Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
2.
Comput Intell Neurosci ; 2022: 5842039, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35720891

RESUMEN

In recent years, with the continuous increase of financial business, the risk of business is on the rise. Among them, major risk cases are frequent, the cases are increasingly complex, and the means of committing crimes are concealed. The main research contents of this paper include the preprocessing of internal and external financial data and the structure design of recurrent NNs. Its purpose is to design a financial risk control model based on a deep learning NNs, thereby reducing financial risk. The Borderline-SMOTE algorithm is used first to preprocess the sample data, and the oversampling method is used to eliminate the imbalance of the data, and then, the long short-term memory deep NNs algorithm is introduced to process the sample data with time series characteristics. The final experiment shows that LSTM has a better accuracy, reaching 0.9715, compared with traditional methods; the sample preprocessing method and risk control model proposed in this paper have better ability to identify fraudulent customers, and the model itself has faster iteration efficiency.


Asunto(s)
Aprendizaje Profundo , Algoritmos , Memoria a Largo Plazo , Redes Neurales de la Computación
3.
Bioorg Med Chem Lett ; 28(23-24): 3681-3684, 2018 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-30385160

RESUMEN

Our internal casein kinase 1ε lead inhibitor, compound 1 was partially cleared by the polymorphic cytochrome P450 2D6. CYP2D6 involvement in metabolism implies more extensive clinical trials. We therefore wanted to reduce the contribution to clearance by this enzyme. We utilized metabolism reports for compound 1 performed in recombinant CYP2D6 together with structure-metabolism variation in structures of closely related analogs in order to see if we could incorporate similar substitution patterns in our lead compound. In addition, we utilized a previously established docking method using a modified CYP2D6 crystal structure to see if the metabolism patterns in CYP2D6 could be reproduced to afford the metabolites in the metabolism reports as well as those for the compounds used in the structure-metabolism relationship. All three of these steps, the metabolism report, the establishment of structure-metabolism relationships and the docking, lead to compound 10 where CYP2D6 was not involved in the clearance pathways.


Asunto(s)
Caseína Cinasa 1 épsilon/antagonistas & inhibidores , Citocromo P-450 CYP2D6/metabolismo , Inhibidores de Proteínas Quinasas/metabolismo , Sitios de Unión , Caseína Cinasa 1 épsilon/metabolismo , Cristalografía por Rayos X , Citocromo P-450 CYP2D6/genética , Concentración 50 Inhibidora , Simulación del Acoplamiento Molecular , Inhibidores de Proteínas Quinasas/química , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo
4.
Bioorg Med Chem Lett ; 28(19): 3194-3196, 2018 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-30146095

RESUMEN

This work describes the rational amelioration of Cytochrome P450 4/5 (CYP3A4/5) induction through the Pregnane-X Receptor (PXR) pathway in a series of compounds that modulate the metabotropic glutamate Receptor 2 (mGluR2) via an allosteric mechanism. The compounds were initially shown to induce CYP3A4/5 via the gold-standard induction assay measured in primary human hepatocytes. This was followed up by testing the compounds in a PXR assay which correlated well with the assay in primary cells. Further, one of the compounds was crystallized with PXR (pdb code 6DUP). Analysis of this co-crystal structure, together with previously published PXR co-crystal structures, lead to modification ideas. The compounds synthesized based on these ideas were shown not to be CYP3A4/5 inducers. The mGluR2 activity of the resulting compounds was maintained.


Asunto(s)
Citocromo P-450 CYP3A/biosíntesis , Receptor X de Pregnano/fisiología , Receptores de Glutamato Metabotrópico/efectos de los fármacos , Regulación Alostérica , Animales , Cristalografía por Rayos X , Inducción Enzimática/fisiología , Humanos , Receptor X de Pregnano/química , Ratas
5.
J Pharm Sci ; 107(1): 419-425, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29107790

RESUMEN

A roadmap for the selection of a pharmaceutical salt form for a development candidate is presented. The free base of the candidate did not have sufficient chemical stability for development. The initially selected salt form turned out to be undevelopable because it was unstable during scale-up synthesis and storage. The rationale for the new solid form screening and the criteria for selection are discussed. Before the final selection, the pH solubility profiles of the 2 new salts, a benzoate and a besylate, were compared. Atypical solubility behavior was observed for the benzoate salt in hydrochloric acid with and without normal saline. A scheme is proposed illustrating how the pKas of the counterion and active pharmaceutical ingredient, the medium composition, and final pH affect the solubility and solution equilibria of the 2 selected salt forms. This scheme also includes the equilibria between solution and solid phases in different pH ranges. The pharmaceutical importance of this research is that it sheds light on how the acidity of the counterion can affect the solubility of the selected salt form in the gastric environment. With a well-designed formulation strategy, this property potentially can be translated to optimal biopharmaceutical performance of the drug product.


Asunto(s)
Preparaciones Farmacéuticas/química , Sales (Química)/química , Solubilidad/efectos de los fármacos , Benzoatos/química , Estabilidad de Medicamentos , Ácido Clorhídrico/química , Concentración de Iones de Hidrógeno
6.
J Pharm Sci ; 106(5): 1190-1196, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28153596

RESUMEN

Salt formation is one of the primary approaches to improve the developability of ionizable poorly water-soluble compounds. Solubility determination of the salt candidates in aqueous media or biorelevant fluids is a critical step in salt screening. Salt solubility measurements can be complicated due to dynamic changes in both solution and solid phases. Because of the early implementation of salt screening in research, solubility measurements often are performed using minimal amount of material. Some salts have transient high solubility on dissolution. Recognition of these transients can be critical in developing these salts into drug products. This minireview focuses on challenges in salt solubility measurements due to the changes in solution caused by self-buffering effects of dissolved species and the changes in solid phase due to solid-state phase transformations. Solubility measurements and their accurate interpretation are assessed in the context of dissolution monitoring and solid-phase analysis technologies. A harmonized method for reporting salt solubility measurements is recommended to reduce errors and to align with the U.S. Pharmacopeial policy and Food and Drug Administration recommendations for drug products containing pharmaceutical salts.


Asunto(s)
Química Farmacéutica/métodos , Preparaciones Farmacéuticas/química , Preparaciones Farmacéuticas/metabolismo , Sales (Química)/química , Sales (Química)/metabolismo , Química Farmacéutica/normas , Concentración de Iones de Hidrógeno , Solubilidad
7.
Eur J Med Chem ; 63: 907-23, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23685886

RESUMEN

Previously, quinolinium-based tetraazacyclophanes, such as UCL 1684 and UCL 1848, have been shown to be extraordinarily sensitive to changes in chemical structure (especially to the size of the cyclophane system) with respect to activity as potent non-peptidic blockers of the small conductance Ca(2+)-activated K(+) ion channels (SKCa). The present work has sought to optimize the structure of the linking chains in UCL 1848. We report the synthesis and SKCa channel-blocking activity of 29 analogues of UCL 1848 in which the central CH2 of UCL 1848 is replaced by other groups X or Y = O, S, CF2, CO, CHOH, CC, CHCH, CHMe to explore whether subtle changes in bond length or flexibility can improve potency still further. The possibility of improving potency by introducing ring substituents has also been explored by synthesizing and testing 25 analogues of UCL 1684 and UCL 1848 with substituents (NO2, NH2, CF3, F, Cl, CH3, OCH3, OCF3, OH) in the 5, 6 or 7 positions of the aminoquinolinium rings. As in our earlier work, each compound was assayed for inhibition of the afterhyperpolarization (AHP) in rat sympathetic neurons, an action mediated by the SK3 subtype of the SKCa channel. One of the new compounds (39, R(7) = Cl, UCL 2053) is twice as potent as UCL 1848 and UCL 1684: seven are comparable in activity.


Asunto(s)
Activación del Canal Iónico/fisiología , Bloqueadores de los Canales de Potasio/síntesis química , Canales de Potasio Calcio-Activados/metabolismo , Compuestos de Quinolinio/síntesis química , Potenciales de Acción/efectos de los fármacos , Alcanos/química , Alcanos/farmacología , Animales , Células Cultivadas , Relación Dosis-Respuesta a Droga , Activación del Canal Iónico/efectos de los fármacos , Modelos Químicos , Estructura Molecular , Neuronas/citología , Neuronas/efectos de los fármacos , Neuronas/fisiología , Bloqueadores de los Canales de Potasio/química , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio Calcio-Activados/antagonistas & inhibidores , Compuestos de Quinolinio/química , Compuestos de Quinolinio/farmacología , Ratas Sprague-Dawley , Ganglio Cervical Superior/citología
8.
J Med Chem ; 47(21): 5126-39, 2004 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-15456256

RESUMEN

A series of new analogues of 2-methoxyestradiol (1) were synthesized to further elucidate the relationships between structure and activity. The compounds were designed to diminish the potential for metabolic deactivation at positions 2 and 17 and were analyzed as inhibitors of tubulin polymerization and for cytotoxicity. 17alpha-methyl-beta-estradiol (30), 2-propynyl-17alpha-methylestradiol (39), 2-ethoxy-17-(1'-methylene)estra-1,3,5(10)-triene-3-ol (50) and 2-ethoxy-17alpha-methylestradiol (51) showed similar or greater tubulin polymerization inhibition than 2-methoxyestradiol (1) and contained moieties that are expected to inhibit deactivating metabolic processes. All of the compounds tested were cytotoxic in the panel of 55 human cancer cell cultures, and generally, the derivatives that displayed the most activity against tubulin were also the most cytotoxic.


Asunto(s)
Antineoplásicos/síntesis química , Estradiol/análogos & derivados , Estradiol/síntesis química , Tubulina (Proteína)/química , 2-Metoxiestradiol , Antineoplásicos/química , Antineoplásicos/farmacología , Biopolímeros , División Celular/efectos de los fármacos , Línea Celular Tumoral , Cristalografía por Rayos X , Ensayos de Selección de Medicamentos Antitumorales , Estradiol/química , Estradiol/farmacología , Humanos , Modelos Moleculares , Estructura Molecular , Relación Estructura-Actividad
9.
Bioorg Med Chem Lett ; 14(7): 1709-12, 2004 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-15026055

RESUMEN

New arylpiperazines related to buspirone, gepirone and NAN-190 were designed and screened in silico for their 5-HT(1A) affinity and potential sites of metabolism by human cytochrome p450 (CYP3A4). Modifications to these structures were assessed in silico for their influence on both 5HT(1A) affinity and metabolism. Selected new molecules were synthesized and purified in a parallel chemistry approach to determine structure activity relationships (SARs). The resulting molecules were assessed in vitro for their 5HT(1A) affinity and half-life in a heterologously expressed human CYP3A4 assay. Molecular features responsible for 5-HT(1A) affinity and CYP3A4 stability are described.


Asunto(s)
Diseño de Fármacos , Piperazinas/metabolismo , Receptor de Serotonina 5-HT1A/metabolismo , Serotoninérgicos/metabolismo , Citocromo P-450 CYP3A , Sistema Enzimático del Citocromo P-450/metabolismo , Humanos , Ligandos , Piperazinas/síntesis química , Serotoninérgicos/síntesis química
10.
J Org Chem ; 67(20): 6871-7, 2002 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-12353976

RESUMEN

Several analogues of a hypothetical intermediate in the reaction catalyzed by lumazine synthase were synthesized and tested as inhibitors of both Bacillus subtilis lumazine synthase and Escherichia coli riboflavin synthase. The new compounds were designed by replacement of a two-carbon fragment of several 5-phosphonoalkyl-6-D-ribitylaminopyrimidinedione lumazine synthase inhibitors with an amide linkage that was envisioned as an analogue of a Schiff base moiety of a hypothetical intermediate in the enzyme-catalyzed reaction. The incorporation of the amide group led to an unexpected reversal in selectivity for inhibition of lumazine synthase vs riboflavin synthase. Whereas the parent 5-phosphonoalkyl-6-D-ribitylaminopyrimidinediones were lumazine synthase inhibitors and did not inhibit riboflavin synthase, the amide-containing derivatives inhibited riboflavin synthase and were only very weak or inactive as lumazine synthase inhibitors. Molecular modeling of inhibitor-lumazine synthase complexes did not reveal a structural basis for these unexpected findings. However, molecular modeling of one of the inhibitors with E. coli riboflavin synthase demonstrated that the active site of the enzyme could readily accommodate two ligand molecules.


Asunto(s)
Amidas/química , Inhibidores Enzimáticos/síntesis química , Complejos Multienzimáticos/antagonistas & inhibidores , Pirimidinonas/síntesis química , Riboflavina Sintasa/antagonistas & inhibidores , Sitios de Unión , Cristalografía por Rayos X , Diseño de Fármacos , Inhibidores Enzimáticos/química , Escherichia coli/enzimología , Cinética , Ligandos , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Estructura Molecular , Complejos Multienzimáticos/química , Conformación Proteica , Pteridinas , Riboflavina Sintasa/química , Relación Estructura-Actividad
11.
J Org Chem ; 67(16): 5807-16, 2002 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-12153285

RESUMEN

A series of 6-carboxyalkyl and 6-phosphonoxyalkyl derivatives of 7-oxo-8-D-ribityllumazine were synthesized as inhibitors of both Escherichia coli riboflavin synthase and Bacillus subtilis lumazine synthase. The compounds were designed to bind to both the ribitylpurine binding site and the phosphate binding site of lumazine synthase. In the carboxyalkyl series, maximum activity against both enzymes was observed with the 3'-carboxypropyl compound 22. Lengthening or shortening the chain linking the carboxyl group to the lumazine by one carbon resulted in decreased activity. In the phosphonoxyalkyl series, the 3'-phosphonoxypropyl compound 33 was more potent than the 4'-phosphonoxybutyl derivative 39 against lumazine synthase, but it was less potent against riboflavin synthase. Molecular modeling suggested that the terminal carboxyl group of 6-(3'-carboxypropyl)-7-oxo-8-D-ribityllumazine (22) may bind to the side chains of Arg127 and Lys135 of the enzyme. A hypothetical molecular model was also constructed for the binding of 6-(2'-carboxyethyl)-7-oxolumazine (15) in the active site of E. coli riboflavin synthase, which demonstrated that the active site could readily accommodate two molecules of the inhibitor.


Asunto(s)
Inhibidores Enzimáticos/síntesis química , Complejos Multienzimáticos/antagonistas & inhibidores , Pteridinas/síntesis química , Ribitol/análogos & derivados , Riboflavina Sintasa/antagonistas & inhibidores , Sitios de Unión , Diseño de Fármacos , Inhibidores Enzimáticos/química , Escherichia coli/enzimología , Cinética , Modelos Moleculares , Conformación Molecular , Complejos Multienzimáticos/química , Conformación Proteica , Pteridinas/química , Pteridinas/farmacología , Ribitol/síntesis química , Ribitol/química , Ribitol/farmacología , Riboflavina Sintasa/química , Relación Estructura-Actividad
12.
J Org Chem ; 64(13): 4635-4642, 1999 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-11674533

RESUMEN

The reaction catalyzed by riboflavin synthase utilizes two identical 6,7-dimethyl-8-D-ribityllumazine substrate molecules. Three bis(6,7-dimethyl-8-D-ribityllumazines) were, therefore, synthesized in which the two lumazine moieties were connected through their N-3 nitrogen atoms by polymethylene linker chains containing three, four, and five carbon atoms. The compounds with three and five carbon linkers were found to be very weak inhibitors of riboflavin synthase, having inhibition constants of 320 and >1000 &mgr;M, respectively. In contrast, the bis(lumazine) with a four-carbon linker was much more potent, with an inhibition constant of 37 &mgr;M. These results have potential implications for understanding the distance between the donor and acceptor sites of riboflavin synthase and the orientations of the two 6,7-dimethyl-8-D-ribityllumazine substrate molecules which occupy these two sites.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...