RESUMO
The gastric stability of eight barbiturates (BARs) (barbital, primidone, allobarbital, phenobarbital, cyclobarbital, pentobarbital, secobarbital, and thiobutabarbital (TBB)) was examined in artificial gastric juice using LC/UV detection. Among the eight BARs, only TBB was degraded at higher temperatures. Furthermore, the degradation product of TBB was isolated, structurally analyzed, and finally identified as 5-butan-2-yl-5-ethyl-1,3-diazinane-2,4,6-trione, also known as butabarbital. The study elucidated that butabarbital was formed by substituting the sulfur atom of the carbonyl group at the 2-position of TBB with an oxygen atom under acidic condition.
Assuntos
Barbitúricos , Suco Gástrico , Humanos , Barbitúricos/química , Estabilidade de Medicamentos , Suco Gástrico/química , Suco Gástrico/metabolismo , Estrutura Molecular , Estômago/químicaRESUMO
Herein, we have reported a red-emitting 4-methyl coumarin fused barbituric acid azo dye (4-MCBA) synthesized by conventional method. Density functional theory (DFT) studies of tautomer compounds were done using (B3LYP) with a basis set of 6-31G(d,p). NLO analysis has shown that tautomer has mean first-order hyperpolarisabilities (ß) value of 1.8188 × 10-30 esu and 1.0470 × 10-30 esu for azo and hydrazone forms, respectively, which is approximately nine and five times greater than the magnitude of urea. 4-MCBA exhibited two absorption peaks in the range of 290-317 and 379-394 nm, and emission spectra were observed at 536 nm. CV study demonstrated that the modified 4-MCBA/MGC electrode exhibited excellent electrochemical sensitivity towards the detection of catechol and the detection limit is 9.39 µM under optimum conditions. The 4-MCBA employed as a fluorescent probe for the visualisation of LFPs on various surfaces exhibited Level-I to level-II LFPs, with low background interference.
Assuntos
Barbitúricos , Catecóis , Cumarínicos , Técnicas Eletroquímicas , Barbitúricos/química , Catecóis/química , Catecóis/análise , Técnicas Eletroquímicas/instrumentação , Cumarínicos/química , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Estrutura Molecular , Teoria da Densidade Funcional , EletrodosRESUMO
Gyrase and topoisomerase IV are the cellular targets for fluoroquinolones, a critically important class of antibacterial agents used to treat a broad spectrum of human infections. Unfortunately, the clinical efficacy of the fluoroquinolones has been curtailed by the emergence of target-mediated resistance. This is especially true for Neisseria gonorrhoeae, the causative pathogen of the sexually transmitted infection gonorrhea. Spiropyrimidinetriones (SPTs), a new class of antibacterials, were developed to combat the growing antibacterial resistance crisis. Zoliflodacin is the most clinically advanced SPT and displays efficacy against uncomplicated urogenital gonorrhea in human trials. Like fluoroquinolones, the primary target of zoliflodacin in N. gonorrhoeae is gyrase, and topoisomerase IV is a secondary target. Because unbalanced gyrase/topoisomerase IV targeting has facilitated the evolution of fluoroquinolone-resistant bacteria, it is important to understand the underlying basis for the differential targeting of zoliflodacin in N. gonorrhoeae. Therefore, we assessed the effects of this SPT on the catalytic and DNA cleavage activities of N. gonorrhoeae gyrase and topoisomerase IV. In all reactions examined, zoliflodacin displayed higher potency against gyrase than topoisomerase IV. Moreover, zoliflodacin generated more DNA cleavage and formed more stable enzyme-cleaved DNA-SPT complexes with gyrase. The SPT also maintained higher activity against fluoroquinolone-resistant gyrase than topoisomerase IV. Finally, when compared to zoliflodacin, the novel SPT H3D-005722 induced more balanced double-stranded DNA cleavage with gyrase and topoisomerase IV from N. gonorrhoeae, Escherichia coli, and Bacillus anthracis. This finding suggests that further development of the SPT class could yield compounds with a more balanced targeting against clinically important bacterial infections.
Assuntos
Antibacterianos , DNA Girase , DNA Topoisomerase IV , Neisseria gonorrhoeae , Inibidores da Topoisomerase II , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/enzimologia , DNA Topoisomerase IV/metabolismo , DNA Topoisomerase IV/antagonistas & inibidores , DNA Topoisomerase IV/genética , DNA Girase/metabolismo , DNA Girase/genética , DNA Girase/química , Antibacterianos/farmacologia , Antibacterianos/química , Inibidores da Topoisomerase II/farmacologia , Inibidores da Topoisomerase II/química , Humanos , Oxazolidinonas/farmacologia , Oxazolidinonas/química , Barbitúricos/farmacologia , Barbitúricos/química , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana , Isoxazóis , Morfolinas , Compostos de EspiroRESUMO
Cyanine derivatives are organic dyes widely used for optical imaging. However, their potential in longitudinal optoacoustic imaging and photothermal therapy remains limited due to challenges such as poor chemical stability, poor photostability, and low photothermal conversion. In this study, we present a new structural modification for cyanine dyes by introducing a strongly electron-withdrawing group (barbiturate), resulting in a new series of barbiturate-cyanine dyes (BC810, BC885, and BC1010) with suppressed fluorescence and enhanced stability. Furthermore, the introduction of BC1010 into block copolymers (PEG114-b-PCL60) induces aggregation-caused quenching, further boosting the photothermal performance. The photophysical properties of nanoparticles (BC1010-NPs) include their remarkably broad absorption range from 900 to 1200 nm for optoacoustic imaging, allowing imaging applications in NIR-I and NIR-II windows. The combined effect of these strategies, including improved photostability, enhanced nonradiative relaxation, and aggregation-caused quenching, enables the detection of optoacoustic signals with high sensitivity and effective photothermal treatment of in vivo tumor models when BC1010-NPs are administered before irradiation with a 1064 nm laser. This research introduces a barbiturate-functionalized cyanine derivative with optimal properties for efficient optoacoustics-guided theranostic applications. This new compound holds significant potential for biomedical use, facilitating advancements in optoacoustic-guided diagnostic and therapeutic approaches.
Assuntos
Barbitúricos , Carbocianinas , Nanopartículas , Técnicas Fotoacústicas , Fototerapia , Animais , Técnicas Fotoacústicas/métodos , Carbocianinas/química , Carbocianinas/administração & dosagem , Nanopartículas/química , Barbitúricos/química , Barbitúricos/administração & dosagem , Fototerapia/métodos , Humanos , Camundongos Endogâmicos BALB C , Feminino , Camundongos Nus , Linhagem Celular Tumoral , Corantes Fluorescentes/química , Corantes Fluorescentes/administração & dosagem , Camundongos , Terapia Fototérmica/métodos , Neoplasias/terapiaRESUMO
A rapid, straightforward, and sensitive approach to quantifying enantiomeric barbiturates in serum was developed by integrating ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) with large-volume sample stacking (LVSS) in capillary electrophoresis (CE). UA-DLLME was employed for sample preparation, and on-column preconcentration by using LVSS with polarity switching was implemented to enhance sensitivity. We thoroughly investigated and optimized various parameters influencing extraction and stacking to achieve optimal detection performance with the highest enrichment efficiencies. Under optimal extraction conditions (injection of a mixed solution containing 40 µL of CHCl3 and 200 µL of tetrahydrofuran into 1 mL of a sample solution at pH 10.0), LVSS was performed using 600 mM Tris-boric acid (pH 9.5) containing 35 mM hydroxypropyl-ß-cyclodextrin and sodium taurodeoxycholate hydrate. A voltage of 20 kV was applied and a preinjection water plug was loaded at a height of 25 cm for 10 s. Subsequently, the sample solution was injected at a height of 25 cm for 480 s, after which a voltage of -20 kV was applied and the sample stacking was initiated. The stacking process was completed when 95 % of the separation current was attained. Under optimized conditions, the contraction folds of the four barbiturate analytes (R, S-Secobarbital, R, S-pentobarbital) were improved by approximately 6400-fold, achieving detection limits of 0.1 ng/mL. The limits of quantification for all analyte enantiomers were 0.5-50 ng/mL, demonstrating good linearity (r > 0.997). Migration times exhibited a relative standard deviation of less than 1.7 %, whereas peak areas for the four analytes exhibited a deviation of 8.7 %. Finally, the established method was effectively applied to the analysis of human serum samples.
Assuntos
Barbitúricos , Eletroforese Capilar , Limite de Detecção , Microextração em Fase Líquida , Eletroforese Capilar/métodos , Microextração em Fase Líquida/métodos , Estereoisomerismo , Humanos , Barbitúricos/sangue , Barbitúricos/química , Reprodutibilidade dos TestesRESUMO
Uracil-thymine dehydrogenase (UTDH), which catalyzes the irreversible oxidation of uracil to barbituric acid in oxidative pyrimidine metabolism, was purified from Rhodococcus erythropolis JCM 3132. The finding of unusual stabilizing conditions (pH 11, in the presence of NADP+ or NADPH) enabled the enzyme purification. The purified enzyme was a heteromer consisting of three different subunits. The enzyme catalyzed oxidation of uracil to barbituric acid with artificial electron acceptors such as methylene blue, phenazine methosulfate, benzoquinone, and α-naphthoquinone; however, NAD+, NADP+, flavin adenine dinucleotide, and flavin mononucleotide did not serve as electron acceptors. The enzyme acted not only on uracil and thymine but also on 5-halogen-substituted uracil and hydroxypyrimidine (pyrimidone), while dihydropyrimidine, which is an intermediate in reductive pyrimidine metabolism, and purine did not serve as substrates. The activity of UTDH was enhanced by cerium ions, and this activation was observed with all combinations of substrates and electron acceptors.
Assuntos
Oxirredução , Pirimidinas , Rhodococcus , Uracila , Uracila/metabolismo , Uracila/química , Pirimidinas/metabolismo , Rhodococcus/enzimologia , NADP/metabolismo , Azul de Metileno/metabolismo , Azul de Metileno/química , Barbitúricos/metabolismo , Barbitúricos/química , Benzoquinonas/metabolismo , Benzoquinonas/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/química , Concentração de Íons de Hidrogênio , Timina/metabolismo , Timina/química , Especificidade por Substrato , Metilfenazônio Metossulfato/metabolismo , Metilfenazônio Metossulfato/químicaRESUMO
The primary aim of this research is to comprehensively assess the applicability of chitosan biopolymer towards water treatment application and to enhance its adsorption capacity towards Remazol brilliant blue R-19 dye. This has been achieved through physical modification to obtain the material in hydrogel form and chemical modification by crosslinking it with barbituric acid. The characterization of the resulting Chitosan-barbituric acid hydrogel (CBH) was carried out using various analytical techniques such as SEM-EDX, FT-IR, TGA-DTA, XRD, and BET. CBH was employed as the adsorbent to eliminate R-19 dye from aqueous media. Utilizing response surface methodology (RSM), the parameters were fine-tuned, leading to the achievement of more than a 95% removal for R-19 dye. The adsorption behavior closely adhered to the Langmuir isotherm and pseudo-second-order kinetics. An interesting observation indicated that the rise in temperature leads to rise in adsorption capacity of CBH. The maximum adsorption capacities evaluated at 301.15 K, 313.15 K, 318.15 K, and 323.15 K were 566.6 mg g-1, 624.7 mg g-1, 671.3 mg g-1, and 713.5 mg g-1 respectively, in accordance with the Langmuir isotherm model. Examining the thermodynamics of the adsorption process revealed its spontaneous nature (ΔG = -21.14 to -27.09 kJ mol-1) across the entire temperature range. Furthermore, the assessment of the isosteric heat of adsorption (ΔHads) was conducted using the Clausius-Clapeyron equation, with results indicating an increase in ΔHads from 1.85 to 2.16 kJ mol-1 with temperature rise from 301.15 K to 323.15 K due to augmented surface loading. This suggested the existence of lateral interactions between the adsorbed dye molecules. The potential of adsorbent for regeneration was investigated, demonstrating the ability to reuse the material. Sustainability parameter calculated for synthesis process reflected a notably low E-factor value of 0.32 demonstrated the synthesis is environment friendly.
Assuntos
Quitosana , Poluentes Químicos da Água , Quitosana/química , Adsorção , Poluentes Químicos da Água/química , Poluentes Químicos da Água/análise , Hidrogéis/química , Antraquinonas/química , Cinética , Barbitúricos/química , Purificação da Água/métodos , Corantes/químicaRESUMO
A concept of piezo-responsive hydrogen-bonded π-π-stacked organic frameworks made from Knoevenagel-condensed vanillin-barbiturate conjugates was proposed. Replacement of the substituent at the ether oxygen atom of the vanillin moiety from methyl (compound 3a) to ethyl (compound 3b) changed the appearance of the products from rigid rods to porous structures according to optical microscopy and scanning electron microscopy (SEM), and led to a decrease in the degree of crystallinity of corresponding powders according to X-ray diffractometry (XRD). Quantum chemical calculations of possible dimer models of vanillin-barbiturate conjugates using density functional theory (DFT) revealed that π-π stacking between aryl rings of the vanillin moiety stabilized the dimer to a greater extent than hydrogen bonding between carbonyl oxygen atoms and amide hydrogen atoms. According to piezoresponse force microscopy (PFM), there was a notable decrease in the vertical piezo-coefficient upon transition from rigid rods of compound 3a to irregular-shaped aggregates of compound 3b (average values of d33 coefficient corresponded to 2.74 ± 0.54 pm/V and 0.57 ± 0.11 pm/V), which is comparable to that of lithium niobate (d33 coefficient was 7 pm/V).
Assuntos
Barbitúricos , Oxigênio , Barbitúricos/química , Benzaldeídos , Hidrogênio , Ligação de Hidrogênio , Modelos MolecularesRESUMO
The electrochemical thiocyanation of barbituric acids with NH4SCN was disclosed in an undivided cell under constant current conditions. The electrosynthesis is the most efficient at a record high current density (janode ≈50-70 mA cm-2). NH4SCN has a dual role as the source of the SCN group and as the electrolyte. Electrochemical thiocyanation of barbituric acids starts with the generation of (SCN)2 from the thiocyanate anion. The addition of thiocyanogen to the double bond of the enol tautomer of barbituric acid gives thiocyanated barbituric acid. A variety of thiocyanated barbituric acids bearing different functional groups were obtained in 18-95% yields and were shown to exhibit promising antifungal activity.
Assuntos
Barbitúricos , Barbitúricos/química , Barbitúricos/farmacologiaRESUMO
Carbonyl-centered hydrogen bonds with various strength and geometries are often exploited in materials to embed dynamic and adaptive properties, with the use of thiocarbonyl groups as hydrogen-bonding acceptors remaining only scarcely investigated. We herein report a comparative study of C2=O and C2=S barbiturates in view of their differing hydrogen bonds, using the 5,5-disubstituted barbiturate B and the thiobarbiturate TB as model compounds. Owing to the different hydrogen-bonding strength and geometries of C2=O vs. C2=S, we postulate the formation of different hydrogen-bonding patterns in C2=S in comparison to the C2=O in conventional barbiturates. To study differences in their association in solution, we conducted concentration- and temperature-dependent NMR experiments to compare their association constants, Gibbs free energy of association ∆Gassn., and the coalescence behavior of the N-Hâ§â§â§S=C bonded assemblies. In Langmuir films, the introduction of C2=S suppressed 2D crystallization when comparing B and TB using Brewster angle microscopy, also revealing a significant deviation in morphology. When embedded into a hydrophobic polymer such as polyisobutylene, a largely different rheological behavior was observed for the barbiturate-bearing PB compared to the thiobarbiturate-bearing PTB polymers, indicative of a stronger hydrogen bonding in the thioanalogue PTB. We therefore prove that H-bonds, when affixed to a polymer, here the thiobarbiturate moieties in PTB, can reinforce the nonpolar PIB matrix even better, thus indicating the formation of stronger H-bonds among the thiobarbiturates in polymers in contrast to the effects observed in solution.
Assuntos
Barbitúricos/química , Polímeros/química , Tiobarbitúricos/química , Cristalização , Cristalografia por Raios X , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , TemperaturaRESUMO
BACKGROUND: Cancer is one of the most important reasons for mortality worldwide. Several synthetic products have shown valuable efficiency as an anticancer medicines. Chromene derivatives have long been used as the promising compounds which are potent in inhibition of the growth of tumors. METHODS AND RESULTS: In this study, we investigate an anticancer activity of barbituric/thiobarbituric acid-based chromene derivates. For this purpose, viability, antioxidant and apoptotic assays were conducted using three different cancer cell lines (A2780, MCF7, and A549). In most cases, the antiproliferative activity of barbituric acid-based derivatives was higher than that of thiobarbituric acid-based compounds. Among 14 compounds, compound 4g was the most potent one, which showed the highest effect on cells by increasing the accumulation of ROS (up to 540% increase), increasing the level of caspase-3 and caspase-9 (~ 35% increase), and decreasing the mitochondrial membrane potential (2.5 folds reduction). To characterize the type of cell death involved into our experiment Annexin V/PI double staining of compound 4g was performed. The results showed that the number of late apoptotic and/or necrotic cells (Ann V + /PI +) increased fourfold upon treatment with IC50 concentration of 4g. CONCLUSIONS: Overall, the anti-proliferative activity of barbituric acid-based derivatives was higher than that of thiobarbituric acid compounds, and compound 4g can be introduced as a potential candidate to prevent various cancers.
Assuntos
Barbitúricos/farmacologia , Benzopiranos/farmacologia , Neoplasias/tratamento farmacológico , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Barbitúricos/química , Benzopiranos/química , Caspase 3 , Caspase 9 , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Humanos , Neoplasias/metabolismo , Espécies Reativas de Oxigênio , Relação Estrutura-Atividade , Tiobarbitúricos/química , Tiobarbitúricos/farmacologiaRESUMO
We report a series of synthetic cationic amphipathic barbiturates inspired by the pharmacophore model of small antimicrobial peptides (AMPs) and the marine antimicrobials eusynstyelamides. These N,N'-dialkylated-5,5-disubstituted barbiturates consist of an achiral barbiturate scaffold with two cationic groups and two lipophilic side chains. Minimum inhibitory concentrations of 2-8 µg/mL were achieved against 30 multi-resistant clinical isolates of Gram-positive and Gram-negative bacteria, including isolates with extended spectrum ß-lactamase-carbapenemase production. The guanidine barbiturate 7e (3,5-di-Br) demonstrated promising in vivo antibiotic efficacy in mice infected with clinical isolates of Escherichia coli and Klebsiella pneumoniae using a neutropenic peritonitis model. Mode of action studies showed a strong membrane disrupting effect and was supported by nuclear magnetic resonance and molecular dynamics simulations. The results express how the pharmacophore model of small AMPs and the structure of the marine eusynstyelamides can be used to design highly potent lead peptidomimetics against multi-resistant bacteria.
Assuntos
Antibacterianos/farmacologia , Barbitúricos/farmacologia , Produtos Biológicos/farmacologia , Guanidinas/farmacologia , Indóis/farmacologia , Proteínas Citotóxicas Formadoras de Poros/farmacologia , Tensoativos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Barbitúricos/síntese química , Barbitúricos/química , Produtos Biológicos/síntese química , Produtos Biológicos/química , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Guanidinas/síntese química , Guanidinas/química , Indóis/síntese química , Indóis/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Proteínas Citotóxicas Formadoras de Poros/síntese química , Proteínas Citotóxicas Formadoras de Poros/química , Relação Estrutura-Atividade , Tensoativos/síntese química , Tensoativos/químicaRESUMO
Helical folding of randomly coiled linear polymers is an essential organization process not only for biological polypeptides but also for synthetic functional polymers. Realization of this dynamic process in supramolecular polymers (SPs) is, however, a formidable challenge because of their inherent lability of main chains upon changing an external environment that can drive the folding process (e.g., solvent, concentration, and temperature). We herein report a photoinduced reversible folding/unfolding of rosette-based SPs driven by photoisomerization of a diarylethene (DAE). Temperature-controlled supramolecular polymerization of a barbiturate-functionalized DAE (open isomer) in nonpolar solvent results in the formation of intrinsically curved, but randomly coiled, SPs due to the presence of defects. Irradiation of the randomly coiled SPs with UV light causes efficient ring-closure reaction of the DAE moieties, which induces helical folding of the randomly coiled structures into helicoidal ones, as evidenced by atomic force microscopy and small-angle X-ray scattering. The helical folding is driven by internal structure ordering of the SP fiber that repairs the defects and interloop interaction occurring only for the resulting helicoidal structure. In contrast, direct supramolecular polymerization of the ring-closed DAE monomers by temperature control affords linearly extended ribbon-like SPs lacking intrinsic curvature that are thermodynamically less stable compared to the helicoidal SPs. The finding represents an important concept applicable to other SP systems; that is, postpolymerization (photo)reaction of preorganized kinetic structures can lead to more thermodynamically stable structures that are inaccessible directly through temperature-controlled protocols.
Assuntos
Etilenos/química , Polímeros/química , Raios Ultravioleta , Barbitúricos/química , Isomerismo , Substâncias Macromoleculares/química , Microscopia de Força Atômica , Polimerização , Temperatura , TermodinâmicaRESUMO
Microtubule-associated protein tau (MAPT) is a key protein, which is mainly identified as an essential factor for microtubule dynamics and neuronal outgrowth. Though tau has several functions, regulation of insulin signaling is one among them to control type 2 diabetes. Abnormal expression of tau protein leads to hyperphosphorylation and is known as tauopathies. The presence of alloxan occurs in refined wheat flour, especially in various baking products such as parotta, a well-known South Indian dish. In this study, the reduced form of alloxan called dialuric acid can enter the beta cells of islets of Langerhans and binds MAPT to induce toxicity by hyperphosphorylating the tau protein, which ultimately causes destruction to pancreatic beta cells, and it leads to diabetes mellitus. Here, the toxic effects of dialuric acid targeting MAPT through in silico computational predictions have been investigated. The 3D structure of MAPT protein was constructed through I-Tasser, and it has been refined and validated by GalaxyRefine and PROCHECK. The structure of ligand was retrieved from PubChem. Molecular docking was accomplished by AutoDock 4.2 software, and the results indicate the strong binding affinity between dialuric acid and MAPT protein, and it showed a binding free energy (∆G) of - 3.72 kcal/mol. Dialuric acid binds with the active region SER 232 of MAPT whereby it hyperphosphorylates the protein to become toxic. Also, ADMET results strongly suggest that the compound dialuric acid possesses toxic property, and similarly, Ames test confirmed that it was found to be mutagenic. Thus, our results strongly revealed that dialuric acid was found to be toxic which could be able to damage the beta cells of the pancreas and abates insulin signaling, and finally, it leads to DM.
Assuntos
Barbitúricos , Diabetes Mellitus Tipo 2 , Proteínas tau/química , Aloxano/química , Aloxano/toxicidade , Animais , Barbitúricos/química , Barbitúricos/farmacocinética , Barbitúricos/toxicidade , Proteínas Sanguíneas/metabolismo , Permeabilidade da Membrana Celular , Sistema Enzimático do Citocromo P-450/metabolismo , Canal de Potássio ERG1/antagonistas & inibidores , Farinha , Contaminação de Alimentos , Humanos , Absorção Intestinal , Modelos Biológicos , Simulação de Acoplamento Molecular , Testes de Mutagenicidade , Mutagênicos/química , Mutagênicos/farmacocinética , Mutagênicos/toxicidade , Oxirredução , Ligação Proteica , Absorção Cutânea , Testes de Toxicidade , TriticumRESUMO
Neurodegenerative disease is caused by the abnormal build-up of proteins in and around cells called amyloid. The amyloid fibril formation and its mechanism have been investigated with various techniques, including dye-binding assay. Thioflavin T (ThT) has been one of the most widely used dyes for quantifying amyloid deposits, but ThT has a weak fluorescence signal especially at low concentration of amyloid fibrils, low lipophilicity and positive charge that makes it unable to cross the blood-brain barrier (BBB) to detect amyloid fibrils in vivo. Hence, there is a strong motivation for designing and developing the new compounds for in vitro amyloid quantification and in vivo amyloid imaging. The need for new probes to detect amyloid fibrils, especially within the cell, is highlighted by the fact that an accurate understanding of the molecular details of amyloid fibril formation is required to design and develop strategies for controlling the amyloid formation, and this needs more reliable probes for amyloid identification. In this work, we synthesized and applied barbituric and thiobarbituric acid-based chromene derivatives, as new fluorescent dyes to quantitatively detect the amyloid fibrils of bovine serum albumin (BSA) and human insulin in comparison with native soluble proteins or amorphous aggregation. Our results showed that among the 14 synthesized compounds, five compounds 4a, 4h, 4j, 4k, and 4l could selectively and specifically bind to amyloid fibrils while other compounds demonstrated a low-affinity binding. Furthermore, according to the cell viability experiment, compounds 4a, 4j and 4l at low concentration of compounds are not toxic, especially compound 4j which could be used as a suitable candidate for in vivo study. Further studies are needed to determine all the properties of compounds, especially in vivo experiments.
Assuntos
Amiloide/química , Barbitúricos/química , Benzopiranos/química , Benzopiranos/farmacologia , Agregados Proteicos/efeitos dos fármacos , Tiobarbitúricos/química , Animais , Benzopiranos/síntese química , Técnicas de Química SintéticaRESUMO
BACKGROUND: Cancer Stem Cells (CSCs) are a subpopulation within the tumor that play a role in the initiation, progression, recurrence, resistance to drugs and metastasis of cancer. It is well known that epigenetic changes lead to tumor formation in cancer stem cells and show drug resistance. Epigenetic modulators and /or their combination with different agents have been used in cancer therapy. OBJECTIVE: In our study, we scope out the effects of a combination of a histone deacetylases inhibitor, Valproic Acid (VPA), and Cu(II) complex [Cu(barb-κN)(barb-κ2N,O)(phen-κN,N')]·H2O] on cytotoxicity/apoptosis in a stem-cell enriched population (MCF-7s) obtained from parental breast cancer cell line (MCF-7). METHODS: The viability of the cells was measured by the ATP assay. Apoptosis was elucidated via the assessment of caspase-cleaved cytokeratin 18 (M30 ELISA) and a group of flow cytometry analysis (caspase 3/7 activity, phosphatidylserine translocation by annexin V-FITC assay, DNA damage and oxidative stress) and 2',7'- dichlorofluorescein diacetate staining. RESULTS: The VPA combined with Cu(II) complex showed anti-proliferative activity on MCF-7s cells in a doseand time-dependent manner. Treatment with a combination of 2.5 mM VPA and 3.12 µM Cu(II) complex induced oxidative stress in a time-dependent manner, as well as apoptosis evidenced by the increase in caspase 3/7 activity, positive annexin-V-FITC, and increase in M30 levels. CONCLUSION: The results suggest that the combination therapy induces apoptosis following increased oxidative stress, thereby making it a possible promising therapeutic strategy for which further analysis is required.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Barbitúricos/farmacologia , Complexos de Coordenação/farmacologia , Cobre/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Ácido Valproico/farmacologia , Antineoplásicos/química , Barbitúricos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/química , Cobre/química , Dano ao DNA , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores de Histona Desacetilases/química , Humanos , Células MCF-7 , Células Tumorais Cultivadas , Ácido Valproico/químicaRESUMO
Donor-acceptor Stenhouse adducts (DASAs) are a novel class of solvatochromic photoswitches with increasing importance in photochemistry. Known for their reversibility between open triene and closed cyclized states, these push-pull molecules are applicable in a suite of light-controlled applications. Recent works have sought to understand the DASA photoswitching mechanism and reactive state, as DASAs are vulnerable to irreversible "dark switching" in polar protic solvents. Despite the utility of fluorescence spectroscopy for providing information regarding the electronic structure of organic compounds and gaining mechanistic insight, there have been few studies of DASA fluorescence. Herein, we characterize various photophysical properties of two common DASAs based on Meldrum's acid and dimethylbarbituric acid by fluorescence spectroscopy. This approach is applied in tandem with complexation by cyclodextrins and cucurbiturils to reveal the zwitterionic charge separation of these photoswitches in aqueous solution and the protective nature of supramolecular complexation against degradative dark switching. DASA-M, for example, was found to form a weak host-guest inclusion complex with (2-hydroxypropyl)-γ-cyclodextrin, with a binding constant K = 60 M-1, but a very strong inclusion complex with cucurbit[7]uril, with K = 27,000 M-1. This complexation within the host cavity was found to increase the half-life of both DASAs in aqueous solution, indicating the significant and potentially useful stabilization of these DASAs by host encapsulation.
Assuntos
Hidrocarbonetos Aromáticos com Pontes/química , Ciclodextrinas/química , Corantes Fluorescentes/química , Imidazóis/química , Barbitúricos/química , Dioxanos/química , Modelos Moleculares , Processos Fotoquímicos , Espectrometria de FluorescênciaRESUMO
BACKGROUND/AIM: Previously, we reported the identification of a cytotoxic chemotype compound CC-I (1a), a derivative of thiobarbituric acid. We also reported the anticancer activity of a series of novel thio- and seleno-barbituric acid analogs. MATERIALS AND METHODS: We herein evaluated the effect of 1a and its modified compounds on in vitro and in vivo lung cancer models. RESULTS: The compounds 1b and 2a showed more potent cytotoxicity than 1a to lung cancer cells. Moreover, 1b did not have any cytotoxicity on normal cells, such as fibroblasts. In the human lung cancer A549 mouse tumor xenograft model, 1b and 2a showed more pronounced antitumor effects than 1a In the A549 lung cancer cells, 1a induced cell death mainly via JNK and p38 MAPK activation. However, compound 1b and 2a induced lung cancer cell death mostly through JNK activation. CONCLUSION: The results suggest that 1b and 2a can be useful therapeutic agents for lung cancer.
Assuntos
Barbitúricos/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Tiobarbitúricos/uso terapêutico , Células A549 , Barbitúricos/síntese química , Barbitúricos/química , Barbitúricos/farmacologia , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas de Neoplasias/metabolismo , Fosforilação/efeitos dos fármacos , Tiobarbitúricos/química , Tiobarbitúricos/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Six series based on barbituric acid 5a-e, 10a-d; thiobarbituric acid 6a-e, 11a-d and 1,3-dimethylbarbituric acid 7a-e, 12a-d were prepared and screened for their in vitro PARP1 inhibition. They revealed promising inhibition at nanomolar level especially compounds 5c, 7b, 7d and 7e (IC50â¯=â¯30.51, 41.60, 41.53 and 36.33â¯nM) with higher potency than olaparib (IC50â¯=â¯43.59â¯nM). Moreover, compounds 5b, 5d, 7a, 12a and 12c exhibited good comparable activity (IC50â¯=â¯65.93, 58.90, 66.57, 45.40 and 50.62â¯nM, respectively). Furthermore, the most active compounds 5c, 7b, 7d, 7e, 12a and 12c against PARP1 in vitro were evaluated in the BRCA1 mutated triple negative breast cancer cell line MDA-MB-436 where 5c and 12c showed higher potency compared to olaparib and result in cell cycle arrest at G2/M phase. 5c and 12c showed apoptotic effects in MDA-MB-436 and potentiated the cytotoxicity of temozolomide in A549 human lung epithelial cancer cell line. Compounds 5c and 12c represent interesting starting points towards PARP1 inhibitors.
Assuntos
Antineoplásicos/farmacologia , Barbitúricos/farmacologia , Desenho de Fármacos , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Barbitúricos/síntese química , Barbitúricos/química , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/síntese química , Inibidores de Poli(ADP-Ribose) Polimerases/química , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
Daprodustat (DUVROQ) is a small molecule inhibitor of hypoxia-inducible factor prolyl hydroxylase (PHD) developed by GlaxoSmithKline for the treatment of anaemia in patients with chronic kidney disease (CKD). Inhibition of PHD prevents degradation of hypoxia-inducible factor (HIF), leading to the production of erythropoietin and subsequent induction of erythropoiesis. In June, daprodustat received its first approval in Japan for the treatment of renal anaemia. Clinical studies of daprodustat are underway in multiple countries worldwide. This article summarizes the milestones in the development of daprodustat leading to this first approval for the treatment of renal anaemia.