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European chemical bulletinVol. 7., No. 7-8. (2018.)


Classical chemical sciences

  • Kiran Singh ,
    Prerna Turk ,
    Anita Dhanda :

    Co(II), Ni(II), Cu(II) and Zn(II) complexes with the bidentate ligand 4-[(3-ethoxy-4-hydroxybenzylidene)amino]-3-mercapto-6-methyl-5-oxo-1,2,4-triazine have been synthesized. The Schiff base and its metal complexes have been characterized by various physicochemical techniques like IR, 1H-NMR, ESR, electronic and fluorescence spectroscopy and cyclic voltammetry. Elemental analysis, conductivity measurements and thermal analysis of synthesized compounds were also carried out. All the complexes were colored and non-electrolytic in nature. In vitro biological activities of the ligand and complexes have been checked against some pathogenic gram positive, gram negative bacteria and different fungi and then compared with some standard drugs as control.

    Keywords: Metal complexes; Schiff base; 4-[(3-ethoxy-4-hydroxybenzylidene)amino]-3-mercapto-6-methyl-5-oxo-1,2,4-triazine

  • Haritha Meda ,
    G. Devala Rao ,
    V. Harini Chowdary ,
    Mandava Bhuvan Tej :

    In the present study, an attempt was made to prepare oral nanosuspension of Tadalafil. Tadalafil is a PDE5 inhibitor used for treating erectile dysfunction (ED) and pulmonary arterial hypertension. Tadalafil nanosuspensions were prepared by nanoprecipitation method using different polymers (such as sodium lauryl sulphate (SLS), TWEEN-80, TWEEN-20, Pluronic F127) and acetone. Estimation of Tadalafil was carried out spectrophotometrically at 285nm. The oral nanosuspension were evaluated for various physical and biological parameters, drug content uniformity, particle size analysis, zeta potential, invitro drug release, short-term stability, drug-excipient interactions (FTIR). Out of the formulation from F1 to F12, F11 containing TWEEN-20 (0.3 %) showed 99.74 % release at the end of 30min and follows first order drug release kinetics.

    Keywords: Tadalafil; oral nano suspension; sodium lauryl sulphate; Tween-20; Pluronic F127; Tween-80

  • Vasiliy G. Shtamburg ,
    Victor V. Shtamburg ,
    Andrey A. Anishchenko ,
    Alexander V. Mazepa ,
    Svetlana V. Kravchenko ,
    Svetlana V. Shishkina :

    A convenient method of synthesis of 2-hydroxy-1-aryl-2-(indol-3-yl)ethanones and their isomerization to 2-hydroxy-2-aryl-1-(indol-3- yl)ethanones in the presence of triethylamine on heating or in the presence of EtONa at room temperature have been studied. The spectral tests of isomers structures are presented. The structures of 2-hydroxy-1-phenyl-2-(indol-3-yl)ethanone and 2-hydroxy-2-phenyl-1-(indol-3- yl)ethanone have been studied by XRD technique.

    Keywords: Arylglyoxals, α- and ß-benzoins, indole, synthesis, 2-hydroxy-1-aryl-2-(indol-3-yl)ethanones, 2-hydroxy-2-aryl-1-(indol- 3-yl)ethanones, spectral characteristics

Materials and environmental chemistry

  • Hadeel H. El-Shalakany ,
    M. S. A. Hamza ,
    Ayman H. Kamel :

    A simple spectrophotometric method with good selectivity and high sensitivity towards sulfide ions has been introduced. The method is based on the replacement of the axial water molecule of the aquacyanocobyrinic acid heptamethyl ester (ACCbs) reagent after the reaction with HS- ions, and forming stable complex. ACCbs reagent is characterized with three distinguishable absorption bands with absorption maxima at 353, 497 and 527 nm. After adding HS-, a new absorption band at 582 nm has been obtained. The decrease of the absorption bands of the reaction product at 353, 497 and 527 nm and the enhancement of the band at 582 nm are quantitatively linear to HS- concentration over the concentration range 0.02-1.543 μg mL-1 with lower limit of detection 0.019 μg mL-1. No noticeable interferences are caused by most common ions. Suitability for the assessment of HS- in complex matrices without prior treatment was shown after validation of the method according to the standards of quality assurance. The results compare fairly well with data obtained using the standard method.

    Keywords: Aquacyanocobyrinic acid heptamethylester (aquacyanocobester), spectrophotometry, hydrosulfide determination

Chemical and biological aspects of life

  • Olawale H. Oladimeji ,
    Ngozi O. Onu :

    In the present study a semi-pure residue each from Pycnanthus angolensis (Welw.) Warb and Bryophyllum pinnatum (Lam) for the presence of biologically active compound(s) were investigated. This exercise led to two compounds whose identities have been established to be 1,6-dihydro-2-methyl-4-hydroxy-6-oxo-3-pyridine carboxylic acid ethyl ester (1,6-dihydro-2-methyl-4-hydroxy-6-oxo-3-nicotinic acid ethyl ester) (5-ethoxycarb, NG5-a) and 1-ethoxy-2-hydroxy-4-prophenylguaethol (vanitrope, KF-1a), respectively using MS and IR spectral techniques. NG-5a was proved to be bacteriostatic against Escherichia coli but recorded no activity against Staphylococcus aureus and Candida albicans. KF-1a recorded only minimal activity against S. aureus but demonstrated no activities against E. coli or C. albicans.

    Keywords: Pycnanthus angolensis; Bryophyllum pinnatum; chromatography; bioactivity

  • Abdullatif Azab :

    In this study, three extracts of the aerial parts of Notobasis syriaca and Scolymus maculatus were prepared. Each extract was tested for antifungal activity against Rhizopus stolonifer (black mold), and its total phenolic content (TPC) and antioxidant activity were measured. As for these measurements, we report here a facile method that we developed. Our results show moderate antifungal activity for both plants extracts, notably high TPC and antioxidant capacities. They are also in very good agreement with the partial published data, and our new method is consistent and validated by very well known, yet complicated or expensive methods.

    Keywords: Notobasis syriaca; Scolymus maculatus; Rhizopus stolonifera; total phenolic content; antioxidant capacity