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1.
Artigo em Inglês | MEDLINE | ID: mdl-38920070

RESUMO

BACKGROUND: A highly efficient superior catalyst of Ni (II) and VO (IV) metal complexes supported on MCM-41 has been synthesized and developed for chemoselective oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using H2O2 as a green and efficient procedure. All sulfoxides and disulfides were obtained in short reaction times with excellent yields. The over-oxidation of sulfides or thiols was not observed and all products were synthesized in high purity. These catalysts could be recovered and reused several times without any significant loss in their catalytic activity. Compared to the old catalysts in the literature, these catalysts showed better activity and selectivity for the synthesis of sulfoxide and disulfide derivatives, which shows the novelty of this work. METHODS: At first, the mesoporous MCM-41 was synthesized, and further, its surface was modified by (3-chloropropyl)-triethoxysilane (CPTES). Then, the modified MCM-41 (nPrCl-MCM- 41) was functionalized by adenine. In the next step, the functionalized MCM-41 (6AP-MCM- 41) was used as support for the immobilization of nickel and oxo-vanadium as final catalysts (Ni-6AP-MCM-41 or VO-6AP-MCM-41). The structure and properties of these catalysts have been identified by XRD, SEM, TGA, FT-IR, and AAS spectral analyses. These catalysts were used in the chemoselective oxidation of sulfides and oxidative coupling of thiols. RESULTS: These complexes catalyzed all reactions well at room temperature. According to the results obtained, the hydroxyl groups of some derivatives, including 2-(methylthio) ethanol or 2,2-(phenylthio) ethanol, remained unchanged during the reaction. CONCLUSION: The method has been found to possess the advantages of low cost, high efficiency, high yields, recovery, and reusability for several runs without significant loss in the catalytic activity.

2.
Angew Chem Int Ed Engl ; : e202408158, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38923731

RESUMO

Polysulfides are significant compounds in life science, pharmaceutical science, and material science. Therefore, polysulfide construction is in great demand. The controllable sequential installation on both ends of S-S motif faces an enormous challenge, due to the reversible covalent S-S bond. A library was established with two divergent mask groups for bilateral unsymmetrical disulfurating reagents (R1O-SS-SO2R2). Sequential coupling was successfully achieved with preferential activation of S-SO2 bond (37.6 kcal/mol) and controllable activation of S-O bond (54.8 kcal/mol) superior to S-S bond (62.0 kcal/mol), enabled untrammeled installation on the bilateral sides of S-S motif to afford unsymmetrical disulfides and trisulfides, even for natural products, pharmaceuticals, peptides, and protein (bovine serum albumin) cross-linkage successively.

3.
Chem Asian J ; 19(11): e202400272, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38577719

RESUMO

Palladium-catalyzed thioarylation of indoles by diaryl disulfides in the presence of phenyliododiacetate is reported. The directing potential of weakly coordinating aldehyde group present at 3-position of indole was exploited for regioselective C2-H thioarylation over the possible C4-H functionalization. Mechanistic studies reveal that the process involves initial generation of thioaryl radical followed by sequential C-H activation, thiolate transfer, and reductive elimination.

4.
Heliyon ; 10(7): e28929, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38601696

RESUMO

Volatile sulfur compounds (VSCs) are important aroma and flavour characters in food and beverage products. The identification and quantification of these extremely reactive and volatile compounds pose analytical challenges which demand selective and sensitive methods. In this study, a novel quantification method was developed to analyse sulfhydryls as well as the total pool of sulfhydryls which can be released after tris(2-carboxyethyl)phosphine (TCEP) addition from disulfides, polysulfides, metal-bound and other yet to be identified sources naturally present in wine. The majority of methods for VSC quantification analyse VSCs in wine headspace, whereas this method measures sulfhydryls and TCEP-releasable sulfhydryl species, which likely include free and metal-bound sulfhydryl forms, in the liquid phase of wine using UHPLC-MS/MS. Sulfhydryls were derivatised with N-(2-ferroceneethyl) maleimide (FEM), subsequently, followed by differential labelling of sulfhydryls released after TCEP addition with ferrocenecarboxylic acid-(2-maleimidoyl)ethylamide (FMEA). Analysis of commercial wines revealed the presence of hydrogen sulfide, methanethiol, ethanethiol, and 2-mercaptoethanol at aroma-active concentrations. Significant positive correlations were found between MeSH and CH3-S-R TCEP-releasable species, and significant positive correlations were found between EtSH and CH3-CH2-S-R TCEP-releasable species. This method provides important information on sulfhydryls, and may also provide insights into a wine's risk of developing 'reductive' faults post-bottling from latent sources.

5.
Anal Bioanal Chem ; 416(7): 1599-1612, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38296860

RESUMO

Characterization at the subunit level enables detailed mass spectrometric characterization of posttranslational modifications (PTMs) of monoclonal antibodies (mAbs). The implemented reduction often leaves the intramolecular disulfide bridges intact. Here, we present a capillary electrophoretic (CE) method based on a neutral-coated capillary for the separation of immunoglobulin G-degrading enzyme of Streptococcus pyogenes (IdeS) digested and reduced mAb subunits followed by mass spectrometry (MS), MS/MS identification, and trapped ion mobility mass spectrometry (timsTOF). Our CE approach enables the separation of (i) different subunit moieties, (ii) various reduction states, and (iii) positional isomers of these partly reduced subunit moieties. The location of the remaining disulfide bridges can be determined by middle-down electron transfer higher energy collisional dissociation (EThcD) experiments. All these CE-separated variants show differences in ion mobility in the timsTOF measurements. Applying the presented CE-MS/MS method, reduction parameters such as the use of chaotropic salts were studied. For the investigated antibodies, urea improved the subunit reduction significantly, whereas guanidine hydrochloride (GuHCl) leads to multiple signals of the same subunit in the CE separation. The presented CE-MS method is a powerful tool for the disulfide-variant characterization of mAbs on the subunit level. It enables understanding disulfide bridge reduction processes in antibodies and potentially other proteins.


Assuntos
Dissulfetos , Espectrometria de Massas em Tandem , Dissulfetos/química , Eletroforese Capilar/métodos , Anticorpos Monoclonais/química , Processamento de Proteína Pós-Traducional
6.
Antiviral Res ; 222: 105806, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38211737

RESUMO

After three years of the SARS-CoV-2 pandemic, the search and availability of relatively low-cost benchtop therapeutics for people not at high risk for a severe disease are still ongoing. Although vaccines and new SARS-CoV-2 variants reduce the death toll, the long COVID-19 along with neurologic symptoms can develop and persist even after a mild initial infection. Reinfections, which further increase the risk of sequelae in multiple organ systems as well as the risk of death, continue to require caution. The spike protein of SARS-CoV-2 is an important target for both vaccines and therapeutics. The presence of disulfide bonds in the receptor binding domain (RBD) of the spike protein is essential for its binding to the human ACE2 receptor and cell entry. Here, we demonstrate that thiol-reducing peptides based on the active site of oxidoreductase thioredoxin 1, called thioredoxin mimetic (TXM) peptides, can prevent syncytia formation, SARS-CoV-2 entry into cells, and infection in a mouse model. We also show that TXM peptides inhibit the redox-sensitive HIV pseudotyped viral cell entry. These results support disulfide targeting as a common therapeutic strategy for treating infections caused by viruses using redox-sensitive fusion. Furthermore, TXM peptides exert anti-inflammatory properties by lowering the activation of NF-κB and IRF signaling pathways, mitogen-activated protein kinases (MAPKs) and lipopolysaccharide (LPS)-induced cytokines in mice. The antioxidant and anti-inflammatory effects of the TXM peptides, which also cross the blood-brain barrier, in combination with prevention of viral infections, may provide a beneficial clinical strategy to lower viral infections and mitigate severe consequences of COVID-19.


Assuntos
COVID-19 , Vacinas , Animais , Humanos , Camundongos , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Síndrome de COVID-19 Pós-Aguda , Peptídeos/farmacologia , Vacinas/farmacologia , Tiorredoxinas/química , Tiorredoxinas/metabolismo , Tiorredoxinas/farmacologia , Anti-Inflamatórios/farmacologia , Dissulfetos/farmacologia , Células Gigantes , Ligação Proteica
7.
Arterioscler Thromb Vasc Biol ; 44(3): e82-e98, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38205640

RESUMO

BACKGROUND: Integrins mediate the adhesion, crawling, and migration of neutrophils during vascular inflammation. Thiol exchange is important in the regulation of integrin functions. ERp72 (endoplasmic reticulum-resident protein 72) is a member of the thiol isomerase family responsible for the catalysis of disulfide rearrangement. However, the role of ERp72 in the regulation of Mac-1 (integrin αMß2) on neutrophils remains elusive. METHODS: Intravital microscopy of the cremaster microcirculation was performed to determine in vivo neutrophil movement. Static adhesion, flow chamber, and flow cytometry were used to evaluate in vitro integrin functions. Confocal fluorescent microscopy and coimmunoprecipitation were utilized to characterize the interactions between ERp72 and Mac-1 on neutrophil surface. Cell-impermeable probes and mass spectrometry were used to label reactive thiols and identify target disulfide bonds during redox exchange. Biomembrane force probe was performed to quantitatively measure the binding affinity of Mac-1. A murine model of acute lung injury induced by lipopolysaccharide was utilized to evaluate neutrophil-associated vasculopathy. RESULTS: ERp72-deficient neutrophils exhibited increased rolling but decreased adhesion/crawling on inflamed venules in vivo and defective static adhesion in vitro. The defect was due to defective activation of integrin Mac-1 but not LFA-1 (lymphocyte function-associated antigen-1) using blocking or epitope-specific antibodies. ERp72 interacted with Mac-1 in lipid rafts on neutrophil surface leading to the reduction of the C654-C711 disulfide bond in the αM subunit that is critical for Mac-1 activation. Recombinant ERp72, via its catalytic motifs, increased the binding affinity of Mac-1 with ICAM-1 (intercellular adhesion molecule-1) and rescued the defective adhesion of ERp72-deficient neutrophils both in vitro and in vivo. Deletion of ERp72 in the bone marrow inhibited neutrophil infiltration, ameliorated tissue damage, and increased survival during murine acute lung injury. CONCLUSIONS: Extracellular ERp72 regulates integrin Mac-1 activity by catalyzing disulfide rearrangement on the αM subunit and may be a novel target for the treatment of neutrophil-associated vasculopathy.


Assuntos
Lesão Pulmonar Aguda , Antígeno de Macrófago 1 , Animais , Camundongos , Lesão Pulmonar Aguda/genética , Lesão Pulmonar Aguda/metabolismo , Adesão Celular , Dissulfetos , Molécula 1 de Adesão Intercelular/metabolismo , Antígeno-1 Associado à Função Linfocitária/metabolismo , Antígeno de Macrófago 1/genética , Antígeno de Macrófago 1/metabolismo , Infiltração de Neutrófilos , Neutrófilos/metabolismo , Compostos de Sulfidrila/metabolismo
8.
Small ; 20(12): e2302410, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37635113

RESUMO

Herein, a hybrid substrate for surface-enhanced Raman scattering (SERS) is fabricated, which couples localized surface plasmon resonance (LSPR), charge transfer (CT) resonance, and molecular resonance. Exfoliated 2D TiS2 nanosheets with semimetallic properties accelerate the CT with the tested analytes, inducing a remarkable chemical mechanism enhancement. In addition, the LSPR effect is coupled with a concave gold array located underneath the thin TiS2 nanosheet, providing a strong electromagnetic enhancement. The concave gold array is prepared by etching silicone nanospheres assembled on larger polystyrene nanospheres, followed by depositing a gold layer. The LSPR intensity near the gold layer can be adjusted by changing the layer thickness to couple the molecular and CT resonances, in order to maximize the SERS enhancement. The best SERS performance is recorded on TiS2-nanosheet-coated plasmonic substrates, with a detectable methylene blue concentration down to 10-13 m and an enhancement factor of 2.1 × 109 and this concentration is several orders of magnitude lower than that of the TiS2 nanosheet (10-11 m) and plasmonic substrates (10-9 m). The present hybrid substrate with triple-coupled resonance further shows significant advantages in the label-free monitoring of curcumin (a widely applied drug for treating multiple cancers and inflammations) in serum and urine.

9.
Chem Asian J ; 19(1): e202300883, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-37950799

RESUMO

Organochalcogen molecules have extensive applications in various fields. They serve as pharmaceuticals, ligands, organocatalysts, agrochemicals, and other functional materials. Difunctionalization of olefins, which belong to a class of multicomponent reactions, is a successful technique for introducing two functional moieties in a single-step reaction, both in terms of atom economy and step economy. The difunctionalization of olefins with diorganyl dichalcogenides may effectively increase the molecular complexity, which has achieved significant advancements in recent decades. This article describes recent advancements in the difunctionalization of olefins with diorganyl diselenides and diorganyl disulfides.

10.
ACS Appl Mater Interfaces ; 16(1): 1511-1520, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38129176

RESUMO

Given the substantial environmental challenge posed by global plastic waste, recycling technology for thermosetting polymers has become a huge research topic in the polymer industry. Covalent adaptive networks (CANs), which can reversibly dissociate and reconstruct their network structure, represent a key technology for the self-healing, reprocessing, and recycling of thermosetting polymers. In the present study, we introduce a new series of polyurethane CANs whose network structure can dissociate via the self-catalyzed formation of dithiolane from the CANs' polydisulfide linkages when the CANs are treated in N,N-dimethylformamide (DMF) or dimethyl sulfoxide at 60 °C for 1 h. More interestingly, we found that this network dissociation even occurs in tetrahydrofuran-DMF solvent mixtures with low DMF concentrations. This feature enables a reduction in the use of high-boiling, toxic polar aprotic solvents. The dissociated network structure of the CANs was reconstructed under UV light at 365 nm with a high yield via ring-opening polydisulfide linkage formation from dithiolane pendant groups. These CAN films, which were prepared by a sequential organic synthesis and polymerization process, exhibited high thermal stability and good mechanical properties, recyclability, and self-healing performance. When lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt was added to the CAN films, the films exhibited a maximum ion conductivity of 7.48 × 10-4 S cm-1 because of the contribution of the high concentration of the pendant ethylene carbonate group in the CANs. The ion-conducting CAN films also showed excellent recyclability and a self-healing performance.

11.
Int J Mol Sci ; 24(21)2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37958865

RESUMO

Monoterpene thiols are one of the classes of natural flavors that impart the smell of citrus fruits, grape must and wine, black currants, and guava and are used as flavoring agents in the food and perfume industries. Synthetic monoterpene thiols have found an application in asymmetric synthesis as chiral auxiliaries, derivatizing agents, and ligands for metal complex catalysis and organocatalysts. Since monoterpenes and monoterpenoids are a renewable source, there are emerging trends to use monoterpene thiols as monomers for producing new types of green polymers. Monoterpene thioderivatives are also known to possess antioxidant, anticoagulant, antifungal, and antibacterial activity. The current review covers methods for the synthesis of acyclic, mono-, and bicyclic monoterpene thiols, as well as some investigations related to their usage for the preparation of the compounds with antimicrobial properties.


Assuntos
Vitis , Vinho , Monoterpenos/farmacologia , Compostos de Sulfidrila , Vinho/análise
12.
Nanomicro Lett ; 16(1): 29, 2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-37994956

RESUMO

The laminated transition metal disulfides (TMDs), which are well known as typical two-dimensional (2D) semiconductive materials, possess a unique layered structure, leading to their wide-spread applications in various fields, such as catalysis, energy storage, sensing, etc. In recent years, a lot of research work on TMDs based functional materials in the fields of electromagnetic wave absorption (EMA) has been carried out. Therefore, it is of great significance to elaborate the influence of TMDs on EMA in time to speed up the application. In this review, recent advances in the development of electromagnetic wave (EMW) absorbers based on TMDs, ranging from the VIB group to the VB group are summarized. Their compositions, microstructures, electronic properties, and synthesis methods are presented in detail. Particularly, the modulation of structure engineering from the aspects of heterostructures, defects, morphologies and phases are systematically summarized, focusing on optimizing impedance matching and increasing dielectric and magnetic losses in the EMA materials with tunable EMW absorption performance. Milestones as well as the challenges are also identified to guide the design of new TMDs based dielectric EMA materials with high performance.

13.
Micromachines (Basel) ; 14(11)2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-38004853

RESUMO

Utilizing interface engineering to construct abundant heterogeneous interfaces is an important means to improve the absorbing performance of microwave absorbers. Here, we have prepared the MXene/MoS2-ReS2 (MMR) composite with rich heterogeneous interfaces composed of two-dimensional Ti3C2Tx MXene and two-dimensional transition metal disulfides through a facile hydrothermal process. The surface of MXene is completely covered by nanosheets of MoS2 and ReS2, forming a hybrid structure. MRR exhibits excellent absorption performance, with its strongest reflection loss reaching -51.15 dB at 2.0 mm when the filling ratio is only 10 wt%. Meanwhile, the effective absorption bandwidth covers the range of 5.5-18 GHz. Compared to MXene/MoS2 composites, MRR with a MoS2-ReS2 heterogeneous interface exhibits stronger polarization loss ability and superior absorption efficiency at the same thickness. This study provides a reference for the design of transition metal disulfides-based absorbing materials.

14.
ACS Appl Mater Interfaces ; 15(38): 44773-44785, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37721368

RESUMO

Supramolecular self-assembly has gained increasing attention to construct multicomponent drug delivery systems for cancer diagnosis and therapy. Despite that these self-assembled nanosystems present surprising properties beyond that of each subcomponent, the spontaneous nature of co-self-assembly causes significant difficulties in control of the synthesis process and consequently leads to unsatisfactory influences in downstream applications. Hence, we utlized an in situ dynamic covalent reaction based on thiol-disulfide exchange to slowly produce disulfide macrocycles, which subsequently triggered the co-self-assembly of an anticancer drug (doxorubicin, DOX) and a magnetic resonance imaging (MRI) contrast agent of ultrasmall iron oxide nanoparticles (IO NPs). It showed concentration regulation of macrocyclic disulfides, DOX, and IO NPs by a dynamic covalent self-assembly (DCS) strategy, resulting in a stable codelivery nanosystem with high drug loading efficiency of 37.36%. More importantly, disulfide macrocycles in the codelivery system could be reduced and broken by glutathione (GSH) in tumor cells, thus leading to disassembly of nanostructures and intellgent release of drugs. These stimuli-responsive performances have been investigated via morphologies and molecular structures, revealing greatly enhanced dual-modal MRI abilities and smart drug release under the trigger of GSH. Moreover, the codelivery system conjugated with a targeting molecule of cyclic Arg-Gly-Asp (cRGD) exhibited significant biocompatibility, MR imaging, and chemotherapeutic anticancer effect in vitro and in vivo. These results indicated that in situ dynamic covalent chemistry enhanced the control over co-self-assembly and paved the way to develop more potential drug delivery systems.


Assuntos
Antineoplásicos , Nanopartículas , Neoplasias , Humanos , Dissulfetos/química , Nanopartículas/química , Antineoplásicos/química , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Doxorrubicina/química , Sistemas de Liberação de Medicamentos/métodos , Imageamento por Ressonância Magnética , Glutationa , Meios de Contraste/uso terapêutico
15.
Redox Biol ; 65: 102832, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37536083

RESUMO

Redox modifications of specific cysteinyl and methionyl residues regulate key enzymes and signal-transducing proteins in various pathways. Here, we analyzed the effect of redox modifications on protein structure screening the RCSB protein data bank for oxidative modifications of proteins, i.e. protein disulfides, mixed disulfides with glutathione, cysteinyl sulfenic acids, cysteinyl S-nitrosylation, and methionyl sulfoxide residues. When available, these structures were compared to the structures of the same proteins in the reduced state with respect to both pre-requirements for the oxidative modifications as well as the structural consequences of the modifications. In general, the conformational changes induced by the redox modification are small, i.e. within the range of normal fluctuations. Some redox modifications, disulfides in particular, induces alterations in the electrostatic properties of the proteins. Solvent accessibility does not seem to be a strict pre-requirement for the redox modification of a particular residue. We identified an enrichment of certain other amino acid residues in the vicinity of the susceptible residues, for disulfide and sulfenic acid modifications, for instance, histidyl and tyrosyl residues. These motifs, as well as the specific features of the susceptible sulfur-containing amino acids, may become helpful for the prediction of redox modifications.


Assuntos
Glutationa , Fatores de Transcrição , Oxirredução , Fatores de Transcrição/metabolismo , Glutationa/metabolismo , Dissulfetos/metabolismo , Cisteína/metabolismo
16.
Clin Psychopharmacol Neurosci ; 21(3): 572-582, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37424424

RESUMO

Objective: This study aimed to investigate the blood serum levels of biomarkers specifying oxidative stress status and systemic inflammation between people using methamphetamine (METH) and the control group (CG). Serum thiol/disulfide balance and ischemia-modified albumin levels were studied to determine oxidative stress, and serum interleukin-6 (IL-6) levels and complete blood count (CBC) were to assess inflammation. Methods: Fifty patients with METH use disorder (MUD) and 36 CG participants were included in the study. Two tubes of venous blood samples were taken to measure oxidative stress, serum thiol/disulfide balance, ischemia-modified albumin, and IL-6 levels between groups. The correlation of parameters measuring oxidative stress and inflammation between groups with sociodemographic data was investigated. Results: In this study, serum total thiol, free thiol levels, disulfide/native thiol percentage ratios, and serum ischemia- modified albumin levels of the patients were statistically significantly higher than the healthy controls. No difference was observed between the groups in serum disulfide levels and serum IL-6 levels. Considering the regression analysis, only the duration of substance use was a statistically significant factor in explaining serum IL-6 levels. The parameters showing inflammation in the CBC were significantly higher in the patients than in the CG. Conclusion: CBC can be used to evaluate systemic inflammation in patients with MUD. Parameters measuring thiol/disulfide homeostasis and ischemia-modified albumin can be, also, used to assess oxidative stress.

17.
Polymers (Basel) ; 15(14)2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37514489

RESUMO

Disulfide bonds are dynamic covalent bonds, which are easy to cleave and reform upon chemical stimulus. Various methods including the oxidative coupling of thiols and polymerization of disulfide-containing monomers have been developed for the synthesis of poly(disulfide)s. However, installing small amounts of disulfide units in the main chain of polyolefins has received much less attention. Herein, we report a novel strategy for incorporating cleavable disulfide units into the backbone of polyolefins using commercially available diallyl disulfide (DADS) as a comonomer via metathesis copolymerization. The copolymerization of diallyl disulfide with cyclooctene occurred using the second-generation Grubbs catalyst under mild conditions, allowing for the synthesis of copolymers with adjustable disulfide content ranging from 0.7 to 8.5 mol%, and the molecular weight of the obtained copolymers ranged from 5.8 kg·mol-1 to 42.8 kg·mol-1. The resulting polyolefins with disulfide insertion retained excellent thermal processability and exhibited degradability. Treatment of the copolymer (8.5 mol% disulfide content) with tri-n-butylphosphine resulted in a significant reduction in molecular weight from 5.8 kg·mol-1 to 1.6 kg·mol-1. Successful copolymerization with diallyl disulfide provides a convenient and effective method for obtaining degradable polyolefins.

18.
Front Pharmacol ; 14: 1185004, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37266150

RESUMO

Background: Severe acute respiratory syndrome coronavirus (SARS-CoVs) have emerged as a global health threat, which had caused a high rate of mortality. There is an urgent need to find effective drugs against these viruses. Objective: This study aims to predict the activity of unsymmetrical aromatic disulfides by constructing a QSAR model, and to design new compounds according to the structural and physicochemical attributes responsible for higher activity towards SARS-CoVs main protease. Methods: All molecules were constructed in ChemOffice software and molecular descriptors were calculated by CODESSA software. A regression-based linear heuristic method was established by changing descriptors datasets and calculating predicted IC50 values of compounds. Then, some new compounds were designed according to molecular descriptors from the heuristic method model. The compounds with predicted values smaller than a set point were constantly screened out. Finally, the properties analysis and molecular docking were conducted to further understand the structure-activity relationships of these finalized compounds. Results: The heuristic method explored the various descriptors responsible for bioactivity and gained the best linear model with R2 0.87. The success of the model fully passed the testing set validation, proving that the model has both high statistical significance and excellent predictive ability. A total of 5 compounds with ideal predicted IC50 were found from the 96 newly designed derivatives and their properties analyze was carried out. Molecular docking experiments were conducted for the optimal compound 31a, which has the best compound activity with good target protein binding capability. Conclusion: The heuristic method was quite reliable for predicting IC50 values of unsymmetrical aromatic disulfides. The present research provides meaningful guidance for further exploration of the highly active inhibitors for SARS-CoVs.

19.
Angew Chem Int Ed Engl ; 62(28): e202304252, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-37157140

RESUMO

The transannular disulfide functions as a key structural element imparting diverse biological activities to epidithiodiketopiperazines (ETPs). Although mechanisms were proposed in previous studies, α,ß'-disulfide formation in ETPs is not well-determined owing to the failure to identify the hypothetical intermediate. Herein, we characterize the key ortho-quinone methide (o-QM) intermediate and prove its involvement in the carbon-sulfur migration from an α,α'- to an α,ß'-disulfide by elucidating pretrichodermamide A biosynthesis, which is catalyzed by a FAD-dependent thioredoxin oxygenase TdaE harboring a noncanonical CXXQ motif. Biochemical investigations of recombinant TdaE and mutants demonstrated that the construction of the α,ß'-disulfide was initiated by Gln140 triggering proton abstraction for generation of the essential o-QM intermediate, accompanied by ß'-acetoxy elimination. Subsequent attack on the α,α'-disulfide by Cys137 led to disulfide migration and spirofuran formation. This study expands the biocatalytic toolbox for transannular disulfide formation and sets the stage for the targeted discovery of bioactive ETPs.


Assuntos
Dissulfetos , Indolquinonas , Indolquinonas/química
20.
Angew Chem Int Ed Engl ; 62(23): e202303170, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37005223

RESUMO

A method for automated solid-phase synthesis of oligo(disulfide)s was developed. It is based on a synthetic cycle comprising removal of a protecting group from a resin-bound thiol followed by treatment with monomers containing a thiosulfonate as an activated precursor. For ease of purification and characterization, the disulfide oligomers were synthesized as extensions of oligonucleotides on an automated oligonucleotide synthesizer. Six different dithiol monomer building blocks were synthesized. Sequence-defined oligomers of up to seven disulfide units were synthesized and purified. The sequence of the oligomer was confirmed by tandem MS/MS analysis. One of the monomers contains a coumarin cargo that can be released by a thiol-mediated release mechanism. When the monomer was incorporated into an oligo(disulfide) and subjected to reducing conditions, the cargo was released under near-physiological conditions, which underlines the potential use of these molecules in drug delivery systems.


Assuntos
Dissulfetos , Espectrometria de Massas em Tandem , Técnicas de Síntese em Fase Sólida/métodos , Compostos de Sulfidrila
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