Screening of Mineral Elements in Cistus ladanifer and Cistus libanotis Essential Oils and their Leaves

peer reviewedThe aim of this study was to determine the levels of mineral compounds in Cistus ladanifer and Cistus libanotis growing in Eastern Morocco from two different regions Jerada (arid climate) and Tafoughalt (humid climate). A total of fifteen elements (Cd, Co, Cr, Cu, Hg, Na, Ni, P, Pb, Zn, Al, Ca, Fe, K and Mg) has been measured by inductive coupled plasma atomic emission spectrometry. Their concentrations have been found to vary in leaves and their essential oils. From the results of the study, P, Al, Ca, Fe, K and Mg are highest in all the samples analysed. Cr and Pb were not detected in essential oil of Cistus libanotis from Jerada and Tafoughalt, respectively. These plants were found to contain appreciable amounts of the elements K, Ca, Fe, Mg, P, Al, Ni, Li, Zn and Cu Witch are important in many biological mechanisms. This study also provides a comprehensive survey of the concentration of elements in plants due to their wide utilisation as herbal fusion or decoction in Eastern Morocco

Inhibition of the acid corrosion of iron with new pyrazole derivatives

Some new synthetized pyrazole organic-type compounds have been tested as inhibitors for the corrosion of iron in 1M HCl by weight-loss and electrochemical polarization methods. Both techniques gave the same order of inhibition. The compound l,3-bis(3' chloromethyl-5'-methyl-1'-pyrazolyl)propane (Inh.9) was the better inhibitor and its inhibition efficiency increased with increase of concentration and reaching 95% at 4.10-4M. Polarization measurements have shown that the pyrazole substances studied inhibited both the anodic reaction of iron dissolution and the cathodic reaction of hydrogen evolution. These products act without changing the mechanism of the cathodic hydrogen evolution reaction. The corrosion inhibition of pyrazoles studied is regarded by a simple blocked fraction of the electrode surface related to adsorption of inhibitor species according to Langmuir isotherm model on the iron surface. The introduction in the pyrazole ring of a substituent such as -OH, -CO2H, -CO2CH3, and -Cl in the position 3, enhances the inhibiting effect of the pyrazole compounds. The effect of temperature on the corrosion behaviour of iron indicated that inhibition efficiencies of (Inh.9) increased with increasing temperature in the range of 25 - 50 °C. The apparent activation energy for iron corrosion process are modified by addition of (Inh.9)

Studies of Catecholase Activities of N-donor Bidentates Ligands derivated from Benzoxazole with Copper (II) Salts

International audienceThree functional, N-donorbidentates ligands, L1 2-(pyridin-2-yl) benzoxazole L2 2-(quinolin-2-yl) benzoxazole and L3 2-(4-(trifluoromethyl) pyridin-2-yl) benzoxazole have been examined for their catalytic oxidative activities. The dioxygen complexes of Cu(II) were generated in situ by stirring copper salts and bidentates ligands derivated from benzoxazole. It has been found that these compounds are very efficient to give oquinone. The nature of the ligands, the counter anion copper (II) salts and solvent have been investigated. These three parameters have an important effect on the oxidation reaction rate

Anti-Corrosive Properties and Quantum Chemical Studies of (Benzoxazol) Derivatives on Mild Steel in HCl (1 M)

International audienceThis work is a contribution to the study about the inhibition of mild steel corrosion in a molar hydrochloric acid medium by some benzoxazol derivatives compounds. The study was carried out using gravimetric and electrochemical methods (stationary and transient). We have considered the influence of the inhibitor concentration, the temperature of the medium and the duration of the immersion of the metal sample in the aggressive medium. These studies are complemented with theoretical calculations aimed to correlate the results obtained from experimental measurements using the DFT method. The results obtained in this work through gravimetric and both transient and stationary electrochemical methods showed a satisfied coherence. Theoretical calculations also revealed a good correlation with the experimental results for our compounds