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1.
Small ; : e2401044, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38516941

ABSTRACT

Atomically precise metal clusters serve as a unique model for unraveling the intricate mechanism of the catalytic reaction and exploring the complex relationship between structure and activity. Herein, three series of water-soluble heterometallic clusters LnCu6, abbreviated as LnCu6-AC (Ln = La, Nd, Gd, Er, Yb; HAC = acetic acid), LnCu6-IM (Ln = La and Nd; IM = Imidazole), and LnCu6-IDA (Ln = Nd; H2IDA = Iminodiacetic acid) are presented, each featuring a uniform metallic core stabilized by distinct protected ligands. Crystal structure analysis reveals a triangular prism topology formed by six Cu2+ ions around one Ln3+ ion in LnCu6, with variations in Cu···Cu distances attributed to different ligands. Electrocatalytic oxygen evolution reaction (OER) shows that these different LnCu6 clusters exhibit different OER activities with remarkable turnover frequency of 135 s-1 for NdCu6-AC, 79 s-1 for NdCu6-IM and 32 s-1 for NdCu6-IDA. Structural analysis and Density Functional Theory (DFT) calculations underscore the correlation between shorter Cu···Cu distances and improves OER catalytic activity, emphasizing the pivotal role of active-site distance in regulating electrocatalytic OER activities. These results provide valuable insights into the OER mechanism and contribute to the design of efficient homogeneous OER electrocatalysts.

2.
J Am Chem Soc ; 144(19): 8837-8847, 2022 05 18.
Article in English | MEDLINE | ID: mdl-35503109

ABSTRACT

Here, we report the molecular self-assembly of hydroxido-bridged {Ln5Ni6} ((Ln3+ = Dy3+, Y3+) metal clusters by the reaction of enantiopure chiral ligands, namely, (R/S)-(2-hydroxy-3-methoxybenzyl)-serine), with NiII and LnIII precursors. Single-crystal diffraction analysis reveals that these compounds are isostructural sandwich-like 3d-4f heterometallic clusters showing helical chirality. Direct current magnetic measurements on {Dy5Ni6} indicates ferromagnetic coupling between DyIII and NiII centers, whereas those on {Y5Ni6} denote that the NiII centers are antiferromagnetically coupled and/or magnetically anisotropic. Magneto-chiral dichroism (MChD) measurements on {Dy5Ni6} and its comparison to that of {Y5Ni6} provide the first experimental observation of intense multimetal site MChD signals in the visible-near-infrared region. Moreover, the comparison of MChD with natural and magnetic circular dichroism spectra unambiguously demonstrate for the first time that the MChD signals associated with the NiII d-d transitions are mostly driven by natural optical activity and those associated with the DyIII f-f transitions are driven by magnetic optical activity.


Subject(s)
Lanthanoid Series Elements , Organometallic Compounds , Crystallography, X-Ray , Lanthanoid Series Elements/chemistry , Magnetic Phenomena , Magnetics , Organometallic Compounds/chemistry
3.
J Food Sci Technol ; 59(10): 4108-4121, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36193355

ABSTRACT

Dongli, or frozen pear, is a traditional Chinese snack with a unique flavor. This study identified the aroma-active volatile compounds (VOCs) in Dongli using quantitative descriptive analysis (QDA), gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS), and gas chromatography-olfactometry (GC-O). QDA indicated that Dongli of all cultivars presented increased sweet and wine aromas. A total of 21 VOCs were identified by GC-MS/MS. Bidirectional orthogonal partial least square (O2PLS) analysis, GC-O analysis, detection frequency analysis (DFA), and relative odor activity values (ROAV) showed that: estragole and anethole contributing "anise, green" aromas were the key aromatic VOCs of fresh pears, while ethyl butanoate, butyl acetate, heptyl acetate, benzaldehyde, and geranyl acetone contributing "sweet, fruity, green" aromas were the key aromatic VOCs of Dongli. The results revealed that the repeated freezing treatment promoted a unique aroma in pears. This study would contribute to developing new pear products. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05463-8.

4.
Biochem Biophys Res Commun ; 553: 172-179, 2021 05 14.
Article in English | MEDLINE | ID: mdl-33773140

ABSTRACT

BACKGROUND: Cardiac fibrosis will increase wall stiffness and diastolic dysfunction, which will eventually lead to heart failure. Asenapine maleate (AM) is widely used in the treatment of schizophrenia. In the current study, we explored the potential mechanism underlying the role of AM in angiotensin II (Ang II)-induced cardiac fibrosis. METHODS: Cardiac fibroblasts (CFs) were stimulated using Ang II with or without AM. Cell proliferation was measured using the cell counting kit-8 assay and the Cell-Light EdU Apollo567 In Vitro Kit. The expression levels of proliferating cell nuclear antigen (PCNA) and α-smooth muscle actin (α-SMA) were detected using immunofluorescence or western blotting. At the protein level, the expression levels of the components of the transforming growth factor beta 1 (TGFß1)/mitogen-activated protein kinase (MAPK) signaling pathway were also detected. RESULTS: After Ang II stimulation, TGFß1, TGFß1 receptor, α-SMA, fibronectin (Fn), collagen type I (Col1), and collagen type III (Col3) mRNA levels increased; the TGFß1/MAPK signaling pathway was activated in CFs. After AM pretreatment, cell proliferation was inhibited, the numbers of PCNA -positive cells and the levels of cardiac fibrosis markers decreased. The activity of the TGFß1/MAPK signaling pathway was also inhibited. Therefore, AM can inhibit cardiac fibrosis by blocking the Ang II-induced activation through TGFß1/MAPK signaling pathway. CONCLUSIONS: This is the first report to demonstrate that AM can inhibit Ang II-induced cardiac fibrosis by down-regulating the TGFß1/MAPK signaling pathway. In this process, AM inhibited the proliferation and activation of CFs and reduced the levels of cardiac fibrosis markers. Thus, AM represents a potential treatment strategy for cardiac fibrosis.


Subject(s)
Angiotensin II/pharmacology , Dibenzocycloheptenes/pharmacology , Fibroblasts/drug effects , Fibroblasts/metabolism , MAP Kinase Signaling System/drug effects , Reactive Oxygen Species/metabolism , Transforming Growth Factor beta1/metabolism , Animals , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Cell Survival/drug effects , Fibroblasts/cytology , Fibrosis/metabolism , Fibrosis/prevention & control , Myocardium/cytology , Myocardium/metabolism , Rats , Rats, Wistar , Schizophrenia/drug therapy
5.
BMC Urol ; 20(1): 69, 2020 Jun 15.
Article in English | MEDLINE | ID: mdl-32539828

ABSTRACT

BACKGROUND: Holmium laser lithotripsy is the most common technique for the management of ureteral stone. Studies founded that holmium laser firing can produce heat which will cause thermal injury towards ureter. The aim of our current study is to explore factors affecting thermal effect of holmium laser during ureteroscopic lithotripsy. METHODS: An in vitro experimental model is design to simulate the ureteroscopic lithotripsy procedure. Different laser power settings (10w (0.5JX20Hz, 1.0 JX10Hz), 20w (1.0 JX20Hz, 2.0 JX10Hz), 30w (1.5JX20Hz, 3.0 JX10Hz)) with various firing time (3 s, 5 s, 10s) and irrigation flow rates(10 ml/min, 15 ml/min, 20 ml/min and 30 ml/min) were employed in the experiment. The temperature around the laser tip was recorded by thermometer. RESULTS: The temperature in the "ureter" rises significantly with the increasing laser power, prolonging firing time and reducing irrigation flow. The highest regional temperature is 78.0 °C at the experimental set-up, and the lowest temperature is 23.5 °C. Higher frequency setting produces more heat at the same power. Laser power < =10w, irrigation flow> = 30 ml/min and "high-energy with low-frequency" can permit a safe working temperature. CONCLUSION: We clarify that the thermal effect of holmium laser is related with both laser working parameters and irrigation flow. The proper setting is the key factor to ensure the safety during ureteroscopic holmium laser lithotripsy.


Subject(s)
Burns/etiology , Lasers, Solid-State/adverse effects , Lithotripsy, Laser/methods , Ureteral Calculi/therapy , Ureteroscopy , Lasers, Solid-State/therapeutic use , Models, Theoretical
6.
Nucleic Acids Res ; 45(21): 12551-12564, 2017 12 01.
Article in English | MEDLINE | ID: mdl-30053256

ABSTRACT

RecJ nucleases specifically degrade single-stranded (ss) DNA in the 5' to 3' direction. Archaeal RecJ is different from bacterial RecJ in sequence, domain organization, and substrate specificity. The RecJ from archaea Pyrococcus furiosus (PfuRecJ) also hydrolyzes RNA strands in the 3' to 5' direction. Like eukaryotic Cdc45 protein, archaeal RecJ forms a complex with MCM helicase and GINS. Here, we report the crystal structures of PfuRecJ and the complex of PfuRecJ and two CMPs. PfuRecJ bind one or two divalent metal ions in its crystal structure. A channel consisting of several positively charged residues is identified in the complex structure, and might be responsible for binding substrate ssDNA and/or releasing single nucleotide products. The deletion of the complex interaction domain (CID) increases the values of kcat/Km of 5' exonuclease activity on ssDNA and 3' exonuclease activity on ssRNA by 5- and 4-fold, respectively, indicating that the CID functions as a regulator of enzymatic activity. The DHH domain of PfuRecJ interacts with the C-terminal beta-sheet domain of the GINS51 subunit in the tetrameric GINS complex. The relationship of archaeal and bacterial RecJs, as well as eukaryotic Cdc45, is discussed based on biochemical and structural results.


Subject(s)
Bacterial Proteins/chemistry , Exodeoxyribonucleases/chemistry , Pyrococcus furiosus/enzymology , Amino Acid Motifs , Amino Acid Sequence , Bacterial Proteins/physiology , Cations , Cell Cycle Proteins , Conserved Sequence , Crystallography, X-Ray , DNA Repair , DNA Replication , DNA, Bacterial/metabolism , DNA, Single-Stranded/metabolism , DNA-Binding Proteins/metabolism , Evolution, Molecular , Exodeoxyribonucleases/physiology , Models, Molecular , Multiprotein Complexes/metabolism , Phosphodiesterase I/metabolism , Protein Binding , Protein Conformation , Protein Domains , Sequence Alignment , Sequence Homology, Amino Acid
7.
Molecules ; 24(16)2019 Aug 12.
Article in English | MEDLINE | ID: mdl-31408943

ABSTRACT

A multi-residue method for the determination of 107 pesticide residues in wolfberry has been developed and validated. Similar pretreatment approaches were compared, and the linearity, matrix effect, analysis limits, precision, stability and accuracy were validated, which verifies the satisfactory performance of this new method. The LODs and LOQs were in the range of 0.14-1.91 µg/kg and 0.46-6.37 µg/kg, respectively. The recovery of analytes at three fortification levels (10 µg/kg, 50 µg/kg, 100 µg/kg) ranged from 63.3-123.0%, 72.0-118.6% and 67.0-118.3%, respectively, with relative standard deviations (RSDs) below 15.0%. The proposed method was applied to the analysis of fifty wolfberry samples collected from supermarkets, pharmacies and farmers' markets in different cities of Shandong Province. One hundred percent of the samples analyzed included at least one pesticide, and a total of 26 pesticide residues was detected in fifty samples, which mainly were insecticides and bactericide. Several pesticides with higher detection rates were 96% for acetamiprid, 82% for imidacloprid, 54% for thiophanate-methyl, 50% for blasticidin-S, 42% for carbendazim, 42% for tebuconazole and 36% for difenoconazole in wolfberry samples. This study proved the adaptability of the developed method to the detection of multiple pesticide residues in wolfberry and provided basis for the research on the risks to wolfberry health.


Subject(s)
Liquid-Liquid Extraction/methods , Lycium/chemistry , Pesticide Residues/isolation & purification , Benzimidazoles/isolation & purification , Carbamates/isolation & purification , Chromatography, High Pressure Liquid/methods , Humans , Neonicotinoids/isolation & purification , Nitro Compounds/isolation & purification , Nucleosides/isolation & purification , Pesticide Residues/classification , Tandem Mass Spectrometry/methods , Thiophanate/isolation & purification , Triazoles/isolation & purification
8.
Org Biomol Chem ; 14(3): 1024-30, 2016 Jan 21.
Article in English | MEDLINE | ID: mdl-26633006

ABSTRACT

An organocatalytic dearomative [3 + 2]-annulation of N-alkyl-3-alkylindoles with quinone monoketals is developed. The reaction provides a mild and straightforward way to various benzofuro[2,3-b]indolines of potential biological and pharmaceutical interest in moderate to good yields. Moreover, when 3-phenylindole, a problematic substrate in previous relevant studies, was used as the substrate under the otherwise same reaction conditions, a novel 1,2-shift of the phenyl group occurred followed by aromatization to provide 2,3-diaryl indoles useful for cancer therapy studies in moderate yields.


Subject(s)
Acids/chemistry , Benzoquinones/chemistry , Indoles/chemistry , Indoles/chemical synthesis , Catalysis , Cyclization , Models, Molecular , Molecular Structure
9.
J Chem Theory Comput ; 20(12): 4977-4985, 2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38758038

ABSTRACT

Molecular dynamics (MD) simulation is a popular method for elucidating the structures and functions of biomolecules. However, exploring the conformational space, especially for large systems with slow transitions, often requires enhanced sampling methods. Although conducting MD at high temperatures provides a straightforward approach, resulting conformational ensembles diverge significantly from those at low temperatures. To address this discrepancy, we propose a novel probability density-based reweighting (PDR) method. PDR exhibits robust performance across four distinct systems, including a miniprotein, a cyclic peptide, a protein loop, and a protein-peptide complex. It accurately restores the conformational distributions at high temperatures to those at low temperatures. Additionally, we apply PDR to reweight previously studied high-T MD simulations of 12 protein-peptide complexes, enabling a comprehensive investigation of the conformational space of protein-peptide complexes.

10.
Chem Sci ; 15(2): 511-515, 2024 Jan 03.
Article in English | MEDLINE | ID: mdl-38179510

ABSTRACT

The water oxidation half reaction in water splitting for hydrogen production is extremely rate-limiting. This study reports the synthesis of two heterometallic clusters (Gd6Cu24-IM and Gd6Cu24-AC) for application as efficient water oxidation catalysts. Interestingly, the maximum turnover frequency of Gd6Cu24-IM in an NaAc solution of a weak acid (pH 6) was 319 s-1. The trimetallic catalytic site, H2O-GdIIICuII2-H2O, underwent two consecutive two-electron two-proton coupled transfer processes to form high-valent GdIII-O-O-CuIII2 intermediates. Furthermore, the O-O bond was formed via intramolecular interactions between the CuIII and GdIII centers. The results of this study revealed that synergistic catalytic water oxidation between polymetallic sites can be an effective strategy for regulating O-O bond formation.

11.
Water Res ; 260: 121943, 2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38909423

ABSTRACT

Krypton chloride (KrCl*) excimer lamps (222 nm) are used as a promising irradiation source to drive ultraviolet-based advanced oxidation processes (UV-AOPs) in water treatment. In this study, the UV222/peracetic acid (PAA) process is implemented as a novel UV-AOPs for the degradation of emerging contaminants (ECs) in water. The results demonstrate that UV222/PAA process exhibits excellent degradation performance for carbamazepine (CBZ), with a removal rate of 90.8 % within 45 min. Notably, the degradation of CBZ in the UV222/PAA process (90.8 %) was significantly higher than that in the UV254/PAA process (15.1 %) at the same UV dose. The UV222/PAA process exhibits superior electrical energy per order (EE/O) performance while reducing resource consumption associated with the high-energy UV254/PAA process. Quenching experiments and electron paramagnetic resonance (EPR) detection confirm that HO• play a dominant role in the reaction. The contributions of direct photolysis, HO•, and other active species (RO• and 1O2) are estimated to be 5 %, 88 %, and 7 %, respectively. In addition, the effects of Cl-, HCO3-, and humic acid (HA) on the degradation of CBZ are evaluated. The presence of relatively low concentrations of Cl-, HCO3-, and HA can inhibit CBZ degradation. The UV222/PAA oxidation process could also effectively degrade several other ECs (i.e., iohexol, sulfamethoxazole, acetochlor, ibuprofen), indicating the potential application of this process in pollutant removal. These findings will propel the development of the UV222/PAA process and provide valuable insights for its application in water treatment.

12.
Regen Ther ; 27: 365-380, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38694448

ABSTRACT

Brachial plexus injury (BPI) with motor neurons (MNs) damage still remain poor recovery in preclinical research and clinical therapy, while cell-based therapy approaches emerged as novel strategies. Previous work of rat skin precursor-derived Schwann cells (SKP-SCs) provided substantial foundation for repairing peripheral nerve injury (PNI). Given that, our present work focused on exploring the repair efficacy and possible mechanisms of SKP-SCs implantation on rat BPI combined with neurorrhaphy post-neurotomy. Results indicated the significant locomotive and sensory function recovery, with improved morphological remodeling of regenerated nerves and angiogenesis, as well as amelioration of target muscles atrophy and motor endplate degeneration. Besides, MNs could restore from oxygen-glucose-deprivation (OGD) injury upon SKP-SCs-sourced secretome treatment, implying the underlying paracrine mechanisms. Moreover, rat cytokine array assay detected 67 cytokines from SKP-SC-secretome, and bioinformatic analyses of screened 32 cytokines presented multiple functional clusters covering diverse cell types, including inflammatory cells, Schwann cells, vascular endothelial cells (VECs), neurons, and SKP-SCs themselves, relating distinct biological processes to nerve regeneration. Especially, a panel of hypoxia-responsive cytokines (HRCK), can participate into multicellular biological process regulation for permissive regeneration milieu, which underscored the benefits of SKP-SCs and sourced secretome, facilitating the chorus of nerve regenerative microenvironment. Furthermore, platelet-derived growth factor-AA (PDGF-AA) and vascular endothelial growth factor-A (VEGF-A) were outstanding cytokines involved with nerve regenerative microenvironment regulating, with significantly elevated mRNA expression level in hypoxia-responsive SKP-SCs. Altogether, through recapitulating the implanted SKP-SCs and derived secretome as niche sensor and paracrine transmitters respectively, HRCK would be further excavated as molecular underpinning of the neural recuperative mechanizations for efficient cell therapy; meanwhile, the analysis paradigm in this study validated and anticipated the actions and mechanisms of SKP-SCs on traumatic BPI repair, and was beneficial to identify promising bioactive molecule cocktail and signaling targets for cell-free therapy strategy on neural repair and regeneration.

13.
Food Chem ; 415: 135717, 2023 Jul 30.
Article in English | MEDLINE | ID: mdl-36848832

ABSTRACT

Microplastics (MPs) released from food packaging have attracted widespread attention. In this study, drip bags made from polyethylene (PE), polypropylene (PP), polyester (PET), and rayon selected from eight brands were employed to investigate MPs releasing. Fourier-transform infrared microspectroscopy (µ-FTIR), optical microscope and scanning electron microscope (SEM) were used to study the effects of brewing time and temperature on the release of MPs. The results showed that a single plastic coffee bag steeped at 95 ℃ for 5 min could release more than 10,000 MPs particles into a cup of coffee. Irregular blocks, long strips, and size range of 10-500 µm MPs were easier to be released, implying that consuming 3-4 cups of coffee will lead to an intake of 50 thousand MPs particles daily. Rayon was the primary type of released MPs, accounting for over 80% of the total amount of the released MPs. Our results are hoped to provide evaluation standards of material selection for processing coffee bags.


Subject(s)
Microplastics , Water Pollutants, Chemical , Plastics , Environmental Monitoring , Water Pollutants, Chemical/analysis , Water
14.
World J Gastrointest Surg ; 15(6): 1080-1092, 2023 Jun 27.
Article in English | MEDLINE | ID: mdl-37405106

ABSTRACT

BACKGROUND: For the management of lateral lymph node (LLN) metastasis in patients with rectal cancer, selective LLN dissection (LLND) is gradually being accepted by Chinese scholars. Theoretically, fascia-oriented LLND allows radical tumor resection and protects of organ function. However, there is a lack of studies comparing the efficacy of fascia-oriented and traditional vessel-oriented LLND. Through a preliminary study with a small sample size, we found that fascia-oriented LLND was associated with a lower incidence of postoperative urinary and male sexual dysfunction and a higher number of examined LLNs. In this study, we increased the sample size and refined the postoperative functional outcomes. AIM: To compare the effects of fascia- and vessel-oriented LLND regarding short-term outcomes and prognosis. METHODS: We conducted a retrospective cohort study on data from 196 patients with rectal cancer who underwent total mesorectal excision and LLND from July 2014 to August 2021. The short-term outcomes included perioperative outcomes and postoperative functional outcomes. The prognosis was measured based on overall survival (OS) and progression-free survival (PFS). RESULTS: A total of 105 patients were included in the final analysis and were divided into fascia- and vessel-oriented groups that included 41 and 64 patients, respectively. Regarding the short-term outcomes, the median number of examined LLNs was significantly higher in the fascia-oriented group than in the vessel-oriented group. There were no significant differences in the other short-term outcomes. The incidence of postoperative urinary and male sexual dysfunction was significantly lower in the fascia-oriented group than in the vessel-oriented group. In addition, there was no significant difference in the incidence of postoperative lower limb dysfunction between the two groups. In terms of prognosis, there was no significant difference in PFS or OS between the two groups. CONCLUSION: It is safe and feasible to perform fascia-oriented LLND. Compared with vessel-oriented LLND, fascia-oriented LLND allows the examination of more LLNs and may better protect postoperative urinary function and male sexual function.

15.
J Agric Food Chem ; 71(22): 8673-8684, 2023 Jun 07.
Article in English | MEDLINE | ID: mdl-37232431

ABSTRACT

Lipids are the key aroma contributors and nutrients in fermented fish products. A total of 376 lipid molecules were identified in mandarin fish during fermentation by untargeted lipidomics, including glycerolipids, glycerophospholipids, lysoglycerophospholipid, sphingolipids, fatty acids (FAs), and sterol lipids. Both lipid composition and content changed dynamically during fermentation. Triglyceride (TAG, 30.05%) and phosphatidylcholine (PC, 14.87%) were the two major lipids, with especially 39.36% saturated FAs in PCs and 35.34% polyunsaturated FAs in TAGs. The content of TAGs and PCs reached a peak point at 0 and 6 days, respectively. Fermented mandarin fish expressed a high nutritional value, and the ratio of total linoleic acid/total linolenic acid was about 5:1. Glycerophospholipid metabolism was a potential metabolic pathway, and the oxidation of derived FAs contributed to flavor. These data progress in understanding lipid dynamic variation during fermentation and provide thoughts on controlling the flavor quality and safety of fermented fish products.


Subject(s)
Fishes , Lipidomics , Animals , Fermentation , Fatty Acids , Sphingolipids
16.
Foods ; 12(10)2023 May 19.
Article in English | MEDLINE | ID: mdl-37238872

ABSTRACT

The release of flavor compounds is a critical factor that influences the quality of fermented foods. A recent study investigated the interactions between four fermentation-stinky compounds (indole, isovaleric acid, dimethyl disulfide, and dibutyl phthalate) and myofibrillar proteins (MPs). The results indicated that all four fermentation-stinky compounds had different degrees of binding to MPs, with dibutyl phthalate and dimethyl disulfide exhibiting stronger interactions. Reduced hydrophobicity enhanced these interactions. Multi-spectroscopy showed that static fluorescence quenching was dominant in the MPs-fermentation-stinky compound complexes. The interaction altered the secondary structure of MPs, predominantly transitioning from ß-sheets to α-helix or random coil structures via hydrogen bond interactions. Molecular docking confirmed that these complexes maintained steady states due to stronger hydrogen bonds, van der Waals forces, ionic bonds, conjugate systems, and lower hydrophobicity interactions. Hence, it is a novel sight that the addition of hydrophobic bond-disrupting agents could improve the flavor of fermented foods.

17.
Food Chem ; 418: 135874, 2023 Aug 30.
Article in English | MEDLINE | ID: mdl-36963134

ABSTRACT

Volatolomics and metabolomics were performed to explore the generation mechanism of the characteristic flavor of mandarin fish during fermentation. This study revealed a novel finding that umami-tasting amino acids, succinic acid, and peptides increased, while taste-presenting nucleotides decreased after fermentation. The results showed that 19 key aroma compounds were identified. The most nitrogenous compounds were produced after fermentation, the total concentration of which was >5 mg/kg. A high odor activity value of 443 was established for stinky indole. PLS-DA showed that sn-glycero-3-phosphocholine, hypoxanthine, creatine, and trimethylamine N-oxide were the key metabolites associated with the key volatiles. Umami-tasting amino acids could contribute to the characteristic taste. Metabolic pathway analysis revealed that tryptophan metabolism, trimethylamine metabolism, and monoterpenoid biosynthesis were the potential generation pathways of indole, trimethylamine, and terpenoids, respectively. Collectively, the results provide thoughts for targeted controlling the flavor of fermented mandarin fish.


Subject(s)
Metabolomics , Taste , Animals , Metabolomics/methods , Fishes , Fermentation , Amino Acids/analysis
18.
Int J Biochem Cell Biol ; 165: 106480, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37884171

ABSTRACT

The occurrence of autophagy dysregulation is vital in the development of myelodysplastic syndrome and its transformation to acute myeloid leukemia. However, the mechanisms are largely unknown. Here, we have investigated the mechanism of the bcl6 corepressor mutation in myelodysplastic syndrome development and its transformation to acute myeloid leukemia. We identified a novel pathway involving histone deacetylase 6 and forkhead box protein O1, which leads to autophagy defects following the bcl6 corepressor mutation. And this further causes apoptosis and cell cycle arrest. The bcl6 corepressor-mutation-repressed autophagy resulted in the accumulation of damaged mitochondria, DNA, and reactive oxygen species in myelodysplastic syndrome cells, which could then lead to genomic instability and spontaneous mutation. Our results suggest that the bcl6 corepressor inactivating mutations exert pro-carcinogenic effects through survival strike, which is only an intermediate process. These findings provide mechanistic insights into the role of the bcl6 corepressor gene in myelodysplastic syndrome.


Subject(s)
Leukemia, Myeloid, Acute , Myelodysplastic Syndromes , Humans , Transcription Factors/metabolism , Myelodysplastic Syndromes/genetics , Mutation , Autophagy/genetics , Co-Repressor Proteins/genetics
19.
Food Chem ; 409: 135238, 2023 May 30.
Article in English | MEDLINE | ID: mdl-36584531

ABSTRACT

This study focused on the effects of freeze drying (FD) and sprays drying (SD) on the structure and emulsifying properties of yam soluble protein (YSP). The results showed that the surface hydrophobicity (Ho) value, free sulfhydryl group (SH) content, turns content, denaturation temperature and enthalpy value of spray-dried YSP (SD-YSP) were higher than freeze-dried YSP (FD-YSP), but the apparent hydrodynamic diameter (Dh) value of SD-YSP was smaller. The smaller Dh, higher Ho and free SH led to higher percentage of adsorbed proteins and stronger binding between protein and oil droplet in emulsions. Thus, the emulsifying properties of SD-YSP were better, and the SD-YSP-stabilized emulsion had better dynamical rheological properties. Molecular dynamics (MD) simulations suggested that some intramolecular disulfide bonds and hydrogen bonds of dioscorin were broken, and some helices transformed into turns during the SD process. These structural changes resulted in better thermal stability and emulsification properties of SD-YSP.


Subject(s)
Dioscorea , Molecular Dynamics Simulation , Spray Drying , Freeze Drying/methods , Emulsions/chemistry
20.
Structure ; 31(12): 1604-1615.e8, 2023 12 07.
Article in English | MEDLINE | ID: mdl-37794595

ABSTRACT

4-Hydroxyphenylpyruvate dioxygenase (HPPD) has attracted increasing attention as a target for treating type I tyrosinemia and other diseases with defects in tyrosine catabolism. Only one commercial drug, 2-(2-nitro-4-trifluoromethylbenzoyl)-1, 3-cyclohexanedione (NTBC), clinically treat type I tyrosinemia, but show some severe side effects in clinical application. Here, we determined the structure of human HPPD-NTBC complex, and developed new pyrazole-benzothiadiazole 2,2-dioxide hybrids from the binding of NTBC. These compounds showed improved inhibition against human HPPD, among which compound a10 was the most active candidate. The Absorption Distribution Metabolism Excretion Toxicity (ADMET) predicted properties suggested that a10 had good druggability, and was with lower toxicity than NTBC. The structure comparison between inhibitor-bound and ligand-free form human HPPD showed a large conformational change of the C-terminal helix. Furthermore, the loop 1 and α7 helix were found adopting different conformations to assist the gating of the cavity, which explains the gating mechanism of human HPPD.


Subject(s)
Herbicides , Thiadiazoles , Tyrosinemias , Humans , Tyrosinemias/drug therapy , Thiadiazoles/pharmacology , Thiadiazoles/therapeutic use , Pyrazoles/pharmacology , Enzyme Inhibitors/pharmacology
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