RESUMEN

In this study, four novel phosphoramide ligands (L1-L4) are synthesized and characterized by 31PNMR, 1HNMR, MASS, and FT-IR spectroscopies. In vitro cell growth inhibition is studied by the MTT assay to evaluate the cytotoxicity of ligands against MCF-7 cell line; the result of the assay demonstrates that all ligands significantly suppress the proliferation of breast cancer cells in a concentration-dependent manner. The calculated IC50 values are in the range of 3.6-10.77 µg ml-1, of which the lowest value is attributed to L1. Then a facile approach was developed to functionalize graphene oxide (GO) surface by L1. The data which are obtained by XRD, FT-IR, and EDX analysis confirmed the deposition of phosphoramide on the surface of GO. The cell viability of GO-L1 compound at different concentrations is investigated in 24 h experiment. Excellent synergistic antitumor effects of GO and L1 lead to a decrease in IC50 value up to 2.13 µg ml-1. The Quantum calculations of compounds are used to study energies and HOMO and LUMO values, dipole moments (µ), global hardness (η), global softness (σ), and electrophilicity index (ω) using DMol3 module in Material studio2017. The docking calculations are performed to describe the mode of the binding to DNA and DNA polymerase IIα. Adsorption calculations of ligands (L1-L4) on GO sheet in the presence of water showed that L1 and L2 were located on GO via π electrons of anisole ring. While, L3 and L4 were located on GO by π - π interactions of aniline ring.

Asunto(s)

Antineoplásicos/química , Antineoplásicos/farmacología , Grafito/química , Grafito/farmacología , Fosforamidas/análogos & derivados , Fosforamidas/farmacología , Antineoplásicos/síntesis química , Supervivencia Celular/efectos de los fármacos , Grafito/síntesis química , Humanos , Ligandos , Células MCF-7 , Simulación del Acoplamiento Molecular , Neoplasias/tratamiento farmacológico , Fosforamidas/síntesis química

RESUMEN

Personalized medicine is pushing forward new diagnostic techniques to aid in controlling drug therapeutic levels and their toxic effects. This study aims to develop a high-throughput screening method for therapeutic drug monitoring (TDM) and occupational exposure of cyclophosphamide (CP), an alkylating agent used as a chemotherapeutic and immunosuppressive drug. In order to achieve this goal, an immunizing hapten that exposes the cyclophosphamide moiety has been designed for the first time. Antibodies produced against this hapten have been used to develop an indirect competitive ELISA for the quantification of CP with high specificity and low cross-reactivity with some metabolites and other anticancer drugs. The assay obtained showed a LOD of 22 ± 6 nM in serum samples, with concentrations much below the blood CP levels of patients treated with the drug. A new tool for the detection and quantification of CP is provided which could be relevant for future pharmacokinetic studies and for therapeutic index improvement.

Asunto(s)

Ciclofosfamida/sangre , Animales , Anticuerpos/inmunología , Ciclofosfamida/inmunología , Monitoreo de Drogas/métodos , Ensayo de Inmunoadsorción Enzimática/métodos , Haptenos/química , Haptenos/inmunología , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Inmunoensayo/métodos , Límite de Detección , Fosforamidas/síntesis química , Fosforamidas/inmunología , Conejos

RESUMEN

In an attempt to achieve a new class of phosphoramide inhibitors with high potency and resistance to the hydrolysis process against urease enzyme, we synthesized a series of bisphosphoramide derivatives (01-43) and characterized them by various spectroscopic techniques. The crystal structures of compounds 22 and 26 were investigated using X-ray crystallography. The inhibitory activities of the compounds were evaluated against the jack bean urease and were compared to monophosphoramide derivatives and other known standard inhibitors. The compounds containing aromatic amines and their substituted derivatives exhibited very high inhibitory activity in the range of IC50 = 3.4-1.91 × 10-10 nM compared with monophosphoramides, thiourea, and acetohydroxamic acid. It was also found that derivatives with PO functional groups have higher anti-urease activity than those with PS functional groups. Kinetics and docking studies were carried out to explore the binding mechanism that showed these compounds follow a mixed-type mechanism and, due to their extended structures, can cover the entire binding pocket of the enzyme, reducing the formation of the enzyme-substrate complex. The quantitative structure-activity relationship (QSAR) analysis also revealed that the interaction between the enzyme and inhibitor is significantly influenced by aromatic rings and PO functional groups. Collectively, the data obtained from experimental and theoretical studies indicated that these compounds can be developed as appropriate candidates for urease inhibitors in this field.

Asunto(s)

Canavalia/enzimología , Inhibidores Enzimáticos/farmacología , Fosforamidas/farmacología , Relación Estructura-Actividad Cuantitativa , Ureasa/antagonistas & inhibidores , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Cinética , Simulación del Acoplamiento Molecular , Estructura Molecular , Fosforamidas/síntesis química , Fosforamidas/química , Ureasa/metabolismo

RESUMEN

A new family of thirteen phosphoramidate prodrugs (ProTides) of different 6-substituted-5-fluorouridine nucleoside analogues were synthesized and evaluated as potential anticancer agents. In addition, antiviral activity against Chikungunya (CHIKV) virus was evaluated using a cytopathic effect inhibition assay. Although a carboxypeptidase Y assay supported a putative mechanism of activation of ProTides built on 5-fluorouridine with such C6-modifications, the Hint docking studies revealed a compromised substrate-activity for the Hint phosphoramidase-type enzyme that is likely responsible for phosphoramidate bioactivation through P-N bond cleavage and free nucleoside 5'-monophosphate delivery. Our observations may support and explain to some extent the poor in vitro biological activity generally demonstrated by the series of 6-substituted-5-fluorouridine phosphoramidates (ProTides) and will be of guidance for the design of novel phosphoramidate prodrugs.

Asunto(s)

Fosforamidas/síntesis química , Profármacos/síntesis química , Uridina/análogos & derivados , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/toxicidad , Antivirales/síntesis química , Antivirales/química , Antivirales/farmacología , Sitios de Unión , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Virus Chikungunya/fisiología , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Simulación del Acoplamiento Molecular , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/metabolismo , Fosforamidas/química , Fosforamidas/farmacología , Profármacos/química , Profármacos/farmacología , Estructura Terciaria de Proteína , Relación Estructura-Actividad , Uridina/síntesis química , Uridina/química , Uridina/farmacología , Internalización del Virus/efectos de los fármacos

RESUMEN

PURPOSE: Corticosteroids are effective in the management of a variety of disease states, such as several forms of neoplasia (leukemia and lymphoma), autoimmune conditions, and severe inflammatory responses. Molecular strategies that selectively "target" delivery of corticosteroids minimize or prevents large amounts of the pharmaceutical moiety from passively diffusing into normal healthy cell populations residing within tissues and organ systems. MATERIALS AND METHODS: The covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide)-[anti-EGFR] was synthesized by reacting dexamethasone-21-monophosphate with a carbodiimide reagent to form a dexamethasone phosphate carbodiimide ester that was subsequently reacted with imidazole to create an amine-reactive dexamethasone-(C21-phosphorylimidazolide) intermediate. Monoclonal anti-EGFR immunoglobulin was combined with the amine-reactive dexamethasone-(C21-phosphorylimidazolide) intermediate, resulting in the synthesis of the covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide)-[anti-EGFR]. Following spectrophotometric analysis and validation of retained epidermal growth factor receptor type 1 (EGFR)-binding avidity by cell-ELISA, the selective anti-neoplasic cytotoxic potency of dexamethasone-(C21-phosphoramide)-[anti-EGFR] was established by MTT-based vitality stain methodology using adherent monolayer populations of human pulmonary adenocarcinoma (A549) known to overexpress the tropic membrane receptors EGFR and insulin-like growth factor receptor type 1. RESULTS: The dexamethasone:IgG molar-incorporation-index for dexamethasone-(C21-phosphoramide)-[anti-EGFR] was 6.95:1 following exhaustive serial microfiltration. Cytotoxicity analysis: covalent bonding of dexamethasone to monoclonal anti-EGFR immunoglobulin did not significantly modify the ex vivo antineoplastic cytotoxicity of dexamethasone against pulmonary adenocarcinoma at and between the standardized dexamethasone equivalent concentrations of 10(-9) M and 10(-5) M. Rapid increases in antineoplastic cytotoxicity were observed at and between the dexamethasone equivalent concentrations of 10(-9) M and 10(-7) M where cancer cell death increased from 7.7% to a maximum of 64.9% (92.3%-35.1% residual survival), respectively, which closely paralleled values for "free" noncovalently bound dexamethasone. DISCUSSION: Organic chemistry reaction regimens were optimized to develop a multiphase synthesis regimen for dexamethasone-(C21-phosphoramide)-[anti-EGFR]. Attributes of dexamethasone-(C21-phosphoramide)-[anti-EGFR] include a high dexamethasone molar incorporation-index, lack of extraneous chemical group introduction, retained EGFR-binding avidity ("targeted" delivery properties), and potential to enhance long-term pharmaceutical moiety effectiveness.

Asunto(s)

Adenocarcinoma/patología , Antineoplásicos/farmacología , Dexametasona/análogos & derivados , Diseño de Fármacos , Neoplasias Pulmonares/patología , Fosforamidas/farmacología , Adenocarcinoma/tratamiento farmacológico , Antineoplásicos/síntesis química , Antineoplásicos/química , Muerte Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Dexametasona/síntesis química , Dexametasona/química , Dexametasona/farmacología , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Fosforamidas/síntesis química , Fosforamidas/química , Relación Estructura-Actividad , Células Tumorales Cultivadas

RESUMEN

Campylobacter jejuni is a leading cause of traveler's diarrhea. Previously, we have shown that a C. jejuni capsule polysaccharide (CPS) conjugate vaccine can fully prevent C.jejuni diarrhea in non-human primates. C.jejuni CPSs are decorated with non-stoichiometric amounts of O-methyl phosphoramidate (MeOPN) units that are key serospecific markers. In the case of C.jejuni serotype complex HS23/36, the MeOPN are at positions 2 and 6 of the CPS galactose (Gal). We describe here the synthesis of the p-methoxyphenyl glycoside of MeOPN→6-α-D-Galp, and its immunodetection by antisera raised by C.jejuni CPS conjugates with MeOPN at primary positions. The synthetic approach in this work served as the foundation for a similar MeOPN→6-Gal construct used in a conjugate vaccine, whose synthesis, immunogenicity and efficacy will be described elsewhere.

Asunto(s)

Campylobacter jejuni/inmunología , Galactósidos/inmunología , Fosforamidas/inmunología , Polisacáridos Bacterianos/inmunología , Vacunas Conjugadas/inmunología , Campylobacter jejuni/química , Conformación de Carbohidratos , Galactósidos/síntesis química , Galactósidos/química , Fosforamidas/síntesis química , Fosforamidas/química , Polisacáridos Bacterianos/síntesis química , Polisacáridos Bacterianos/química , Vacunas Conjugadas/química

RESUMEN

Although numerous reports on the synthesis of atom-specific (15)N-labeled nucleosides exist, fast and facile access to the corresponding phosphoramidites for RNA solid-phase synthesis is still lacking. This situation represents a severe bottleneck for NMR spectroscopic investigations on functional RNAs. Here, we present optimized procedures to speed up the synthesis of (15)N(1) adenosine and (15)N(1) guanosine amidites, which are the much needed counterparts of the more straightforward-to-achieve (15)N(3) uridine and (15)N(3) cytidine amidites in order to tap full potential of (1)H/(15)N/(15)N-COSY experiments for directly monitoring individual Watson-Crick base pairs in RNA. Demonstrated for two preQ1 riboswitch systems, we exemplify a versatile concept for individual base-pair labeling in the analysis of conformationally flexible RNAs when competing structures and conformational dynamics are encountered.

Asunto(s)

Adenosina/síntesis química , Citidina/química , Guanosina/síntesis química , Nucleósidos/química , Fosforamidas/química , Fosforamidas/síntesis química , ARN/química , Uridina/química , Adenosina/química , Emparejamiento Base , Guanosina/química , Espectroscopía de Resonancia Magnética , Conformación de Ácido Nucleico , Técnicas de Síntesis en Fase Sólida

RESUMEN

In this study, the synthesis and spectroscopic characterization of new phosphoramides based on 3-amino-5-methylisoxazole with the formula R2P(O)[NH-C4H4NO], R = C6H5O (1), C6H5 (2), RP(O)[NH-C4H4NO]2, R = C6H5O (3), CH3-C6H4O (4), C6H5NH (5), (C6H5)ClP(O)[NH-C4H4NO] (6) and two lanthanide complexes [Ln(2)2(NO3)3(EtOH)]·EtOH, Ln(III) = Ce (7) and Eu (8), have been reported. The structural study of (3) shows the presence of two conformers (crystallographically independent molecules) in the crystalline lattice, caused by different orientations of the phenyl and isoxazole rings. For (3), the intermolecular interactions have been studied by Hirshfeld surface analysis and fingerprint plots. Furthermore, the electronic and energy aspects of hydrogen bonds between molecules of (3) have been explored by density functional theory (DFT) calculations. X-ray crystallography of complexes (7) and (8) reveals that two phosphoramide ligands take part in coordination to the metal, one as monodentate from O(phosphoryl), and the other one as chelate through O(phosphoryl) and N(ring). The complexes are also composed of two conformers in the solid-state structure. Quantum theory of atoms in molecules (QTAIM) analysis discloses the electrostatic nature of the Ln-ligand interaction.

Asunto(s)

Cerio/química , Complejos de Coordinación/química , Europio/química , Isoxazoles/química , Fosforamidas/química , Complejos de Coordinación/síntesis química , Cristalografía por Rayos X , Enlace de Hidrógeno , Isoxazoles/síntesis química , Ligandos , Modelos Moleculares , Fosforamidas/síntesis química , Teoría Cuántica , Análisis Espectral

RESUMEN

Conjugate addition of α-nitrophosphonates to enones was carried out in the presence of two sets of organocatalysts, viz. a quinine-thiourea and a quinine-squaramide. The quinine-thiourea provided the products possessing an α-quaternary chiral center in high enantioselectivities only in the case of electron rich enones. On the other hand, the quinine-squaramide was more efficient in that a wide variety of electron rich and electron poor enones underwent Michael addition of nitrophosphonates to afford the quaternary α-nitrophosphonates in excellent yields and enantioselectivities. The hydrogen bonding donor ability of the bifunctional catalyst, as shown in the proposed transition states, appears primarily responsible for the observed selectivity. However, a favorable π-stacking between the aryl groups of thiourea/squaramide and aryl vinyl ketone also appeared favorable. The reaction was amenable to scale up, and the enantioenriched quaternary α-nitrophosphonates could be easily transformed to synthetically and biologically useful quaternary α-aminophosphonates and other multifunctional molecules.

Asunto(s)

Amidas/química , Cetonas/química , Fosforamidas/química , Fosforamidas/síntesis química , Quinina/química , Tiourea/química , Fenómenos Biológicos , Catálisis , Estructura Molecular , Estereoisomerismo

RESUMEN

Novel (thio)phosphoramidate derivatives based on piperidincarboxamide with the general formula of (NH2-C(O)-C5H9N)-P(X=O,S)R1R2 (1-5) and (NH2-C(O)-C5H9N)2-P(O)R (6-9) were synthesized and characterized by (31)P, (13)C, (1)H NMR, IR spectroscopy. Furthermore, the crystal structure of compound (NH2-C(O)-C5H9N)2-P(O)(OC6H5) (6) was investigated. The activities of derivatives on cholinesterases (ChE) were determined using a modified Ellman's method. Also the mixed-type mechanisms of these compounds were evaluated by Lineweaver-Burk plots. Molecular docking and quantitative structure-activity relationship (QSAR) were used to understand the relationship between molecular structural features and anti-ChE activity, and to predict the binding affinity of phosphoramido-piperidinecarboxamides (PAPCAs) to ChE receptors. From molecular docking analysis, noncovalent interactions especially hydrogen bonding as well as hydrophobic was found between PAPCAs and ChE. Based on the docking results, appropriate molecular structural parameters were adopted to develop a QSAR model. DFT-QSAR models for ChE enzymes demonstrated the importance of electrophilicity parameter in describing the anti-AChE and anti-BChE activities of the synthesized compounds. The correlation matrix of QSAR models and docking analysis confirmed that electrophilicity descriptor can control the influence of the hydrophobic properties of P=(O, S) and CO functional groups of PAPCA derivatives in the inhibition of human ChE enzymes.

Asunto(s)

Inhibidores de la Colinesterasa/síntesis química , Simulación del Acoplamiento Molecular , Fosforamidas/síntesis química , Relación Estructura-Actividad Cuantitativa , Sitios de Unión , Unión Competitiva , Biocatálisis/efectos de los fármacos , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/farmacología , Colinesterasas/química , Colinesterasas/metabolismo , Humanos , Cinética , Modelos Químicos , Estructura Molecular , Fosforamidas/química , Fosforamidas/farmacología , Estructura Terciaria de Proteína

RESUMEN

The functionalized polyfluorophosphorylated 1-azadienes I have been prepared by a Wittig reaction of ethyl glyoxalate and perfluorophosphorylated conjugated phosphoranes, obtained by reaction of phosphazenes and fluorinated acetylenic phosphonates. Subsequent reduction of both carbon-carbon and carbon-nitrogen double bonds of these 1-azadienes I affords the fluorine-containing ß-aminophosphonates II, with the syn ß-aminophosphonate being obtained as the major diastereoisomer. Base-mediated cyclocondensation of a diastereomeric mixture of aminophosphonates II leads exclusively to a new type of functionalized trans-γ-lactams III in a diastereoselective way. A computational study has also been used to explain the observed diastereoselectivity of these reactions.

Asunto(s)

Flúor/química , Lactamas/química , Lactamas/síntesis química , Fosforamidas/química , Fosforamidas/síntesis química , Estructura Molecular , Estereoisomerismo

RESUMEN

Pyridoxal-5'-phosphate (PLP) represents an active form of Vitamin B(6) that shows relatively fast imine formation with hydrazines under physiological conditions without the need of a catalyst. A convenient phosphate/amine conjugation protocol was developed to covalently link PLP to proteins, affording proteins capable of hydrazone formation with bioorthogonal hydrazinyl functional groups. Thus, the lectin Concanavalin A (Con A) was labeled with PLP. Pretreatment with fluorescein hydrazide gave dye-labeled Con A that labeled cell surfaces efficiently. Alternatively, pretargeting was achieved by labeling cells with Con A-PLP, then treatment in vitro with Alexa Fluor 488 hydrazide.

Asunto(s)

Concanavalina A/química , Hidrazonas/síntesis química , Fosforamidas/síntesis química , Fosfato de Piridoxal/química , Coloración y Etiquetado/métodos , Línea Celular , Células Epiteliales/química , Fluoresceínas/química , Colorantes Fluorescentes/química , Humanos , Hidrazinas/química , Indicadores y Reactivos/química , Estructura Molecular

RESUMEN

Addition of anions derived from dialkyl methylphosphonates to (Ss)-N-tert-butanesulfinyl (3,3,3)-trifluoroacetaldimine afforded (Ss,R) addition adducts in moderate to good yield (53-75%) with excellent diastereoselectivity (94-95% de). After selective removal of the N-sulfinyl group, dipeptides containing enantiomerically pure diethyl 2-amino-3,3,3-trifluoropropylphosphonate were synthesized to investigate the influence of the trifluoromethyl substituent on N-terminal coupling.

Asunto(s)

Dipéptidos/química , Fosforamidas/química , Fosforamidas/síntesis química , Técnicas de Química Sintética , Metilación , Estereoisomerismo