Antimicrobial Activity and Quantum Chemical Calculations of Pyrazol-2,3-Dihydrothiazole Sugar Derivatives

A number of new [(pyrazol-4-yl) methylene] hydrazono-2,3-dihydrothiazoles, sugar hydrazones, and their N-glycoside derivatives were synthesized. The chemical structures of the synthesized compounds were confirmed by 1H NMR technique. The newly synthesized compounds were tested for their antimicrobial activities and showed moderate to high inhibition activities. Quantum chemistry calculations were used to study the molecular geometry and electronic structure of the selected derivatives. The energy gap between the highest occupied molecular orbital (HOMO)and lowest unoccupied molecular orbital (LUMO) has been calculated using the theoretical computations to reflect the chemical reactivity and kinetic stability of compounds. Keywords: 1H-pyrazole, aminothiazole, ethylchloroacetate, quantum chemical calculations, antimicrobial activity

Ultrastructural studies on Vicia faba and its pathogen Botrytis fabae in response to lithium chloride

Ultrastructural investigations of the effect of lithium chloride on Botrytis fabae and its host, Vicia faba are described. Five concentrations (1, 3, 5, 7, 9 mM) of lithium chloride are chosen in the study. The results indicate that the chlorophyll content of host leaves is not affected at lower concentration (3 mM), whereas the higher concentration (9 mM) decreased the chlorophyll content. These two concentrations caused a pronounced cellular disorganization of B. fabae that ranged from disruption of the wall to marked cytoplasmic degeneration. Inoculated host leaves with B. fabae led to the appearance of more vacuolated cytoplasm, a disorganized membrane system of chloroplast and an increase in number of plastoglobuli. These observations are similar to those of host cells treated with 9 mM of lithium chloride. Host cells are not affected by the concentration of 3 mM. Ultarstructural studies indicate that the lower concentration of lithium chloride can be used as a safe fungicide to control B. fabae without a harmful effect on the host (V. faba)

Synthesis of Gemini cationic surfactants based on natural nicotinic acid and evaluation of their inhibition performance at C-steel/1 M HCl interface: Electrochemical and computational investigations

Herein, we prepare effective Gemini cationic surfactants (CSII, CSIV) and characterize them using FT-IR and 1HNMR spectroscopy. The adsorptive properties of CSII and CSIV at HCl/air and C-steel/HCl interfaces were examined with surface tension and electrochemical parameters, respectively. The critical micelle concentration (CMC) of the CSII and CSIV indicated their adsorption affinity at the HCl/air interface. Where, aliphatic chains increase surface coverage percentage and aid in surfactant adsorption. The electrochemical parameters of C-steel in 1 M HCl were studied using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) at different temperatures. The charge transfer resistance of the C-steel electrode was enhanced from 28.2 Ω.cm2 to 770.79 and 831.45 Ω.cm2 after adding 5 × 10−4 M of CSII and CSIV, respectively. Both CSII and CSIV act as mixed inhibitors with inhibition performance exceeding 97% due to their highly adsorption affinity. The chemical adsorption affinity of these compounds is suggested by the higher adsorption energy (∆G*ads) values (>−40 kJ mol−1) according to the Langmuir isotherm model. The theoretical calculations including DFT, and Monte Carlo simulation (MCs) provide insight into the relationship between corrosion inhibition and molecular structure, where the calculated parameters agree with the experimental results

Trace elements: critical insights from 15 years of monitoring in the Venice Lagoon catchment basin (Italy)

The study focused on selected trace elements (As, Cd, Cr, Hg, Ni, Pb) monitored in surface waters of the Venice Lagoon catchment basin (North East Italy) over the period 2000-2015. The monitoring was undertaken to verify the achievement of the quality objectives set by the European and national legislations. The available results have been analyzed to evaluate the chemical status of water bodies. The limit of quantification (LOQ) of the applied analytic techniques appears critical for the adequate water monitoring; for some parameters, the percentage of not visible values due to non-satisfactory LOQ was higher in the beginning of the period; the subsequent improvement of LOQ allowed assessing the respect of environmental quality standards (EQSs). The study analyzes time trends in single stations and the differences between detected concentrations in the considered stations. Moreover, maximum concentrations and water flows have been considered to understand the potential correlation. Cumulated frequency curves for the most critical parameters have been built to identify situation of potential overtaking of the EQSs in force. The most polluted sampling stations of the drainage basin for the six trace elements were found in Cuori and Fiumazzo rivers. Although LOQs changed over time, the recorded trends show a quality improvement and a good compliance with respect to EQSs set by European legislation, while considering EQSs set by local special legislation, the objectives are not yet satisfied. Arsenic is ubiquitous; thus, it can be supposed to be originated as a background environmental concentration, while nickel appears of industrial origin according to its point and local presence

السلوك الكهروكيميائي لبعض مشتقات البيريميدينات : الأختزال البولاروجرافي لـ 1، 3 - ثنافي ميثيل - 2 ، 4 ، 6 (IH, 3H, 5H ) بيريميد ين ثلاثي الكيتون و5 -فينيل آزو

The polarographic behaviour and spectrophotometric pKa of 1,3-dimethyl barbituric acid and 5-phenylazo substituted products were investigated in buffer solution of pH ~ 2-11. The results revealed an azo form of the substituted products, a mechanism for the electroreduction pathway was suggested. Half wave potentials showed fair correlation with o constants while pKa showed practically no dependence on substitutes.درس الاختزال البولاروجرافي لـ 3.1 - ثنائي ميثيل حمض البربتيوريك (I) وكذْلك 3.1 ثنائي ميثيل - 5 - فينيل اَزو حمض البربتيوريك في محاليل منظمة ذات رقم هيدروجين 2-40,11 % (حجم /حجم ) كحولية (II) وأوضح ا لاختزال البولاروجراني ل (I) وجود موجه اختزالية لمجموعة كيتون واحدة . وبالنسبة ل (II) سجلت النتائج موجتين اختزاليتين الأولى (الاكثر إيجابية) لمجموعة الآزو والثانية (الاكثر سالبية) لمجموعة كيتون واحدة . وقد أقترح نسق الاختزال الكهربي لكلا المركبين . كما درس تأثير المجموعات الاستبدالي على كلِ من جهود نصف الموجه وقيم ثابت التأين الحمضي pkd لتباين مدى انطباق علاقات الطاقَة الحرة الخطية على المركبات موضع الدراسة