RESUMO
The disrupted oxidative redox homeostasis plays a critical role in the progress of ulcerative colitis (UC). Herein, hydrogel-forming viscous liquid (HSD) composed of cysteamine-grafted hyaluronic acid (HS) and superoxide dismutase (SOD) has been designed for UC. When the viscous HSD liquid was infused into colitis colon, SOD would convert the pathological superoxide (O2·-) to hydrogen peroxides (H2O2), which was subsequently scavenged by HS. Accordingly, the sol-gel transition of HSD was initiated by scavenging H2O2, enhancing its adhesion toward colitis colon. H2O2-treated HSD presented the higher storage modulus and stronger adhesion force toward porcine colon than the untreated HSD. Besides, H2O2-treated HSD presented the slower erosion profile in the colitis-mimicking medium (pH 3-5), while its rapid degradation was displayed in physiologic condition (pH7.4). The combination of pH-resistant erosion and ROS-responsive adhesion for HSD rendered it with the specifical retention on the inflamed colonic mucosa of DSS-induced colitis mice. Rectally administrating HSD could effectively hinder the body weight loss, reduce the disease activity index and improve the colonic shorting of DSS-induced colitis mice. Moreover, the pro-inflammatory cytokines (IL-1ß, IL-6 and TNF-α) were substantially decreased, the colonic epitheliums were well rearranged and the tight junction proteins were greatly recovered after HSD treatment. Besides, HSD also modulated the gut flora, markedly augmenting the abundance of Firmicutes, Barnesiella and Lachnospiraceae. Moreover, HSD treatment could regulate oxidative redox homeostasis via activating Nrf2-HO-1 pathway to reduce ROS and malondialdehyde and upregulate antioxidant enzymes (SOD, GPx and GSH). Collectively, HSD might be a promising therapy for UC treatments. STATEMENT OF SIGNIFICANCE: Herein, a hydrogel-forming viscous liquid (HSD) was designed by cysteamine-grafted hyaluronic acid (HS) and superoxide dismutase (SOD) for UC treatments. When the viscous HSD liquid was infused into a colitis colon, SOD would convert the pathological superoxide to hydrogen peroxides (H2O2), which was subsequently scavenged by HS. Accordingly, the sol-gel transition of HSD was initiated by scavenging H2O2, enhancing its adhesion to the colitis colon. The colonic epitheliums of DSS-induced colitis mice were well rearranged and the tight junction proteins (Zonula-1 and Claudin-5) were greatly recovered after the HSD treatment. Moreover, the HSD treatment could regulate oxidative redox homeostasis via activating the Nrf2-HO-1 pathway to reduce ROS and malondialdehyde and upregulate antioxidant enzymes (SOD, GPx and GSH).
Assuntos
Colite , Homeostase , Mucosa Intestinal , Oxirredução , Animais , Homeostase/efeitos dos fármacos , Colite/tratamento farmacológico , Colite/patologia , Colite/induzido quimicamente , Colite/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Hidrogéis/química , Hidrogéis/farmacologia , Camundongos Endogâmicos C57BL , Colo/patologia , Colo/efeitos dos fármacos , Colo/metabolismo , Viscosidade , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Cisteamina/farmacologia , Cisteamina/química , Superóxido Dismutase/metabolismo , Masculino , Peróxido de Hidrogênio , Citocinas/metabolismo , Sulfato de DextranaRESUMO
Metal nanoclusters (NCs) as a new kind of luminophore have acquired sufficient interest, but their widespread application is restricted on account of their relatively low electrochemiluminescence (ECL) efficiency. Then, aqueous metal NCs with high ECL efficiency were strongly anticipated, especially for the ultrasensitive analysis of biomarkers. Herein, a near-infrared (NIR) ECL biosensing strategy for the test of neuron-specific enolase (NSE) was proposed by utilizing N-acetyl-l-cysteine (NAC)- and cysteamine (Cys)-stabilized gold NCs (NAC/Cys-AuNCs) as ECL emitters with the NIR ECL emission around 860 nm and a metal-organic framework/palladium nanocubes (ZIF-67/PdNCs) hybrid as the coreaction accelerator through their admirable electrocatalytic activity. The NIR emission would reduce photochemical injury to the samples and even realize nondestructive analysis with highly strong susceptibility and suitability. Furthermore, the utilization of ZIF-67/PdNCs could improve the ECL response of NAC/Cys-AuNCs by facilitating the oxidation of the coreactant triethylamine (TEA), leading to the production of a larger quantity of reducing intermediate radical TEAâ¢+. Consequently, NAC/Cys-AuNCs with ZIF-67/PdNCs displayed 2.7 fold enhanced ECL emission compared with the single NAC/Cys-AuNCs using TEA as the coreactant. In addition, HWRGWVC (HWR), a heptapeptide, was introduced to immobilize antibodies for the specially binding Fc fragment of the antibodies, which improved the binding efficiency and sensitivity. As a result, a "signal-on" immunosensor for NSE analysis was obtained with an extensive linear range of 0.1 to 5 ng/mL and a low limit of detection (0.033 fg/mL) (S/N = 3). This study provides a wonderful method for the development of an efficient nondestructive immunoassay.
Assuntos
Biomarcadores , Técnicas Eletroquímicas , Ouro , Medições Luminescentes , Nanopartículas Metálicas , Estruturas Metalorgânicas , Ouro/química , Estruturas Metalorgânicas/química , Nanopartículas Metálicas/química , Imunoensaio/métodos , Técnicas Eletroquímicas/métodos , Biomarcadores/análise , Cobalto/química , Humanos , Fosfopiruvato Hidratase/análise , Limite de Detecção , Cisteamina/química , Paládio/química , Raios Infravermelhos , Técnicas Biossensoriais/métodosRESUMO
A cysteamine functionalized nanodiamond (NDC) was conjugated to gold nanoparticles (AuNPs) to deliver NDC@AuNPs and utilized in enhanced colorimetric detection of Cr3+ at pH 6 environment. The conjugation was validated using FTIR, TEM, PXRD, DLS, and zeta potential investigations. At pH 6, superior sensory response of NDC@AuNPs to Cr3+ than that of other ions was validated by UV-vis spectroscopy and colorimetric photographs. Results from UV-vis titrations displayed a linear regression from 0.01 to 0.4 µM with a LOD of 0.236 ± 0.005 nM. The particle aggregation, size variations, potential changes, and binding modes are investigated using TEM, DLS, and FTIR techniques to explore the underlying mechanisms. By adding the EDTA, sensory response is reversible up to 4 cycles. Finally, spiked real water experiments show improved sensing of Cr3+ at pH 6 via the observed recovery between 96 and 110 %, which is in good agreement with the ICP-mass data.
Assuntos
Nanopartículas Metálicas , Nanodiamantes , Ouro/química , Colorimetria/métodos , Cisteamina/química , Nanopartículas Metálicas/química , Íons , Água , Concentração de Íons de HidrogênioRESUMO
Currently, several biosensors are reported to confirm the absence/presence of an abnormal level of specific human biomarkers in research laboratories. Unfortunately, public marketing and/or pharmacy accessibility are not yet possible for many bodily fluid biomarkers. The questions are numerous, starting from the preparation of the substrates, the wet/dry form of recognizing the (bio)ligands, the exposure time, and the choice of the running buffers. In this context, for the first time, the present overview summarizes the pre-functionalization of standard and nanostructured solid/flexible supports with cysteamine (Cys) and glutaraldehyde (GA) chemicals for robust protein immobilization and detection of biomarkers in body fluids (serum, saliva, and urine) using three transductions: piezoelectrical, electrochemical, and optical, respectively. Thus, the reader can easily access and compare step-by-step conjugate protocols published over the past 10 years. In conclusion, Cys/GA chemistry seems widely used for electrochemical sensing applications with different types of recorded signals, either current, potential, or impedance. On the other hand, piezoelectric detection via quartz crystal microbalance (QCM) and optical detection by surface plasmon resonance (LSPR)/surface-enhanced Raman spectroscopy (SERS) are ultrasensitive platforms and very good candidates for the miniaturization of medical devices in the near future.
Assuntos
Técnicas Biossensoriais , Cisteamina , Biomarcadores , Técnicas Biossensoriais/métodos , Cisteamina/química , Glutaral , Humanos , Técnicas de Microbalança de Cristal de Quartzo , Ressonância de Plasmônio de SuperfícieRESUMO
The objective of the investigation was to determine the ocular biodistribution of cysteamine, a reducing agent used for treatment of cystine crystals in cystinosis, following topical administration of a sustained release formulation and traditional eyedrop formulation. To the right eye only, rabbits received a 50 µL drop of 0.44% cysteamine eyedrops at one drop per waking hour for 2, 6, 12, and 24 h. A second group received one 100 µL drop of a sustained release formulation containing encapsulated cysteamine microspheres suspended in a thermoresponsive gel. Upon serial sacrifice, ocular tissues from both eyes and plasma were obtained and quantified for cysteamine using LC-MS/MS. Cysteamine was detected in the cornea, aqueous humor and vitreous humor. Systemic plasma concentrations of cysteamine from treatment groups were below the limit of detection. As expected, 0.44% cysteamine eyedrops when administered hourly maintained drug concentrations within the cornea at a magnitude 5 times higher than a single dose of the sustained release formulation over 12 h. The sustained release formulation maintained cysteamine presentation across 12 h from a single drop. These studies demonstrate distribution of cysteamine to the eye following topical administration, including high drug uptake to the cornea and low systemic distribution.
Assuntos
Cisteamina , Cistinose , Animais , Cromatografia Líquida , Córnea , Cisteamina/química , Cistinose/tratamento farmacológico , Preparações de Ação Retardada/uso terapêutico , Microesferas , Soluções Oftálmicas , Coelhos , Espectrometria de Massas em Tandem , Distribuição TecidualRESUMO
In this study, a nanodrug carrier (mesoporous silica nanoparticle (MSN)-SS-cysteamine hydrochloride (CS)-hyaluronic acid (HA)) for targeted drug delivery was prepared using MSNs, in which HA was used as a targeting ligand and blocking agent to control drug release. Coumarin is a fluorescent molecule that targets mitochondria. Two conjugates (XDS-DJ and 5-FUA-4C-XDS) were synthesized by chemically coupling nitrogen mustard and 5-fluorouracil with coumarin, which was further loaded into MSN-SS-CS-HA nanocarriers. MTT analysis demonstrated that the nanocomposite MSN-SS-CS@5-FUA-4C-XDS/HA displayed stronger cytotoxicity toward HCT-116 cells than HeLa or QSG-7701 cells. Furthermore, MSN-SS-CS@5-FUA-4C-XDS/HA was able to target the mitochondria of HCT-116 cells, causing decreased mitochondrial membrane potential and excessive production of reactive oxygen species. These results indicate that MSN-SS-CS@5-FUA-4C-XDS/HA has the potential to be a nanodrug delivery system for the treatment of colon cancer.
Assuntos
Cumarínicos/síntese química , Cisteamina/química , Fluoruracila/química , Ácido Hialurônico/química , Mitocôndrias/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cumarínicos/química , Cumarínicos/farmacologia , Composição de Medicamentos , Células HCT116 , Células HeLa , Humanos , Mecloretamina/química , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Nanopartículas , Tamanho da Partícula , Porosidade , Espécies Reativas de Oxigênio/metabolismo , Dióxido de Silício , Nanomedicina TeranósticaRESUMO
Parkinson's disease (PD) is characterized mainly by the loss of dopaminergic neurons in the substantia nigra (SN) mediated via oxidative stress. Although glutaredoxin-1 (GLRX1) is known as one of the antioxidants involved in cell survival, the effects of GLRX1 on PD are still unclear. In this study, we investigated whether cell-permeable PEP-1-GLRX1 inhibits dopaminergic neuronal cell death induced by 1-methyl-4-phenylpyridinium (MPP+) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We showed that PEP-1-GLRX1 protects cell death and DNA damage in MPP+-exposed SH-SY5Y cells via the inhibition of MAPK, Akt, and NF-κB activation and the regulation of apoptosis-related protein expression. Furthermore, we found that PEP-1-GLRX1 was delivered to the SN via the blood-brain barrier (BBB) and reduced the loss of dopaminergic neurons in the MPTP-induced PD model. These results indicate that PEP-1-GLRX1 markedly inhibited the loss of dopaminergic neurons in MPP+- and MPTP-induced cytotoxicity, suggesting that this fusion protein may represent a novel therapeutic agent against PD.
Assuntos
Cisteamina/análogos & derivados , Neurônios Dopaminérgicos/citologia , Glutarredoxinas/administração & dosagem , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Doença de Parkinson/tratamento farmacológico , Peptídeos/química , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/efeitos adversos , 1-Metil-4-fenilpiridínio/efeitos adversos , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Cisteamina/química , Modelos Animais de Doenças , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Glutarredoxinas/química , Glutarredoxinas/farmacologia , Humanos , Masculino , Camundongos , Doença de Parkinson/etiologia , Doença de Parkinson/metabolismo , Substância Negra/químicaRESUMO
The complex pathogenesis of Alzheimer's disease (AD) calls for multi-target approach for disease treatment. Herein, based on the MTDLs strategy, a series of phthalimide-(N-alkylbenzylamine) cysteamide hybrids were designed, synthesized, and investigated in vitro for the purpose. Most of the target compounds were found to be potential multi-target agents. In vitro results showed that compound 9e was the representative compound in this series, endowed with high EeAChE and HuAChE inhibitory potency (IC50 = 1.55 µm and 2.23 µm, respectively), good inhibitory activity against self-induced Aß1-42 aggregation (36.08% at 25 µm), and moderate antioxidant capacity (ORAC-FL value was 0.68 Trolox equivalents). Molecular docking studies rationalized the binding mode of 9e in both PAS and CAS of AChE. Moreover, 9e displayed excellent ability to against H2 O2 -induced PC12 cell injury and penetrate BBB. Overall, these results highlighted that compound 9e was an effective and promising multi-target agent for further anti-AD drug development.
Assuntos
Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Antioxidantes/síntese química , Benzilaminas/química , Inibidores da Colinesterase/síntese química , Cisteamina/química , Fármacos Neuroprotetores/síntese química , Ftalimidas/química , Animais , Antioxidantes/farmacologia , Barreira Hematoencefálica/metabolismo , Desenho de Fármacos , Humanos , Simulação de Acoplamento Molecular , Fármacos Neuroprotetores/farmacologia , Células PC12 , Ligação Proteica , Ratos , Relação Estrutura-AtividadeRESUMO
In this study, we presented elective, sensitive, and rapid UV-Vis spectrophotometry and calorimetric assay for the recognition of digoxin. Therefore, cysteamine-gold nanoparticles (Cys A-AuNPs) in the presence of cysteine acid amine and Silver nanoparticles in the presence of tetramethyl benzidine and hydrogen peroxide (AgNPs-TMB [3,3',5,5'-tetramethylbenzidine]-H2 O2 ) were synthesized and utilized as the desired probe. Finally, color variation of probes was observed in the absence and presence of digoxin. Obtained results indicate that the color of Cys A-AuNPs changed from dark pink to light in the absence and the presence of digoxin, respectively. Also, the color of AgNPs-TMB-H2 O2 changed from dark blue to light blue, in the absence and the presence of digoxin, respectively. Moreover, UV-Vis spectroscopies results indicate digoxin with a low limit of quantification of 0.125 ppm in human plasma samples which linear range was 0.125 to 11 ppm.
Assuntos
Colorimetria/métodos , Digoxina/análise , Nanopartículas Metálicas/química , Espectrofotometria Ultravioleta/métodos , Benzidinas/química , Cisteamina/química , Digoxina/sangue , Digoxina/química , Ouro/química , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Sondas Moleculares/química , Sensibilidade e EspecificidadeRESUMO
α-Methylene-γ-lactones are present in â¼3% of known natural products, and compounds comprising this motif display a range of biological activities. However, this reactive lactone limits informed structure-activity relationships for these bioactive molecules. Herein, we describe chemically tuning the electrophilicity of the α-methylene-γ-lactone by replacement with an α-methylene-γ-lactam. Guaianolide analogues having α-methylene-γ-lactams are synthesized using the allenic Pauson-Khand reaction. Substitution of the lactam nitrogen with electronically different groups affords diverse thiol reactivity. Cellular NF-κB inhibition assays for these lactams were benchmarked against parthenolide and a synthetic α-methylene-γ-lactone showing a positive correlation between thiol reactivity and bioactivity. Cytotoxicity assays show good correlation at the outer limits of thiol reactivity but less so for compounds with intermediate reactivity. A La assay to detect reactive molecules by nuclear magnetic resonance and mass spectrometry peptide sequencing assays with the La antigen protein demonstrate that lactam analogues with muted nonspecific thiol reactivities constitute a better electrophile for rational chemical probe and therapeutic molecule design.
Assuntos
Cisteamina/química , Lactamas/farmacologia , Sesquiterpenos de Guaiano/farmacologia , Células A549 , Animais , Chlorocebus aethiops , Células HEK293 , Humanos , Lactamas/síntese química , Lactamas/toxicidade , NF-kappa B/metabolismo , Estudo de Prova de Conceito , Sesquiterpenos de Guaiano/síntese química , Sesquiterpenos de Guaiano/toxicidade , Transdução de Sinais/efeitos dos fármacos , Células VeroRESUMO
The carrot plant (Daucus carota) and its components are traditionally reported for the management of gastric ulcers. This study was performed to evaluate the role of carrot when administered concurrently with a conventional antiulcer treatment, pantoprazole, in alleviating gastric and duodenal ulcers in female experimental animals. The study involved standard animal models to determine the ulcer preventive effect using pylorus ligation, ethanol, and stress induced acute gastric ulcer models and duodenal ulcer models involving cysteamine. Acetic acid-induced chronic gastric ulcer and indomethacin-induced gastric ulcer models were used to evaluate the ulcer healing effect. Carrot fruit (500 mg/kg) and its co-administration with pantoprazole produced significant protection in an ethanol- and stress-induced acute gastric ulcer and cysteamine-induced duodenal ulcer. The healing of the acetic acid-induced chronic gastric ulcer was also augmented with this combination. Both total proteins and mucin contents were significantly increased in indomethacin-induced gastric ulcers. Similarly, in pylorus ligation, the pepsin content of gastric juice, total acidity, and free acidity were reduced. Overall, both ulcer preventive effects and ulcer healing properties of the pantoprazole were significantly enhanced in animals who received the co-administration of carrot fruit (500 mg/kg).
Assuntos
Antiulcerosos/administração & dosagem , Daucus carota/química , Indometacina/efeitos adversos , Pantoprazol/administração & dosagem , Preparações de Plantas/administração & dosagem , Piloro/efeitos dos fármacos , Ácido Acético/química , Animais , Antioxidantes/farmacologia , Compostos de Bifenilo/química , Cisteamina/química , Sinergismo Farmacológico , Etanol/química , Feminino , Sequestradores de Radicais Livres/química , Concentração Inibidora 50 , Pepsina A/química , Picratos/química , Ratos , Ratos WistarRESUMO
Human monoamine oxidases (MAOs) play important roles in maintaining the homeostasis of biogenic amines. One of its isoforms, monoamine oxidase B (MAOB), is thought to be involved in several neurodegenerative diseases, which make the selective detection of MAOB activity essential. In this work, a novel surface-enhanced Raman scattering (SERS) sensor was fabricated and the MAOB activity was specifically determined by detecting the SERS signals of an enzyme-catalyzed reaction product via an amine-aldehyde click reaction. This process was simply achieved by coating core-shell gold-silver nanoparticles (Au@Ag NPs) on 3-aminopropyl aminopropyl triethoxysilane (APTES)-modified glass, and then, a monolayer of cysteamine (CA) was attached to the nanoparticle surface as a linker through Ag-S bonds. Using phenethylamine (PA) as a specific substrate of MAOB, the enzyme product phenylacetaldehyde (PAA) will produce significant Raman signals via the amine-aldehyde click reaction with CA, while other molecules, such as MAOB and PA, have no signal output because they cannot form close interaction with nanoparticles due to the existence of a CA layer. This sensor was further used for the specific determination of MAOB activity in clinical blood samples and the MAOB inhibitor assessment successfully. Meanwhile, by changing the click reaction types and taking advantage of the SERS fingerprint peaks for the specific click reaction products, this strategy offers huge potential to detect multiple enzyme activities simultaneously and can be used for new click reaction screening, enzyme-related disease diagnosis, drug screening, and clinical diagnosis.
Assuntos
Monoaminoxidase/metabolismo , Análise Espectral Raman/métodos , Aldeídos/química , Aminas/química , Química Click , Cisteamina/química , Ouro/química , Humanos , Nanopartículas Metálicas/química , Prata/química , Propriedades de SuperfícieRESUMO
The mechanism of hair loss caused by aging is related to mitochondrial dysfunction. Pep-1-mediated mitochondrial transplantation is a potential therapeutic application for mitochondrial disorders, but its efficacy against hair aging remains unknown. This study compared platelet-rich plasma (PRP) therapy with mitochondrial transplantation for hair restoration and examined the related regulation in naturally aging mice. After dorsal hair removal, 100-week-old mice received weekly unilateral injections of 200 µg of allogeneic mitochondria-labeled 5-bromo-2'-deoxyuridine with (P-Mito) or without Pep-1 conjugation (Mito) or human PRP with a stamp-type electric injector for 1 month. The contralateral sides were used as corresponding sham controls. Compared with the control and corresponding sham groups, all treatments stimulated hair regrowth, and the effectiveness of P-Mito was equal to that of PRP. However, histology revealed that only P-Mito maintained hair length until day 28 and yielded more anagen follicles with abundant dermal collagen equivalent to that of the PRP group. Mitochondrial transplantation increased the thickness of subcutaneous fat compared with the control and PRP groups, and only P-Mito consistently increased mitochondria in the subcutaneous muscle and mitochondrial DNA copies in the skin layer. Therefore, P-Mito had a higher penetrating capacity than Mito did. Moreover, P-Mito treatment was as effective as PRP treatment in comprehensively reducing the expression of aging-associated gene markers, such as IGF1R and MRPS5, and increasing antiaging Klotho gene expression. This study validated the efficacy of mitochondrial therapy in the restoration of aging-related hair loss and demonstrated the distinct effects of PRP treatment.
Assuntos
Envelhecimento/fisiologia , Cabelo/crescimento & desenvolvimento , Mitocôndrias/transplante , Plasma Rico em Plaquetas , Transplante Autólogo/instrumentação , Transplante Autólogo/métodos , Envelhecimento/genética , Alopecia/fisiopatologia , Animais , Bromodesoxiuridina/farmacologia , Cisteamina/análogos & derivados , Cisteamina/química , Cisteamina/farmacologia , DNA Mitocondrial/biossíntese , DNA Mitocondrial/genética , Expressão Gênica , Glucuronidase/biossíntese , Glucuronidase/genética , Humanos , Proteínas Klotho , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Mitocondriais/biossíntese , Proteínas Mitocondriais/genética , Agulhas , Peptídeos/química , Peptídeos/farmacologia , Receptor IGF Tipo 1/biossíntese , Receptor IGF Tipo 1/genética , Proteínas Ribossômicas/biossíntese , Proteínas Ribossômicas/genéticaRESUMO
Herein, a novel strategy for in situ imaging and real-time monitoring of intracellular tissue transglutaminase (TG2) is presented based on aggregation-induced emission (AIE). It has high sensitivity and specificity, minimal background signal and can also effectively distinguish different cell types (drug-resistant cancer cells, cancer cells and normal cells).
Assuntos
Proteínas de Ligação ao GTP/análise , Microscopia Confocal , Transglutaminases/análise , Linhagem Celular , Cisteamina/química , Cisteamina/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Corantes Fluorescentes/química , Proteínas de Ligação ao GTP/antagonistas & inibidores , Proteínas de Ligação ao GTP/metabolismo , Humanos , Nanocompostos/química , Peptídeos/química , Peptídeos/metabolismo , Agregados Proteicos , Proteína 2 Glutamina gama-Glutamiltransferase , Transglutaminases/antagonistas & inibidores , Transglutaminases/metabolismoRESUMO
The thiolysis of B-type proanthocyanidins in cocoa by cysteamine was evaluated and optimized for its application in cocoa proanthocyanidin quantification. Four thiolysis products consisting of epicatechin, catechin, and their thioethers formed with cysteamine were separated and characterized by reversed-phase UPLC with photo diode array (PDA) detection and high-resolution mass spectrometry (HRMS). A thiolysis time of 20 min under 60 °C temperature was determined as the optimal condition for cocoa proanthocyanidin depolymerization. The optimized thiolysis condition was applied to four cocoa bean samples for proanthocyanidin quantification, using commercially available procyanidin B2 dimer as a reference standard. Satisfactory linearity and quantification and detection limits were achieved for the calibration curves, and proanthocyanidin contents determined by thiolysis were found to be higher than those determined by a published method based on normal-phase HPLC with fluorescence detection. Results in this study suggest promising application potential of cysteamine as an odorless thiolysis agent in routine quantitative analysis of B-type proanthocyanidins. Graphical abstract.
Assuntos
Cacau/química , Cromatografia de Fase Reversa/métodos , Proantocianidinas/análise , Biflavonoides/análise , Catequina/análise , Cromatografia Líquida de Alta Pressão/métodos , Cisteamina/química , Extratos Vegetais/químicaRESUMO
The design of biomimetic model complexes for the cysteine dioxygenase (CDO) and cysteamine dioxygenase (ADO) is reported, where the 3-His coordination of the iron ion is simulated by three pyrazole donors of a trispyrazolyl borate ligand (Tp) and protected cysteine and cysteamine represent substrate ligands. It is found that the replacement of phenyl groups-attached at the 3-positions of the pyrazole units in a previous model-by mesityl residues has massive consequences, as the latter arrange to a more spacious reaction pocket. Thus, the reaction with O2 proceeds much faster and afterwards the first structural characterization of an iron(II) η2 -O,O-sulfinate product became possible. If one of the three Tp-mesityl groups is placed in the 5-position, an even larger reaction pocket results, which leads to yet faster rates and accumulation of a reaction intermediate at low temperatures, as shown by UV/Vis and Mössbauer spectroscopy. After comparison with the results of investigations on the cobalt analogues this intermediate is tentatively assigned to an iron(III) superoxide species.
Assuntos
Cisteamina/química , Cisteína Dioxigenase/química , Cisteína/química , Dioxigenases/química , Superóxidos/química , Biomimética , Boratos/química , Cobalto/química , Cristalografia por Raios X , Cisteína Dioxigenase/metabolismo , Dioxigenases/metabolismo , Ferro/química , Ligantes , PirazóisAssuntos
Cobre , Cisteamina , Imunoterapia , Melanoma Experimental/terapia , Nanopartículas , Estresse Oxidativo , Animais , Linhagem Celular Tumoral , Cobre/química , Cobre/farmacologia , Cisteamina/química , Cisteamina/farmacologia , Melanoma Experimental/imunologia , Melanoma Experimental/metabolismo , Camundongos , Nanopartículas/química , Nanopartículas/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiaçãoRESUMO
A "turn-on" fluorescence sensor was developed for total detection of fumonisin B1, B2 and B3 (FB1, FB2 and FB3) in maize samples. Rhodamine B isothiocyanate (RBITC) and gold nanoparticles (AuNPs) were employed as the energy donor-acceptor pairs. The intensity of restored fluorescence was inversely proportional to the concentration of the FBs. The limit of detection (LOD) of the sensor for FB1 was 23.80 pg/mL. The coefficient of variation (CV) was both less than 7% for intra- and inter-assay. The linear range was from 51.39 to 2125.92 pg/mL. The average recoveries of FBs from maize samples were ranged from 88.7% to 107.2%. The correlation coefficient of the results between the developed sensor and LC-MS/MS was 0.9970. To fulfill the procedure of the assay, only 46 min was needed. These results suggest that the fluorescence "turn-on" sensor has great potential applications in the analysis of FBs in maize samples.
Assuntos
Cisteamina/química , Fumonisinas/análise , Espectrometria de Fluorescência/métodos , Contaminação de Alimentos/análise , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química , Rodaminas/química , Zea mays/química , Zea mays/metabolismoRESUMO
The discrimination of cysteamine (CA) from mercapto amino acids (including glutathione, cysteine and homocysteine, GSH/Cys/Hcy) with high efficiency is essential to detect biothiols in a physiological environment. Herein, a nano-assembly was constructed by combining one-pot synthesized ß-cyclodextrin-modified AuNPs and encapsulated rhodamine 6G (R6G-ß-CD@AuNPs) without covalent modification. Interestingly, when the pH value of the tested solution was approximately the isoelectric point (pI) of the biothiol, the quenched fluorescence of R6G-ß-CD@AuNPs was obviously restored by the introduction of the biothiol, which was due to the replacement of the R6G-ß-CD composite by the biothiol on the surfaces of AuNPs via a stronger S-Au bond. The pI-mediated surface ligand exchange process was designed for the first time for the discrimination and detection of CA and GSH/Cys/Hcy at the pH values of 9.5 and 5.5, respectively. Under the optimized conditions, the enhanced fluorescence intensity displayed a good linear response to the concentration of each biothiol, with the detection limits of CA, GSH, Cys and Hcy calculated as 66.8, 417.6, 652.7 and 603.4 nM, respectively. The ingenious fabrication of the R6G-ß-CD@AuNPs sensing platform eliminated the interferences from cholesterol by host-guest interactions and enabled high selectivity for the detection of biothiols in human serum samples. The pI-mediated sensing platform exhibits great potential for biothiol-related therapeutic drug monitoring.
Assuntos
Aminoácidos/química , Cisteamina/química , Ouro/química , Nanopartículas Metálicas/química , Compostos de Sulfidrila/química , beta-Ciclodextrinas/química , Fluorescência , Ligantes , Tamanho da Partícula , Rodaminas/química , Propriedades de SuperfícieRESUMO
A urinary tract infection (UTI) is a recurrent infection that requires timely diagnosis and appropriate treatment. Conventional urinalysis methods are laborious and time-consuming, and lack sensitivity and specificity. In this context, photoluminescence (PL)-based biosensors have gained more attention due to their fast response time, and enhanced sensitivity and specificity. In relation to this, a PL-based biosensor was developed using ZnO nanoparticles obtained via a microwave-assisted process functionalized with cysteamine (ZnO-Cys) to detect the quorum sensing signalling molecules of Gram-negative bacteria, N-acyl-homoserine lactones (AHLs). These AHLs are involved in bacterial communication and are responsible for activating virulence and pathogenicity. Biosensing measurements based on PL intensity variations corresponding to the O2 acceptor defect level of ZnO with reference to ZnO-Cys were considered. A maximum sensitivity of 97% was achieved in the detection of AHL. The linear detection range of the developed biosensor was 10-120 nM in artificial urine media (AUM). The effect of pH on the sensitivity of the biosensor in AUM was also investigated and reported. The developed sensor was validated using the AHLs produced by Pseudomonas aeruginosa (MCC3101) in real-time analysis, which further confirmed the overall specificity and sensitivity.