Imidazolidine Ring Research Articles

Crystal structure and Hirshfeld surface analyses, crystal voids, intermolecular interaction energies and energy frameworks of 3-benzyl-1-(3-bromopropyl)-5,5-diphenylimidazolidine-2,4-dione

The title molecule, C25H23BrN2O2, adopts a cup shaped conformation with the distinctly ruffled imidazolidine ring as the base. In the crystal, weak C—H...O hydrogen bonds and C—H...π(ring) interactions form helical chains of molecules extending along the b-axis direction that are linked by additional weak C—H...π(ring) interactions across inversion centres. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (51.0%), C...H/H...C (21.3%), Br...H/H...Br (12.8%) and O...H/H...O (12.4%) interactions. The volume of the crystal voids and the percentage of free space were calculated to be 251.24 Å3 and 11.71%, respectively, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated by the dispersion energy.

Crystal structure, Hirshfeld surface analysis, calculations of crystal voids, inter-action energy and energy frameworks as well as density functional theory (DFT) calculations of 3-[2-(morpholin-4-yl)eth-yl]-5,5-di-phenyl-imidazolidine-2,4-dione.

In the title mol-ecule, C21H23N3O3, the imidazolidine ring slightly deviates from planarity and the morpholine ring exhibits the chair conformation. In the crystal, N-H⋯O and C-H⋯O hydrogen bonds form helical chains of mol-ecules extending parallel to the c axis that are connected by C-H⋯π(ring) inter-actions. A Hirshfeld surface analysis reveals that the most important contributions for the crystal packing are from H⋯H (55.2%), H⋯C/C⋯H (22.6%) and H⋯O/O⋯H (20.5%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated to be 236.78 Å3 and 12.71%, respectively. Evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the nearly equal electrostatic and dispersion energy contributions. The DFT-optimized mol-ecular structure at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state. Moreover, the HOMO-LUMO behaviour was elucidated to determine the energy gap.

CoFe2O4 as a source of Co(II) ions for imidacloprid insecticide oxidation using peroxymonosulfate: Influence of process parameters and surface changes

Nanometric cobalt magnetic ferrite (CoFe2O4) synthesized by distinct methods was used for in situ chemical activation of peroxymonosulfate (PMS) under neutral conditions to oxidize imidacloprid (IMD) insecticide. The effect of CoFe2O4 load (0.125–1.0 g L−1) and PMS concentration (250–1000 μM) was investigated as well as the influence of phosphate buffer and Co(II) ions. PMS activation by Co(II) ions, including those leached from CoFe2O4 (>50 μg L−1), exhibited a strong influence on IMD oxidation and, apparently, without substantial contributions from the solid phase. Within the prepared solid materials (i.e., using sol-gel and co-precipitation methods), high oxidation rates (ca. 0.5 min−1) of IMD were attained in ultrapure water. Phosphate buffer had no significant influence on the IMD oxidation rate and level, however, its use and solution pH have shown to be important parameters, since higher PMS consumption was observed in the presence of buffered solutions at pH 7. IMD byproducts resulting from hydroxylation reactions and rupture of the imidazolidine ring were detected by mass spectrometry. At optimum conditions (0.125 g L−1 of CoFe2O4 and 500 μM of PMS), the CoFe2O4 nanoparticles exhibited an increase in the charge transfer resistance and an enhancement in the surface hydroxylation after PMS activation, which led to radical (HO● and SO4●–) and nonradical (1O2) species. The latter specie led to high levels of IMD oxidation, even in a complex water matrix, such as simulated municipal wastewater at the expense of one-order decrease in the IMD oxidation rate.

Biological activities of nitromethylene analogues of imidacloprid with a 4,5-dimethylated imidazolidine ring

Biological activities of nitromethylene analogues of imidacloprid with a 4,5-dimethylated imidazolidine ring

Reactivity and reaction pathways of peroxymonosulfate and peroxydisulfate with neonicotinoid insecticides

Neonicotinoid insecticides (NNIs), which have been detected across diverse aquatic environments, have sparked substantial concerns regarding their potential adverse ecological and health risks. In this study, the removal of NNIs by unactivated peroxymonosulfate (PMS) and peroxydisulfate (PDS) was systematically investigated. Results showed that PMS/PDS direct oxidation is mainly responsible for the degradation of imidacloprid (IMD), and the degradation kinetics can be well described by a second-order kinetics model, first-order in both IMD and PMS/PDS concentration. The species-specific reaction rate constants of HSO5− and SO52− with IMD were calculated to be 429.36 ± 15.41 M−1h−1 and 9.72 ± 35.48 M−1h−1, while the corresponding rate constant between S2O82- and IMD is 25.04 ± 3.04 M−1h−1. Over 100 transformation products in the degradation of IMD by PMS/PDS were identified by HPLC/Q-Orbitrap HRMS, and five major reaction pathways were proposed thereafter: hydroxylation on imidazolidine ring, olefin reaction on imidazolidine ring, desnitro reaction on nitroguanidine moiety, and two chain-breaking reactions between imidazolidine ring and chloro-pyridyl moiety. Toxicity evaluation on the transformation products found that their ecotoxicity is various at a wide range with an overall indeterminacy, while their bioconcentration factors show a definite decrease. The reactivity of six NNIs with PMS/PDS was found varied by structures but generally low, indicating that in-situ oxidation with unactivated PMS/PDS is safe but inefficiency for the mitigation of NNIs. It is thus suggested that further investigations into activated PMS/PDS systems involving radicals promise enhanced remediation of NNIs, and fundamental data in this study has laid the groundwork.

Salicylaldehyde-functionalized polyethyleneimine precursor: Synthesis, characterization, and encapsulation in electrospun nonwoven for moisture-triggered release applications

Salicylaldehyde (SAL) is a natural flavoring agent with broad-spectrum antimicrobial activities but susceptible to degradation. To enhance its stability, SAL was conjugated with branched polyethyleneimine to form a SAL precursor (SALP) for controlled release applications. SAL molecules formed covalent bonds with BrPEI via imine linkages and imidazolidine rings, as confirmed by 1D and 2D NMR and FTIR spectroscopies. SALP was metastable under dry conditions but susceptible to acid-hydrolysis, triggering the release of SAL vapor, as revealed by the 1H NMR analysis. To facilitate end-use applications, SALP was encapsulated in poly(lactic acid)/poly(ethylene oxide) (PLA/PEO) nonwovens prepared by a free-surface electrospinning process. The release of SAL vapor from SALP-loaded nonwovens was studied using a citric acid (CA) solution of different concentrations. Additionally, a tri-layer nonwoven comprised of a SALP-loaded nonwoven sandwiched between two layers of CA-loaded fibers was developed. When exposed to 100 % RH, the composite nonwoven released SAL at a level of 0.046 ± 0.011 mg SAL/mg nonwoven in 4 h. The composite nonwoven exhibited antimicrobial properties against Escherichia coli K12, showing an 8-log reduction after a 4 h exposure to SAL vapor released from a 3 × 3 cm2 nonwoven. The antimicrobial nonwoven could be promising for limiting the proliferation of spoilage and pathogenic microorganisms to enhance the safety and reduce the wastage of food products.

Application of pesticide application measures to reduce residue based on the metabolic transfer law of imidacloprid in banana leaves and soil

An investigation of the metabolism and transfer of imidacloprid (IMI) in banana plants and soil was performed using high-resolution mass spectrometry. Results indicated the presence of eight IMI metabolites in soil and leaves that resulted from hydroxylation of the imidazolidine ring, the reduction and loss of nitro groups, and oxidative cleavage of methylene bridges. Six metabolites, including 4/5-hydroxy IMI (4/5-hydroxy), IMI olefin (olefin), and 6-chloronicotinic acid (6-CNA), were detected in the fruits following leaf treatment, while only three were detected after soil treatment. Quantitative analysis showed that the total amount of imidacloprid and its metabolites transferred from leaves to fruits was higher than that transferred from soil to fruits. Therefore, leaf transfer was considered the main means by which IMI and its metabolites transferred to banana fruits. We found that adjuvants tank-mixed with IMI could reduce the total concentration of pesticide transfer from leaves to fruits, especially reducing the amount of metabolites transformed from the reduction and loss of nitro groups and oxidative cleavage of methylene bridges, thus reducing the pesticide residue in fruits and achieving the purpose of reducing the safety risk.

3-(2-Bromo-eth-yl)-5,5-di-phenyl-imidazolidine-2,4-dione.

The imidazolidine ring in the title mol-ecule, C17H15BrN2O2, is slightly ruffled [r.m.s. deviation = 0.0192 Å], while the attached phenyl rings at the C atom at the position between the amine and carbonyl centres are rotated well out of its mean plane [dihedral angles with the imidazolidine ring = 63.60 (8) and 76.4 (1)°]. In the crystal, a three-dimensional network features N-H⋯O and C-H⋯O hydrogen bonds together with C-H⋯π(ring) inter-actions.

Synthesizing, Studying Molecular Docking, Characterizing, and Preliminary Evaluating Anti-Bacterial Effects of Derivatives of Serotonin Contain Imidazolidine Ring

This study included synthesis of new serotonin derivatives in which imidazolidine rings are present in their structures. The final imidazolidine derivatives compounds were synthesized by reaction of synthesized
 
 Schiff bases derivatives of serotonin with the glycine (NH2-CH2COOH) in presence of tetrahydrofuran (THF) as a solvent. The imidazolidine derivatives were identified by physical characteristics, FT-IR spectroscopy and 1H- NMR spectroscopy. Biological activities against two Gram negative (Klebsiella and E. coli) and two Gram positive (Streptococcus pyogenes and Staphylococcus aureus) bacteria were also distinguished. All the synthesized compounds III(a-d) exhibit moderate activities on four types of bacteria comparing with the activity of standard drug (Trimethoprim) but the highest activities of these compounds occur on Streptococcus pyogenes and their least activities occur on E. coli. The synthesized compounds were studied for the molecular docking to know the interaction and affinity of binding between them and bacteria

N-Substituted Arylidene-3-(Methylsulfonyl)-2-Oxoimidazolidine-1-Carbohydrazide as Cholinesterase Inhibitors: Design, Synthesis, and Molecular Docking Study.

The development of new enzyme inhibitors in degenerative brain diseases has gained more attention. Enzyme inhibitors play an effective role in controlling central nervous system diseases. For this purpose, a novel series of hydrazone derivatives containing imidazolidine ring aimed against Alzheimer's disease (AD), have been designed and synthesized. The acetylcholinesterase (AChE) enzyme inhibitory activity of these compounds was investigated. The structures of the compounds were determined by IR, 1 H and 13 C-NMR and mass spectroscopic methods. Inhibition studies on the cholinesterase (ChE) enzymes and β-amyloid plaque inhibition test of the compounds were performed. Based on the experimental results, compound 3j bearing dimethoxy substituent on the aromatic ring like donepezil exhibited the most AChE inhibitory activity with the IC50 values of 0.023±0.001 μM. Owing to obtained biological activity and molecular docking study results, it is thought that the most active compound 3j may play a role in both symptomatic and palliative treatment of AD.

3-Isobutyl-5,5-di-phenyl-imidazolidine-2,4-dione.

The imidazolidine ring in the title mol-ecule, C19H20N2O2, is slightly 'ruffled'. In the crystal, a layer structure is generated by N-H⋯O and C-H⋯O hydrogen bonds plus C-H⋯π(ring) inter-actions.

Crystal structure and Hirshfeld surface analysis of 5,7-diphenyl-1,2,3,5,6,7-hexa-hydro-imidazo[1,2-a]pyridine-6,6,8-tricarbo-nitrile methanol mono-solvate.

In the title compound, C22H17N5·CH4O, the imidazolidine ring of the 1,2,3,5,6,7-hexa-hydro-imidazo[1,2-a]pyridine ring system is a twisted envelope, while the 1,2,3,4-tetra-hydro-pyridine ring adopts a twisted boat conformation. In the crystal, pairs of mol-ecules are linked by O-H⋯N and N-H⋯O hydrogen bonds via two methanol mol-ecules, forming a centrosymmetric R 4 4(16) ring motif. These motifs are connected to each other by C-H⋯N hydrogen bonds and form columns along the a axis. The columns form a stable mol-ecular packing, being connected to each other by van der Waals inter-actions. A Hirshfeld surface analysis indicates that the most significant contributions to the crystal packing are from H⋯H (43.8%), N⋯H/H⋯N (31.7%) and C⋯H/H⋯C (18.4%) contacts.

Molecular Mechanism of Thymidylate Synthase Inhibition by N4-Hydroxy-dCMP in View of Spectrophotometric and Crystallographic Studies.

Novel evidence is presented allowing further clarification of the mechanism of the slow-binding thymidylate synthase (TS) inhibition by N4-hydroxy-dCMP (N4-OH-dCMP). Spectrophotometric monitoring documented time- and temperature-, and N4-OH-dCMP-dependent TS-catalyzed dihydrofolate production, accompanying the mouse enzyme incubation with N4-OH-dCMP and N5,10-methylenetetrahydrofolate, known to inactivate the enzyme by the covalent binding of the inhibitor, suggesting the demonstrated reaction to be uncoupled from the pyrimidine C(5) methylation. The latter was in accord with the hypothesis based on the previously presented structure of mouse TS (cf. PDB ID: 4EZ8), and with conclusions based on the present structure of the parasitic nematode Trichinella spiralis, both co-crystallized with N4-OH-dCMP and N5,10-methylenetetrahdrofolate. The crystal structure of the mouse TS-N4-OH-dCMP complex soaked with N5,10-methylenetetrahydrofolate revealed the reaction to run via a unique imidazolidine ring opening, leaving the one-carbon group bound to the N(10) atom, thus too distant from the pyrimidine C(5) atom to enable the electrophilic attack and methylene group transfer.

Ribose conversion with amino acids into pyrraline platform chemicals - expeditious synthesis of diverse pyrrole-fused alkaloid compounds.

One-pot conversion of sustainable d-ribose with l-amino acid, methyl esters produced pyrrole-2-carbaldehydes 5 in reasonable yields (32–63%) under pressurized conditions of 2.5 atm at 80 °C. The value-added pyrraline compounds 5 as platform chemicals were utilized for quick installation of poly-heterocyclic cores for the development of pyrrole-motif natural and artificial therapeutic agents. A pyrrole-fused piperazin-2-one scaffold 6 was prepared by reductive amination of pyrralines 5 with benzylamine. While further cyclization of pyrralines 5 with ethane-1,2-diamine produced pyrrolo-piperazin-2-ones 7 with an extra imidazolidine ring, the reaction with 2-amino alcohols derived from natural l-amino acids, alanine, valine, and phenylalanine, respectively provided pyrrolo-piperazin-2-ones 8, 9, and 10 with oxazolidine as the third structural core. Cell viability and an anti-inflammatory effect of the synthesized compounds were briefly tested by the MTT method and the Griess assay, among which 8h and 10g exhibited significant anti-inflammatory effects with negligible cell toxicity.

Crystal structure and Hirshfeld surface analysis of phen-yl(5,7,8a-triphenyl-1,2,3,7,8,8a-hexa-hydro-imidazo[1,2-a]pyridin-6-yl)methanone with an unknown solvent.

In the title compound, C32H28N2O, the imidazolidine and pyridine rings of the central hexa-hydro-imidazo[1,2-a]pyridine ring system adopt envelope and screw-boat conformations, respectively. The mol-ecule exhibits two weak intra-molecular π-π inter-actions between phenyl rings. In the crystal, mol-ecules are linked via pairs of C-H⋯ O hydrogen bonds, forming inversion dimers. The dimers are further linked by pairs of C-H⋯π inter-actions, forming infinite chains along the c-axis direction. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (73.4%), C⋯H/H⋯C (18.8%) and O⋯H/H⋯O (5.7%) contacts. The contribution of some disordered solvent to the scattering was removed using the SQUEEZE routine [Spek (2015 ▸). Acta Cryst. C71, 9-18] in PLATON. The solvent contribution was not included in the reported mol-ecular weight and density.

Phototransformation of biochar-derived dissolved organic matter and the effects on photodegradation of imidacloprid in aqueous solution under ultraviolet light

Dissolved organic matter (DOM) strongly influences the photodegradation of organic pollutants, varying depending on the structure of DOM. With the wide application of biochar, increasing amounts of DOM is released from biochar to the environment, which has different structural characteristics compared to natural DOM. In this study, DOM was derived from maize straw (MS) and pig manure (PM) and biochars by pyrolyzing MS and PM at 300 °C and 500 °C and the optical characteristics of DOM before and after phototransformation were explored via ultraviolet–visible spectroscopy and excitation–emission matrix fluorescence. Photodegradation of an insecticide, imidacloprid (IMI) in the presence of DOM was examined. The results showed that DOM derived from biochar obtained by pyrolyzing MS and PM mainly contained two identified fluorescent components and high pyrolysis temperature (500 °C) was associated with low molecular weight, small light-screening effects and great aromaticity of the DOM. After exposure to UV light, the aromaticity and molecular weight of the DOM declined due to phototransformation. Significant enhancement was observed in IMI photodegradation in the presence of biochar-derived DOM, and the enhancement was the greatest with DOM derived from pig manure biochar pyrolyzed at 500 °C. In addition to the light shielding effect, the 1O2 generated from DOM played an important role in the phototransformation of IMI and DOM. The loss of the nitro group and oxidation at the imidazolidine ring were the main photodegradation pathways for IMI. This study expands our understanding of the fate of biochar-derived DOM and its effects on the fate of coexisting organic pollutants.

Synthesis of a novel phenytoin derivative: Crystal structure, Hirshfeld surface analysis and DFT calculations

Hydantoin compounds are important heterocyclic scaffolds and a class of well-known bioactive molecules with a broad spectrum of pharmacological properties. Consequently, considerable efforts have been devoted to the design and synthesis of a broad range of hydantoin derivatives. In this context, the compound 3-allyl-5,5-diphenylimidazolidine-2,4-dione, C18H16N2O2 (3ADID) was synthesized and its structure was determined by X-ray structure analysis. Further, the molecular structure was examined using Hirshfeld topology analysis and Density Functional Theory (DFT)-B3LYP calculations with the basis set 6–311++G (d,p). In the title molecule, C18H16N2O2, the imidazolidine ring is planar with the allyl substituent oriented nearly perpendicular to it. In the crystal, hydrogen bonded chains of molecules are arranged in sets of three about the 32 axes by C–H···π (ring) interactions. Hirshfeld surface map and 2D fingerprint plots were used to explore intermolecular interactions. The optimized geometry, global reactivity descriptors, and HOMO-LUMO orbitals of the molecule were computed by DFT and discussed. To evaluate the chemical reactivity and charge distribution on the molecule, molecular electrostatic potential (MEP) and atomic charges, computed by Mulliken population analysis and NBO theory were determined. The local reactivity was examined by determining the Fukui functions and dual descriptor indices. DFT calculations at the same level of theory, with the POPNBO keyword, were used to evaluate charge delocalization and hyperconjugative interactions through Natural Bond orbital analysis.

Scholarinine A, a N3 type caged-monoterpene indole alkaloid as Cav3.1 T-type calcium channel inhibitor from Alstonia scholaris

Scholarinine A (1), a new N3-type caged monoterpene indole alkaloid was isolated from the branches and leaves of Alstonia scholaris. Structurally, 1 is featured by unique 6/5/6/5/5/6 carbocyclic skeleton bearing a novel imidazolidine ring E. The structure of 1 was determined by extensive spectroscopic analyses and X-ray crystallography. Biological studies exhibited that compound 1 is a potent Cav3.1 T-type calcium channel inhibitor with an IC50 value of 4.28 μM. In addition, 1 enhanced the neurite outgrowth of nerve growth factor (NGF) mediated PC12 cells at 10 μM.

Crystal structure, Hirshfeld surface analysis and inter-action energy and DFT studies of 5,5-diphenyl-1,3-bis-(prop-2-yn-1-yl)imidazolidine-2,4-dione.

The title compound, C21H16N2O2, consists of an imidazolidine unit linked to two phenyl rings and two prop-2-yn-1-yl moieties. The imidazolidine ring is oriented at dihedral angles of 79.10 (5) and 82.61 (5)° with respect to the phenyl rings, while the dihedral angle between the two phenyl rings is 62.06 (5)°. In the crystal, inter-molecular C-HProp⋯OImdzln (Prop = prop-2-yn-1-yl and Imdzln = imidazolidine) hydrogen bonds link the mol-ecules into infinite chains along the b-axis direction. Two weak C-HPhen⋯π inter-actions are also observed. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (43.3%), H⋯C/C⋯H (37.8%) and H⋯O/O⋯H (18.0%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that the C-HProp⋯OImdzln hydrogen-bond energy in the crystal is -40.7 kJ mol-1. Density functional theory (DFT) optimized structures at the B3LYP/6-311G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

γ-Azaproline Confers pH Responsiveness and Functionalizability on Collagen Triple Helices.

Proline derivatives bearing substituents at Cγ are valuable tools for biological and materials investigations. However, the stereochemistry at Cγ can produce undesired steric or stereoelectronic interactions. Here, we introduce γ-azaproline (γ-azPro), which lacks a stereogenic center at Cγ, as a pH-responsive and functionalizable proline analogue that can adapt to its environment. Conformational analyses by NMR spectroscopy and DFT calculations revealed that the imidazolidine ring of γ-azPro is flexible. Incorporation of γ-azPro into collagen model peptides (CMPs) produced pH-responsive triples helices and triple helices that can be easily functionalized.