Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Más filtros













Base de datos
Intervalo de año de publicación
1.
Inorg Chem ; 63(19): 8822-8831, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38696545

RESUMEN

This study presents the rare examples of S-heteroaryl tetradentate Pt(S^C^N^O) luminescent complexes (PtSZ and PtSZtBu) containing a Pt-S bond. The presence of the Pt-S bond allows the novel Pt(S^C^N^O) complexes to exhibit temperature-dependent phosphorescent emission behavior. The PtSZtBu exhibits dual-emission phenomena and biexponential transient decay spectra above 250 K, indicating the presence of two minimal excited states in the potential energy surface (PES) of the T1 state. Through complementary experimental and computational studies, we have identified changes in orbital composition between Pt(dxy)-S(px) and Pt(dyz)-S(pz) in excited states with increasing temperature. This results in two energy minima, enabling the excited states to decay selectively and radiatively at different temperatures. Consequently, this leads to remarkable steady-state and transient emission spectra changes. Our work not only provides valuable insights for the development of novel Pt-S bond-based tetradentate Pt(II) complexes but also enhances our understanding of the distinctive properties governed by the Pt-S bond.

2.
Hum Mol Genet ; 33(12): 1023-1035, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38491801

RESUMEN

Breast cancer (BRCA) is a highly heterogeneous disease, with significant differences in prognosis among patients. Existing biomarkers and prognostic models have limited ability to predict BRCA prognosis. Moonlighting genes regulate tumor progression and are associated with cancer prognosis. This study aimed to construct a moonlighting gene-based prognostic model for BRCA. We obtained differentially expressed genes (DEGs) in BRCA from The Cancer Genome Atlas and intersected them with moonlighting genes from MoonProt to acquire differential moonlighting genes. GO and KEGG results showed main enrichment of these genes in the response of BRCA cells to environmental stimuli and pentose phosphate pathway. Based on moonlighting genes, we conducted drug prediction and validated results through cellular experiments. After ABCB1 knockdown, viability and proliferation of BRCA cells were significantly enhanced. Based on differential moonlighting genes, BRCA was divided into three subgroups, among which cluster2 had the highest survival rate and immunophenoscore and relatively low tumor mutation burden. TP53 had the highest mutation frequency in cluster2 and cluster3, while PIK3CA had a higher mutation frequency in cluster1, with the majority being missense mutations. Subsequently, we established an 11-gene prognostic model in the training set based on DEGs among subgroups using univariate Cox regression, LASSO regression, and multivariable Cox regression analyses. Model prognostic performance was verified in GEO, METABRIC and ICGC validation sets. In summary, this study obtained three BRCA moonlighting gene-related subtypes and constructed an 11-gene prognostic model. The 11-gene BRCA prognostic model has good predictive performance, guiding BRCA prognosis for clinical doctors.


Asunto(s)
Biomarcadores de Tumor , Neoplasias de la Mama , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Femenino , Pronóstico , Biomarcadores de Tumor/genética , Línea Celular Tumoral , Mutación , Perfilación de la Expresión Génica/métodos , Proteína p53 Supresora de Tumor/genética , Fosfatidilinositol 3-Quinasa Clase I/genética , Proliferación Celular/genética , Subfamilia B de Transportador de Casetes de Unión a ATP/genética
3.
FASEB J ; 38(3): e23449, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38315451

RESUMEN

Adipose tissue is the second most important site of estrogen production, where androgens are converted into estrogen by aromatase. While gastric cancer patients often develop adipocyte-rich peritoneal metastasis, the underlying mechanism remains unclear. In this study, we identified the G-protein-coupled estrogen receptor (GPER1) as a promoter of gastric cancer peritoneal metastasis. Functional in vitro studies revealed that ß-Estradiol (E2) or the GPER1 agonist G1 inhibited anoikis in gastric cancer cells. Additionally, genetic overexpression or knockout of GPER1 significantly inhibited or enhanced gastric cancer cell anoikis in vitro and peritoneal metastasis in vivo, respectively. Mechanically, GPER1 knockout disrupted the NADPH pool and increased reactive oxygen species (ROS) generation. Conversely, overexpression of GPER1 had the opposite effects. GPER1 suppressed nicotinamide adenine dinucleotide kinase 1(NADK1) ubiquitination and promoted its phosphorylation, which were responsible for the elevated expression of NADK1 at protein levels and activity, respectively. Moreover, genetic inhibition of NADK1 disrupted NADPH and redox homeostasis, leading to high levels of ROS and significant anoikis, which inhibited lung and peritoneal metastasis in cell-based xenograft models. In summary, our study suggests that inhibiting GPER1-mediated NADK1 activity and its ubiquitination may be a promising therapeutic strategy for peritoneal metastasis of gastric cancer.


Asunto(s)
Neoplasias Peritoneales , Receptores de Estrógenos , Receptores Acoplados a Proteínas G , Neoplasias Gástricas , Humanos , Estrógenos/metabolismo , NAD/metabolismo , NADP/metabolismo , Oxidación-Reducción , Neoplasias Peritoneales/secundario , Especies Reactivas de Oxígeno/metabolismo , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Neoplasias Gástricas/patología , Animales
4.
Am J Otolaryngol ; 44(5): 103943, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37331127

RESUMEN

Metabolic reprogramming is a common pathological process of cancer. Expression of metabolism-related genes differs in thyroid cancer (TC) patients with different prognoses. This work committed to constructing a prognostic model for TC through identifying metabolism-related signatures. Expression profiles of mRNAs and clinical data of TC, were acquired from The Cancer Genome Atlas. Differential analysis was performed on mRNA expression profiles. The obtained differentially expressed genes (DEGs) were overlapped with metabolism-related genes from MSigDB database to acquire metabolism-related DEGs. Cox regression and Least Absolute Shrinkage and Selection Operator analyses were performed to ascertain feature genes and to build a prognostic model for TC. The model was evaluated comprehensively through survival curve, time-dependent receiver operating characteristic (ROC) curve, gene set enrichment analysis (GSEA), and Cox regression analyses combining varying clinical information. 7 key genes related to metabolism, including AWAT2, GGT6, ENTPD1, PAPSS2, CYP26A, ACY3 and PLA2G10, were identified, based on which a prognostic model was constructed. The survival analysis indicated that high-risk group presented shorter survival time than low-risk group. ROC curve results exhibited that AUC values of 3-year and 5-year survival of TC patients were both >0.70. Besides, GSEA on high/low-risk groups revealed that DEGs were mainly gathered in biological functions and signaling pathways linked with keratan sulfate catabolism and triglyceride catabolism. Combined with clinical information, Cox regression analyses unveiled that the 7-gene prognostic model can be an independent predictor. In conclusion, this model can effectively predict prognoses of TC patients, and also offer guidance for clinical treatment of TC.


Asunto(s)
Neoplasias de la Tiroides , Humanos , Pronóstico , Neoplasias de la Tiroides/genética , Bases de Datos Factuales , ARN Mensajero , Curva ROC
5.
BMC Bioinformatics ; 24(1): 234, 2023 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-37277721

RESUMEN

BACKGROUND: Long non-coding RNA (lncRNA) closely associates with numerous biological processes, and with many diseases. Therefore, lncRNA-disease association prediction helps obtain relevant biological information and understand pathogenesis, and thus better diagnose preventable diseases. RESULTS: Herein, we offer the LDAF_GAN method for predicting lncRNA-associated disease based on association filtering and generative adversarial networks. Experimentation used two types of data: lncRNA-disease associated data without lncRNA sequence features, and fused lncRNA sequence features. LDAF_GAN uses a generator and discriminator, and differs from the original GAN by the addition of a filtering operation and negative sampling. Filtering allows the generator output to filter out unassociated diseases before being fed into the discriminator. Thus, the results generated by the model focuses only on lncRNAs associated with disease. Negative sampling takes a portion of disease terms with 0 from the association matrix as negative samples, which are assumed to be unassociated with lncRNA. A regular term is added to the loss function to avoid producing a vector with all values of 1, which can fool the discriminator. Thus, the model requires that generated positive samples are close to 1, and negative samples are close to 0. The model achieved a superior fitting effect; LDAF_GAN had superior performance in predicting fivefold cross-validations on the two datasets with AUC values of 0.9265 and 0.9278, respectively. In the case study, LDAF_GAN predicted disease association for six lncRNAs-H19, MALAT1, XIST, ZFAS1, UCA1, and ZEB1-AS1-and with the top ten predictions of 100%, 80%, 90%, 90%, 100%, and 90%, respectively, which were reported by previous studies. CONCLUSION: LDAF_GAN efficiently predicts the potential association of existing lncRNAs and the potential association of new lncRNAs with diseases. The results of fivefold cross-validation, tenfold cross-validation, and case studies suggest that the model has great predictive potential for lncRNA-disease association prediction.


Asunto(s)
ARN Largo no Codificante , ARN Largo no Codificante/genética , Algoritmos , Biología Computacional/métodos
6.
Heliyon ; 9(2): e13185, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36747547

RESUMEN

Background: This study aimed to identify prognostic signatures to predict the prognosis of breast cancer (BRCA) patients based on a series of comprehensive analyses of gene expression data. Methods: The RNA-sequencing expression data and corresponding BRCA patient clinical data were collected from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) datasets. Firstly, the differently expressed genes (DEGs) related to prognosis between tumor tissues and normal tissues were ascertained by performing R package "limma". Secondly, the DEGs were used to construct a polygenic risk scoring model by the weighted gene co-expression network analysis (WGCNA) and the least absolute shrinkage and selection operator Cox regression (Lasso-cox) analysis method. Thirdly, survival analysis was performed to investigate the risk score values in the TCGA cohort. And the enrichment analysis, immune cell infiltration levels analysis, and protein-protein internet (PPI) analysis were performed. Simultaneously, the GEO cohort was used to validate the model. Lastly, we constructed a nomogram to explore the influence of polygenic risk score and other clinical factors on the survival probability of patients with BRCA. Results: A total of 1000 DEGs including 396 upregulated genes and 604 downregulated genes were identified from the TCGA-BRCA dataset. We obtained 5 prognosis-related genes, as the key biomarkers by Lasso-cox analysis (FBXL19, HAGHL, PHKG2, PKMYT1, and TXNDC17), all of which were significantly upregulated in breast tumors. The prognostic prediction of the 5 genes model was great in training and validation cohorts. Moreover, the high-risk group had a poorer prognosis. The Cox regression analysis showed that the comprehensive risk score for 5 genes was an independent prognosis factor. Conclusion: The 5 genes risk model constructed in this study had an independent predictive ability to distinguish patients with a high risk of death from those with a low-risk score, and it can be used as a practical and reliable prognostic tool for BRCA.

7.
J Bioinform Comput Biol ; 19(2): 2150001, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33685371

RESUMEN

High-throughput chromosome conformation capture (Hi-C) is one of the most popular methods for studying the three-dimensional organization of genomes. However, Hi-C protocols can be expensive since they require large amounts of sample material and may be time-consuming. Most commonly used Hi-C data are low-resolution. Such data can only be used to identify large-scale genomic interactions and are not sufficient to identify the small-scale patterns. We propose a novel deep learning-based computational approach (named ReHiC) that enhances the resolution of Hi-C data and allows us to achieve high-resolution Hi-C data at a relatively low cost. Our model only requires 1/16 down-sampling ratio of the original sequence reading to predict higher resolution Hi-C data. This is very close to high-resolution data in terms of numerical distribution and interaction distribution. More importantly, our framework stacks deeper and converges faster due to residual blocks in the core of the network. Extensive experiments show that ReHiC performs better than HiCPlus and HiCNN, two recently developed and frequently used methods to look at the spatial organization of chromatin structure in the cell. Moreover, the portability of our framework verified by extensive experiments shows that the trained model can also enhance the Hi-C matrix of other cell types efficiently. In conclusion, ReHiC offers more accurate high-resolution image reconstruction in a broad field.


Asunto(s)
Cromatina , Cromosomas , Genoma , Genómica
8.
Sci Adv ; 6(22): eaaz7677, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32766441

RESUMEN

A persistent enigma is the rarity of polyploidy in animals, compared to its prevalence in plants. Although animal polyploids are thought to experience deleterious genomic chaos during initial polyploidization and subsequent rediploidization processes, this hypothesis has not been tested. We provide an improved reference-quality de novo genome for allotetraploid goldfish whose origin dates to ~15 million years ago. Comprehensive analyses identify changes in subgenomic evolution from asymmetrical oscillation in goldfish and common carp to diverse stabilization and balanced gene expression during continuous rediploidization. The homoeologs are coexpressed in most pathways, and their expression dominance shifts temporally during embryogenesis. Homoeolog expression correlates negatively with alternation of DNA methylation. The results show that allotetraploid cyprinids have a unique strategy for balancing subgenomic stabilization and diversification. Rediploidization process in these fishes provides intriguing insights into genome evolution and function in allopolyploid vertebrates.


Asunto(s)
Carpas , Poliploidía , Animales , Evolución Molecular , Genoma , Genómica , Carpa Dorada/genética
9.
ACS Med Chem Lett ; 9(12): 1164-1169, 2018 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-30613320

RESUMEN

IκB kinase ß (IKKß or IKK2) is a key regulator of nuclear factor kappa B (NF-κB) and has received attention as a therapeutic target. Herein we report on the optimization of a series of 3,5-disubstituted-indole-7-carboxamides for oral activity. In doing so, we focused attention on potency, ligand efficiency (LE), and physicochemical properties and have identified compounds 24 and (R)-28 as having robust in vivo activity.

10.
Polymers (Basel) ; 10(6)2018 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-30966628

RESUMEN

Poly(ethylene terephthalate) (PET) composites containing carbon fiber (CF) or polymethyl methacrylate (PMMA)-grafted carbon fiber (PMMA-g-CF) were prepared by melt compounding. The rheology, non-isothermal crystallization behavior, and mechanical and thermal properties of pure PET, PET/CF and PET/PMMA-g-CF composites were investigated. The results show that the addition of CF or PMMA-g-CF significantly increases the storage modulus (G'), loss modulus (G″), and complex viscosity (η*) of the composites at low frequency. The Cole-Cole plots confirm that the surface modification of CF leads to a better interaction between the CF and PET, and then decreases the heterogeneity of the polymeric systems, which is confirmed by the SEM observation on the tensile fracture surface of the composites. Non-isothermal crystallization analysis shows that the CF or PMMA-g-CF could serve as nucleation agent to accelerate the crystallization rate of the composites, and the effect of PMMA-g-CF is stronger than that of CF. The result is further confirmed by the analysis of the crystallization activation energy for all composites calculated by the Flynn-Wall-Ozawa method. Moreover, the tensile and impact strength and the thermal stability of the composites are improved by CF, while the incorporation of PMMA-g-CF further enhances the tensile and impact strength and thermal stability.

11.
Eur Neurol ; 77(3-4): 197-200, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28190011

RESUMEN

BACKGROUND: The study aimed to evaluate the clinical features in patients with bilateral and unilateral paramedian thalamic infarcts. METHODS: Twenty-one patients with paramedian thalamic infarcts were included, and their case records were reviewed. We focused on the patients' neuroimaging and neurological symptoms including the duration of coma, vertical gaze palsy, and memory impairment. The causes of bilateral and unilateral paramedian thalamic infarcts were also investigated. RESULT: Nine patients had bilateral paramedian thalamic infarcts and 12 patients had unilateral lesions. As an initial symptom, coma had occurred in 5 patients with bilateral lesions and 4 patients with unilateral lesions. Bilateral vertical gaze palsy and memory impairment were found in both groups. Most of them recovered well, except 1 patient who died due to bilateral thalamic paramedian infarction. CONCLUSIONS: Our results show that both bilateral and unilateral paramedian thalamic infarcts can cause coma, vertical gaze palsy, and memory impairment. This may promote our understanding of paramedian thalamic infarction.


Asunto(s)
Infarto Cerebral/patología , Tálamo/patología , Adulto , Anciano , Infarto Cerebral/complicaciones , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neuroimagen , Recuperación de la Función , Estudios Retrospectivos
12.
Sci Rep ; 6: 27040, 2016 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-27265401

RESUMEN

Hybridization and polyploidization are considered important driving forces that form new epigenetic regulations. To study the changing patterns of expression accompanying hybridization and polyploidization, we used RNA-seq and qRT-PCR to investigate global expression and homoeologue expression in diploid and tetraploid hybrids of Carassius auratus red var. (♀) (R) and Cyprinus carpio (♂) (C). By comparing the relative expression levels between the hybrids and their parents, we defined the expression level dominance (ELD) and homoeologue expression bias (HEB) in liver tissue. The results showed that polyploidization contributed to the conversion of homoeologue ELD. In addition, hybridization had more effect on the change in HEB than polyploidization, while polyploidization had more effect on the change of global gene expression than hybridization. Meanwhile, similar expression patterns were found in growth-related genes. The results suggested that hybridization and polyploidization result in differential degrees of maternal HEB in three tissues (liver, muscle and ovary) tested. The results of this study will increase our understanding of the underlying regulation mechanism of rapid growth in diploid hybrids and allotetraploids. The differential degrees of global expression and homoeologue expression contribute to growth heterosis in newly formed hybrids, ensuring the on-going success of allotetraploid speciation.


Asunto(s)
Carpa Dorada/genética , Transcriptoma , Animales , Carpas/genética , Carpas/crecimiento & desarrollo , Carpas/metabolismo , Femenino , Proteínas de Peces/genética , Proteínas de Peces/metabolismo , Especiación Genética , Carpa Dorada/crecimiento & desarrollo , Carpa Dorada/metabolismo , Vigor Híbrido , Hibridación Genética , Hígado/metabolismo , Músculo Esquelético/metabolismo , Especificidad de Órganos , Ovario/metabolismo , Poliploidía , Homología de Secuencia
13.
PLoS One ; 11(4): e0154315, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27120465

RESUMEN

VennPainter is a program for depicting unique and shared sets of genes lists and generating Venn diagrams, by using the Qt C++ framework. The software produces Classic Venn, Edwards' Venn and Nested Venn diagrams and allows for eight sets in a graph mode and 31 sets in data processing mode only. In comparison, previous programs produce Classic Venn and Edwards' Venn diagrams and allow for a maximum of six sets. The software incorporates user-friendly features and works in Windows, Linux and Mac OS. Its graphical interface does not require a user to have programing skills. Users can modify diagram content for up to eight datasets because of the Scalable Vector Graphics output. VennPainter can provide output results in vertical, horizontal and matrix formats, which facilitates sharing datasets as required for further identification of candidate genes. Users can obtain gene lists from shared sets by clicking the numbers on the diagram. Thus, VennPainter is an easy-to-use, highly efficient, cross-platform and powerful program that provides a more comprehensive tool for identifying candidate genes and visualizing the relationships among genes or gene families in comparative analysis.


Asunto(s)
Biología Computacional/métodos , Técnicas Genéticas , Programas Informáticos , Algoritmos , Animales , Gráficos por Computador , Bases de Datos Genéticas , Genoma , Genómica , Gorilla gorilla , Humanos , Hylobates , Macaca mulatta , Pan paniscus , Pongo , Lenguajes de Programación , Especificidad de la Especie , Interfaz Usuario-Computador
14.
Proc Natl Acad Sci U S A ; 113(5): 1327-32, 2016 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-26768847

RESUMEN

Polyploidy is much rarer in animals than in plants but it is not known why. The outcome of combining two genomes in vertebrates remains unpredictable, especially because polyploidization seldom shows positive effects and more often results in lethal consequences because viable gametes fail to form during meiosis. Fortunately, the goldfish (maternal) × common carp (paternal) hybrids have reproduced successfully up to generation 22, and this hybrid lineage permits an investigation into the genomics of hybridization and tetraploidization. The first two generations of these hybrids are diploids, and subsequent generations are tetraploids. Liver transcriptomes from four generations and their progenitors reveal chimeric genes (>9%) and mutations of orthologous genes. Characterizations of 18 randomly chosen genes from genomic DNA and cDNA confirm the chimera. Some of the chimeric and differentially expressed genes relate to mutagenesis, repair, and cancer-related pathways in 2nF1. Erroneous DNA excision between homologous parental genes may drive the high percentage of chimeric genes, or even more potential mechanisms may result in this phenomenon. Meanwhile, diploid offspring show paternal-biased expression, yet tetraploids show maternal-biased expression. These discoveries reveal that fast and unstable changes are mainly deleterious at the level of transcriptomes although some offspring still survive their genomic abnormalities. In addition, the synthetic effect of genome shock might have resulted in greatly reduced viability of 2nF2 hybrid offspring. The goldfish × common carp hybrids constitute an ideal system for unveiling the consequences of intergenomic interactions in hybrid vertebrate genomes and their fertility.


Asunto(s)
Cruzamientos Genéticos , Carpa Dorada/genética , Ploidias , Animales , Cromosomas , Perfilación de la Expresión Génica , Hibridación Fluorescente in Situ
15.
Parkinsonism Relat Disord ; 21(3): 300-2, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25534083

RESUMEN

INTRODUCTION: GWAS meta-analysis identified RIT2 rs12456492 and STX1B rs4889603 as PD susceptible loci. While proteins encoded by the genes, in particular RIT2, may involve in PD pathogenesis, the association of these two variants with PD remains to be further clarified. METHODS: We enrolled a Chinese cohort comprising 537 PD patients and 517 controls, determined the genotypes of rs12456492 and rs4889603, and analyzed these variants in relation to PD. RESULTS: Both rs12456492 and rs4889603 were associated with PD susceptibility (P = 0.012 and 0.03, respectively). The G allele of rs12456492 and the A allele of rs4889603 served as risk alleles toward PD. Statistical differences in genotype distribution between the patients and controls were observed both in rs12456492 (marginal, P = 0.042 for GG vs. AG vs. AA) and in rs4889603 (P = 0.021 for AA + AG vs. GG) CONCLUSION: Our data suggest that the RIT2 and STX1B polymorphisms are associated with PD etiology. The role of RIT2 in PD pathogenesis warrants further mechanistical investigation.


Asunto(s)
Predisposición Genética a la Enfermedad/genética , Proteínas de Unión al GTP Monoméricas/genética , Enfermedad de Parkinson/genética , Polimorfismo de Nucleótido Simple/genética , Sintaxina 1/genética , Anciano , Pueblo Asiatico , Estudios de Cohortes , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Genotipo , Humanos , Masculino , Persona de Mediana Edad
16.
Org Lett ; 16(16): 4232-5, 2014 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-25075871

RESUMEN

The first visible-light induced cross-dehydrogenative coupling between tertiary amines and diazo compounds is described. The reaction proceeds smoothly under mild and metal-free conditions by using air or O2 as the oxidant, affording various ß-amino-α-diazo adducts in moderate to good yields with broad substrate scopes. The resulting products were successfully employed for the synthesis of 4- or 5-ester N-aryl-2,3-dihydrobenzo[d]azepines with high regioselectivity simply switched by the selection of the transition metal catalysts.

17.
ACS Med Chem Lett ; 2(2): 142-7, 2011 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-24900293

RESUMEN

The discovery of potent and selective cyanamide-based inhibitors of the cysteine protease cathepsin C is detailed. Optimization of the template with regard to plasma stability led to the identification of compound 17, a potent cathepsin C inhibitor with excellent selectivity over other cathepsins and potent in vivo activity in a cigarette smoke mouse model.

18.
Org Lett ; 12(23): 5438-41, 2010 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-21043445

RESUMEN

CD spectra for homooligomers (n = 4, 6, 8) of (1S,4R,5R)-5-syn-carboxy-2-azabicyclo[2.1.1]hexane (MPCA), a methano-bridged pyrrolidine ß-carboxylic acid, suggest an ordered secondary structure. Even in the absence of internal hydrogen bonding, solution NMR, X-ray, and in silico analyses of the tetramer are indicative of conformations with trans-amides and C(5)-amide-carbonyls oriented toward the C(4) bridgehead. This highly constrained ß-amino acid could prove useful in the ongoing development of well-defined foldamers.


Asunto(s)
Aminoácidos/química , Pirrolidinas/química , Modelos Moleculares , Estructura Molecular
19.
J Org Chem ; 74(21): 8232-42, 2009 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-19799411

RESUMEN

Nucleophilic displacements of 5(6)-anti-bromo substituents in 2-azabicyclo[2.1.1]hexanes (methanopyrrolidines) have been accomplished. These displacements have produced 5-anti-X-6-anti-Y-difunctionalized-2-azabicyclo[2.1.1]hexanes containing bromo, fluoro, acetoxy, hydroxy, azido, imidazole, thiophenyl, and iodo substituents. Such displacements of anti-bromide ions require an amine nitrogen and are a function of the solvent and the choice of metal salt. Reaction rates were faster and product yields were higher in DMSO when compared to DMF and with CsOAc compared to NaOAc. Sodium or lithium salts gave products, except with NaF, where silver fluoride in nitromethane was best for substitution by fluoride. The presence of electron-withdrawing F, OAc, N(3), Br, or SPh substituents in the 6-anti-position slows bromide displacements at the 5-anti-position.


Asunto(s)
Compuestos de Azabiciclo/química , Hexanos/química , Cristalografía por Rayos X , Espectroscopía de Resonancia Magnética , Espectrometría de Masas
20.
J Org Chem ; 73(6): 2114-21, 2008 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-18290656

RESUMEN

Additions of iodonium-X reagents to N-alkoxycarbonyl-2-azabicyclo[2.2.1]hept-5-enes and the homologous 2-azabicyclo[2.2.2]oct-5-enes have been found to mirror the outcomes of additions of bromonium-X reagents. Only rearranged products were observed for reactions of either of these halonium ion reagents with the azabicylo[2.2.1]hept-5-enes. For the azabicyclo[2.2.2]oct-5-enes, nitrogen participation in addition of IOH or BrOH was dependent on the N-alkoxycarbonyl group. With larger N-Boc, N-Cbz, or N-Troc protecting groups, unrearranged 5-anti-hydroxy-6-syn-I(or Br)-2-azabicyclo[2.2.2]octanes were formed by nucleophilic attack at C(5) on syn-halonium ions. The structure of N-methyl-8-anti-bromo-4-anti-hydroxy-2-azabicyclo[3.2.1]octane has been reassigned by X-ray analysis.


Asunto(s)
Compuestos de Azabiciclo/química , Cicloparafinas/química , Compuestos Onio/química , Compuestos de Bromina/química , Compuestos de Yodo/química , Espectroscopía de Resonancia Magnética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA