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Journal of the American Chemical Society Jun 2024We report a general and functional-group-tolerant method for the Cu-catalyzed amination of base-sensitive aryl bromides including substrates possessing acidic functional...
We report a general and functional-group-tolerant method for the Cu-catalyzed amination of base-sensitive aryl bromides including substrates possessing acidic functional groups and small five-membered heteroarenes. The results presented herein substantially expand the scope of Cu-catalyzed C-N coupling reactions. The combination of , an anionic ,-diarylbenzene-1,2-diamine ligand, along with the mild base NaOTMS leads to the formation of a stable yet reactive catalyst that resists deactivation from coordination to heterocycles or charged intermediates. This system enables the use of low catalyst and ligand loadings. Exploiting the differences in nucleophile deprotonation in C-O and C-N coupling reactions catalyzed by Cu· we developed a method to chemoselectively - and -arylate a variety of amino alcohol substrates. Employing NaO-Bu as the base resulted exclusively in C-O coupling when the amino alcohols featured primary alcohols and more hindered amines or aniline groups. Utilizing NaOTMS enabled the ability to override the steric-based selectivity of these reactions completely and exclusively promoted C-N coupling regardless of the structure of the amino alcohol. The ability to invert the observed chemoselectivity is distinct from previously described methods that require protecting group manipulations or rely entirely on steric effects to control reactivity. These results substantially improve the scope of Cu-catalyzed C-N coupling reactions using ,-diarylbenzene-1,2-diamine ligands and introduce a new chemoselective method to arylate amino alcohols.
PubMed: 38924516
DOI: 10.1021/jacs.4c05246 -
Angewandte Chemie (International Ed. in... Jun 2024The booming demand on data security has aroused great interest for developing smart materials with temporal display feature and dynamic multicolor fluorescence. However,...
The booming demand on data security has aroused great interest for developing smart materials with temporal display feature and dynamic multicolor fluorescence. However, it remains challenging to implement both features on most responsive molecules. Herein, we construct a polymer free volume-controlled "molecular clock and emitter" via covalently embedding a multi-stimuli responsive molecular switch (i.e., spiropyran) into a polymer network (i.e., poly(pentafluorophenyl acrylate)) with programmable crosslink density and free volume. By the aminolysis of pentafluorophenyl ester with different amount of diamine crosslinkers, pPFPA-co-SP networks with controllable crosslink densities are generated, which have different confinement effects on the rate constant of SP/MC isomerization, thus leading to time-dependent photochromism. In addition, PTF1, a fluorescent probe that is sensitive to polymer rigidity, is introduced to further endow pPFPA-co-SP system with phototunable dynamic full-color emission. Therefore, relying on their synergistical responses to the rigidity of the polymer network, we have successfully developed a versatile molecular clock and emitter via an "one stone two birds" manner, which shows time-dependent data display along with dynamic multicolor fluorescence switching, providing great potential for advanced encryption and anticounterfeiting with a high security level.
PubMed: 38923092
DOI: 10.1002/anie.202403973 -
Biometals : An International Journal on... Jun 2024In the present manuscript, novel macrocyclic Schiff base complexes [Zn(NMacL)Cl-Zn(NMacL)Cl] were synthesized by the reaction of ZnCl and macrocyclic ligands...
Novel tetraaza macrocyclic Schiff base complexes of bivalent zinc: microwave-assisted green synthesis, spectroscopic characterization, density functional theory calculations, molecular docking studies, in vitro antimicrobial and anticancer activities.
In the present manuscript, novel macrocyclic Schiff base complexes [Zn(NMacL)Cl-Zn(NMacL)Cl] were synthesized by the reaction of ZnCl and macrocyclic ligands (NMacL-NMacL) derived from diketone and diamines under microwave irradiation method and conventional method. The structures of the obtained complexes were identified by various spectrometric methods such as Fourier transformation infra-red (FT-IR), nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HR-MS), powder X-ray diffraction, molar conductivity, and UV-vis. The structures of the synthesized compounds were optimized by using the def2-TZV/J and def2-SVP/J Coulomb fitting basis sets at B3LYP level in density functional theory (DFT) calculations. The macrocyclic Schiff base complexes exhibited higher activities against Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus), Gram-negative bacteria (Escherichia coli and Xanthomonas campestris), and fungal strains (Fusarium oxysporum and Candida albicans) in comparison to macrocyclic Schiff base ligands. Furthermore, the newly synthesized macrocyclic compounds were assessed for their anticancer activity against three cell lines: A549 (human alveolar adenocarcinoma epithelial cell line), HT-29 (human colorectal adenocarcinoma cell line), and MCF-7 (human breast adenocarcinoma cell line) using the MTT assay. The obtained results showed that the macrocyclic complex [Zn(NMacL)Cl] displayed the highest cytotoxic activity (2.23 ± 0.25 µM, 6.53 ± 0.28 µM, and 7.40 ± 0.45 µM for A549, HT-29, and MCF-7 cancer cell lines, respectively). Additionally, molecular docking investigations were conducted to elucidate potential molecular interactions between the synthesized macrocyclic compounds and target proteins. The results revealed a consistent agreement between the docking calculations and the experimental data.
PubMed: 38922505
DOI: 10.1007/s10534-024-00616-y -
Mikrochimica Acta Jun 2024A ratiometric fluorescence sensing strategy has been developed for the determination of Cu and glyphosate with high sensitivity and specificity based on OPD...
A ratiometric fluorescence sensing strategy has been developed for the determination of Cu and glyphosate with high sensitivity and specificity based on OPD (o-phenylenediamine) and glutathione-stabilized gold nanoclusters (GSH-AuNCs). Water-soluble 1.75-nm size GSH-AuNCs with strong red fluorescence and maximum emission wavelength at 682 nm were synthesized using GSH as the template. OPD was oxidized by Cu, which produced the bright yellow fluorescence oxidation product 2,3-diaminophenazine (DAP) with a maximum fluorescence emission peak at 570 nm. When glyphosate existed in the system, the chelation between glyphosate and Cu hindered the formation of DAP and reduced the fluorescence intensity of the system at the wavelength of 570 nm. Meanwhile, the fluorescence intensity at the wavelength of 682 nm remained basically stable. It exhibited a good linear relationship towards Cu and glyphosate in water in the range 1.0-10 µM and 0.050-3.0 µg/mL with a detection limit of 0.547 µM and 0.0028 µg/mL, respectively. The method was also used for the semi-quantitative determination of Cu and glyphosate in water by fluorescence color changes visually detected by the naked eyes in the range 1.0-10 µM and 0.30-3.0 µg/mL, respectively. The sensing strategy showed higher sensitivity, more obvious color changes, and better disturbance performance, satisfying with the detection demands of Cu and glyphosate in environmental water samples. The study provides a reliable detection strategy in the environment safety fields.
Topics: Glyphosate; Glycine; Copper; Metal Nanoparticles; Phenylenediamines; Gold; Spectrometry, Fluorescence; Limit of Detection; Water Pollutants, Chemical; Colorimetry; Glutathione; Herbicides; Fluorescent Dyes
PubMed: 38922503
DOI: 10.1007/s00604-024-06484-0 -
Dentistry Journal Jun 2024Silver diamine fluoride (SDF) is a topical solution used for managing dental caries. The mixed-methods study consists of a quantitative study (questionnaire survey) and...
Silver diamine fluoride (SDF) is a topical solution used for managing dental caries. The mixed-methods study consists of a quantitative study (questionnaire survey) and a qualitative study (in-depth interview) to explore the knowledge, attitudes, and practices towards SDF among dentists in Vietnam. A descriptive approach and a thematic approach were performed to analyze data, respectively. The questionnaire survey invited 436 licensed dentists registered for the national annual dental meeting and 226 dentists participated (response rate: 52%). Among them, 174 (77%, 174/226) dentists knew SDF, and 69 (40%, 69/174) dentists used SDF for caries management. Most of them considered SDF therapy as non-invasive (84%, 146/174) and simple (80%, 140/174). However, most of them expressed concern that SDF could discolor the tooth (74%, 128/174). Their most preferred teeth for SDF therapy were primary posterior teeth (92%, 160/174). The in-depth interview consulted 16 dentists to reach data saturation. They learned about SDF from outside curriculum resources as an effective anti-caries agent. They understood the advantages (simple, non-invasive, timesaving) and disadvantages (tooth discoloring, ammonia odor) of SDF. They used SDF to arrest caries in uncooperative children in the clinic and people living in rural areas in outreach services. Most dentists in Vietnam are supportive of SDF therapy, and they know its advantages and disadvantages for caries management. The results addressed the aim of the study to investigate Vietnamese dentists' perspectives towards SDF.
PubMed: 38920870
DOI: 10.3390/dj12060169 -
Cureus May 2024Beta-thalassemia is one of the most common inherited hematological diseases caused by more than 350 mutations in the β-globin gene (HBB). Beta-thalassemia carrier or...
Beta-thalassemia is one of the most common inherited hematological diseases caused by more than 350 mutations in the β-globin gene (HBB). Beta-thalassemia carrier or trait is associated with defects in one allele of the HBB gene. The majority of beta-thalassemia trait cases remain concealed in society and remain unnoticed as they are mostly asymptomatic or present with mild symptoms of anemia. There is a 25% chance of having children with beta-thalassemia major and a 50% chance of having carrier babies when two people with beta-thalassemia trait are married. Hence, it is important to identify the individuals with beta-thalassemia trait and provide counseling to understand the risks of pregnancy and its outcome. Aim To study the identification of beta-thalassemia trait cases along with their clinical findings and hematological correlation. Materials and methods Study Design This was a retrospective study conducted at Saveetha Medical College and Hospital for a period of four years from January 2020 to December 2023. Inclusion Criteria Age group more than 18 years, antenatal mother, cases of anemia who were refractory to iron treatment, and screening of family members in the positive cases of beta-thalassemia trait. Exclusion Criteria History of blood transfusion within three months was excluded. A total number of 837 cases were screened to rule out the presence of beta-thalassemia trait/hemoglobin (Hb) variants. A 2 mL of intravenous blood samples were collected in an ethylene diamine tetraacetic acid (EDTA) vacutainer tube and processed in a Sysmex XN 1000 (Hyogo, Japan: Sysmex Corporation) automated hematology analyzer. The hematological parameters were analyzed. Statistical Analysis The study included both descriptive and analytical characteristics. Mean and standard deviation (SD) were calculated for all the hematological parameters. Beta-thalassemia trait was diagnosed with an HbA2 level of more than 4.0% through high-performance liquid chromatography (HPLC) analysis. Results Among the 837 samples studied for HPLC screening, 74 (8.8%) cases were found to have beta-thalassemia trait. The age group included was from 18 years to 56 years. Of 74 cases studied, 32(43%) were females and 42(57%) were males. Among the 74 cases studied, the Mentzer index <13 was seen in 58 (78%) cases and the Mentzer index >13 was seen in 16 cases (22%). Thirty-four cases (46%) of beta-thalassemia traits presented to the hospital with a history of fever for evaluation and antenatal screening accounted for 19 cases (26%). The mean red blood cell (RBC) count was 5.5 million/cu.mm; mean corpuscular volume (MCV) was 63.8 fL; mean corpuscular hemoglobin (MCH) was 19.6 pg; red cell distribution width coefficient of variation (RDW-CV) was 17.8%. Among the 74 cases studied, 37(46%) cases had an Hb of more than 11 g/dL, 22 cases had mild anemia, 12 cases had moderate anemia, and three cases had severe anemia. Conclusion This study concluded that regular monitoring of the Mentzer index along with HPLC analysis is an effective approach in identifying beta-thalassemia trait cases and further providing genetic counseling among the couples that will help in reducing high-risk pregnancy and the birth of a child with thalassemia major.
PubMed: 38919232
DOI: 10.7759/cureus.61093 -
Acta Chimica Slovenica May 2024Three new copper(II) complexes, [CuClL] (1), [CuBrL]n (2) and [CuL(NCS)]n (3), derived from the Schiff base 2,4-dichloro-6-((2-pyrrolidin-1-ylethylimino)methyl)phenol...
Three new copper(II) complexes, [CuClL] (1), [CuBrL]n (2) and [CuL(NCS)]n (3), derived from the Schiff base 2,4-dichloro-6-((2-pyrrolidin-1-ylethylimino)methyl)phenol (HL) have been prepared and characterized by spectroscopy methods, as well as single crystal X-ray determination. The Cu atom in complex 1 is in square planar coordination, and those in complexes 2 and 3 are in square pyramidal coordination. The Schiff base ligand coordinates to the Cu atoms through phenolate oxygen, imino nitrogen and pyrrolidine nitrogen. The antibacterial activities of the Schiff base and the three copper complexes have been assayed on the bacteria Staphylococcus aureus and Escherichia coli, and the yeast Candida parapsilosis.
PubMed: 38919098
DOI: 10.17344/acsi.2024.8707 -
Poultry Science Jun 2024This study was conducted to investigate the protective effects of chlorogenic acid (CGA) on inflammatory responses and intestinal health of lipopolysaccharide...
This study was conducted to investigate the protective effects of chlorogenic acid (CGA) on inflammatory responses and intestinal health of lipopolysaccharide (LPS)-challenged broilers. One hundred and forty-four 1-day-old male broiler chicks were divided into 3 groups with 6 replicates of 8 birds each. The groups were as follows: 1) Control group: birds fed a basal diet; 2) LPS group: LPS-challenged birds fed a basal diet; 3) CGA group: LPS-challenged birds fed a CGA-supplemented diet. The LPS was intraperitoneally administered at a dose of 1 mg/kg of body weight. CGA increased the weight gain and feed intake of LPS-challenged birds by 37.05% and 24.29%, respectively (P < 0.05). CGA also alleviated LPS-induced inflammation, as evidenced by lower levels of pro-inflammatory cytokines in the serum and jejunum (tumor necrosis factor-α, interferon-γ, interleukin-1β, and interleukin-6), and the decreased myeloperoxidase activity in the jejunum (P < 0.05). These effects were accompanied by a decrease in the mRNA abundance of toll-like receptor 4 and myeloid differentiation factor 88 and an inhibition of nuclear factor kappa-B translocation in the jejunum (P < 0.05). CGA reduced circulating diamine oxidase activity and levels of D-lactate and endotoxin, and positively regulated the expression of jejunal claudin-3 and zonula occludens-1 in LPS-challenged broilers (P < 0.05). Compared to the LPS group, CGA reduced the apoptotic rate of epithelial cells and cytochrome c concentration in the jejunum, and normalized the expression of genes responsible for proliferation and apoptosis in jejunal epithelial cells, including cysteine aspartate-specific protease-9, B cell lymphoma-2, and proliferating cell nuclear antigen (P < 0.05). Furthermore, CGA normalized the altered phosphorylation of protein kinase B and glycogen synthase kinase-3β, as well as the translocation of nuclear β-catenin in the jejunum of LPS-challenged broilers (P < 0.05). These results suggested that CGA supplementation improved growth performance, alleviated inflammation, and helped maintain intestinal integrity and barrier function in LPS-challenged broilers, possibly through the regulation of the toll-like receptor 4/nuclear factor kappa-B and protein kinase B/Wnt/β-catenin pathways.
PubMed: 38917604
DOI: 10.1016/j.psj.2024.103949 -
Journal of the American Chemical Society Jun 2024Despite recent advances in porous organic molecular crystals, the engineering of dual-pore systems within the intermolecular voids remains a significant challenge. In...
Despite recent advances in porous organic molecular crystals, the engineering of dual-pore systems within the intermolecular voids remains a significant challenge. In this study, we have achieved the crystallization-induced social self-sorting of "quasi-racemic" dialdehydes into a macrocyclic imine. X-ray crystallographic analysis unambiguously characterizes the resulting structure as incorporating two quasi-racemate pairs with four diamine molecules. Notably, different alkyl substituents on the quasi-racemates afford two types of one-dimensional pores within the macrocyclic imine crystal. The different adsorption properties of these pores were substantiated through adsorption experiments. An intriguing helical arrangement of guest molecules was observed within one of the pores. This study provides pioneering evidence that the social self-sorting of quasi-racemates offers a new methodology for creating dual-functional supramolecular materials.
PubMed: 38916517
DOI: 10.1021/jacs.4c01654 -
Pilot and Feasibility Studies Jun 2024Dental caries remains a significant problem in England, affecting 11% of 3-year-olds and 23% of 5-year-olds. While current approaches have been extensively investigated,...
BACKGROUND
Dental caries remains a significant problem in England, affecting 11% of 3-year-olds and 23% of 5-year-olds. While current approaches have been extensively investigated, their ability to (1) control pain and infection; (2) prevent hospital admissions, and (3) be implemented within the National Health Service (NHS) contractual arrangements, remains unsatisfactory. Silver diamine fluoride (SDF) is an alternative, non-invasive approach that has proven efficacy in arresting caries progression in primary teeth, principally from studies conducted outside of Europe. Its use in primary dental care in the UK is limited, despite the acknowledged need. The clinical and cost-effectiveness of SDF has not been compared to usual care in the UK. Before a pragmatic randomised controlled trial (RCT) can be conducted to compare SDF to usual care for caries management in young children, there are several uncertainties that require investigation. This study aims to establish whether such an RCT is feasible.
METHODS
This mixed-method parallel design study is a feasibility study with an embedded process evaluation, to compare SDF with usual treatment in primary dental care in the UK. It will be individually randomised, with 13 dentists and therapists, in 8 different dental primary care sites with a sample size of 80 child participants aged 1-8 years old. The aim will be to recruit ten participants per site with equal arm allocation. Follow-up will be for 1 year. The study will inform whether an RCT is feasible by resolving several key uncertainties. The acceptability and implementation of SDF and the research processes will be explored. Patient and Public Involvement and Engagement representatives will be involved throughout recruitment and retention strategies, participant documentation, analysis, engagement and dissemination.
DISCUSSION
The ability to conduct an RCT will be evaluated. If feasible, this RCT has the potential to evaluate the effectiveness of a non-invasive approach for the management of untreated caries in young children. A feasibility study also offers the opportunity to consider factors associated with the implementation of SDF at an early stage through a process evaluation that will inform the definitive trial and an implementation strategy for SDF by identifying relevant barriers and facilitators.
TRIAL REGISTRATION
ClinicalTrials.gov identifier: NCT06092151. Date: 19/10/2023.
PubMed: 38915111
DOI: 10.1186/s40814-024-01519-y