RESUMEN
Nemertean worms contain toxins that are used to paralyze their prey and to deter potential predators. Hoplonemerteans often contain pyridyl alkaloids like anabaseine that act through nicotinic acetylcholine receptors and crustacean chemoreceptors. The chemical reactivity of anabaseine, the first nemertean alkaloid to be identified, has been exploited to make drug candidates selective for alpha7 subtype nAChRs. GTS-21, a drug candidate based on the anabaseine scaffold, has pro-cognitive and anti-inflammatory actions in animal models. The circumpolar chevron hoplonemertean Amphiporus angulatus contains a multitude of pyridyl compounds with neurotoxic, anti-feeding, and anti-fouling activities. Here, we report the isolation and structural identification of five new compounds, doubling the number of pyridyl alkaloids known to occur in this species. One compound is an isomer of the tobacco alkaloid anatabine, another is a unique dihydroisoquinoline, and three are analogs of the tetrapyridyl nemertelline. The structural characteristics of these ten compounds suggest several possible pathways for their biosynthesis.
Asunto(s)
Alcaloides , Isoquinolinas , Animales , Alcaloides/farmacología , Alcaloides/química , Alcaloides/aislamiento & purificación , Isoquinolinas/farmacología , Isoquinolinas/química , Isoquinolinas/aislamiento & purificación , Invertebrados/química , Piridinas/farmacología , Piridinas/química , Piridinas/aislamiento & purificación , Receptores Nicotínicos/metabolismo , Receptores Nicotínicos/efectos de los fármacos , Estructura MolecularRESUMEN
Natural products that inhibit cell cycle progression show promise as anticancer agents and chemical probes. In our research on biologically active natural products that affect cell cycle progression of HeLa/fluorescent ubiquitination-based cell cycle indicator (Fucci)2 cells, the extract of the marine sponge Neopetrosia chaliniformis was revealed to inhibit cell proliferation. Purification of the extract afforded four new pyridine alkaloids, neopetrosidines A-D (1-4). Their structures were elucidated by the interpretation of spectroscopic data and chemical degradation. Compounds 1-4 were found to inhibit cell proliferation of HeLa/Fucci2 cells, and time-lapse imaging showed that 1 exerts its effect by increasing the duration of the cell cycle. Furthermore, we show that 1 perturbs bioenergetics to exhibit a cytostatic effect by reducing the mitochondrial membrane potential.
Asunto(s)
Alcaloides/farmacología , Antineoplásicos/farmacología , Poríferos/química , Piridinas/farmacología , Alcaloides/química , Alcaloides/aislamiento & purificación , Animales , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Lactatos/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Estructura Molecular , Piridinas/química , Piridinas/aislamiento & purificación , Relación Estructura-Actividad , Células Tumorales CultivadasRESUMEN
The fungal strain, Fusarium sp. LY019, was obtained from the Red Sea sponge Suberea mollis. Bioassay-directed partition of the antimicrobial fraction of the extract of the culture of the fungus provided two dimeric alkaloids, fusaripyridines A and B (1 and 2). The compounds possess a previously unreported moiety, 1,4-bis(2-hydroxy-1,2-dihydropyridin-2-yl)butane-2,3-dione. Further, the compounds display a highly oxygenated substitution pattern on the dihydropyridine moieties, representing an additional feature of the fusaripyridines. Fusaripyridines A and B are the first examples of natural products possessing 1,4-bis(2-hydroxy-1,2-dihydropyridin-2-yl)butane-2,3-dione backbone. Careful analyses of the one- and two-dimensional NMR and HRESIMS spectra of the compounds secured their structural mapping, while their absolute stereochemistry was established by analyses of their ECD spectra. The production of such dimeric alkaloids with an unprecedented moiety in the culture of Fusarium sp. LY019 supports further understanding of the biosynthetic competences of the cultured marine-derived fungi. Fusaripyridines A and B selectively inhibited the growth of Candida albicans with MIC values down to 8.0 µM, while they are moderately active against S. aureus, E. coli and HeLa cells.
Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Fusarium/química , Piridinas/química , Piridinas/farmacología , Animales , Candida albicans/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Poríferos , Piridinas/aislamiento & purificación , Staphylococcus aureus/efectos de los fármacosRESUMEN
An Electrokinetic Chromatography method was developed for the stereoselective analysis of sulfoxaflor, a novel sulfoximine agrochemical with two chiral centers. A screening with fourteen negatively charged CDs was performed and Succinyl-ß-CD (Succ-ß-CD) was selected. A 15 mM concentration of this CD in a 100 mM borate buffer (pH 9.0), using an applied voltage of 20 kV and a temperature of 15 °C made possible the baseline separation of the four stereoisomers of sulfoxaflor in 13.8 min. The evaluation of the linearity, accuracy, precision, LODs and LOQs of the method developed showed its performance to be applied to the analysis of commercial agrochemical formulations, the evaluation of the stability of sulfoxaflor stereoisomers under biotic and abiotic conditions, and to predict, for the first time, sulfoxaflor toxicity (using real concentrations instead of nominal concentrations), on two non-target aquatic organisms, the freshwater plant, Spirodela polyrhiza, and the marine bacterium, Vibrio fischeri.
Asunto(s)
Cromatografía Capilar Electrocinética Micelar , Piridinas , Compuestos de Azufre , Aliivibrio fischeri/efectos de los fármacos , Araceae/efectos de los fármacos , Estabilidad de Medicamentos , Piridinas/aislamiento & purificación , Piridinas/toxicidad , Estereoisomerismo , Compuestos de Azufre/aislamiento & purificación , Compuestos de Azufre/toxicidad , ToxicologíaRESUMEN
Series of imidazo[1,2-a]pyridines designed from gossypol modification based on Groebke-Blackburn-Bienaymé reaction were discovered as potent Bcl-2 inhibitors. Compound 4 was found to display good anti-proliferative activities for 7 human cancer cell lines (0.33-1.7 µM) among them, which were better than separate gossypol and imidazopyridine moiety compounds. It was capable of suppressing antiapoptotic proteins Bcl-2 and Bcl-XL demonstrated by mechanism studies, and possible binding model was also illustrated by molecular modelling.
Asunto(s)
Antineoplásicos/farmacología , Gosipol/química , Imidazoles/farmacología , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Piridinas/farmacología , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Imidazoles/química , Imidazoles/aislamiento & purificación , Modelos Moleculares , Estructura Molecular , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Piridinas/química , Piridinas/aislamiento & purificación , Relación Estructura-ActividadRESUMEN
The chalcogen bond (ChB) is a noncovalent interaction based on electrophilic features of regions of electron charge density depletion (σ-holes) located on bound atoms of group VI. The σ-holes of sulfur and heavy chalcogen atoms (Se, Te) (donors) can interact through their positive electrostatic potential (V) with nucleophilic partners such as lone pairs, π-clouds, and anions (acceptors). In the last few years, promising applications of ChBs in catalysis, crystal engineering, molecular biology, and supramolecular chemistry have been reported. Recently, we explored the high-performance liquid chromatography (HPLC) enantioseparation of fluorinated 3-arylthio-4,4'-bipyridines containing sulfur atoms as ChB donors. Following this study, herein we describe the comparative enantioseparation of three 5,5'-dibromo-2,2'-dichloro-3-selanyl-4,4'-bipyridines on polysaccharide-based chiral stationary phases (CSPs) aiming to understand function and potentialities of selenium σ-holes in the enantiodiscrimination process. The impact of the chalcogen substituent on enantioseparation was explored by using sulfur and non-chalcogen derivatives as reference substances for comparison. Our investigation also focused on the function of the perfluorinated aromatic ring as a π-hole donor recognition site. Thermodynamic quantities associated with the enantioseparation were derived from van't Hoff plots and local electron charge density of specific molecular regions of the interacting partners were inspected in terms of calculated V. On this basis, by correlating theoretical data and experimental results, the participation of ChBs and π-hole bonds in the enantiodiscrimination process was reasonably confirmed.
Asunto(s)
Calcógenos/química , Cromatografía Liquida/métodos , Compuestos Heterocíclicos/química , Polisacáridos/química , Piridinas/química , Piridinas/aislamiento & purificación , Termodinámica , Electricidad Estática , EstereoisomerismoRESUMEN
A high-throughput screening assay was developed and applied to a large library of natural product extract samples, in order to identify compounds which preferentially inhibited the in vitro 2D growth of a highly metastatic osteosarcoma cell line (MG63.3) compared to a cognate parental cell line (MG63) with low metastatic potential. Evaluation of differentially active natural product extracts with bioassay-guided fractionation led to the identification of lovastatin (IC50 = 11 µm) and the limonoid toosendanin (IC50 = 26 nm). Other statins and limonoids were then tested, and cerivastatin was identified as a particularly potent (IC50 < 0.1 µm) and selective agent. These compounds potently and selectively induced apoptosis in MG63.3 cells, but not MG63. Assays with other cell pairs were used to examine the generality of these results. Statins and limonoids may represent unexplored opportunities for development of modulators of osteosarcoma metastasis. As cerivastatin was previously approved for clinical use, it could be considered for repurposing in osteosarcoma, pending validation in further models.
Asunto(s)
Productos Biológicos/farmacología , Proliferación Celular/efectos de los fármacos , Ensayos Analíticos de Alto Rendimiento/métodos , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Neoplasias Óseas/metabolismo , Neoplasias Óseas/patología , Línea Celular , Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/aislamiento & purificación , Medicamentos Herbarios Chinos/farmacología , Humanos , Lovastatina/química , Lovastatina/aislamiento & purificación , Lovastatina/farmacología , Melia/química , Melia/metabolismo , Monascus/química , Monascus/metabolismo , Osteosarcoma/metabolismo , Osteosarcoma/patología , Extractos Vegetales/química , Piridinas/química , Piridinas/aislamiento & purificación , Piridinas/farmacología , Semillas/química , Semillas/metabolismoRESUMEN
As an anticoagulant, Edoxaban (EDX) is a high risk drug that may cause a life-threatening bleeding. Also, it is prescribed as a chronic therapy for atrial fibrillation and venous thromboembolism patients. They are special population that needs appropriate care and optimum dosing of EDX. Hence, its monitoring in the patient plasma is fundamental, especially in emergency and special circumstances. However, such patient mostly receives many drugs of different pharmacological classes, side by side with EDX. This study represents the first attempt to quantify EDX in plasma without interference of the plasma matrix or concomitant medications. An accurate RP-HPLC-DAD method was developed for this purpose. It succeeded to monitor EDX level, selectively, without interference of plasma matrix or 16 of its frequently co-administered drugs. All drugs were extracted from plasma samples by protein precipitation followed by evaporation and concentration. EDX was well resolved from the co-administered drugs on C8 column using linear gradient elution of methanol and phosphate buffer (pH 4), at a flow rate of 1 mL/min. EDX appeared at retention time 9.6 min and was quantified at its λmax (290 nm). It exhibited a linear response over the concentration range of 0.15-2.2 µg/mL plasma which covers the reported therapeutic concentration. The suggested method fulfilled the US FDA guidelines for bioanalytical method validation. The developed method is fully discussed in comparison with the reported techniques. An in vivo study was performed to ensure applicability of the method on real plasma samples without interference from plasma matrix, co-administered drugs or the expected metabolites. It presented a unique selectivity of the method that guarantees accurate laboratory monitoring of EDX in plasma in almost all combined treatments including such novel oral anticoagulant drug.
Asunto(s)
Anticoagulantes/sangre , Cromatografía Líquida de Alta Presión/métodos , Piridinas/sangre , Tiazoles/sangre , Administración Oral , Animales , Anticoagulantes/administración & dosificación , Anticoagulantes/aislamiento & purificación , Modelos Lineales , Masculino , Piridinas/administración & dosificación , Piridinas/aislamiento & purificación , Ratas , Ratas Wistar , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Tiazoles/administración & dosificación , Tiazoles/aislamiento & purificaciónRESUMEN
Terreuspyridine (1), the first 3,5-demethylorsellinic acid (DMOA) derived meroterpenoid alkaloid, was isolated from the fungus Aspergillus terreus, which represents a new type of meroterpenoid possessing an unexpected tetracyclic 6/6/6/6 architecture. The structure of 1 with absolute configuration was determined by X-ray diffraction analysis. Biogenetically, it was proposed to be derived from the fusion of a DMOA-meroterpenoid and a glutamate. Terreuspyridine (1) exhibited moderate inhibitory activity against the BChE with an IC50 value of 16.4 µM.
Asunto(s)
Alcaloides/química , Compuestos Policíclicos/química , Piridinas/química , Aspergillus , Cristalografía por Rayos X , Estructura Molecular , Compuestos Policíclicos/aislamiento & purificación , Piridinas/aislamiento & purificación , Terpenos/química , Terpenos/aislamiento & purificaciónRESUMEN
An imidazolium ionic-liquid-modified phenolic resin (ILPR) was synthesized using 3-aminophenol as a functional monomer, glyoxylic acid as a green cross-linker, and polyethylene glycol 6000 as a porogen. The obtained ILPR showed better extraction of benzoylurea plant hormones thidiazuron and forchlorfenuron than the unmodified phenolic resin because the imidazolium IL provides more interaction modes with the analytes. ILPR, as a tailored adsorbent for solid-phase extraction, was coupled with high-performance liquid chromatography (ILPRâSPEâHPLC) for the simultaneous determination of thidiazuron and forchlorfenuron in cucumbers. Good linearity of the ILPRâSPEâHPLC method was obtained, ranging from 0.0100 to 5.00 µg g-1 with a correlation coefficient (r) ≥ 0.9999. The recoveries of spiked samples ranged from 91.4% to 100.7% with a relative standard deviation of ≤ 6.0%.
Asunto(s)
Cucumis sativus/química , Formaldehído/química , Imidazoles/química , Líquidos Iónicos/química , Fenoles/química , Compuestos de Fenilurea/aislamiento & purificación , Polímeros/química , Piridinas/aislamiento & purificación , Extracción en Fase Sólida/métodos , Tiadiazoles/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Formaldehído/síntesis química , Líquidos Iónicos/síntesis química , Cinética , Fenoles/síntesis química , Polímeros/síntesis química , Reproducibilidad de los ResultadosRESUMEN
Keywords: NDM-1 inhibitors; marine-derived Streptomyces sp.; carbapenem-resistant Enterobacteriaceae; metal chelators.
Asunto(s)
Antibacterianos/síntesis química , Complejos de Coordinación/síntesis química , Complejos de Coordinación/farmacología , Piridinas/síntesis química , Piridinas/farmacología , Inhibidores de beta-Lactamasas/síntesis química , beta-Lactamasas/metabolismo , Antibacterianos/química , Antibacterianos/farmacología , Complejos de Coordinación/química , Meropenem/farmacología , Pruebas de Sensibilidad Microbiana , Piridinas/aislamiento & purificación , Inhibidores de beta-Lactamasas/farmacología , beta-Lactamasas/químicaRESUMEN
In the present study, a fast multiresidue method determining three novel fungicides fenpicoxamid, isofetamid, and mandestrobin in cereals was developed and validated for the first time using ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Samples were extracted by QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) methodology, and cleaned up using the disposable pipette extraction (DPX) tips containing primary secondary amine (PSA) and silica gel modified with zirconium oxide (Z-Sep) in less than 1 min. Linearity (r > 0.99) of three fungicides in the calibration range of 0.001-0.1 µg mL-1 was satisfactory. Mean recoveries (n = 15) from all matrices were between 84.8% and 100.3% as the corresponding intra-day and inter-day relative standard deviations (RSDs) were less than 10.6%. Limits of quantitation (LOQs) of all analytes in different matrices were defined at 0.01 mg kg-1. The results indicate this method can serve as a sensitive and rapid approach to monitoring contents of fenpicoxamid, isofetamid, and mandestrobin in cereals.
Asunto(s)
Acetamidas/análisis , Cromatografía Líquida de Alta Presión/métodos , Grano Comestible/química , Fungicidas Industriales/análisis , Residuos de Plaguicidas/análisis , Espectrometría de Masas en Tándem/métodos , Tiofenos/análisis , Fraccionamiento Químico/instrumentación , Fungicidas Industriales/química , Fungicidas Industriales/aislamiento & purificación , Lactonas/análisis , Lactonas/química , Lactonas/aislamiento & purificación , Residuos de Plaguicidas/química , Residuos de Plaguicidas/aislamiento & purificación , Piridinas/análisis , Piridinas/química , Piridinas/aislamiento & purificación , Circonio/químicaRESUMEN
(E)-N,N-dimethyl-4-oxo-4-(4-(pyridin-4-yl)phenyl)but-2-enamide hydrochloride (IMB-YH-4py5-2H) is a novel Protein Kinase B (PknB) inhibitor with potent activity against Mycobacterium tuberculosis strains. In the present study, a sensitive and specific liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine IMB-YH-4py5-2H in rat plasma. Sample pretreatment was achieved by liquid-liquid extraction with ethyl acetate, and separation was performed on an XTerra MS C18 column (2.1×50 mm, 3.5 µm) with gradient elution (methanol and 0.1% formic acid) at a flow rate of 0.3 mL/min. Detection was performed in multiple reaction monitoring (MRM) mode. Linear calibration curves were obtained over a concentration range of 1-100 ng/mL. The intra-day and inter-day precisions were lower than 8.46%, and the accuracies ranged from -8.71% to 12.36% at all quality control levels. The extraction recoveries were approximately 70%, and the matrix effects were negligible. All quality control samples were stable under different storage conditions. The validated method was successfully applied to a preclinical pharmacokinetic study in Sprague-Dawley rats. IMB-YH-4py5-2H demonstrated improved pharmacokinetic properties (higher exposure level) compared with its leading compound. IMB-YH-4py5-2H was also distributed throughout the lung pronouncedly, especially inside alveolar macrophages, indicating its effectiveness against lower respiratory infections.
Asunto(s)
Análisis Químico de la Sangre/métodos , Cromatografía Liquida/métodos , Límite de Detección , Piridinas/sangre , Piridinas/farmacocinética , Espectrometría de Masas en Tándem/métodos , Animales , Antituberculosos/sangre , Antituberculosos/aislamiento & purificación , Antituberculosos/farmacocinética , Piridinas/aislamiento & purificación , Ratas , Ratas Sprague-DawleyRESUMEN
A purple cactus pear (Opuntia ficus-indica) extract (CP) was encapsulated in double emulsions (DE) gelled with gelatin (DE-CP-G) and with gelatin and transglutaminase (DE-CP-GT), as well as in a DE with a liquid external aqueous phase (DE-CP), in order to study the retention of betanin as colorant agent. Both gelled DEs showed a predominantly elastic behavior, in contrast with DE-CP. The degradation rate constant of betanin was significantly higher in DE-CP-GT (90.2 x 10-3 days-1) than in DE-CP-G (11.0 x 10-3 days-1) and DE-CP (14.6 x 10-3 days-1) during cold-storage (4 °C). A shift towards yellow color was found in all the systems during cold-storage (4 °C) and after thermal treatment (70°C/30 min), especially in DE-CP-GT, denoting a higher degradation of betanin. Betalamic acid, cyclo-Dopa 5-O-ß-glucoside, 17-decarboxy-betanin and neobetanin were identified by UHPLC-MS/MS as degradation products of betanin.
Asunto(s)
Betacianinas/química , Geles/química , Opuntia/química , Extractos Vegetales/química , Betalaínas/química , Betalaínas/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Emulsiones/química , Frutas/química , Pigmentos Biológicos/química , Piridinas/química , Piridinas/aislamiento & purificación , Espectrometría de Masas en Tándem , Transglutaminasas/químicaRESUMEN
Aim: To develop and validate a simple method using UPLC-MS/MS for determination of apatinib and its three active metabolites in a Phase IV clinical trial. Materials & methods: All compounds were separated on a Hypersil GOLD™ aQ C18 Polar Endcapped LC column (50 × 2.1 mm, 1.9 µm, Thermo) using 5 mmol/l ammonium acetate with 0.1% formic acid:acetonitrile (20:80, v/v) as the mobile phase after a rapid liquid-liquid extraction. This method was validated over the linear concentration range of 1.00-1000 ng/ml for each compound. Results: The interassay precision and accuracy were less than ±15%. The validated method was successfully applied to determine concentrations of clinical samples in non-small-cell lung cancer patients.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Cromatografía Líquida de Alta Presión/métodos , Ensayos Clínicos Fase IV como Asunto , Neoplasias Pulmonares/metabolismo , Piridinas/metabolismo , Espectrometría de Masas en Tándem/métodos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Humanos , Límite de Detección , Modelos Lineales , Extracción Líquido-Líquido , Neoplasias Pulmonares/tratamiento farmacológico , Piridinas/aislamiento & purificación , Piridinas/uso terapéuticoRESUMEN
Venomous imported fire ants cause significant medical problems. Alkaloids are an important component of imported fire ant venom. Piperidine and piperideine alkaloids have been identified in fire ant venom. In this study, we studied the venom alkaloids of the red imported fire ant, Solenopsis invicta Buren, the black imported fire ant, Solenopsis richteri Forel, and the hybrid, S. invicta × S. richteri. Pyridine alkaloids were detected the first time in fire ants using solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (SPME-GC-MS). The thermal desorption process was manipulated to facilitate the isolation and identification of pyridine alkaloids that were coeluted with piperidine or piperideine alkaloids in GC. After SPME extraction of ant venom, we conducted a series of consecutive GC-MS injections, each with a partial desorption. Hidden pyridine alkaloid peaks were revealed after the overlapping piperidine or piperidiene alkaloid peaks had been desorbed. Using this approach, 10 2-methyl-6-alkyl (or alkenyl)pyridines (1-10) were found the first time in the venom of imported fire ants. Structures of three pyridine alkaloids were confirmed by synthesis, including 2-methyl-6-undecylpyridine (1), 2-methyl-6-tridecylpyridine (7), and 2-methyl-6-pentadecylpyridine (10). We also developed a silica gel column chromatography method to separate the pyridine alkaloids from other alkaloids. Using column chromatography and GC-MS with single ion monitoring at 107 m/z, five pyridine alkaloids were quantified for both workers and female alates of S. invicta and S. richteri.
Asunto(s)
Alcaloides/química , Venenos de Hormiga/química , Hormigas/química , Piridinas/química , Alcaloides/aislamiento & purificación , Animales , Femenino , Cromatografía de Gases y Espectrometría de Masas , Estructura Molecular , Piridinas/aislamiento & purificación , Microextracción en Fase SólidaRESUMEN
Iakyricidins A-D (1-4), a carbonyl-containing piericidin derivative and three novel piericidin analogues bearing cyclic skeletons, were isolated from the mangrove sediment derived strain Streptomyces iakyrus SCSIO NS104. These structures were established by spectroscopic techniques, Mosher's method, and ECD calculations. Compounds 2-4 represent a novel skeleton of piericidins with branched chain C-C cyclization, and their biosynthetic pathways are proposed. Compound 1, the first natural carbonyl-containing piericidin derivate, exhibited potent antiproliferative activity against ACHN with an IC50 value of 20 nM.
Asunto(s)
Antineoplásicos/farmacología , Piridinas/farmacología , Streptomyces/química , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Mitocondrias/efectos de los fármacos , Estructura Molecular , Piridinas/química , Piridinas/aislamiento & purificación , Células Tumorales CultivadasRESUMEN
Over the latest years phytochemical consumption has been associated to a decreased risk of both the onset and the development of a number of pathological conditions. In this context indicaxanthin, a betalain pigment from Opuntia ficus-indica fruit, has been the object of sound research. Explored, at first, for its mere antioxidant potential, Indicaxanthin is now regarded as a redox-active compound able to exert significant poly-pharmacological effects against several targets in a number of experimental conditions both in vivo and in vitro. This paper aims to provide an overview on the therapeutical effects of indicaxanthin, ranging from the anti-inflammatory to the neuro-modulatory and anti-tumoral ones and favored by its high bioavailability. Moreover, biochemical and molecular modelling investigations are aimed to identify the pharmacological targets the compound is able to interact with and to address the challenging development in the future research.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Betaxantinas/farmacología , Productos Biológicos/farmacología , Frutas/química , Neoplasias/tratamiento farmacológico , Fármacos Neuroprotectores/farmacología , Fitoquímicos/farmacología , Piridinas/farmacología , Animales , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Betaxantinas/química , Betaxantinas/aislamiento & purificación , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Barrera Hematoencefálica/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Inflamación/tratamiento farmacológico , Ratones , Ratones Endogámicos C57BL , Modelos Moleculares , Estructura Molecular , Neoplasias/patología , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/aislamiento & purificación , Opuntia/química , Fitoquímicos/química , Fitoquímicos/aislamiento & purificación , Piridinas/química , Piridinas/aislamiento & purificación , Relación Estructura-ActividadRESUMEN
INTRODUCTION: Alzheimer's disease is a common neurodegenerative disease that is characterized by the presence of Aß plaques in the brain. The FDA has approved the use of Amyvid (florbetapir f18, AV-45) as a PET imaging agent for detecting Aß plaques in the living human brain. In an attempt to reduce N-demethylation in vivo by taking advantage of more stable C-D bonds, an analog of AV-45, [18F]D3FSP ([18F]7), was synthesized to improve image contrast for detecting and monitoring the Aß plaques. A convenient and improved preparation of [18F]D3FSP ([18F]7) is needed for widespread clinical application. We report herein the optimization of the radiosynthesis and solid-phase extraction (SPE) procedure. METHODS: Radiosyntheses of [18F]D3FSP ([18F]7) under different fluorination conditions were evaluated, and the intermediate, containing an N-Boc protecting group, was deprotected using different acids. One of the major objectives was to simplify the final purification step via SPE to avoid the commonly employed HPLC purification and maximize the radiochemical yields of [18F]D3FSP ([18F]7) while simultaneously removing several chemical impurities (pseudocarriers). Washing various solid-phase cartridges with different combinations of ethanol/water and acetonitrile/water was explored to optimize the purification step. To evaluate the potential interference in Aß plaques imaging from the presence of pseudocarriers, each chemical was identified and quantified by LC/MS and HPLC. An in vitro binding assay was employed to evaluate the binding affinities of [18F]D3FSP ([18F]7) and the pseudocarriers to Aß plaques using postmortem AD brain tissue. RESULTS: Using the optimized radiosynthesis method and SPE purification, the final dose of [18F]D3FSP ([18F]7) was obtained in 50â¯min with a very low content of pseudocarriers (21.7⯱â¯5.5⯵g). The radiochemical yield was 44.4⯱â¯5.7% (decay corrected), and the radiochemical purity was >95%. SPE-purified doses of [18F]D3FSP ([18F]7) displayed excellent binding affinity and specificity for Aß plaques as measured in an in vitro binding assay using AD brain homogenates, and the OH-pseudocarrier, 8 (Kiâ¯=â¯19.5⯱â¯0.5â¯nM), and the Cl-pseudocarrier, 10 (Kiâ¯=â¯18.6⯱â¯3.9â¯nM), showed lower binding affinities for Aß plaques than those of AV-45 (Kiâ¯=â¯8.6⯱â¯0.5â¯nM) and D3FSP, 7 (Kiâ¯=â¯9.8⯱â¯0.5â¯nM). CONCLUSIONS: An optimized radiosynthesis and fast SPE purification method suitable for the preparation of clinical doses of [18F]D3FSP ([18F]7) was accomplished. The results of quality control tests and binding studies suggested that the SPE-purified doses of [18F]D3FSP ([18F]7) are appropriate for imaging Aß plaques in the human brain.
Asunto(s)
Placa Amiloide/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Piridinas/aislamiento & purificación , Radioisótopos/química , Extracción en Fase Sólida/métodos , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Humanos , Piridinas/química , RadioquímicaRESUMEN
Antibiotic resistance is a problem that continues to challenge the healthcare sector, especially in clinically significant pathogens like methicillin-resistant Staphylococcus aureus (MRSA). Herein is described the isolation and structure elucidation of a bioactive compound from Allium stipitatum with antimicrobial activity. Crude Allium stipitatum dichloromethane extract (ASDE) was subjected to systematic purification by chromatographic procedures to afford various bioactive fractions. A fraction that exhibited anti-MRSA activity (4 µg·mL-1) was further characterized to determine the structure. The structure of the compound was elucidated as 2-(methyldithio)pyridine-3-carbonitrile (2-Medpy-3-CN). The 2-Medpy-3-CN compound, which was screened for antimicrobial activity, exhibited minimum inhibitory concentrations (MICs) in the range of 0.5 to >64 µg·mL-1 for tested bacterial species and 0.25 to 2 µg·mL-1 for Candida spp. Further studies are important to confirm the drug target and mechanism of action.