Towards a theoretical understanding of alkaloid-extract Cytisine derivatives ofRetama monosperma (L.) Boiss. Seeds, as eco-friendly inhibitor for carbon steel corrosion in acidic 1M HCl solution

Abstract

Because of their availability, lower cost, biodegradability, respect for health, environmental standards and their extremely high efficiency [Benmessaoud Left D, Zertoubi M, Irhzo A, Azzi M, Revue: Huiles et extraits de plantes comme inhibiteurs de corrosion pour différents métaux et alliages dans le milieu acide chlorhydrique, J Mater Environ Sci 4:855–866, 2013], the green corrosion inhibitors are currently the most sought after candidates. The ultimate aim of this work is to study the selectivity and reactivity of a series of three molecules, namely Cytisine, Dehydro-Cytisine and N-methyl Cytisine which are the major constituents of Retama monosperma seeds alkaloid extract (AERS) as eco-friendly inhibitors of corrosion of carbon steel in acidic medium HCl (1M), using the density functional theory (DFT) at B3LYP/aug-cc-pvdz levels. Indeed, this alkaloid extract AERS has proven experimentally its corrosion inhibitory power for carbon steel in 1 M HCl even at lower concentration (94.42% at 400[Formula: see text]mg/L). Besides, its adsorption on the steel surface in 1 M HCl solution followed Langmuir’s isotherm [El Hamdani N, Fdil R, Tourabi M, Jama C, Bentiss F, Alkaloids extract of Retama monosperma (L.) Boiss. seeds used as novel eco-friendly inhibitor for carbon steel corrosion in 1 M HCl solution: Electrochemical and surface studies, Appl Surf Sci 357:1294–1305, 2015, doi: 10.1016/j.apsusc.2015.09.159; El Hamdani N, Contribution a la valorisation des parties aériennes de Retama Monosperma, phytochimie, activités antimicrobiennes et propriétés anticorrosives, Universite Chouaib Doukkali Faculte des sciences El jadida, 2015]. Herein, the major aim of this work is to investigate the likelihood of the carbon steel corrosion being inhibited by the protonated species in the aqueous acidic solution. For this purpose, after proving that the most favorable protonation site for protonation was N9, we have evaluated the structural, global and local reactivity descriptors, partial atomic charge in terms of Natural bond orbital (NBO) of the three protonated inhibitors at the level of N9, which are the most stable in the aqueous acidic solution. NBO analysis and the thermodynamic properties such as entropy, enthalpy, heat capacity and Gibbs free energy were also done. In conclusion, it was observed that three protonated molecules showed a high propensity to adsorb to the mild steel surface with a priority of the molecule d-CytN9H+.

Electronic and optical spectroscopic insights into 2.3.4-trimethyl pentane conformations by long-range corrected DFT calculations, experimental low frequency Raman and IR temperature sensitivity and scaled vibrational assignment

“…Using Gaussian 09 software [8], the computational calculations were investigated through the DFT/CAM-B3LYP and DFT/WB97XD functionals to take into account the dispersion correction at long distance. The basis set chosen was aug-cc-pVTZ (correlation consisting polarized basis set) which includes layers of polarization functions -to gain in terms of convergence of the electronic energy towards the complete base limit -and augmented by diffuse functions serving to describe long-range interactions [9], [10]. The results of the conformational analysis of 2.2.3-TMP were slightly different from the DFT/CAM-B3LYP and DFT/WB97XD functionals.…”

A Spotlight on Retama spp., The Mediterranean Evergreen Stem-assimilating Xerophyte

“…Alkaloids were more analogous in these three species of Mediterranean distribution than its profile between the organs of the same species. The major alkaloids detected in stem were retamine and sparteine; while fruits and flowers were dominated by cytisine, lupanine, N-methylcytisine and retamine (El-Shazly et al, 1996); and seeds are the storage organ of cytisine alkaloid (El-Shazly et al, 1996;Sadik et al, 2020). Sadik et al (2020), reported the presence of three alkaloids in R. monosperma seeds in descending percentages as 77.60% cytisine, 13% N-methylcytisine and 9.40% dehydro-cytisine.…”

“…The major alkaloids detected in stem were retamine and sparteine; while fruits and flowers were dominated by cytisine, lupanine, N-methylcytisine and retamine (El-Shazly et al, 1996); and seeds are the storage organ of cytisine alkaloid (El-Shazly et al, 1996;Sadik et al, 2020). Sadik et al (2020), reported the presence of three alkaloids in R. monosperma seeds in descending percentages as 77.60% cytisine, 13% N-methylcytisine and 9.40% dehydro-cytisine. While the stem contains ten alkaloids: Ammodendrine, Anagyrine, Cytisine, Dehydrosparteine, 5,6-Dehydrolupanine, 11,12-Dehydrolupanine, Isolupanine, N-methylcytisine, 17-Oxosparteine and Sparteine.…”

Synthesis and Evaluation of Antimicrobial Activity of the Rearranged Abietane Prattinin A and Its Synthetic Derivatives

“…The important parameter descriptors of global reactivity, such as the energy gap (∆E), electronic affinity (EA), ionization potential (EI), electronegativity (χ), chemical hardness (η), global softness (σ), electrophilicity (ω), and electronegativity (χ) index, were calculated using the Equations ( 1)- (7), to explain the chemical reactivity of the newly synthesized molecular [44,45]…”