Synthesis, spectroscopic characterization (FT-IR, NMR, UV-Vis), DFT study, antibacterial and antioxidant in vitro investigations of 4,6-bis((E)-1-((3-(1H-imidazol-1-yl)propyl)imino)ethyl)benzene-1,3-diol

Preparation of novel thiolated chitosan with significant antioxidant activity

The aim of this study was to synthesize thiolated chitosan derivative and evaluated its antioxidant activity. Thiol groups were introduced into chitosan and hydroxypropyl trimethylammonium chloride chitosan quaternary ammonium salt (HACC) by microwave reaction, respectively. At the same time, a series of compounds containing thiol groups were introduced at the amino site. The structure of the chitosan derivatives was identified by FTIR and 1H NMR. The thiol groups content, thermal stability, water solubility and cytotoxicity of the chitosan derivative were evaluated. The antioxidant activity of chitosan derivatives was evaluated using superoxide anion radical scavenging activity assay, DPPH radical scavenging activity assay, hydroxyl radical scavenging activity assay and reducing power assay. The results showed that the thiolated chitosan derivatives obtained in this study possessed excellent antioxidant activity, which provides a new idea for the further study of chitosan antioxidants.

Theoretical study on the influence of OH group position on the free radical scavenging ability of tryptamine derivatives

A density functional theory (DFT) study investigated the influence of hydroxyl (OH) groups on the free radical scavenging capacity of tryptamine derivatives (OH-TAs). Stable forms of OH-TAs were evaluated in both gaseous and aqueous environments. While neutral forms predominate in the gas phase, cationic forms (protonated at the NH2 group) are favored in aqueous solution. Frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) analyses identified active sites. Electron-donating regions are primarily located on the benzene and pyrrole rings, whereas electron-accepting areas are concentrated on the OH and NH groups. In water, the lowest unoccupied molecular orbitals (LUMOs) of OH-TAs shift and localize on the NH3 + group. Calculated global reactivity descriptors indicate that 9-OH-TA exhibits the highest free radical scavenging efficiency. Molecular electrostatic potential (MEP) analysis further reveals that the hydrogen atoms in the -OH groups of the OH-TAs are the most favorable sites for nucleophilic attacks. Thermodynamic parameters, including bond dissociation energy (BDE), ionization potential (IP), and proton affinity (PA), were calculated to assess antioxidant properties. Reaction mechanism analyses reveal that hydrogen atom transfer (HAT) is the preferred pathway in the gas phase, while the single electron transfer (SET) mechanism dominates in aqueous solutions at physiological pH (7.4). Among the studied derivatives, 9-OH-TA demonstrates the highest efficiency in scavenging HOO˙ radicals, with total rate constants of 1.9 × 107 M-1 s-1 in the gas phase and 5.2 × 107 M-1 s-1 in water.

Synthesis of Imidazolidin-2-ones from trans-(R,R)-Diaminocyclohexane: A Statistical Analysis-Based Pseudo-Multicomponent Protocol

A pseudo-multicomponent one-pot protocol for the synthesis of 1,3-disubstituted imidazolidin-2-one is described, employing trans-(R,R)-diaminocyclohexane for the in situ formation of the Schiff base, followed by reduction to produce the respective diamine and cyclization with carbonyldiimidazole (CDI). This approach utilizes statistical analysis to optimize the reaction conditions, allowing a pseudo-multicomponent protocol to be proposed. The developed method demonstrates sustainability, efficiency, and potential applications in green chemistry, achieving yields ranging from 55% to 81%. This represents a significant advance in synthesizing heterocyclic compounds with biological and pharmacological applications.

Molecular Modeling, Synthesis, and Antihyperglycemic Activity of the New Benzimidazole Derivatives - Imidazoline Receptor Agonists

Introduction

The paper presents the results of a study on the first synthesized benzimidazole derivatives obtained from labile nature carboxylic acids. The synthesis conditions of these substances were studied, their structure was proved, and some components were found to have sugar-reducing activity on the model of alloxan diabetes in rats.

Methods

The study used molecular modeling methods such as docking based on the evolutionary model (igemdock), RP_HPLC method to monitor the synthesis reaction, and 1H NMR and 13C NMR, and other methods of organic chemistry to confirm the structures of synthesized substances.

Results & Discussion

The docking showed that the ursodeoxycholic acid benzimidazole derivatives have high tropics to all imidazoline receptor carriers (PDB ID: 2XCG, 2bk3, 3p0c, 1QH4). The ursodeoxycholic acid benzimidazole derivative and arginine and histidine benzimidazole derivatives showed the highest sugar-lowering activity in the experiment on alloxan-diabetic rats. For these derivatives, the difference in glucose levels of treated rats was significant against untreated control. Therefore, the new derivatives of benzimidazole and labile natural organic acids can be used to create new classes of imidazoline receptor inhibitors for the treatment of diabetes mellitus and hypertension.