Imidazoline derivatives: a patent review (2006 – present)

Single-Step Sustainable Production of Hydroxy-Functionalized 2-Imidazolines from Carbohydrates

Manufacturing valuable N-containing chemicals from biomass is highly desirable yet challenging. Herein, a novel strategy was developed for efficient production of 2-(1-hydroxyethyl)-imidazoline (HI), a high-value and versatile building block for synthesizing a myriad of bioactive targets, directly from carbohydrates under mild reaction conditions. With this strategy, bio-based HI was produced from fructose in one step with as high as 77 C % isolated yield in the presence of ethylenediamine (EDA) and InCl₃ at 130 °C. The synergistic functions of EDA and InCl₃ were identified for the transformation, wherein EDA promoted the scission of C-C bond of fructose backbone via retro-aldol (R-A) reaction and rapidly trapped in-situ formed reactive carbonyl-containing C₃ intermediate for HI formation to avoid undesired side reaction, and InCl₃ facilitated the formation of this C₃ intermediate and the final 1,2-hydrid shift step.

Characterization of a Solvent-Tolerant Amidohydrolase Involved in Natural Product Heterocycle Formation

Heterocycles are important building blocks in pharmaceutical drugs and their enzymatic synthesis is attracting increasing interest. In recent years, various enzymes of the amidohydrolase superfamily were reported to catalyze heterocycle-forming condensation reactions. One of these enzymes, MxcM, is biochemically and kinetically characterized in this study. MxcM generates an imidazoline moiety in the biosynthesis of the natural product pseudochelin A, which features potent anti-inflammatory properties. The enzyme shows maximal activity at 50 °C and pH 10 as well as a kcat/Km value of 22,932 s−1 M−1 at its temperature optimum. Experimental data suggest that the activity of MxcM does not depend on a catalytic metal ion, which is uncommon among amidohydrolases. MxcM is highly active in diverse organic solvents and concentrated salt solutions. Furthermore, we show that MxcM is also capable to introduce imidazoline rings into derivatives of its natural substrate myxochelin B. Overall, MxcM is a solvent-stable, halotolerant enzyme with promising biochemical and kinetic properties and, in future, might become a valuable biocatalyst for the manufacturing of pharmaceutical drugs.

Electrochemical and Computational Insights on the Application of Expired Metformin Drug as a Novel Inhibitor for the Sweet Corrosion of C1018 Steel

An expired metformin drug (MET) was used as a corrosion inhibitor for C1018 carbon steel in a CO2-saturated 3.5 wt % NaCl + 340 ppm acetic acid solution under static conditions. The inhibitor was evaluated using electrochemical methods complemented with surface analytical measurements and computational modeling. The drug displayed a high inhibition efficiency of ∼90% at 200 ppm. Impedance analyses revealed a rise in the charge transfer resistance at the steel-solution interface upon the addition of the inhibitor. Polarization measurements suggested that MET acted more like a cathodic-type corrosion inhibitor and significantly reduced the corrosion current density. The adsorption of MET on the steel substrate followed the Langmuir isotherm, showing a mixed type of physical and chemical modes of adsorption. The thermodynamic parameters revealed strong and spontaneous adsorption on the steel surface. The surface analysis using SEM supported the inhibitor adsorption on the steel substrate. Based on the DFT simulation, inhibition by MET is mainly achieved by its protonated form, which leads to the formation of a thin film on the steel surface rather than the modification of the work function of the steel surface. The experimental and theoretical estimations of pKa complemented the DFT results, both agreeing that the monoprotonated form of MET is the dominant form in which the inhibitor adsorbs on the steel surface to form a thin film rather than modify the work function of the steel surface.

Chemical Variations on the p53 Reactivation Theme

Among the tumor suppressor genes, p53 is one of the most studied. It is widely regarded as the "guardian of the genome", playing a major role in carcinogenesis. In fact, direct inactivation of the TP53 gene occurs in more than 50% of malignancies, and in tumors that retain wild-type p53 status, its function is usually inactivated by overexpression of negative regulators (e.g., MDM2 and MDMX). Hence, restoring p53 function in cancer cells represents a valuable anticancer approach. In this review, we will present an updated overview of the most relevant small molecules developed to restore p53 function in cancer cells through inhibition of the p53-MDMs interaction, or direct targeting of wild-type p53 or mutated p53. In addition, optimization approaches used for the development of small molecules that have entered clinical trials will be presented.

Metal-free one-pot synthesis of 1,3-diazaheterocyclic compounds via I2-mediated oxidative C–N bond formation

A variety of 1,3-diazaheterocyclic compounds, including quinazolinones, benzimidazoles, and cyclic amidines, were readily synthesized through this metal-free one-pot annulation reaction.