Three rare heteromultinuclear complexes, ∞NiL(4,4′‐bipy)Pr (NO3)3·(CH3)2CHOH (1), {CuLSm (NO3)3}2(4,4′‐bipy)·CH3OH (2) and {CuL (CH3CH2OH)Eu (NO3)3 (3) with a symmetrical salamo‐like hexadentate ...ligand H2L have been synthesized, and characterized by FT‐IR, UV–vis and X‐ray crystallography. Complex 1 is a 1D coordination polymer constructed from heterobimetallic Ni(L)Pr (NO3)3 units which are connected by the exo‐dentate ligand 4,4′‐bipy bearing nitrogen‐donor atoms. Complex 2 is a heterotetranuclear dimer based on Cu(L)Sm (NO3)3 moieties which are linked through the exo‐dentate 4,4′‐bipy hasing nitrogen‐donor atoms. Complex 3 is a heterodinuclear structure, Cu (II) atom is five‐coordinate possessing a distorted square pyramidal geometry, and Eu (III) atom is a deca‐coordinate adopting a distorted bicapped square antiprism. In addition, fluorescence and antimicobial properties of the ligand H2L and its complexes 1–3 have also been discussed.
Three rare heteromultinuclear complexes, ∞NiL(4,4′‐bipy)Pr (NO3)3·(CH3)2CHOH (1), {CuLSm (NO3)3}2(4,4′‐bipy)·CH3OH (2) and {CuL (CH3CH2OH)Eu (NO3)3 (3) with a symmetrical salamo‐like hexadentate ligand H2L have been synthesized, and characterized by FT‐IR, UV–vis and X‐ray crystallography. In addition, fluorescence and antimicobial properties of the ligand H2L and its complexes 1–3 have also been discussed.
Iridium/f‐Amphol‐catalyzed asymmetric hydrogenation of various benzo‐fused five to seven‐membered cyclic ketones was successfully developed, affording a series of chiral benzo‐fused cyclic alcohols ...with excellent results (75%–99% yields, 93%–>99% ee, and TON up to 297 000). The enantioenriched products can be employed as key intermediates or motifs for the synthesis of some important biologically active compounds, such as rasagiline mesylate TVP‐1012 used for the treatment of Parkinson's disease, the enantiomer of anticonvulsant drug eslicarbazepine acetate (BIA 2‐093).
Histamine (HA) is a biogenic amine that can accumulate to high concentration levels in food as a result of microbial activity and can cause toxic effects in consumers. In this work, a portable ...electrochemical immunosensor capable of detecting HA with high sensitivity and selectivity was developed. Prussian blue-chitosan-gold nanoparticle (PB-CS-AuNP) nanocomposite films with excellent biocompatibility were synthesized and characterized by scanning electron microscopy and energy dispersive X-ray analysis. The PB-CS-AuNP were coated onto a screen-printed electrode by one-step electrodeposition and used to conjugate the HA ovalbumin conjugate (HA-Ag). HA was determined by a competition between the coating HA-Ag and the HRP labeled HA antibody (HRP-HA-Ab). After careful optimization of assay conditions and Box-Behnken analysis, the developed immunosensor showed a linear range from 0.01 to 100μg/mL for HA in fish samples. The average recoveries from spiked samples ranged from 97.25% to 105%. The biosensor also showed good specificity, reproducibility, and stability, indicating its potential application in monitoring HA in a simple and low cost manner.
•A portable immunosensor for sensitive detection of histamine was developed.•Prussian blue-chitosan-gold nanoparticles were used as signal amplification materials.•The immunosensor showed a detection limit of 1.25ng/mL for histamine in fish samples.
We have successfully developed a series of novel and modular ferrorence‐based amino‐phosphine‐alcohol (f‐Amphol) ligands, and applied them to iridium‐catalyzed asymmetric hydrogenation of various ...simple ketones to afford the corresponding chiral alcohols with excellent enantioselectivities and conversions (98–99.9 % ee, >99 % conversion, turnover number up to 200 000). Control experiments and density functional theory (DFT) calculations have shown that the hydroxyl group of our f‐Amphol ligands played a key role in this asymmetric hydrogenation.
Pure and simple: A series of novel and modular ferrorence‐based amino‐phosphine‐alcohol (f‐Amphol) ligands have been developed and applied to iridium‐catalyzed asymmetric hydrogenation of various simple ketones to afford the corresponding chiral alcohols with excellent enantioselectivities and conversions (see scheme). Control experiments and density functional calculations have shown that the hydroxyl group of the f‐Amphol ligands played a key role in this asymmetric hydrogenation.
A new asymmetric Salamo‐based ligand H2L was synthesized using 3‐tert‐butyl‐salicylaldehyde and 6‐methoxy‐2‐O‐(1‐ethyloxyamide)‐oxime‐1‐phenol. By adjusting the ratio of the ligand H2L and Cu (II), ...Co (II), and Ni (II) ions, mononuclear, dinuclear, and trinuclear transition metal (II) complexes, Cu(L), {Co(L)}2, and {Ni(L)(CH3COO)(CH3CH2OH)}2Ni with the ligand H2L possessing completely different coordination modes were obtained, respectively. The optical spectra of ligand H2L and its Cu (II), Co (II) and Ni (II) complexes were investigated. The Cu (II) complex is a mononuclear structure, and the Cu (II) atom is tetracoordinated to form a planar quadrilateral structure. The Co (II) complex is dinuclear, and the two Co (II) atoms are pentacoordinated and have coordination geometries of distorted triangular bipyramid. The Ni (II) complex is a trinuclear structure, and the terminal and central Ni (II) atoms are all hexacoordinated, forming distorted octahedral geometries. Furthermore, optical properties including UV–Vis, IR, and fluorescence of the Cu (II), Co (II), and Ni (II) complexes were investigated. Finally, the antibacterial activities of the Cu (II), Co (II), and Ni (II) complexes were explored. According to the experimental results, the inhibitory effect was found to be enhanced with increasing concentrations of the Cu (II), Co (II), and Ni (II) complexes.
The Cu (II), Co (II), and Ni (II) complexes with ligand H2L have been synthesized. The Cu (II) complex was formed by the coordination of ligand (L)2− unit and one Cu (II) atom in the ratio of 1:1. The Co (II) complex was formed by the coordination of the two ligand (L)2− units and two Co (II) atoms in the ratio of 2:2. The Ni (II) complex was composed of two completely deprotonated ligand (L)2− units, three Ni (II) atoms, two bridging acetate groups, and two coordinated ethanol molecules.
The iridium‐catalyzed cycloisomerization of various alkynoic acids was successfully developed, and a series of five‐, six‐, and especially seven‐membered unsaturated lactones were constructed with ...moderate yields and excellent regioselectivities (up to 68% yield, >99:1 rr). In addition, the indole compound can be easily prepared with 75% yield through this efficient synthetic methodology. Moreover, a plausible mechanism for this Ir‐catalyzed cycloisomerization of alkynoic acids was proposed.
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•Study quality changes in frozen mackerel via multi-omics techniques.•Employed mixed-factor analysis for cooked mackerel's sensory attributes.•PLSR used to link DEPs, DEMs, and ...mackerel quality.•The prediction of fishiness based on DEPs and DEMs through the use of machine learning.
This study employed gas chromatography-mass spectrometry with olfactory (GC–MS–O) and multi-omics methods to investigate the changes in volatile flavor compounds during the freezing process of Pacific chub mackerel (Scomber japonicus) from Japan and China, and Spanish mackerel (Scomberomorus niphonius). A total of 18 volatile flavor compounds were identified, and significant differences in volatile flavor components were observed among samples frozen for 1 week, 1 year, and 2 years. The results of the Partial least squares regression (PLSR) indicated that the fishy odor was correlated with independent variables such as fatty acids (FA 22:4, FA 28:6, FA 24:4), differentially expressed genes (Gene.2425 (NDUFA5), Gene.38 (GPX1), and Gene.2844 (DAD1)). Classification and regression tree (CART) analysis revealed that the peak area values of fatty acids (FA 22:5, FA 20:4) and fatty acid esters of hydroxy fatty acids (FAHFA 18:0/22:3) were the main differentiating factors for fishy odor perception.
Iridium‐catalyzed asymmetric hydrogenation of prochiral halogenated ketones was successfully developed to prepare various chiral halohydrins with high reactivities and excellent enantioselectivities ...under basic reaction condition (up to >99% conversion, 99% yield, >99% ee). Moreover, gram‐scale experiment was performed well in the presence of just 0.005 mol% (S/C=20 000) Ir/f‐amphox catalyst with 99% yield and >99% ee.
An atom‐ and step‐economical and redox‐neutral cascade reaction enabled by asymmetric bimetallic relay catalysis by merging a ruthenium‐catalyzed asymmetric borrowing‐hydrogen reaction with ...copper‐catalyzed asymmetric Michael addition has been realized. A variety of highly functionalized 2‐amino‐5‐hydroxyvaleric acid esters or peptides bearing 1,4‐non‐adjacent stereogenic centers have been prepared in high yields with excellent enantio‐ and diastereoselectivity. Judicious selection and rational modification of the Ru catalysts with careful tuning of the reaction conditions played a pivotal role in stereoselectivity control as well as attenuating undesired α‐epimerization, thus enabling a full complement of all four stereoisomers that were otherwise inaccessible in previous work. Concise asymmetric stereodivergent synthesis of the key intermediates for biologically important chiral molecules further showcases the synthetic utility of this methodology.
An atom‐ and step‐economical and redox‐neutral cascade reaction enabled by dual‐metal relay catalysis by merging borrowing‐hydrogen and Michael addition reactions provided access to all stereoisomers of 2‐amino‐5‐hydroxyvaleric acid derivatives with 1,4‐non‐adjacent stereocenters. Concise stereodivergent synthesis of key intermediates for the synthesis of biologically important chiral molecules further showcases the synthetic utility of the approach.
The Iridium‐catalyzed asymmetric hydrogenation of cyclic sulfamidate imines was successfully developed with N‐methylated ZhaoPhos L2 as the ligand. A variety of chiral cyclic sulfamidates were ...obtained with excellent results (up to 99% yield, 99% ee). Furthermore, this asymmetric hydrogenation can be employed as the key reaction step to prepare the important intermediates in organic synthesis.
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