer inlet under ambient condition. This method provided comparable sensitivity with the solid-phase microextraction (SPME) in analysis of the amphetaminic compounds where no derivatization or adduct formation was required. The present method also facilitated the sensitivity enhancement with about one order of magnitude in urine compared to standard solution. Carbonate alkali solution showed the highest sensitivity for detection of the drug compounds in urine and the sensitivity was enhanced by using NH3. The limits of detection (LODs) of the various amphetaminic molecules were found to be in the range of 0.10-0.80 ng/mL for standard solutions while those for urine were in the range of 0.04-0.40 ng/mL. The analytical figures of merit of this method were evaluated under ambient condition using suitable internal standard. Results suggested the suitability of this method for analytical routine work in detection of amine-based drugs in doping test and/or in forensic laboratories. A mechanism of enhanced sensitivity by the ammoniated carbonate alkali solution in urine is also discussed.

  • Hierarchical nanocrystalline NiO with coral-like structure derived from nickel galactarate dihydrate: An active mesoporous catalyst for methyl ethyl ketone production
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-14
    Samih A. Halawy, Mohamed A. Mohamed, Adel Abdelkader

    Nanocrystalline NiO with a coral-like structure (38 nm) has been prepared via thermal decomposition of a new precursor, nickel galactarate (NiC6H8O8·2H2O), at 500 °C for 3 h in air. Thermal decomposition of that precursor was studied by TG and DSC techniques. The resultant NiO was physicochemically characterized by XRD, FTIR, SEM, surface area, porosity and CO2-TPD. NiO was found to exhibit a remarkable activity towards the synthesis of MEK from 2-butanol between 200 and 325 °C. In addition, it has shown a great tendency to ease regeneration of the used catalyst after 192 h in stream by simple refreshing method.

  • Porous multifunctional fluoropolymer composite foams prepared via humic acid modified Fe3O4 Nanoparticles stabilized Pickering high internal phase emulsion using cationic fluorosurfactant as co-stabilizer
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-14
    Umair Azhar, Chenxi Huyan, Xiaozheng Wan, Chuanyong Zong, Anhou Xu, Jitao Liu, Jiachen Ma, Shuxiang Zhang, Bing Geng

    Fluoropolymers are very important owing to their excellent application performances, especially in extreme conditions. On the other hand, the preparation of porous fluoropolymers is a difficult task due to unavailability of suitable surfactants as well as tedious synthesis steps. Here we prepared multifunctional porous fluoropolymer composite foams with a simple process of “high internal phase emulsion (HIPE)” by using humic acid modified iron oxide nanoparticles (HA-Fe3O4 NPs) and cationic fluorosurfactant (CFS) (PDMAEMA-b-PHFBA) as co-stabilizer. The inclusion of HA-Fe3O4 NPs in the system made fluoro-HIPE more stable than the emulsion prepared using only CFS or other conventional stabilizers. Morphology of the prepared polyHIPE was easily controlled by altering the concentration of HA-Fe3O4 and/or CFS in the original formulation. Adjustment of the porous structure with open/close cells was performed and the average diameter of the pores tuned between 4.9-23 μm. With the increase in specific surface area by using nanoparticles (NPs) and CFS as co-surfactants, Pickering HIPE monoliths adsorbed double amount of oil compared to foams based solely on HIPE template. Multiple functional groups were bound onto Fe3O4 NPs through HA modification that made the fluoro-monolith capable of adsorbing dye, i.e. methylene blue, from water. A simple centrifugation enabled regeneration of the oil soaked foams and adsorption capacity was not decreased after 10 adsorption/regeneration cycles.

  • Microparticles based on carboxymethyl starch/chitosan polyelectrolyte complex as vehicles for drug delivery systems
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-16
    Rafael F.N. Quadrado, André R. Fajardo

    Microparticles with oval-shape morphology and rough and porous surfaces were prepared by polyelectrolyte complexation of carboxymethyl starch (CMS) and chitosan (Cs). CMS with DS of 0.5, the polyanionic moiety, was synthesized from rice starch with low content of amylose (6%). A preliminary investigation revealed that this kind of starch is more susceptive to esterification than rice starches with higher contents of amylose. The CMS/Cs microparticles showed higher chemical and thermal stability than microparticles prepared by conventional ionotropic crosslinking of Cs with TPP ions. The carboxymethyl groups of CMS are more efficient to neutralize the positive groups of Cs and, also, enhance the entrapment of bovine serum albumin (BSA) in the CMS/Cs matrix as compared to Cs/TPP. In vitro experiments conducted in simulated gastric fluid (pH 1.2) and simulated intestinal fluid (pH 6.8) with the testing microparticles revealed that the CMS/Cs-BSA microparticles exhibit a highlighted pH-dependent release profile. This desirable property allows controlling the release of BSA more efficiently, which minimizes undesirable issues (e.g. burst effect and non-sustained release). Furthermore, the BSA release from CMS/Cs-BSA microparticles in SIF follows an ideal Zero-order kinetics, which is very attractive for a drug delivery system. Therefore, microparticles based on CMS/Cs polyelectrolyte complex may be promising to control the drug release in specific regions of the gastrointestinal tract.

  • Acetocatechol functionalized viologen as polyfunctional material that responds to anion, cation and reductant in aqueous and organic solvents
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-17
    Huanhuan Qiao, Yue-Ling Bai, Yongmei Zhao, Feifei Xing, Ming-Xing Li, Shourong Zhu

    Both viologen and catechol have been studied extensively. However, the stability of catechol-Fe(III) without additional oxidant is still not well understood. In this paper, we introduced acetocatechol into viologen to investigate its interactions with anion, cation, and reductant, as well as the stability of its Fe(III) complexes. This acetocatechol functionalized viologen, 1,1'-bis(2-(3,4-dihydroxyphenyl)-2-oxoethyl)- [4,4'-bipyridine]-1,1'-diium chloride (H6V·Cl2) exists in central symmetric ketone cation form in solid state. Viologen cation increased the acidity of the aceto group and deprotonated the enolic proton to form monodeprotonated enolic H5V+ in the presence of anion/base, which had the deepest color in organic solvents. The absorbance maximum of H5V+ increased with the decrease of solvent polarity. It also interacted with B4O72- and MoO42- by forming catechol ester in DMSO solution. The catechol moiety can coordinate to metal ion, especially Fe(III), in both aqueous and DMSO solution. In particular, it coordinated to Fe(III) much more readily in aqueous solution than in DMSO. Green monocatecholato Fe(III) and red-brown bis-catecholato Fe(III) complex also formed in aqueous solution. The monocatecholato Fe(III) complex first-order dimerized in aqueous solution at room temperature but underwent second-order decomposition to Fe(II) complex at 60°C. The biscatecholato Fe(III) complex also transferred to other Fe(III) complexes at first- and second-order at room-temperature and 60 °C respectively. The t1/2 varied from several hours at room-temperature and several minutes at 60 °C at 10-4 M concentration. The interactions of Fe(III) in DMSO is much more complex than that of acetocatecholate without viologen. Fe(III) can also be reduced to free viologen radicals in the presence of sodium Na2S2O4, but not N2H4. In conclusion, this polyfunctional compound responds to anion via aceto and catechol, metal ion via catechol hydroxyl, while reductant via viologen.

  • Impact of annealing on the structural and optical properties of ZnO nanoparticles and tracing the formation of clusters via DFT calculation
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-22
    Rezq Naji Aljawfi, Mohammad Jane Alam, F. Rahman, Shabbir Ahmad, Aga Shahee, Shalendra Kumar

    In this report, nanoparticles (NPs) of zinc oxide (ZnO) were synthesized through auto-combustion route and annealed in air at different temperatures: 200, 400, 600 and 800 °C. The single phase nature has been confirmed via X-ray diffraction (XRD) and selected area electron diffraction (SAED) analysis. The average of crystallite sizes increased progressively as the thermal annealing increase and ranging between 13.8 and 39.7 nm. Raman spectra resembled to that of hexagonal ZnO wurtzite structure, the narrowing in E2H (438 cm−1) Raman phonon mode in sequence with further annealing indicates improvement in the crystallinity and reduction in the local atomic defects of oxygen vacancy (Vo2+). The defects create energy deep bands within the band gap region and diminish the UV emission efficiency that has been assessed through photoluminescence (PL) spectroscopic. The donor band of oxygen vacancy (Vo2+) was ∼1 eV above valence band (VB), whereas the acceptor band of zinc vacancy (VZn2−) was at ∼0.85 eV above the VB. The ZnO NPs that was annealed at lowest temperature of 200 °C exhibited different behavior trend in which the UV-PL band was diminished clearly, blue shifted to lower wave length and appeared as small plateau at the range of 380–270 nm corresponding to high band gap energy (3.8–4.6 eV), which is indicative to low crystal quality and presence of clusters. We used density function theory (DFT) calculation for computing the HOMO-LUMO band gap of supposed clusters ZnnOn (n = 2, 3, 5, 10). The high band gap energy of the simulated clusters was agreed with that of ZnO NPs annealed at 200 °C that gives indirect evidence on the formation of clusters.

  • Integration of virtual screening and computational simulation identifies photodynamic therapeutics against human Protoporphyrinogen Oxidase IX (hPPO)
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-25
    Amir Zeb, Chanin Park, Minky Son, Ayoung Baek, Yeongrae Cho, Donghwan Kim, Shailima Rampogu, Gihwan Lee, Youn-Sig Kwak, Seok Ju Park, Keun Woo Lee

    Photodynamic therapy (PDT) is a rapidly evolving area of cancer management against solid tumors. PDT is either administrated by injecting photosensitizer (porphyrins) or by accumulation of intracellular protoporphyrin IX via the inhibition of human Protoporphyrinogen Oxidase IX (hPPO). In this study, novel inhibitors of hPPO have been investigated by integrating virtual screening, molecular docking, and molecular dynamics (MD) simulation. A ligand-based pharmacophore was generated from a training set of 22 inhibitors of hPPO. The selected pharmacophore had four chemical features including three hydrogen bond acceptors and one hydrophobic. The pharmacophore was characterized by highest correlation coefficient of 0.96, cost difference of 53.20, and lowest root mean square deviation of 0.73. The resultant pharmacophore was validated by Fischer’s Randomization and Test Set Validation methods. The validated pharmacophore was used as a 3D query to screen chemical databases including NCI, Asinex, Chembridge, and Maybridge. The screening of chemical databases and the subsequent application of Lipinski’s Rule of Five, and ADMET Assessment Test, retrieved 1176 drug-like compounds. The drug-like compounds were subjected to molecular docking studies in the active site of hPPO to eliminate false positive hits and to elucidate their true binding orientation. Top three candidate molecules with high docking scores and hydrogen bond interactions with catalytic active residues were selected as best candidate inhibitors against hPPO. The binding stability of selected candidate inhibitors was evaluated by MD simulation. The MD simulation of hits portrayed strong hydrogen bonds and key hydrophobic interactions with catalytic active residues of hPPO including R59, R97, G159, G332 and flavin moiety of FAD (coenzyme of hPPO). Our study predicts three hit compounds against hPPO, which could possibly accumulate high concentration of protoporphyrinogen-IX, and thereby acting as an intracellular photosensitizer against tumor cells through photodynamic therapy.

  • Anchoring N-Halo (sodium dichloroisocyanurate) on the nano-Fe3O4 surface as “chlorine reservoir”: Antibacterial properties and wastewater treatment
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-25
    Ardeshir Khazaei, Negin Sarmasti, Jaber Yousefi Seyf, Zohreh Merati

    A novel retrievable bifunctional magnetic nano-structure (sodium dichloroisocyanurate immobilized on the Fe3O4@SiO2@Si(CH2)3Cl surface) was synthesized. Its antibacterial performance as water disinfectant successfully evaluated. The value of Minimum Bactericidal Concentration (625 ppm) and Minimum Inhibitory Concentration (314.5 ppm) show that magnetic nano-structure is a very effective antibacterial structure against the E. coli bacteria. In addition the viability of bacteria (%) was evaluated at different contact time against magnetic nano-structure. The disinfection procedure is very clean without any residual cyanuric acid in water. In other hand, oxidizing performance of nano-structure against the azo dye (acid red-18) was evaluated which attributed to the releasing HOCl in water. Kinetic of dye removal was measured at 0.01, 0.05, 0.1, and 0.5 g of nano-structure. Reducing pH and increasing temperature leads to increased Acid Red 18 degradation. Chemical oxygen demand (COD) measurement shows the effectiveness of nano-structure in acid red-18 degradation.The nano-structure turns to be magnetically retrievable, clean disinfectant, wastewater treatment agent, and its chlorine can be regenerated simply by exposure to household bleach such as Ca(OCl)2.

  • Low-loading of oxidized platinum nanoparticles into mesoporous titanium dioxide for effective and durable hydrogen evolution in acidic media
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-25
    Mabrook S. Amer, Mohamed A. Ghanem, Abdullah M. Al-Mayouf, Prabhakarn Arunachalam, Nezar H. Khdary

    Low-loading of oxidized platinum nanoparticles (0.1–0.5 wt%) was incorporated into mesoporous titanium dioxide support (Ptx/meso-TiO2) via evaporation self-assembly (ESA) approach followed by a two-step calcination processes. The physicochemical characterizations showed that the oxidized Ptx/meso-TiO2 catalysts exhibit high surface area around 200 m2/g and Pt nanoparticles having an average size of 3.0 nm are uniformly incorporated into the mesoporous TiO2 matrix with the existence of Pt(II) and Pt(IV) oxidation states. The Ptx/meso-TiO2 electrocatalysts showed an enhanced electrocatalytic activity with hydrogen evolution onset potential at −10 mV vs. RHE, Tafel slope of −110 mV/dec, small charge transfer resistance, and mass activity that reaches up to 25.7 A/mgPt at −300 mV vs. RHE. The hydrogen evolution mass activity of Ptx/meso-TiO2 electrocatalysts is significantly more efficient than the commercial Pt/C catalysts and Pt nanoparticles supported on nanostructured carbon substrates. Moreover, the Ptx/meso-TiO2 electrocatalysts exhibit excellent durability for a 24-hour electrolysis in acid solution with a further current activation during the prolonged electrolysis. The enhanced mass activity and durability are attributed to the substrate mesoporosity, uniform distribution and strong bonding between the oxidized Pt nanoparticles and the TiO2 substrate. These results demonstrate the promise of the mesoporous TiO2 substrate modified with low loading of platinum nanoparticles for energy conversion technologies.

  • Nanostructured pH-responsive biocompatible chitosan coated copper oxide nanoparticles: A polymeric smart intracellular delivery system for doxorubicin in breast cancer cells
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-25
    Nipun Babu Varukattu, Raju Vivek, Chandrababu Rejeeth, Ramar Thangam, Thondhi Ponraj, Alok Sharma, Soundarapandian Kannan

    In this study, we report a novel feasible single step reduction method for the active synthesis of biocompatible chitosan coated copper oxide nanoparticles (Cs-CuO NPs), for loading and delivery of doxorubicin (DOX) into breast cancer cells. The formulated nanoparticles (NPs) were characterized by size, shape and surface charge using various sophisticated instruments. Interestingly, these formulated particles showed profound drug loading activity and also showed its versatile nature of DOX release at different pH which makes them as ideal particles for breast cancer therapy. Intracellular uptake was evaluated through fluorescence microscopy studies with the help of coumarin. Morphological and apoptotic studies with the DOX-Cs-CuO NPs on MCF-7 cells showed its ability to induce apoptosis in breast cancer cells, which was clearly substantiated by ROS generation with the loss of mitochondrial membrane potential. Our results clearly showed the therapeutic nature of novel biocompatible Cs-CuO NPs in delivering DOX with a pH-dependent manner.

  • Unveiling interactions between DNA and cytotoxic 2-arylpiperidinyl-1,4-naphthoquinone derivatives: A combined electrochemical and computational study
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-25
    Christian Espinosa-Bustos, Camila Canales, Galo Ramírez, Pablo Jaque, Cristian O. Salas

    Three 2-arylpiperidinyl-1,4-naphthoquinone derivatives were synthesized and evaluated in vitro to determine their cytotoxicity on cancer and normal cell lines. In order to establish their possible action mechanism, the electrochemical behaviour of these quinones was examined using cyclic voltammetry (CV) as technique by using a three-electrode setup: a glassy carbon, Ag/AgCl (in 3 M KCl), and platinum wire as working, reference, and counter electrodes, respectively. Kinetic studies were done to determine the control of the reduction reaction and the number of transferred electrons in the process. Furthermore, the addition of dsDNA to the quinone solutions allowed for the observation of an interaction between each quinone and dsDNA as the current-peaks became lower in presence of dsDNA. Otherwise, motivated to support the aforementioned results, electronic structure calculations at the TPSS-D3/6-31+G(d,p) level of theory were carried out in order to find the most favourable noncovalently bonded complexes between quinones and DNA. Noncovalent complexes formed between DNA and 2-arylpiperidinyl-1,4-naphthoquinones and stabilized by π-stacking interactions along with the well-known hydrogen-bonded complexes were found, with the former being more stable than the latter. These results suggest that the intercalation of these quinone derivatives in DNA is the most likely action mechanism.

  • Supramolecular drug inclusion complex of Capecitabine with cucurbit[7]uril and inverted cucurbit[7]uril
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-25
    Hai-Yan Wang, Yang Zhou, Ji-Hong Lu, Qing-Yun Liu, Gui-Ying Chen, Zhu Tao, Xin Xiao

    The interaction of capecitabine (CAP) with cucurbit[7]uril (Q[7]) and inverted cucurbit[7]uril (iQ[7]) was investigated using nuclear magnetic resonance, fluorescence spectroscopy, MALDI-TOF mass spectrometry and isothermal titration calorimetry. The obtained results revealed that the alkyl chain of CAP is located inside the cavities of Q[7] or iQ[7], whereas the other section of CAP remains outside the portal. Our results suggest that both Q[7] and iQ[7] could be promising candidates for excipients used in medicinal and pharmaceutical research fields.

  • Green biosynthesis of superparamagnetic magnetite Fe3O4 nanoparticles and biomedical applications in targeted anticancer drug delivery system: A review
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-26
    Yen Pin Yew, Kamyar Shameli, Mikio Miyake, Nurul Bahiyah Bt Ahmad Khairudin, Shaza Eva Bt Mohamad, Takeru Naiki, Kar Xin Lee

    This review discussed about the green biosynthesis of magnetite nanoparticles (Fe3O4-NPs) and the biomedical applications, which mainly focus on the targeted anticancer drug delivery. Fe3O4-NPs have been studied and proved that Fe3O4-NPs can be used in various fields of application, due to “superparamagnetic” property that Fe3O4-NPs possessed. In targeted drug delivery system, drug loaded Fe3O4-NPs can accumulate at the tumor site by the aid of external magnetic field. This can increase the effectiveness of drug release to the tumor site and vanquish cancer cells without harming healthy cells. In order to apply Fe3O4-NPs in human body, Fe3O4-NPs have to be biocompatible and biodegradable to minimize the toxicity. So, green biosynthesis plays a crucial role as the biosynthesized Fe3O4-NPs is safe to be consumed by human because the materials used are from biological routes, such as plant extract and natural polymer. However, biosynthesis using plant extract is the most popular among them all as plant extract can act as both reducing and stabilizing agents in the synthesizing process of nanoparticles. This approach is not merely simple, yet economic and less waste production, which is environmental friendly. Several biomedical applications of Fe3O4-NPs are included in this review, but anticancer drug delivery study is discussed in detail. The criteria for Fe3O4-NPs to be used as drug delivery vehicle are discussed so as to study the optimum condition of Fe3O4-NPs in drug delivery application. Many researches showed the promising results of Fe3O4-NPs in treating cancer cells via in vitro study. Hence, this review is significant which summarize the vital points of Fe3O4-NPs in targeted anticancer drug delivery system. Conclusions have been made according to the literature reviewed and some points of view were proposed for future study.

  • Synthesis of CeO2 doped ZnO nanoparticles and their application in Zn-composite coating on mild steel
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-04-27
    Deepa Kallappa, Venkatesha Thimmappa Venkatarangaiah

    CeO2 doped ZnO nanoparticles were synthesized by co-precipitation method and their size, structure and composition were characterized by XRD, SEM and EDAX analysis. The nanoparticles were used for generation of Zn-CeO2 doped ZnO composite (Zn-composite) coating on mild steel by electroplating. The surface morphology, elemental composition of Zn coated and Zn-composite coated samples were examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDAX) respectively. Corrosion experiments were carried out by electrochemical techniques such as OCP, Tafel polarization, Anodic polarization and electrochemical impedance spectroscopy. The electrochemical corrosion behavior of Zn-composite coating was compared with pure zinc coating. The morphology of the deposits after corrosion tests was analyzed by SEM images. Incorporation of CeO2 doped ZnO nanoparticles into Zn-matrix significantly improved the corrosion resistance property of Zn-coating.

  • Synthesis and characterization of surface-active antimicrobial hyperbranched polyurethane coatings based on oleo-ethers of boric acid
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-10
    Younes Ahmadi, Mohammad Tahir Siddiqui, Qazi Mohd. Rizwanul Haq, Sharif Ahmad

    Present study reports a facile synthesis of surface-active antimicrobial hyperbranched polyurethane coatings using oleo-ethers of boric acid (BA) as branching and biocidal moiety (BHPU). The antimicrobial branching center was synthesized via polycondensation reaction of BA and vegetable oil-based diol. The structural characterization of synthesized BHPU and its linear counterpart was investigated using Fourier-transform infrared (FTIR) and nuclear magnetic resonance (1H, 13C, and 11B NMR) spectroscopy techniques. The cured coatings were examined by physico-mechanical, thermogravimetric (TG) analysis and differential scanning calorimetry (DSC). The antimicrobial behavior of these polymers against Gram-positive and Gram-negative bacteria was carried out by well diffusion technique. The appearance of zone of inhibition (ZOI) in case of BHPU confirmed its antimicrobial activity, which arisen due to the presence of cationic moiety in its structure. These investigations showed that the utilization of oleo-ethers of BA as branching agent in synthesis of BHPU coatings induced prominent effect on its physico-mechanical, thermal, and biocidal properties. In addition, soil burial study for 210 days was conducted on BHPU film to confirm its contact-killing mechanism against soil-borne bacteria. These results suggest the potential scope of BHPU in various applications such as long-term antimicrobial surface-active coatings for medical devices, packaging industry, paints, etc.

  • Unlocking the Synthetic Potential of Aziridine and Cyclopropane-Fused Quinolin-2-ones by Regioselective Fragmentation of its Three-membered Rings
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-11
    Javier Diaz, Daniel Rodenas, Francisco-Jose Ballester, Mateo Alajarin, Raul-Angel Orenes, Pilar Sanchez-Andrada, Angel Vidal

    The cyclization of cis-2-(2-azidophenyl)-1-benzyl-3-ethoxycarbonylaziridines and trans-2-(2-azidophenyl)-3-nitrocyclopropane-1,1-dicarboxylates yielded the respective aziridino[2,3-c]quinolin-2-ones and cyclopropa[c]quinolin-2-ones. Ring-opening of the aziridine-fused species under silica gel catalysis provided 3-aminoquinolin-2-ones whereas the ring-expansion of the cyclopropane-fused derivatives by the action of sodium hydride gave 1-benzazepin-2-ones, in both cases in a regioselective manner. A computational study using DFT methods revealed that the mechanism for the transformation of cyclopropa[c]quinolin-2-ones into 1-benzazepin-2-ones involves the initial deprotonation step of its amide function followed by two pericyclic events: a 6π-electrocyclic ring opening and a subsequent [1,5]-H shift.

  • Highly selective and sensitive optosensing of glutathione based on fluorescence resonance energy transfer of upconversion nanoparticles coated with a Rhodamine B derivative
    Arab. J. Chem. (IF 2.969) Pub Date : 2018-07-06
    Thu-Thuy T. Nguyen, Bui The Huy, Salah M. Tawfik, Gerelkhuu Zayakhuu, Hyo Hyun Cho, Yong-Ill Lee

    A Glutathione (GSH) optical sensor with high sensitivity and exceptional selectivity was developed using one-step synthesized-upconversion nanoparticles (UCNPs, NaLuF4:Gd3+,Yb3+,Er3+) in conjunction with a Rhodamine B derivative (RBD). RBD was loaded on the surface of the UCNPs though non-covalent bonding to serve as an energy acceptor, while UCNPs served as energy donors. The sensor based on a coupling fluorescence resonance energy transfer (FRET) process at an excitation of 980 nm wavelength from UCNP to RBD with a ring-opening process of RBD after the addition of GSH. The sensing probe exhibits a remarkable limit of detection (LOD = 50 nM) for GSH through the enhancement of the fluorescence intensity of RBD at 592 nm, together with a concomitant reduction in the green band of the UCNPs. In addition, the sensing mechanism, characterization of UCNPs, and the selectivity of the fluorescence sensor toward GSH were discussed. The proposed sensor was evaluated on real human serum and urine samples and demonstrated as a highly selective and sensitive probe for the detection of GSH.

Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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