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RSC Advances Jun 2024A new eco-friendly method for creating an optical sensor membrane specifically designed to detect yttrium ions (Y) has been developed. The proposed sensor membrane is...
A new eco-friendly method for creating an optical sensor membrane specifically designed to detect yttrium ions (Y) has been developed. The proposed sensor membrane is fabricated by integrating 4-(2-arsonophenylazo) salicylic acid (APASA), sodium tetraphenylborate (Na-TPB), and tri--octyl phosphine oxide (TOPO) into a plasticized poly(vinyl chloride) matrix with dimethyl sebacate (DMS) as the plasticizer. In this sensor membrane, APASA functions dually as an ionophore and a chromoionophore, while TOPO enhances the complexation of Y ions with APASA. The composition of the sensor membrane has been meticulously optimized to achieve peak performance. The current membrane exhibits a linear dynamic range for Y ions from 8.0 × 10 to 2.3 × 10 M, with detection and quantification limits of 2.3 × 10 and 7.7 × 10 M, respectively. No interference from other potentially interfering cations and anions was observed in the determination of Y. The membrane showed strong stability and a swift response time of about 3.0 minutes, with no signs of APASA leaching. This sensor is highly selective for Y ions and can be renewed by treating it with 0.15 M HNO. It has been effectively applied to measure Y in nickel-based alloys, as well as in biological and environmental samples.
PubMed: 38946767
DOI: 10.1039/d4ra03854a -
Journal of Peptide Science : An... Jun 2024Self-assembled peptides are used for diverse applications in the biomedical and technological fields. The morphology and function of the assembled systems are dictated...
Self-assembled peptides are used for diverse applications in the biomedical and technological fields. The morphology and function of the assembled systems are dictated by the peptide sequence and length. In this work, a supramolecular catalyst was obtained upon self-assembly of the diphenylalanine peptide conjugated to a triphenylphosphine Au(I) complex in acetonitrile. The assembled molecules were characterized by spectroscopic techniques and by scanning electron microscopy. The activity of the catalyst was tested on two substrates in cyclization reactions. The morphology and the dimensions of the assembled systems vary depending on the presence of a carboxyl versus an amide C-terminal end. The catalyst efficiently promotes intramolecular cyclization reactions. Results obtained encourage the use of self-assembled peptides for the obtainment of new and efficient catalysts.
PubMed: 38943521
DOI: 10.1002/psc.3630 -
Journal of the American Chemical Society Jun 2024In recent years, progress has been made in the development of catalytic methods that allow remote functionalizations based on alkene isomerization. In contrast,...
In recent years, progress has been made in the development of catalytic methods that allow remote functionalizations based on alkene isomerization. In contrast, protocols based on alkyne isomerization are comparatively rare. Herein, we report a general Pd-catalyzed long-range isomerization of alkynyl alcohols. Starting from aryl-, heteroaryl-, or alkyl-substituted precursors, the optimized system provides access preferentially to the thermodynamically more stable α,β-unsaturated aldehydes and is compatible with potentially sensitive functional groups. We showed that the migration of both π-components of the carbon-carbon triple bond can be sustained over several methylene units. Computational investigations served to shed light on the key elementary steps responsible for the reactivity and selectivity. These include an unorthodox phosphine-assisted deprotonation rather than a more conventional β-hydride elimination in the final tautomerization event.
PubMed: 38941513
DOI: 10.1021/jacs.4c05136 -
Angewandte Chemie (International Ed. in... Jun 2024The Wittig reaction is renowned as exceptionally versatile method for converting a diversity of aldehydes and ketones into alkenes. Recently, strategies for chiral...
The Wittig reaction is renowned as exceptionally versatile method for converting a diversity of aldehydes and ketones into alkenes. Recently, strategies for chiral phosphine catalysis under PIII/PV=O redox cycling emerged to render this venerable transformation stereoselective. Herein, we describe that phosphine redox catalysis enables the enantioselective synthesis of pertinent biaryl atropisomers by means of a stereocontrolled arene-forming Wittig reaction. Key to the process is the release of an endogenous base from readily accessible tert-butyloxycarbonylated Morita-Baylis-Hillman adducts triggered by catalyst intramolecularization, permitting mild phosphine redox catalysis for atroposelective Wittig reactions. By this strategy, a broad diversity of biaryl atropisomers is obtained with up to 94:6 enantioselectivity.
PubMed: 38940901
DOI: 10.1002/anie.202408159 -
Frontiers in Bioscience (Landmark... May 2024Phosphine resistance in challenges grain storage. This study investigates the impact of cytochrome P450 (CYP) enzymes and CYP346 family genes on phosphine resistance in...
BACKGROUND
Phosphine resistance in challenges grain storage. This study investigates the impact of cytochrome P450 (CYP) enzymes and CYP346 family genes on phosphine resistance in Indian Tribolium castaneum populations.
METHODS
Seven field populations of were compared with Lab- susceptible population for their resistance to phosphine. The levels of cytochrome P450 enzyme and expression of certain CYP346 family genes were tracked in these populations.
RESULTS
The highly resistant Patiala population showed significantly increased CYP450 activity (11.26 ± 0.14 nmol/min/mg protein, 7.41-fold higher) compared to the lab-susceptible population (1.52 ± 0.09 nmol/min/mg protein) when assayed using 8 mM p-nitroanisole as the substrate. The mRNA expression was measured relative to the standard gene and revealed significant upregulation of and in highly resistant populations Moga and Patiala (: 12.09 ± 2.19 to 21.74 ± 3.82; : 59.097 ± 10.265 to 50.148 ± 8.272). Patiala's exhibited an impressive 685.76-fold change, and Moga's showed a 361.893-fold change compared to lab-susceptible. Linear regression confirmed robust fits for each gene (R2: 0.693 to 0.756). Principal component analysis (PCA) demonstrated a strong positive correlation between genes expression; and cytochrome P450 activity. Patiala, Moga, and Hapur populations showed conformity, associating higher resistance with increased P450 activity and CYP346 gene expression. Cluster analysis highlighted a potential correlation between , , and and P450 activity, with Patiala and Moga clustering together.
CONCLUSIONS
Variability in and in strong resistance populations may contribute to adaptation and resistance mechanisms. The study provides insights into specific CYP346 family genes associated with phosphine resistance, emphasizing the intricate interaction between CYP450 detoxifying enzymes, CYP346 family genes, and resistance mechanisms. The upregulation of genes suggests a survival advantage for against phosphine, diminishing phosphine's efficacy as a pest control measure.
Topics: Tribolium; Cytochrome P-450 Enzyme System; Insecticide Resistance; Phosphines; Insecticides; India; Animals
PubMed: 38940033
DOI: 10.31083/j.fbl2906203 -
JACS Au Jun 2024Iminophosphoranes are commonly used reagents in organic synthesis and are, therefore, of great interest. An efficient and sustainable iodide-mediated electrochemical...
Iminophosphoranes are commonly used reagents in organic synthesis and are, therefore, of great interest. An efficient and sustainable iodide-mediated electrochemical synthesis of -sulfonyl iminophosphoranes from readily available phosphines and sulfonamides is reported. This method features low amounts of supporting electrolytes, inexpensive electrode materials, a simple galvanostatic setup, and high conversion rates. The broad applicability could be demonstrated by synthesizing 20 examples in yields up to 90%, having diverse functional groups including chiral moieties and biologically relevant species. Furthermore, electrolysis was performed on a 20 g scale and could be run in repetitive mode by recycling the electrolyte, which illustrates the suitability for large-scale production. A reaction mechanism involving electrochemical mediation by the iodide-based supporting electrolyte is proposed, completely agreeing with all of the results.
PubMed: 38938819
DOI: 10.1021/jacsau.4c00156 -
Dalton Transactions (Cambridge, England... Jun 2024Palladium(II) complexes have stimulated research interest mainly due to their cytotoxicity against various cancer cell lines and their low cytotoxicity in healthy...
Palladium(II) complexes have stimulated research interest mainly due to their cytotoxicity against various cancer cell lines and their low cytotoxicity in healthy cells. Thus, in this work, we combined Pd(II)/phosphine systems with the natural product curcumin as a ligand, obtaining a series of complexes, [Pd(cur)(PPh)]PF (A1), [Pd(cur)(dppe)]PF (A2), [Pd(cur)(dppp)]PF (A3), [Pd(cur)(dppb)]PF (A4) and [Pd(cur)(dppf)]PF (A5), where dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane, dppb = 1,4-bis(diphenylphosphino)butane, and dppf = 1,1'-bis(diphenylphosphino)ferrocene (P-P), which were characterized by elemental analysis, molar conductivity analysis, and mass, NMR (H, C, P{H}), UV-vis, and IR spectroscopies, and four of them (A1, A2, A4, and A5) by X-ray crystallography. The cell viability of the complexes A1-A5, cisplatin, and the free ligand curcumin against MDA-MB-231 (human triple-negative breast tumor cells), SK-BR-3 (human breast tumor cells), A549 (human lung tumor cells), MRC-5 (non-tumor human lung cells), A2780 (human ovarian carcinoma cells), and A2780cis (cisplatin-resistant human ovarian carcinoma cells), was evaluated by the MTT colorimetric assay. For the tumor cell lines tested, the complexes showed good anticancer activities. The results showed that in general the complexes had lower IC values than free curcumin and the precursors [PdCl(P-P)]. IC results obtained for the A1-A5 complexes, in the MCF-7 cell line, are similar to those that had already been observed for some Pd/bipy/curcumin complexes. In the MDA-MB-231 cell line, complexes A1 and A5 stood out, with their lowest IC values, around 5 μmol L, and the complexes appeared to be more active (lower IC values) against the ovarian cell lines. Complex A1 was 23 and 22-fold more cytotoxic than cisplatin, against the A2780 and A2780cis cells, respectively. The complex A1 was studied on A2780cis cells and it was found that this complex inhibits colony formation and induces cell cycle arrest in the sub-G1 phase in a concentration-dependent manner and leads to cell death by apoptosis. The DCFDA assay revealed a potent ROS induction for complex A1.
PubMed: 38938129
DOI: 10.1039/d4dt01045k -
Hemodialysis International.... Jun 2024Phosphide metal poisoning results in tens of thousands of fatalities per year worldwide. The mortality in critically ill patients often exceeds 50%. The available...
BACKGROUND
Phosphide metal poisoning results in tens of thousands of fatalities per year worldwide. The mortality in critically ill patients often exceeds 50%. The available treatment is supportive and there is no antidote. Dialysis is recommended to treat advanced complications but has not been prescribed early in the process. In this study we report our experience in using dialysis in the early hours of presentation of the patients and suggest it can favorably improve the prognosis. We also draw attention to the risk of suicide under conditions of chronic conflict such as those in northwestern Syria, and to the lack of necessary mental health support for patients after suicide attempts.
METHODS
Retrospective review of records of patients poisoned with aluminum phosphide and admitted to critical care facilities in northwestern Syria between July 2022 and June 2023.
RESULTS
During the observation period 16 cases were encountered. Suicide was the reason of the poisoning in 15 patients, the median patient age was 18 years and over two thirds of the patients were female. Early dialysis was used in 11 patients who were critically ill and their mortality rate was 18%.
CONCLUSIONS
Phosphide metal poisoning is common in the disasters stricken area of northwestern Syria. Most cases are suicidal and impact young females. Early dialytic interventions may favorably impact the outcomes.
PubMed: 38937150
DOI: 10.1111/hdi.13168 -
The Journal of Organic Chemistry Jun 2024A series of amides, including α-bromo hydroxamates, -alkoxyamides, and -aryloxyamides, were subjected to phosphine-catalyzed ring-opening -selective addition with...
A series of amides, including α-bromo hydroxamates, -alkoxyamides, and -aryloxyamides, were subjected to phosphine-catalyzed ring-opening -selective addition with cyclopropenones, producing various special -unsaturated esters containing oxime ether motif, in moderate to excellent yields, with high regioselectivity, and exclusive -selectivity. The methodology is highly atom-economical, with simple operation procedures, and compatible with a wide substrate scope (more than 44 examples).
PubMed: 38935753
DOI: 10.1021/acs.joc.4c00941 -
Angewandte Chemie (International Ed. in... Jun 2024Positively charged phosphorus-containing heterocycles are characteristic core skeletons for functional molecules. While various phosphonium-containing five- or...
Positively charged phosphorus-containing heterocycles are characteristic core skeletons for functional molecules. While various phosphonium-containing five- or six-membered ring compounds have been reported, seven-membered ring phosphepinium has not yet been fully studied. In this study, dithieno[2,3-b;3,2-f]phosphepinium ions containing electron-donating aminophenyl groups were synthesized. An X-ray crystallographic analysis of the resulting donor-acceptor-donor dyes revealed a bent conformation of the central seven-membered ring. This compound exhibited fluorescence in the near-infrared region with a bathochromic shift of 70 nm compared to phosphepine oxide congener and a large Stokes shift. High fluorescence quantum yields were obtained even in polar solvents due to the suppression of the nonradiative decay process. The theoretical study revealed that the phosphepinium skeleton is highly electron-accepting owing to the orbital interaction between a px orbital of the phosphonium moiety and a π* orbital of the 1,3,5-hexatriene moiety. Owing to the lower-lying px orbital in the phosphonium moiety compared with that of the phosphine oxide and the bent conformation of the seven-membered ring, the phosphepinium ring effectively furnishes a px-π* conjugation. A large structural relaxation with the contribution of a quinoidal resonance structure is suggested in the excited state, which is responsible for the intense emission with a large Stokes shift.
PubMed: 38935519
DOI: 10.1002/anie.202410204