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1.
J Am Chem Soc ; 146(35): 24257-24264, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39172734

RESUMO

The C-H hydroxylation of the pyridine C3 position is a highly desirable transformation but remains a great challenge due to the inherent electronic properties of this heterocycle core which bring difficulties in chemical reactivity and regioselectivity. Herein we present an efficient method for formal C3 selective hydroxylation of pyridines via photochemical valence isomerization of pyridine N-oxides. This metal-free transformation features operational simplicity and compatibility with a diverse array of functional groups, and the resulting hydroxylated products are amenable to further elaboration to synthetically useful building blocks. The synthetic utility of this strategy is further demonstrated in the effective late-stage functionalization of pyridine-containing medicinally relevant molecules and versatile derivatizations of 3-pyridinols.

2.
J Am Chem Soc ; 146(31): 21769-21777, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39072677

RESUMO

Aryl amines are one of the most common moieties in biologically active molecules, and approximately 37% of drug candidates contain aromatic amines. Recent advancements in medicinal chemistry, coined "escaping from flatland", have led to a greater focus on accessing highly functionalized C (sp3)-rich amines to improve the physicochemical and pharmacokinetic properties of compounds. This article presents a modular and operationally straightforward three-component alkyl Petasis boron-Mannich (APBM) reaction that utilizes ubiquitous starting materials, including amines, aldehydes, and alkyl boronates. By adaptation of this transformation to high-throughput experimentation (HTE), it offers rapid access to an array of diverse C(sp3)-rich complex amines, amenable for rapid identification of drug candidates.

3.
Anal Chem ; 96(13): 5331-5339, 2024 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-38498948

RESUMO

At present, there is a lack of sufficiently specific laboratory diagnostic indicators for schizophrenia. Serum homocysteine (Hcy) levels have been found to be related to schizophrenia. Cysteine (Cys) is a demethylation product in the metabolism of Hcy, and they always coexist with highly similar structures in vivo. There are few reports on the use of Cys as a diagnostic biomarker for schizophrenia in collaboration with Hcy, mainly because the rapid, economical, accurate, and high-throughput simultaneous detection of Cys and Hcy in serum is highly challenging. Herein, a click reaction-based surface-enhanced Raman spectroscopy (SERS) sensor was developed for simultaneous and selective detection of Cys and Hcy. Through the efficient and specific CBT-Cys click reaction between the probe containing cyan benzothiazole and Cys/Hcy, the tiny methylene difference between the molecular structures of Cys and Hcy was converted into the difference between the ring skeletons of the corresponding products that could be identified by plasmonic silver nanoparticle enhanced molecular fingerprint spectroscopy to realize discriminative detection. Furthermore, the SERS sensor was successfully applied to the detection in related patient serum samples, and it was found that the combined analysis of Cys and Hcy can improve the diagnostic accuracy of schizophrenia compared to a single indicator.


Assuntos
Nanopartículas Metálicas , Esquizofrenia , Humanos , Cisteína/química , Células HeLa , Esquizofrenia/diagnóstico , Corantes Fluorescentes/química , Prata , Espectrometria de Fluorescência/métodos , Homocisteína , Glutationa/análise
4.
Acc Chem Res ; 56(24): 3604-3615, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38051914

RESUMO

ConspectusCross-coupling methods are the most widely used synthetic methods in medicinal chemistry. Existing reactions are dominated by methods such as amide coupling and arylation reactions that form bonds to sp2-hybridized carbon atoms and contribute to the formation of "flat" molecules. Evidence that three-dimensional structures often have improved physicochemical properties for pharmaceutical applications has contributed to growing demand for cross-coupling methods with sp3-hybridized reaction partners. Substituents attached to sp3 carbon atoms are intrinsically displayed in three dimensions. These considerations have led to efforts to establish reactions with sp3 cross-coupling partners, including alkyl halides, amines, alcohols, and carboxylic acids. As C(sp3)-H bonds are much more abundant that these more conventional coupling partners, we have been pursuing C(sp3)-H cross-coupling reactions that achieve site-selectivity, synthetic utility, and scope competitive with conventional coupling reactions.In this Account, we outline Cu-catalyzed oxidative cross-coupling reactions of benzylic C(sp3)-H bonds with diverse nucleophilic partners. These reactions commonly use N-fluorobenzenesulfonimide (NFSI) as the oxidant. The scope of reactivity is greatly improved by using a "redox buffer" that ensures that the Cu catalyst is available in the proper redox state to promote the reaction. Early precedents of catalytic Cu/NFSI oxidative coupling reactions, including C-H cyanation and arylation, did not require a redox buffer, but reactions with other nucleophiles, such as alcohols and azoles, were much less effective under similar conditions. Mechanistic studies show that some nucleophiles, such as cyanide and arylboronic acids, promote in situ reduction of CuII to CuI, contributing to successful catalytic turnover. Poor reactivity was observed with nucleophiles, such as alcohols, that do not promote CuII reduction in the same manner. This insight led to the identification of sacrificial reductants, termed "redox buffers", that support controlled generation of CuI during the reactions and enable successful benzylic C(sp3)-H cross-coupling with diverse nucleophiles. Successful reactions include those that feature direct coupling of (hetero)benzylic C-H substrates with coupling partners (alcohols, azoles) and sequential C(sp3)-H functionalization/coupling reactions. The latter methods feature generation of a synthetic linchpin that can undergo subsequent reaction with a broad array of nucleophiles. For example, halogenation/substitution cascades afford benzylic amines, (thio)ethers, and heterodiarylmethane derivatives, and an isocyanation/amine-addition sequence generates diverse benzylic ureas.Collectively, these Cu-catalyzed (hetero)benzylic C(sp3)-H cross-coupling reactions rapidly access diverse molecules. Analysis of their physicochemical and topological properties highlights the "drug-likeness" and enhanced three-dimensionality of these products relative to existing bioactive molecules. This consideration, together with the high benzylic C-H site-selectivity and the broad scope of reactivity enabled by the redox buffering strategy, makes these C(sp3)-H cross-coupling methods ideally suited for implementation in high-throughput experimentation platforms to explore novel chemical space for drug discovery and related applications.

5.
Microb Pathog ; 193: 106773, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38960213

RESUMO

Meyerozyma guilliermondii (Candida guilliermondii) is one of the Candida species associated with invasive candidiasis. With the potential for expressing industrially important enzymes, M. guilliermondii strain SO possessed 99 % proteome similarity with the clinical ATCC 6260 isolate and showed pathogenicity towards zebrafish embryos. Recently, three secreted aspartyl proteinases (SAPs) were computationally identified as potential virulence factors in this strain without in vitro verification of SAP activity. The quantification of Candida SAPs activity in liquid broth were also scarcely reported. Thus, this study aimed to characterize M. guilliermondii strain SO's ability to produce SAPs (MgSAPs) in different conditions (morphology and medium) besides analyzing its growth profile. MgSAPs' capability to cleave bovine serum albumin (BSA) was also determined to propose that MgSAPs as the potential virulence factors compared to the avirulent Saccharomyces cerevisiae. M. guilliermondii strain SO produced more SAPs (higher activity) in yeast nitrogen base-BSA-dextrose broth compared to yeast extract-BSA-dextrose broth despite insignificantly different SAP activity in both planktonic and biofilm cells. FeCl3 supplementation significantly increased the specific protein activity (∼40 %). The BSA cleavage by MgSAPs at an acidic pH was proven through semi-quantitative SDS-PAGE, sharing similar profile with HIV-1 retropepsin. The presented work highlighted the MgSAPs on fungal cell wall and extracellular milieu during host infection could be corroborated to the quantitative production in different growth modes presented herein besides shedding lights on the potential usage of retropepsin's inhibitors in treating candidiasis. Molecular and expression analyses of MgSAPs and their deletion should be further explored to attribute their respective virulence effects.


Assuntos
Ácido Aspártico Proteases , Biofilmes , Candidíase , Soroalbumina Bovina , Fatores de Virulência , Fatores de Virulência/metabolismo , Fatores de Virulência/genética , Ácido Aspártico Proteases/metabolismo , Ácido Aspártico Proteases/genética , Candidíase/microbiologia , Soroalbumina Bovina/metabolismo , Biofilmes/crescimento & desenvolvimento , Animais , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Meios de Cultura/química , Candida/patogenicidade , Candida/metabolismo , Candida/genética , Saccharomycetales/metabolismo , Saccharomycetales/patogenicidade , Saccharomycetales/genética , Virulência
6.
Med Mycol ; 62(1)2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38061839

RESUMO

Invasive candidiasis caused by the pathogenic Candida yeast species has resulted in elevating global mortality. The pathogenicity of Candida spp. is not only originated from its primary invasive yeast-to-hyphal transition; virulence factors (transcription factors, adhesins, invasins, and enzymes), biofilm, antifungal drug resistance, stress tolerance, and metabolic adaptation have also contributed to a greater clinical burden. However, the current research theme in fungal pathogenicity could hardly be delineated with the increasing research output. Therefore, our study analysed the research trends in Candida pathogenesis over the past 37 years via a bibliometric approach against the Scopus and Web of Science databases. Based on the 3993 unique documents retrieved, significant international collaborations among researchers were observed, especially between Germany (Bernhard Hube) and the UK (Julian Naglik), whose focuses are on Candida proteinases, adhesins, and candidalysin. The prominent researchers (Neils Gow, Alistair Brown, and Frank Odds) at the University of Exeter and the University of Aberdeen (second top performing affiliation) UK contribute significantly to the mechanisms of Candida adaptation, tolerance, and stress response. However, the science mapping of co-citation analysis performed herein could not identify a hub representative of subsequent work since the clusters were semi-redundant. The co-word analysis that was otherwise adopted, revealed three research clusters; the cluster-based thematic analyses indicated the severeness of Candida biofilm and antifungal resistance as well as the elevating trend on molecular mechanism elucidation for drug screening and repurposing. Importantly, the in vivo pathogen adaptation and interactions with hosts are crucial for potential vaccine development.


International research collaborations have evident its significance in impactful work covering all aspects of Candida pathogenicity. Its current, diverse research was discussed thematically based on the comprehensive scientometric analysis with unidentified hub representatives for subsequent work.


Assuntos
Candidíase , Vacinas , Animais , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candida/genética , Candidíase/microbiologia , Candidíase/veterinária , Testes de Sensibilidade Microbiana/veterinária , Virulência , Bibliometria
7.
Inorg Chem ; 63(40): 18689-18698, 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39303191

RESUMO

Due to the unique photosensitivity of silver compounds, they exhibit good photocatalytic activity as photocatalysts in the degradation of water pollutants. However, silver compounds have poor cycling stability and are prone to decomposition and reaction under light to form metallic silver, which greatly limits their practical application. Herein, a (2-(2-(diphenylphosphaneyl)ethyl)-9-methyl-1.10-phenanthroline (PSNNP)) pincer ligand was designed for stabilizing the central metal. The in situ-formed PSNNP ligand could be readily generated in one pot with the participation of silver halides. The reaction of silver halides with dppeda (N,N,N',N'-tetra(diphenylphosphanylmethyl)ethylene diamine) in the presence of dmp (2,9-dimethyl-1,10-phenanthroline) in acetonitrile afforded complexes Ag2X2 (PSNNP)2 (complexes 1, 2) (X = Cl, Br). Single-crystal X-ray diffraction shows that the tridentate coordination of the pincer ligand provides strong binding with metal centers and leads to high stability of the pincer metal unit. The removal rate of rhodamine B (RhB) by complexes 1 and 2 can reach up to 100%, demonstrating an excellent photocatalytic degradation performance for organic dyes. The important effect of PSNNP ligands on photocatalytic properties after coordination with central metals was studied through experiments and discrete Fourier transform (DFT) calculations. The photocatalytic reaction mechanism of complexes 1 and 2 was also studied. This result provides an effective pathway for the first synthesis of PSNNP and interesting insights into photocatalytic degradation chemistry.

8.
Environ Sci Technol ; 58(4): 1966-1975, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38153028

RESUMO

Polysaccharides in extracellular polymeric substances (EPS) can form a hybrid matrix network with proteins, impeding waste-activated sludge (WAS) fermentation. Amino sugars, such as N-acetyl-d-glucosamine (GlcNAc) polymers and sialic acid, are the non-negligible components in the EPS of aerobic granules or biofilm. However, the occurrence of amino sugars in WAS and their degradation remains unclear. Thus, amino sugars (∼6.0%) in WAS were revealed, and the genera of Lactococcus and Zoogloea were identified for the first time. Chitin was used as the substrate to enrich a chitin-degrading consortium (CDC). The COD balances for methane production ranged from 83.3 and 95.1%. Chitin was gradually converted to oligosaccharides and GlcNAc after dosing with the extracellular enzyme. After doing enriched CDC in WAS, the final methane production markedly increased to 60.4 ± 0.6 mL, reflecting an increase of ∼62%. Four model substrates of amino sugars (GlcNAc and sialic acid) and polysaccharides (cellulose and dextran) could be used by CDC. Treponema (34.3%) was identified as the core bacterium via excreting chitinases (EC 3.2.1.14) and N-acetyl-glucosaminidases (EC 3.2.1.52), especially the genetic abundance of chitinases in CDC was 2.5 times higher than that of WAS. Thus, this study provides an elegant method for the utilization of amino sugar-enriched organics.


Assuntos
Quitinases , Esgotos , Amino Açúcares , Fermentação , Ácido N-Acetilneuramínico , Quitina/química , Quitina/metabolismo , Polissacarídeos , Quitinases/química , Quitinases/metabolismo , Metano
9.
Environ Sci Technol ; 58(32): 14282-14292, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39083369

RESUMO

Biodegradable flocculants are rarely used in waste activated sludge (WAS) fermentation. This study introduces an alginate-based biodegradable flocculant (ABF) to enhance both the dewatering and degradation of WAS during its fermentation. Alginate was identified in structural extracellular polymeric substances (St-EPS) of WAS, with alginate-producing bacteria comprising ∼4.2% of the total bacterial population in WAS. Owing to its larger floc size, higher contact angle, and lower free energy resulting from the Lewis acid-base interaction, the addition of the prepared ABF with a network structure significantly improved the dewaterability of WAS and reduced capillary suction time (CST) by 72%. The utilization of ABF by an enriched alginate-degrading consortium (ADC) resulted in a 35.5% increase in the WAS methane yield owing to its higher hydrolytic activity on both ABF and St-EPS. Additionally, after a 30 day fermentation, CST decreased by 62% owing to the enhanced degradation of St-EPS (74.4%) and lower viscosity in the WAS + ABF + ADC group. The genus Bacteroides, comprising 12% of ADC, used alginate lyase (EC 4.2.2.3) and pectate lyase (EC 4.2.2.2 and EC 4.2.2.9) to degrade alginate and polygalacturonate in St-EPS, respectively. Therefore, this study introduces a new flocculant and elucidates its dual roles in enhancing both the dewaterability and degradability of WAS. These advancements improve WAS fermentation, resulting in higher methane production and lower CSTs.


Assuntos
Alginatos , Fermentação , Floculação , Esgotos , Anaerobiose , Eliminação de Resíduos Líquidos , Biodegradação Ambiental
10.
J Gastroenterol Hepatol ; 39(10): 2060-2068, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38943533

RESUMO

BACKGROUND: We aimed to verify the effectiveness of electroacupuncture on postoperative ileus prevention after abdominal surgery by meta-analysis and trial sequential analysis (TSA). METHODS: From inception to May 14, 2024, PubMed, the Cochrane Library, Web of Science, and Embase databases were searched. TSA was used to determine an optimal sample size and control false-positive findings. The primary outcome was the time to first defecation (hours). RESULTS: Fourteen studies were included, with 1105 participants. Meta-analysis and TSA revealed firm evidence for benefits that electroacupuncture shorted the time to first defecation (mean difference [MD] -12.73 h, I2 = 22%, P < 0.01), the time to first flatus (MD -7.03 h, I2 = 25%, P < 0.01), the time to start of sips of water (MD -12.02 h, I2 = 0%, P < 0.01), and the time to start of liquid diet (MD -12.97 h, I2 = 0%, P < 0.01) compared with usual care. While compared with sham electroacupuncture, meta-analysis and TSA also confirmed that electroacupuncture shortened the time to first defecation (MD -10.81 h, I2 = 31%, P = 0.02) and the time to first flatus (MD -10.81 h, I2 = 0%, P < 0.01). However, TSA revealed that firm evidence for benefit or futility was not reached for the length of hospital stay and the rates of postoperative prolonged ileus. CONCLUSIONS: Electroacupuncture shortened the duration of postoperative ileus in patients undergoing abdominal surgery, and the adverse events related to electroacupuncture were minor. Further investigation of the effect of electroacupuncture on the risk of prolonged postoperative ileus is warranted in the future.


Assuntos
Defecação , Eletroacupuntura , Íleus , Complicações Pós-Operatórias , Ensaios Clínicos Controlados Aleatórios como Assunto , Eletroacupuntura/métodos , Íleus/prevenção & controle , Íleus/etiologia , Humanos , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/etiologia , Resultado do Tratamento , Abdome/cirurgia , Fatores de Tempo , Feminino
11.
Brain Inj ; 38(11): 889-895, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-38747037

RESUMO

OBJECTIVE: Hyperoxia has been suggested as a mechanism for secondary injury following adult traumatic brain injury (TBI), but its effects have not been well described in pediatric patients. METHODS: Pediatric (≤18yo) TBI patients were identified in a prospective institutional registry from October 2008 to April 2022. The first, highest, and the Area Under the Curve (AUC) PaO2 in the first 24 hours were collected and calculated for each patient from arterial blood gas reports after admission to the ICU. Neurological outcome after 6 months was measured using dichotomized modified Rankin Scale (mRS) and Glasgow Outcome Scale - Extended (GOS-E). Multivariable logistic regression models were used to determine if the three measurements for hyperoxia predicted an unfavorable outcome after controlling for well-established clinical and imaging predictors of outcome. RESULTS: We identified 98 pediatric patients with severe accidental TBI during the study period. Hyperoxia (PaO2 > 300 mmHg) occurred in 33% of the patients. The presence of elevated PaO2 values, determined by all three evaluations of hyperoxia, was not associated with unfavorable outcome after 6 months. CONCLUSION: Utilizing multiple methods to assess exposure, hyperoxia was present in a substantial number of patients with severe TBI but was not associated with an unfavorable outcome.


Assuntos
Lesões Encefálicas Traumáticas , Hiperóxia , Humanos , Masculino , Feminino , Lesões Encefálicas Traumáticas/complicações , Hiperóxia/complicações , Criança , Adolescente , Pré-Escolar , Lactente , Estudos Prospectivos , Sistema de Registros , Escala de Resultado de Glasgow , Gasometria
12.
Brain Inj ; 38(12): 1015-1025, 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-38965876

RESUMO

OBJECTIVE: To determine the safety and proof of concept of a parcel-guided, repetitive Transcranial Magnetic Stimulation (rTMS) in patients who develop a heterogeneous array of symptoms, known collectively as post-concussive syndrome (PCS), following traumatic brain injury (TBI). METHODS: We performed a retrospective review of off-label, individualized, parcel-guided rTMS in 19 patients from December 2020 to May 2023. Patients had at least one instance of mild, moderate, or severe TBI and developed symptoms not present prior to injury. rTMS targets were identified based on machine learning connectomic software using functional connectivity anomaly matrices compared to healthy controls. EuroQol (EQ-5D), as a measurement of quality of life, and additional questionnaires dependent on individual's symptoms were submitted prior to, after, and during follow-up from rTMS. RESULTS: Nineteen patients showed improvement in EQ-5D and Rivermead Post Concussion Symptoms Questionnaires - 3 after treatment and follow-up. For nine patients who developed depression, five (55%) attained response and remission based on the Beck Depression Inventory after treatment. Eight of ten patients with anxiety had a clinically significant reduction in Generalized Anxiety Disorder-7 scores during follow-up. CONCLUSION: Parcel-guided rTMS is safe and may be effective in reducing PCS symptoms following TBI and should incite further controlled studies.


Assuntos
Síndrome Pós-Concussão , Estimulação Magnética Transcraniana , Humanos , Síndrome Pós-Concussão/terapia , Estimulação Magnética Transcraniana/métodos , Masculino , Feminino , Adulto , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto Jovem , Resultado do Tratamento , Qualidade de Vida , Estudo de Prova de Conceito , Lesões Encefálicas Traumáticas/complicações
13.
Angew Chem Int Ed Engl ; 63(16): e202400562, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38382041

RESUMO

Halide solid electrolytes, known for their high ionic conductivity at room temperature and good oxidative stability, face notable challenges in all-solid-state Li-ion batteries (ASSBs), especially with unstable cathode/solid electrolyte (SE) interface and increasing interfacial resistance during cycling. In this work, we have developed an Al3+-doped, cation-disordered epitaxial nanolayer on the LiCoO2 surface by reacting it with an artificially constructed AlPO4 nanoshell; this lithium-deficient layer featuring a rock-salt-like phase effectively suppresses oxidative decomposition of Li3InCl6 electrolyte and stabilizes the cathode/SE interface at 4.5 V. The ASSBs with the halide electrolyte Li3InCl6 and a high-loading LiCoO2 cathode demonstrated high discharge capacity and long cycling life from 3 to 4.5 V. Our findings emphasize the importance of specialized cathode surface modification in preventing SE degradation and achieving stable cycling of halide-based ASSBs at high voltages.

14.
BMC Genomics ; 24(1): 57, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36721086

RESUMO

OBJECTIVES: To explore the causes of sudden unexpected death (SUD) and to search for high-risk people, whole exome sequencing (WES) was performed in families with SUDs.  METHODS: Whole exome sequencing of 25 people from 14 SUD families were screened based on cardiac disease-associated gene variants, and their echocardiograms and electrocardiograms (ECG) were also examined. The protein function of mutated genes was predicted by SIFT, PolyPhen2 and Mutation Assessor. RESULTS: In the group of 25 people from 14 SUD families, 49 single nucleotide variants (SNVs) of cardiac disease-associated genes were found and verified by Sanger sequencing. 29 SNVs of 14 cardiac disorder-related genes were predicted as pathogens by software. Among them, 7 SNVs carried by two or more members were found in 5 families, including SCN5A (c.3577C > T), IRX4 (c.230A > G), LDB3 (c.2104 T > G), MYH6 (c.3G > A), MYH6 (c.3928 T > C), TTN (c.80987C > T) and TTN (c.8069C > T). 25 ECGs were collected. In summary, 4 people had J-point elevation, 2 people had long QT syndrome (LQTS), 4 people had prolonged QT interval, 3 people had T-wave changes, 3 people had sinus tachycardia, 4 people had sinus bradycardia, 4 people had left side of QRS electrical axis, and 3 people had P wave broadening. Echocardiographic results showed that 1 person had atrial septal defect, 1 person had tricuspid regurgitation, and 2 people had left ventricular diastolic dysfunction. CONCLUSIONS: Of the 14 heart disease-associated genes in 14 SUDs families, there are 7 possible pathological SNVS may be associated with SUDs. Our results indicate that people with ECG abnormalities, such as prolonged QT interval, ST segment changes, T-wave change and carrying the above 7 SNVs, should be the focus of prevention of sudden death.


Assuntos
Cardiopatias , Humanos , Sequenciamento do Exoma , China , Morte Súbita , Mutação
15.
J Am Chem Soc ; 145(17): 9434-9440, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37084265

RESUMO

Copper-catalyzed radical-relay reactions provide a versatile strategy for selective C-H functionalization; however, reactions with peroxide-based oxidants often require excess C-H substrate. Here, we report a photochemical strategy to overcome this limitation by using a Cu/2,2'-biquinoline catalyst that supports benzylic C-H esterification with limiting C-H substrate. Mechanistic studies indicate that blue-light irradiation promotes carboxylate-to-copper charge transfer, reducing resting-state CuII to CuI, which activates the peroxide to generate an alkoxyl radical hydrogen-atom-transfer species. This "photochemical redox buffering" introduces a unique strategy to sustain the activity of Cu catalysts in radical-relay reactions.

16.
J Am Chem Soc ; 145(1): 25-31, 2023 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-36548026

RESUMO

Heterocycles are the backbone of modern medical chemistry and drug development. The derivatization of "an olefin" inside aromatic rings represents an ideal approach to access functionalized saturated heterocycles from abundant aromatic building blocks. Here, we report an operationally simple, efficient, and practical method to selectively access hydrosilylated and reduced N-heterocycles from bicyclic aromatics via a key diradical intermediate. This approach is expected to facilitate complex heterocycle functionalizations that enable access to novel medicinally relevant scaffolds.


Assuntos
Quinolinas , Isoquinolinas , Estrutura Molecular , Catálise , Desenvolvimento de Medicamentos
17.
Microb Pathog ; 176: 106025, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36754101

RESUMO

Meyerozyma guilliermondii is a rare opportunistic fungal pathogen that causes deadly invasive candidiasis in human. M. guilliermondii strain SO is a local yeast isolate that possesses huge industrial interests but also pathogenic towards zebrafish embryos. Enolases that bind to human extracellular matrix (ECM) proteins are among the fungal virulence factors. To understand its pathogenicity mechanism down to molecular level, especially in the rare M. guilliermondii, this study aimed to identify and characterize the potentially virulence-associated enolase in M. guilliermondii strain SO using bioinformatics approaches. Profile Hidden-Markov model was implemented to identify enolase-related sequences in the fungal proteome. Sequence analysis deciphered only one (MgEno4581) out of nine sequences exhibited potent virulence traits observed similarly in the pathogenic Candida albicans. MgEno4581 structure that was predicted via SWISS-MODEL using C. albicans enolase (CaEno1; PDB ID: 7vrd) as the homology modeling template portrayed a highly identical motif with CaEno1 that facilitates ECM proteins binding. Amino acid substitutions (D234K, K235A, Y238H, K239D, G243K, V248C and Y254F) in ECM-binding motif of Saccharomyces cerevisiae enolase (ScEno) compared to MgEno4581 and CaEno1 caused changes in motif's surface charges. Protein-protein docking indicated F253 in ScEno only interacted hydrophobically with human plasminogen (HPG). Hydrogen linkages were observed for both MgEno4581 and CaEno1, suggesting a stronger interaction with HPG in the hydrophilic host microenvironments. Thus, our in silico characterizations on MgEno4581 provided new perspectives on its potential roles in candidiasis (fungal-host interactions) caused by M. guilliermondii, especially M. guilliermondii strain SO on zebrafish embryos that mimic the immunocompromised individuals as previously evident.


Assuntos
Fatores de Virulência , Peixe-Zebra , Animais , Humanos , Fosfopiruvato Hidratase , Interações entre Hospedeiro e Microrganismos , Candida albicans
18.
Virol J ; 20(1): 60, 2023 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-37016444

RESUMO

BACKGROUND: Norovirus is a leading cause of acute gastroenteritis among children. Previous studies based on symptomatic infections indicated that mutations, rather than recombination drove the evolution of the norovirus ORF2. These characteristics were found in hospital-based symptomatic infections, whereas, asymptomatic infections are frequent and contribute significantly to transmission. METHODS: We conducted the first norovirus molecular epidemiology analysis covering both symptomatic and asymptomatic infections derived from a birth cohort study in the northern China. RESULTS: During the study, 14 symptomatic and 20 asymptomatic norovirus infections were detected in 32 infants. Out of the 14 strains that caused symptomatic infections, 12 strains were identified as GII.3[P12], and others were GII.4[P31]. Conversely, 17 asymptomatic infections were caused by GII.4[P31], two by GII.2[P16], and one by GII.4[P16]. Regardless of symptomatic and asymptomatic infections, the mutations were detected frequently in the ORF2 region, and almost all recombination were identified in the RdRp-ORF2 region. The majority of the mutations were located around the predefined epitope regions of P2 subdomain indicating a potential for immune evasion. CONCLUSION: The role of symptomatic as well as asymptomatic infections in the evolution of norovirus needs to be evaluated continuously.


Assuntos
Infecções por Caliciviridae , Norovirus , Humanos , Lactente , Infecções Assintomáticas/epidemiologia , Infecções por Caliciviridae/epidemiologia , Estudos de Coortes , População do Leste Asiático , Fezes , Genótipo , Epidemiologia Molecular , Norovirus/genética , Filogenia
19.
Acta Pharmacol Sin ; 44(9): 1737-1747, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37076634

RESUMO

Epilepsy is not well controlled by current anti-seizure drugs (ASDs). High mobility group box 1 (HMGB1) is a DNA-binding protein in the nucleus regulating transcriptional activity and maintaining chromatin structure and DNA repair. In epileptic brains, HMGB1 is released by activated glia and neurons, interacting with various receptors like Toll-like receptor 4 (TLR4) and downstream glutamatergic NMDA receptor, thus enhancing neural excitability. But there is a lack of small-molecule drugs targeting the HMGB1-related pathways. In this study we evaluated the therapeutic potential of inflachromene (ICM), an HMGB-targeting small-molecule inhibitor, in mouse epilepsy models. Pentylenetetrazol-, kainic acid- and kindling-induced epilepsy models were established in mice. The mice were pre-treated with ICM (3, 10 mg/kg, i.p.). We showed that ICM pretreatment significantly reduced the severity of epileptic seizures in all the three epilepsy models. ICM (10 mg/kg) exerted the most apparent anti-seizure effect in kainic acid-induced epileptic status (SE) model. By immunohistochemical analysis of brain sections from kainic acid-induced SE mice, we found that kainic acid greatly enhanced HMGB1 translocation in the hippocampus, which was attenuated by ICM pretreatment in subregion- and cell type-dependent manners. Notably, in CA1 region, the seizure focus, ICM pretreatment mainly inhibited HMGB1 translocation in microglia. Furthermore, the anti-seizure effect of ICM was related to HMGB1 targeting, as pre-injection of anti-HMGB1 monoclonal antibody (5 mg/kg, i.p.) blocked the seizure-suppressing effect of ICM in kainic acid-induced SE model. In addition, ICM pretreatment significantly alleviated pyramidal neuronal loss and granule cell dispersion in kainic acid-induced SE model. These results demonstrate that ICM is an HMGB-targeting small molecule with anti-seizure potential, which may help develop a potential drug for treating epilepsy.


Assuntos
Epilepsia , Proteína HMGB1 , Camundongos , Animais , Ácido Caínico/efeitos adversos , Ácido Caínico/metabolismo , Epilepsia/induzido quimicamente , Epilepsia/tratamento farmacológico , Epilepsia/metabolismo , Hipocampo/metabolismo , Proteínas HMGB/metabolismo , Proteínas HMGB/farmacologia , Proteína HMGB1/metabolismo , Modelos Animais de Doenças
20.
Eur J Pediatr ; 182(8): 3691-3700, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37269377

RESUMO

Postoperative acute kidney injury (AKI) is a prevalent condition and associated with increased morbidity and mortality following cardiac surgery. This study aimed to investigate the association of underweight and obesity with adverse postoperative renal outcomes in infants and young children undergoing congenital heart surgery. This retrospective cohort study included patients aged from 1 month to 5 years who underwent congenital heart surgery with cardiopulmonary bypass at the Second Xiangya Hospital of Central South University from January 2016 to March 2022. On the basis of the percentile of body mass index (BMI) for age and sex, eligible participants were divided into three nutritional groups: normal bodyweight, underweight (BMI P5), and obesity (BMI P95). Primary outcomes included postoperative AKI and major adverse kidney events within 30 days (MAKE30). Multivariable logistic regression was performed to determine the association of underweight and obesity with postoperative outcomes. The same analyses were reproduced for classifying patients using weight-for-height instead of BMI. A total of 2,079 eligible patients were included in the analysis, including 1,341 (65%) patients in the normal bodyweight group, 683 (33%) patients in the underweight group, and 55 (2.6%) patients in the obesity group. Postoperative AKI (16% vs. 26% vs. 38%; P < 0.001) and MAKE30 (2.5% vs. 6.4% vs. 9.1%; P < 0.001) were more likely to occur in the underweight and obesity groups. After adjusting for potential confounders, underweight (OR1.39; 95% CI 1.08-1.79; P = 0.008) and obesity (OR 3.85; 95% CI 1.97-7.50; P < 0.001) were found to be associated with an increased risk of postoperative AKI. In addition, both underweight (OR 1.89; 95% CI 1.14-3.14; P = 0.014) and obesity (OR 3.14; 95% CI 1.08-9.09; P = 0.035) were independently associated with MAKE30. Similar results were also found when weight-for-height was used instead of BMI.    Conclusion: In infants and young children undergoing congenital heart surgery, underweight and obesity are independently associated with postoperative AKI and MAKE30. These results may help assess prognosis in underweight and obese patients, and will guide future quality improvement efforts. What is Known: • Postoperative acute kidney injury (AKI) is prevalent and associated with increased morbidity and mortality following pediatric cardiac surgery. • Major adverse kidney events within 30 days (MAKE30) have been recommended as a patient-centered endpoint for evaluating AKI clinical trajectories. A growing concern arises for underweight and obesity in children with congenital heart disease. What is New: • Prevalence of underweight and obesity among infants and young children undergoing congenital heart surgery was 33% and 2.6%, respectively. • Both underweight and obesity were independently associated with postoperative AKI and MAKE30 following congenital heart surgery.


Assuntos
Injúria Renal Aguda , Cardiopatias Congênitas , Obesidade Infantil , Humanos , Criança , Lactente , Pré-Escolar , Estudos Retrospectivos , Fatores de Risco , Magreza/complicações , Magreza/epidemiologia , Obesidade Infantil/complicações , Obesidade Infantil/cirurgia , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/cirurgia , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/etiologia , Rim , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia
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