RESUMO
To unlock the potential of indigenous non-Saccharomyces cerevisiae and develop novel starters to enhance the aromatic complexity of kiwifruit wine, Zygosaccharomyces rouxii, Pichia kudriavzevii and Meyerozyma guilliermondii were pairwise combined and then used in sequential fermentation with Saccharomyces cerevisiae. The impact of different starter cultures on the chemical composition and flavor profile of the kiwifruit wines was comprehensively analyzed, and the aroma evolution during alcoholic fermentation was investigated by examining the changes in key volatiles and their loss rates. Compared with Saccharomyces cerevisiae, mixed starter cultures not only improve antioxidant capacity but also increase esters and alcohols yields, presenting intense floral and fruity aromas with high sensory acceptability. The results indicated that sequential inoculation of non-Saccharomyces cerevisiae combination and Saccharomyces cerevisiae promoted the development of volatiles while maintaining the stability of key aroma compounds in the winemaking environment and reducing the aroma loss rates during alcoholic fermentation.
RESUMO
Late-stage specific and selective diversifications of peptides and proteins performed at target residues under ambient conditions are recognized to be the most facile route to various and abundant conjugates. Herein, we report an orthogonal modification of cysteine residues using alkyl thianthreium salts, which proceeds with excellent chemoselectivity and compatibility under mild conditions, introducing a diverse array of functional structures. Crucially, multifaceted bioconjugation is achieved through clickable handles to incorporate structurally diverse functional molecules. This "two steps, one pot" bioconjugation method is successfully applied to label bovine serum albumin. Therefore, our technique is a versatile and powerful tool for late-stage orthogonal bioconjugation.
Assuntos
Cisteína , Peptídeos , Soroalbumina Bovina , Cisteína/química , Peptídeos/química , Soroalbumina Bovina/química , Sais/química , Química Click/métodos , Animais , Proteínas/química , BovinosRESUMO
To further explore strain potential and develop an aromatic kiwifruit wine fermentation technique, the feasibility of simultaneous inoculation by non-Saccharomyces yeast and lactic acid bacteria was investigated. Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, and Limosilactobacillus fermentum, which have robust ß-glucosidase activity as well as good acid and ethanol tolerance, were inoculated for simultaneous fermentation with Zygosaccharomyces rouxii and Meyerozyma guilliermondii, respectively. Subsequently, the chemical compositions and sensory characteristics of the wines were comprehensively evaluated. The results showed that the majority of the simultaneous protocols effectively improved the quality of kiwifruit wines, increasing the content of polyphenols and volatile compounds, thereby enhancing sensory acceptability compared to the fermentation protocols inoculated with non-Saccharomyces yeast individually. Particularly, the collaboration between Lacp. plantarum and Z. rouxii significantly increased the diversity and content of esters, alcohols, and ketones, intensifying floral and seeded fruit odors, and achieving the highest overall acceptability. This study highlights the potential significance of simultaneous inoculation in kiwifruit wine production.
Assuntos
Actinidia , Fermentação , Frutas , Odorantes , Paladar , Compostos Orgânicos Voláteis , Vinho , Actinidia/microbiologia , Vinho/microbiologia , Vinho/análise , Frutas/microbiologia , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/análise , Odorantes/análise , Humanos , Polifenóis/metabolismo , Polifenóis/análise , Lactobacillales/metabolismo , Leveduras/metabolismo , Zygosaccharomyces/metabolismo , Zygosaccharomyces/crescimento & desenvolvimentoRESUMO
Late-stage modification of peptides could potentially endow peptides with significant bioactivity and physicochemical properties, and thereby provide novel opportunities for peptide pharmaceutical studies. Since tryptophan (Trp) bears a unique indole ring residue and plays various critical functional roles in peptides, the modification methods for tryptophan were preliminarily developed with considerable progress via transition-metal mediated C-H activation. Herein, we report an unprecedented tertiary amine catalyzed peptide allylation via the SN2'-SN2' pathway between the N1 position of the indole ring of Trp and Morita-Baylis-Hillman (MBH) carbonates. Using this method that proceeds under mild conditions, we demonstrated an extremely broad scope of Trp-containing peptides and MBH carbonates to prepare a series of peptide conjugates and cyclic peptides. The reaction is amenable to either solid-phase (on resin) or solution-phase conditions. In addition, the modified peptides can be further conjugated with other biomolecules at Trp, providing a new handle for bioconjugation.
RESUMO
A method for introducing a range of phosphonates into oligopeptides through a Michael addition reaction between dehydroalanine and phosphite is presented. The method offers a mild, cheap, and straightforward approach to peptide phosphorylation that has potential applications in chemical biology and medicinal chemistry. Moreover, the introduction of a phosphonate group into short antibacterial peptides is described to demonstrate its utility, leading to the discovery of phosphonated antibacterial peptides with potent broad-spectrum antibacterial activity.
Assuntos
Alanina , Antibacterianos , Oligopeptídeos , Organofosfonatos , Fosfitos , Organofosfonatos/química , Organofosfonatos/síntese química , Oligopeptídeos/química , Fosfitos/química , Estrutura Molecular , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/síntese química , Alanina/química , Alanina/análogos & derivados , Testes de Sensibilidade Microbiana , FosforilaçãoRESUMO
Antimicrobial peptides (AMPs), which have a low probability of developing resistance, are considered the most promising antimicrobial agents for combating antibiotic resistance. Feleucin-K3 is an amphiphilic cationic AMP that exhibits broad-spectrum antimicrobial activity. In our previous research, the first phenylalanine residue was identified as the critical position affecting its biological activity. Here, a series of Feleucin-K3 analogs containing hydrophobic D-amino acids were developed, leveraging the low sensitivity of proteases to unnatural amino acids and the regulatory effect of hydrophobicity on antimicrobial activity. Among them, K-1dF, which replaced the phenylalanine of Feleucin-K3 with its enantiomer (D-phenylalanine), exhibited potent antimicrobial activity with a therapeutic index of 46.97 and MICs between 4 to 8 µg/ml against both sensitive and multidrug-resistant Acinetobacter baumannii. The introduction of D-phenylalanine increased the salt tolerance and serum stability of Feleucin-K3. Moreover, K-1dF displayed a rapid bactericidal effect, a low propensity to develop resistance, and a synergistic effect when combined with antibiotics. More importantly, it exhibited considerable or superior efficacy to imipenem against pneumonia and skin abscess infection. In brief, the K-1dF obtained by simple and effective modification strategy has emerged as a promising candidate antimicrobial agent for tackling multidrug-resistant Acinetobacter baumannii infections.
Assuntos
Acinetobacter baumannii , Antibacterianos , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Acinetobacter baumannii/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/fisiologia , Animais , Antibacterianos/farmacologia , Antibacterianos/administração & dosagem , Substituição de Aminoácidos , Camundongos , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/química , Peptídeos Antimicrobianos/administração & dosagem , Estabilidade de Medicamentos , FemininoRESUMO
Peptide and protein postmodification have gained significant attention due to their extensive impact on biomolecule engineering and drug discovery, of which cysteine-specific modification strategies are prominent due to their inherent nucleophilicity and low abundance. Herein, the study introduces a novel approach utilizing multifunctional 5-substituted 1,2,3-triazine derivatives to achieve multifaceted bioconjugation targeting cysteine-containing peptides and proteins. On the one hand, this represents an inaugural instance of employing 1,2,3-triazine in biomolecular-specific modification within a physiological solution. On the other hand, as a powerful combination of precision modification and biorthogonality, this strategy allows for the one-pot dual-orthogonal functionalization of biomolecules utilizing the aldehyde group generated simultaneously. 1,2,3-Triazine derivatives with diverse functional groups allow conjugation to peptides or proteins, while bi-triazines enable peptide cyclization and dimerization. The examination of the stability of bi-triazines revealed their potential for reversible peptide modification. This work establishes a comprehensive platform for identifying cysteine-selective modifications, providing new avenues for peptide-based drug development, protein bioconjugation, and chemical biology research.
Assuntos
Cisteína , Peptídeos , Proteínas , Triazinas , Cisteína/química , Triazinas/química , Peptídeos/química , Proteínas/químicaRESUMO
The emergence and increasing prevalence of multidrug-resistant (MDR) bacteria have posed an urgent demand for novel antibacterial drugs. Currently, antimicrobial peptides (AMPs), potential novel antimicrobial agents with rare antimicrobial resistance, represent an available strategy to combat MDR bacterial infections but suffer the limitation of protease degradation. In this study, we developed a highly effective method for optimizing the stability of AMPs by introducing fluorinated sulfono-γ-AApeptides, and successfully synthesized novel Feleucin-K3-analogs. The results demonstrated that the incorporation of fluorinated sulfono-γ-AA into Feleucin-K3 effectively improved stability and afforded optimal peptides, such as CF3-K11, which exhibited 8-9 times longer half-lives than Feleucin-K3. Moreover, CF3-K11 displayed potent antimicrobial activity against clinically isolated Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), excellent biosafety, low resistance propensity, and possessed powerful antimicrobial efficacy for both local skin infection and pneumonia infection. The optimal CF3-K11 exhibited strong therapeutic potential and offered a superior approach for treating MDR bacterial infections.
Assuntos
Anti-Infecciosos , Staphylococcus aureus Resistente à Meticilina , Infecções por Pseudomonas , Humanos , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções por Pseudomonas/tratamento farmacológico , Testes de Sensibilidade MicrobianaRESUMO
To explore the diversity and fermentation potential of non-Saccharomyces cerevisiae associated with kiwifruit, indigenous yeasts isolated from kiwifruit and natural fermentation were comprehensively analyzed. A total of 166 indigenous yeasts were isolated, of which 54 representative strains were used for subsequent enzyme activity characterization. Different colorimetric methods were used to verify the ability of these strains to secrete hydrolytic enzymes, and then six strains were selected for sequential fermentation by specific activity assay. The performance of indigenous yeasts in improving organic acids, polyphenols, volatile compounds and sensory characteristics of wines was evaluated holistically. Results indicated that most sequential fermentations exhibited significant improvements in vitamin C and polyphenols. Remarkably, the involvement of Zygosaccharomyces rouxii, Meyerozyma guilliermondii, and Pichia kudriavzevii increased the concentrations of ethyl esters, acetates and alcohols, enhancing floral and tropical fruit odors and ultimately achieving the highest overall sensory acceptability, thereby highlighting their potential in kiwifruit wine fermentation.
Assuntos
Vitis , Vinho , Vinho/análise , Leveduras , Álcoois , Acetatos/análise , Fermentação , Odorantes/análise , PolifenóisRESUMO
A visible-light mediated deoxygenative radical addition of carboxylic acids to dehydroalanines has been disclosed. The method can be used in ß-acyl alanine derivative synthesis, including those chiral and deuterated variants, and late-stage peptide modification with various functional groups, both in the homogeneous phase and on the resin in SPPS. It provides a new tool kit for rapid construction of bioactive peptide analogues, which has been demonstrated by modification of the antimicrobial peptide Feleucin-K3.
Assuntos
Ácidos Carboxílicos , Peptídeos , Alanina , Fotoquímica/métodosRESUMO
A photo and Cu-mediated radical-radical approach enabling the one-step synthesis of the phthalideisoquinoline skeleton has been reported. Under mild reaction conditions, a series of N-aryl phthalideisoquinolines containing various substituents were synthesized in moderate to good yields. Bioactivity data demonstrated that a new compound 4x can efficiently inhibit the growth of multiple tumor cell lines with enhancements of more than 10-fold by significantly increasing G2/M arrest compared with noscapine.
Assuntos
Antineoplásicos , Noscapina , Antineoplásicos/farmacologia , Noscapina/farmacologia , Linhagem Celular TumoralRESUMO
Innovations in synthetic chemistry have a profound impact on the drug discovery process, and will always be a necessary driver of drug development. As a result, it is of significance to develop novel simple and effective synthetic installation of medicinal modules to promote drug discovery. Herein, we have developed a NaClO-mediated cross installation of indoles and azoles, both of which are frequently encountered in drugs and natural products. This effective toolbox provides a convenient synthetic route to access a library of N-linked 2-(azol-1-yl) indole derivatives, and can be used for late-stage modification of drugs, natural products and peptides. Moreover, biological screening of the library has revealed that several adducts showed promising anticancer activities against A549 and NCI-H1975 cells, which give us a hit for anticancer drug discovery.
Assuntos
Azóis , Produtos Biológicos , Indóis , Descoberta de DrogasRESUMO
The prevalence of multidrug-resistant bacterial infections has led to dramatically increased morbidity and mortality. Antimicrobial peptides (AMPs) have great potential as new therapeutic agents to reverse this dangerous trend. Herein, a series of novel AMP Feleucin-K3 analogues modified with unnatural peptidomimetic sulfono-γ-AA building blocks were designed and synthesized. The structure-activity, structure-toxicity, and structure-stability relationships were investigated to discover the optimal antimicrobial candidates. Among them, K122 exhibited potent and broad-spectrum antimicrobial activity and high selectivity. K122 had a rapid bactericidal effect and a low tendency to induce resistance. Surprisingly, K122 showed excellent effectiveness against bacterial pneumonia. For biofilm and local skin infections, K122 significantly decreased the bacterial load and improved tissue injury at a dose of only 0.25 mg/kg, which was 160 times lower than the concentration deemed to be safe for local dermal applications. In summary, K122 is an outstanding candidate for the treatment of multidrug-resistant bacteria and biofilm infections.
Assuntos
Anti-Infecciosos , Staphylococcus aureus Resistente à Meticilina , Pseudomonas aeruginosa , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
We have developed a method of introducing biological oxime ether fragments into peptides by CuI-catalyzed late-stage modification and functionalization of peptides, utilizing their acid moiety and varied 2H-azirines. As a result of its mild conditions, high atom economy, moderate yield, and excellent functional-group tolerance, the method can provide access to late-stage peptide modification and functionalization at their acid sites both in the homogeneous phase and on resins in SPPS, providing a new tool kit for peptide functionalization, diversification, and fluorescent labeling.
Assuntos
Cobre , Éteres , Ácidos Carboxílicos , Oximas , Peptídeos , CatáliseRESUMO
Herein, we explored an unprecedented mild, nonirritating, conveniently available, and recyclable coupling reagent NDTP, which could activate the carboxylic acids via acyl thiocyanide and enable the rapid amide and peptide synthesis at very mild conditions. In addition, the methodology was compatible with Fmoc-SPPS, which may provide an alternative to peptide manufacturing.
Assuntos
Amidas/síntese química , Peptídeos/síntese química , Amidas/química , Ácidos Carboxílicos/química , Estrutura Molecular , Peptídeos/química , Estereoisomerismo , Tiocianatos/químicaRESUMO
The dramatic increase in antimicrobial resistance (AMR) highlights an urgent need to develop new antimicrobial therapies. Thus, antimicrobial peptides (AMPs) have emerged as promising novel antibiotic alternatives. Feleucin-K3 is an amphiphilic α-helical nonapeptide that has powerful antimicrobial activity. In our previous study, it was found that the fourth residue of Feleucin-K3 is important for antimicrobial activity. After α-(4-pentenyl)-Ala was introduced into this position, both the antimicrobial activity and stability were greatly improved. Herein, to improve the limitations of Feleucin-K3, this unnatural amino acid was further introduced into different positions of Feleucin-K3. Among these synthetic Feleucin-K3 analogs, the N-terminal-substituted analog Feleucin-K65 (K65) and C-terminal-substituted analog Feleucin-K70 (K70) had preferable antimicrobial activity. In particular, their antimicrobial activities against multidrug-resistant bacteria were more potent than that of antibiotics. The stabilities of these peptides in salt and serum environments were improved compared with those of Feleucin-K3. In addition, these analogs had low hemolytic activity and AMR. More importantly, they effectively inhibited biofilm formation and exhibited considerable efficacy compared with traditional antibiotics against biofilm infection caused by methicillin-resistant Staphylococcus aureus (MRSA). In antimicrobial mechanism studies, K65 and K70 mainly permeated the outer membrane and depolarized the cytoplasmic membrane, resulting in cellular component leakage and cell death. In summary, analogs K65 and K70 are potential antimicrobial alternatives to solve the antibiotic crisis.
Assuntos
Antibacterianos/administração & dosagem , Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Biofilmes/crescimento & desenvolvimento , Staphylococcus aureus Resistente à Meticilina/fisiologia , Infecções Estafilocócicas/tratamento farmacológico , Alanina/química , Animais , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/síntese química , Peptídeos Catiônicos Antimicrobianos/química , Biofilmes/efeitos dos fármacos , Estabilidade de Medicamentos , Feminino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Secundária de Proteína , Sais/química , Soro/químicaRESUMO
The development of antimicrobial compounds is now regarded as an urgent problem. Antimicrobial peptides (AMPs) have great potential to become novel antimicrobial drugs. Feleucin-K3 is an α-helical cationic AMP isolated from the skin secretion of the Asian bombinid toad species Bombina orientalis and has antimicrobial activity. In our previous studies, amino acid scanning of Feleucin-K3 was performed to determine the key site affecting its activity. In this study, we investigated and synthesized a series of analogues that have either a natural or an unnatural hydrophobic amino acid substitution at the fourth amino acid residue of Feleucin-K3. Among these analogues, Feleucin-K59 (K59), which has an α-(4-pentenyl)-Ala substitution, was shown to have increased antimicrobial activity against both standard and drug-resistant strains of clinical common bacteria, improved stability, no hemolytic activity at antimicrobial concentrations, and no resistance. In addition, K59 has potent antibiofilm activity in vitro. More importantly, K59 showed better antimicrobial and antibiofilm activities against drug-resistant bacteria in in vivo experiments in mice than traditional antibiotics. In this preliminary study of the mechanism of action, we found that K59 could rapidly kill bacteria by a dual-action mechanism of disrupting the cell membrane and binding to intracellular DNA, thus making it difficult for bacteria to develop resistance.
Assuntos
Anti-Infecciosos , Peptídeos Catiônicos Antimicrobianos , Animais , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Biofilmes , Camundongos , Testes de Sensibilidade MicrobianaRESUMO
A non-catalytic, mild, and easy-to-handle protecting group switched 1,3-dipolar cycloaddition (1,3-DC) between bi- or mono-N-protected Dha and C,N-cyclic azomethine imines, which afford various quaternary amino acids with diverse scaffolds, is disclosed. Specifically, normal-electron-demand 1,3-DC reaction occurs between bi-N-protected Dha and C,N-cyclic azomethine imines, while inverse-electron-demand 1,3-DC reaction occurs between mono-N-protected Dha and C,N-cyclic azomethine imines. Above all, the reactions can be carried out between peptides with Dha residues at the position of interest and C,N-cyclic azomethine imines, both in homogeneous phase and on resins in SPPS. It provides a new toolkit for late-stage peptide modification, labeling, and peptide-drug conjugation. To shed light on the high regioselectivity of the reaction, DFT calculations were carried out, which were qualitatively consistent with the experimental observations.
RESUMO
A direct enantioselective N1 aminoalkylation of 3-substituted indoles is efficiently catalyzed by a phosphoric acid catalyst under mild conditions to afford diverse enantioenriched propargyl aminals. The strategy could be applied to the modification of tryptophan containing oligopeptides. Additionally, structurally diverse and multifunctional transformations of the propargyl aminal products reveal the potential synthetic utility of this protocol.
RESUMO
Novel 10π-electron cyclic amidines with excellent fluorescence properties were synthesized by a general and efficient 6π-electrocyclic ring closure of ketenimine and imine starting from N-sulfonyl triazoles and arylamines. The photophysical properties of cyclic amidine fluorophores have been studied in detail and have shown good properties of a large Stokes shift, pH insensitivity, low cytotoxicity and higher photostability, which have great potential for biological imaging. Furthermore, this novel fluorophore was successfully applied to the localization of the NK-1 receptor in living systems.