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CELSR1 gene, encoding cadherin EGF LAG seven-pass G-type receptor 1, is mainly expressed in neural stem cells during the embryonic period. It plays an important role in neurodevelopment. However, the relationship between CELSR1 and disease of the central nervous system has not been defined. In this study, we performed trios-based whole-exome sequencing in a cohort of 356 unrelated cases with partial epilepsy without acquired causes and identified CELSR1 variants in six unrelated cases. The variants included one de novo heterozygous nonsense variant, one de novo heterozygous missense variant, and four compound heterozygous missense variants that had one variant was located in the extracellular region and the other in the cytoplasm. The patients with biallelic variants presented severe epileptic phenotypes, whereas those with heterozygous variants were associated with a mild epileptic phenotype of benign epilepsy with centrotemporal spikes (BECTS). These variants had no or low allele frequency in the gnomAD database. The frequencies of the CELSR1 variants in this cohort were significantly higher than those in the control populations. The evidence from ClinGen Clinical-Validity Framework suggested a strong association between CELSR1 variants and epilepsy. These findings provide evidence that CELSR1 is potentially a candidate pathogenic gene of partial epilepsy of childhood.
Assuntos
Epilepsias Parciais , Humanos , Epilepsias Parciais/genética , Caderinas/genética , Alelos , Heterozigoto , Mutação de Sentido Incorreto/genéticaRESUMO
MicroRNA-24-3p (miR-24-3p) has been implicated as a key promoter of chemotherapy resistance in numerous cancers. Meanwhile, cancer-associated fibroblasts (CAFs) can secret exosomes to transfer miRNAs, which mediate tumour development. However, little is known regarding the molecular mechanism of CAF-derived exosomal miR-24-3p in colon cancer (CC). Hence, this study intended to characterize the functional relevance of CAF-derived exosomal miR-24-3p in CC cell resistance to methotrexate (MTX). We identified differentially expressed HEPH, CDX2 and miR-24-3p in CC through bioinformatics analyses, and validated their expression in CC tissues and cells. The relationship among HEPH, CDX2 and miR-24-3p was verified using ChIP and dual-luciferase reporter gene assays. Exosomes were isolated from miR-24-3p inhibitor-treated CAFs (CAFs-exo/miR-24-3p inhibitor), which were used in combination with gain-of-function and loss-of-function experiments and MTX treatment. CCK-8, flow cytometry and colony formation assays were conducted to determine cell viability, apoptosis and colony formation, respectively. Based on the findings, CC tissues and cells presented with high expression of miR-24-3p and low expression of HEPH and CDX2. CDX2 was a target gene of miR-24-3p and could up-regulate HEPH. Under MTX treatment, overexpressed CDX2 or HEPH and down-regulated miR-24-3p reduced cell viability and colony formation and elevated cell apoptosis. Furthermore, miR-24-3p was transferred into CC cells via CAF-derived exosomes. CAF-derived exosomal miR-24-3p inhibitor diminished cell viability and colony formation and increased cell apoptosis in vitro and inhibited tumour growth in vivo under MTX treatment. Altogether, CAF-derived exosomal miR-24-3p accelerated resistance of CC cells to MTX by down-regulating CDX2/HEPH axis.
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Fator de Transcrição CDX2/metabolismo , Neoplasias do Colo/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Exossomos/genética , Proteínas de Membrana/metabolismo , Metotrexato/farmacologia , MicroRNAs/genética , Idoso , Animais , Antimetabólitos Antineoplásicos/farmacologia , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Fator de Transcrição CDX2/genética , Fibroblastos Associados a Câncer/metabolismo , Fibroblastos Associados a Câncer/patologia , Proliferação de Células , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Hepatocellular cancer (HCC) has been reported to belong to one of the highly vascularized solid tumours accompanied with angiogenesis of human umbilical vein endothelial cells (HUVECs). KDM5A, an attractive drug target, plays a critical role in diverse physiological processes. Thus, this study aims to investigate its role in angiogenesis and underlying mechanisms in HCC. ChIP-qPCR was utilized to validate enrichment of H3K4me3 and KDM5A on the promotor region of miR-433, while dual luciferase assay was carried out to confirm the targeting relationship between miR-433 and FXYD3. Scratch assay, transwell assay, Edu assay, pseudo-tube formation assay and mice with xenografted tumours were conducted to investigate the physiological function of KDM5A-miR-433-FXYD3-PI3K-AKT axis in the progression of HCC after loss- and gain-function assays. KDM5A p-p85 and p-AKT were highly expressed but miR-433 was down-regulated in HCC tissues and cell lines. Depletion of KDM5A led to reduced migrative, invasive and proliferative capacities in HCC cells, including growth and a lowered HUVEC angiogenic capacity in vitro. Furthermore, KDM5A suppressed the expression of miR-433 by demethylating H3K4me3 on its promoterregion. miR-433 negatively targeted FXYD3. Depleting miR-433 or re-expressing FXYD3 restores the reduced migrative, invasive and proliferative capacities, and lowers the HUVEC angiogenic capacity caused by silencing KDM5A. Therefore, KDM5A silencing significantly suppresses HCC tumorigenesis in vivo, accompanied with down-regulated miR-433 and up-regulated FXYD3-PI3K-AKT axis in tumour tissues. Lastly, KDM5A activates the FXYD3-PI3K-AKT axis to enhance angiogenesis in HCC by suppressing miR-433.
Assuntos
Carcinoma Hepatocelular/patologia , Proteínas de Membrana/antagonistas & inibidores , MicroRNAs/genética , Proteínas de Neoplasias/antagonistas & inibidores , Neovascularização Patológica/prevenção & controle , Fosfatidilinositol 3-Quinases/química , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteína 2 de Ligação ao Retinoblastoma/antagonistas & inibidores , Idoso , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína 2 de Ligação ao Retinoblastoma/genética , Proteína 2 de Ligação ao Retinoblastoma/metabolismo , Taxa de Sobrevida , Células Tumorais CultivadasRESUMO
Liquid chromatography-Mass Spectrometry (LC-MS) has been widely used in natural product analysis. Global detection and identification of nontargeted components are desirable in natural product research, for example, in quality control of Chinese herbal medicine. Nontargeted components analysis continues to expand to exciting life science application domains such as metabonomics. With this background, the present review summarizes recent developments in the analysis of minor unknown natural products using LC-MS and mainly focuses on the determination of the molecular formulae, selection of precursor ions, and characteristic fragmentation patterns of the known compounds. This review consists of three parts. Firstly, the methods used to determine unique molecular formula of unknown compounds such as accurate mass measurements, MSn spectra, or relative isotopic abundance information, are introduced. Secondly, the methods improving signal-to-noise ratio of MS/MS spectra by manual-MS/MS or workflow targeting-only signals were elucidated; pure precursor ions can be selected by changing the precursor ion isolated window. Lastly, characteristic fragmentation patterns such as Retro-Diels-Alder (RDA), McLafferty rearrangements, "internal residue loss," and so on, occurring in the molecular ions of natural products are summarized. Classical application of characteristic fragmentation patterns in identifying unknown compounds in extracts and relevant fragmentation mechanisms are presented (RDA reactions occurring readily in the molecular ions of flavanones or isoflavanones, McLafferty-type fragmentation reactions of some natural products such as epipolythiodioxopiperazines; fragmentation by "internal residue loss" possibly involving ion-neutral complex intermediates). © 2016 Wiley Periodicals, Inc. Mass Spec Rev 37:202-216, 2018.
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BACKGROUND: Recently, evidence has emerged that palliative gastrectomy in patients with stage IV gastric cancer may offer some survival benefits. However, the decision whether to perform primary tumor surgery remains challenging for surgeons, and investigations into models that are predictive of prognosis are scarce. Current study aimed to develop and validate prognostic nomograms for patients with metastatic gastric adenocarcinoma treated with palliative gastrectomy. METHODS: The development dataset comprised 1186 patients from the Surveillance, Epidemiology, and End Results Program who were diagnosed with metastatic gastric adenocarcinoma in 2004-2011, while the validation dataset included 407 patients diagnosed in 2012-2015. Variables were incorporated into a Cox proportional hazards model to identify independent risk factors for survival. Both pre- and postoperative nomograms for predicting 1- or 2-year survival probabilities were constructed using the development dataset. The concordance index (c-index) and calibration curves were plotted to determine the accuracy of the nomogram models. Finally, the cut-off value of the calculated total scores based on preoperative nomograms was set and validated by comparing survival with contemporary cases without primary tumor surgery. RESULTS: Age, tumor size, location, grade, T stage, N stage, metastatic site, scope of gastrectomy, number of examined lymph node(s), chemotherapy and radiotherapy were risk factors of survival and were included as variables in the postoperative nomogram; the c-indices of the development and validation datasets were 0.701 (95% confidence interval [CI]: 0.693-0.710) and 0.699 (95% CI: 0.682-0.716), respectively. The preoperative nomogram incorporated age, tumor size, location, grade, depth of invasion, regional lymph node(s) status, and metastatic site. The c-indices for the internal (bootstrap) and external validation sets were 0.629 (95% CI: 0.620-0.639) and 0.607 (95% CI: 0.588-0.626), respectively. Based on the preoperative nomogram, patients with preoperative total score > 28 showed no survival benefit with gastrectomy compared to no primary tumor surgery. CONCLUSIONS: Our survival nomograms for patients with metastatic gastric adenocarcinoma undergoing palliative gastrectomy can assist surgeons in treatment decision-making and prognostication.
Assuntos
Adenocarcinoma/cirurgia , Gastrectomia/métodos , Nomogramas , Neoplasias Gástricas/cirurgia , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Cuidados Paliativos , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Análise de Sobrevida , Resultado do TratamentoRESUMO
Tea plant [Camellia sinensis (L.) O. Kuntze] is a typical leaf-type beverage crop. Many secondary metabolites, such as tea polyphenols, theanine, and caffeine that accumulated in tea leaves are beneficial to human health. The fresh leaves of tea plant are harvested and timely processed into tea products with different flavors. The withering of fresh tea leaves is the first step in tea processing and directly affects tea color, taste, and fragrance. To understand the molecular mechanism that influences tea quality during withering, we investigated the dynamic changes in the proteome of postharvest tea leaves in four withering stages (0, 1, 4, and 12 h treatments). A total of 863 unique differentially expressed proteins (DEPs) were identified by iTRAQ. The up- and down-regulated DEPs and the protein-protein interaction networks in different samples presented dynamic changes in their characteristics. The results of the functional annotation revealed that the molecular characteristics of tea withering are similar to leaf senescence. The biosynthesis of main tea-specific compounds that constitute tea color, taste, and fragrance of tea is restricted during withering. The substance transformation and degradation may have positive contributions to tea quality in withering technology. The proteome dynamics can be a useful aid for understanding the withering mechanisms and providing available information for functional discovery of proteins in the future.
Assuntos
Camellia sinensis/genética , Folhas de Planta/genética , Proteínas de Plantas/biossíntese , Proteômica , Cafeína/genética , Regulação da Expressão Gênica de Plantas , Glutamatos/genética , Humanos , Folhas de Planta/crescimento & desenvolvimentoRESUMO
Tea plant (Camellia sinensis (L.) O. Kuntze) is an important leaf-type woody crop used for producing of non-alcoholic beverages worldwide. The GROWTH-REGULATING FACTOR (GRF) transcription factors cooperated with GRF-INTERACTING FACTOR (GIF) transcriptional coactivators positively regulate leaf development. In the present study, six GRF and two GIF genes were identified and characterized in the leaf transcriptome of C. sinensis, respectively. The alignment results showed that the feature structures of the predicted homologous GRF and GIF proteins of C. sinensis hold a high identity with Arabidopsis and rice. The presence of C. sinensis miR396 target sites suggested that these miR396 members are the potential post-transcriptional regulators of CsGRF genes. The expression profiles of CsGRF and CsGIF1 genes were higher in tender leaves and consistently downregulated during tea plant leaf development. Those results suggested that these genes may be actively involved in the early stage leaf tissue formation in tea plant. The divergence of CsGRF and CsGIF genes in response to different hormonal stimuli revealed the possible multiple functions of these genes in hormonal regulation. This study provided the potential molecular basis of the CsGRF and CsGIF family genes for future functional research on leaf development and hormonal stimuli in C. sinensis.
Assuntos
Camellia sinensis/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Camellia sinensis/crescimento & desenvolvimento , Camellia sinensis/metabolismo , MicroRNAs/genética , Família Multigênica , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Homologia de Sequência , Fatores de Transcrição/química , Fatores de Transcrição/metabolismoRESUMO
RATIONALE: In addition to their biological properties, oxovanadium complexes have been widely applied as catalysts because of their excellent catalytic-oxidation capability. Recently, monometallic oxovanadium(IV) complexes have been used as catalysts in the electrophilic trifluoromethylation of silyl ketene imines. The study of catalysts can contribute to an understanding of the reaction mechanism. METHODS: Six monometallic oxovanadium(IV) complexes were analyzed by electrospray ionization time-of flight mass spectrometry (ESI-TOFMS), and collision-induced dissociation mass spectrometry (CID-MS) experiments were conducted for selected cations [M]+ of oxovanadium(IV) complexes as well as a deuterium-labeled complex. Different collision gases were used to understand the source of the O2 and H2 O engaged in the gas-phase ion-molecule reaction. RESULTS: The oxovanadium(IV) complexes formed [M]+ ions by loss of an electron, with [M + 14]+ ions being formed from [M]+ by loss of H2 O and addition of O2 . The fragmentation pathways of the [M]+ cations were further studied by ESI-MS/MS, and several ions produced by gas-phase ion-molecule reactions were detected and characterized, including vanadium-oxo, -peroxo and derivatives. CONCLUSIONS: Several unexpected ions were detected, including [M]+ , [M + 14]+ and ions produced from gas-phase ion-molecule reactions. The study has contributed to the understanding of the structure and character of oxovanadium(IV) complexes, and it could facilitate the design of new oxovanadium catalysts and an understanding of their reaction mechanism.
RESUMO
A series of coumarins were analyzed using electrospray ionization quadrupole time-of-flight tandem mass spectrometry in the positive-ion mode. Unexpected hydrated ions ([M + H2O + Na]+) was observed upon collision-induced dissociation of the sodiated ions ([M + Na]+) of eight coumarins. Several factors which affected relative abundance of [M + H2O + Na]+ ions such as collision energy, concentration and solvent were investigated. None of them have effect on the relative abundance of [M + H2O + Na]+. However, the peak of hydrated ions was not detected in the further collision-induced dissociation of protonated ions of coumarins. Apigenin and Quercetin sharing similar benzopyrone structural unit with coumarins are selected for tandem mass spectrometry analysis. There were no hydrated ions in their tandem mass spectrometry spectra of the precursor [M + Na]+ ions. Thus, both coumarins and sodium were necessary for the formation of [M + H2O + Na]+. Together with the result that hydrated ions are not formed by hydrolysis reactions, a six-membered ring structure which involves with the formation of [M + H2O + Na]+ was presented. And D-labeling experiment indicates that the H2O molecule did not come from solvent.
Assuntos
Cumarínicos/análise , Cumarínicos/química , Íons/química , Sódio/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Água/química , Hidrólise , Sódio/análiseRESUMO
Tea plant [Camellia sinensis (L.) O. Kuntze] is a leaf-type healthy non-alcoholic beverage crop, which has been widely introduced worldwide. Tea is rich in various secondary metabolites, which are important for human health. However, varied climate and complex geography have posed challenges for tea plant survival. The WRKY gene family in plants is a large transcription factor family that is involved in biological processes related to stress defenses, development, and metabolite synthesis. Therefore, identification and analysis of WRKY family transcription factors in tea plant have a profound significance. In the present study, 50 putative C. sinensis WRKY proteins (CsWRKYs) with complete WRKY domain were identified and divided into three Groups (Group I-III) on the basis of phylogenetic analysis results. The distribution of WRKY family transcription factors among plantae, fungi, and protozoa showed that the number of WRKY genes increased in higher plant, whereas the number of these genes did not correspond to the evolutionary relationships of different species. Structural feature and annotation analysis results showed that CsWRKY proteins contained WRKYGQK/WRKYGKK domains and C2H2/C2HC-type zinc-finger structure: D-X18-R-X1-Y-X2-C-X4-7-C-X23-H motif; CsWRKY proteins may be associated with the biological processes of abiotic and biotic stresses, tissue development, and hormone and secondary metabolite biosynthesis. Temperature stresses suggested that the candidate CsWRKY genes were involved in responses to extreme temperatures. The current study established an extensive overview of the WRKY family transcription factors in tea plant. This study also provided a global survey of CsWRKY transcription factors and a foundation of future functional identification and molecular breeding.
Assuntos
Camellia sinensis/genética , Genes de Plantas/genética , Proteínas de Plantas/genética , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Transcriptoma/genética , Evolução Molecular , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/genética , Genoma de Planta/genética , Família Multigênica/genética , Filogenia , TemperaturaRESUMO
An organocatalytic asymmetric Michael addition reaction of 3-pyrrolyloxindoles to ß-phthalimidonitroethene has been developed with a bifunctional thiourea-tertiary amine as the catalyst. A range of 3,3'-disubstituted oxindoles bearing contiguous 3,α,ß-triamino functionality could be obtained in high yields with good diastereoselectivities and high enantioselectivities (up to 99% yield, 99:1 dr, and 98% ee). The higher reactivity of ß-phthalimidonitroethene compared to the reactivity of ordinary nitroalkenes in the reaction with 3-pyrrolyloxindoles was demonstrated by contrast experiments.
RESUMO
An organocatalyzed direct asymmetric vinylogous Michael addition reaction of α,ß-unsaturated γ-butyrolactam to 2-enoylpyridines has been developed with a chiral bifunctional amine-squaramide as the catalyst. This approach provides easy access to a series of optically active α,ß-unsaturated γ-substituted butyrolactams in high yields (up to 99%) with excellent diastereoselectivities (up to >99 : 1) and enantioselectivities (up to >99% ee).
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Investigation of the ethanol extract of the whole plant of Ainsliaea yunnanensis led to the isolation of four new dimeric sesquiterpene lactones, ainsliadimer F-I (1-4), together with seven known dimeric sesquiterpene lactones (5-11) and ten sesquiterpenes (12-21). Their structures were elucidated by spectroscopic methods. The relative stereochemistry of ainsliadimer F was further confirmed by single crystal X-ray diffraction analysis. Compounds 1-21 were tested for the inhibition of nuclear factor kappa B (NF-κB) in the 293-NF-κB-luciferase reporter cell line induced by lipopolysaccharide (LPS), and Compounds 5, 18, 20 and 21 were further tested for the production of TNF-α, IL-1ß, IL-6 and IL-10 in RAW 264.7 macrophages induced by LPS. Compounds 5, 18, 20 and 21 exhibited significant activity in anti-inflammatory activity assays.
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Anti-Inflamatórios/química , Asteraceae/química , Citocinas/metabolismo , Lactonas/química , Sesquiterpenos/química , Animais , Anti-Inflamatórios/farmacologia , Cristalografia por Raios X , Regulação da Expressão Gênica/efeitos dos fármacos , Lactonas/farmacologia , Lipopolissacarídeos/efeitos adversos , Camundongos , NF-kappa B/antagonistas & inibidores , Células RAW 264.7 , Sesquiterpenos/farmacologiaRESUMO
Tea plant (Camellia sinensis) is an important natural resource for the global supply of non-alcoholic beverage production. The extension of tea plant cultivation is challenged by biotic and abiotic stresses. Transcription factors (TFs) of the APETALA 2 (AP2)/ethylene-responsive factor (ERF) family are involved in growth and anti-stresses through multifaceted transcriptional regulation in plants. This study comprehensively analyzed AP2/ERF family TFs from C. sinensis on the basis of the transcriptome sequencing data of four tea plant cultivars, namely, 'Yunnanshilixiang', 'Chawansanhao', 'Ruchengmaoyecha', and 'Anjibaicha'. A total of 89 putative AP2/ERF transcription factors with full-length AP2 domain were identified from C. sinensis and classified into five subfamilies, namely, AP2, dehydration-responsive-element-binding (DREB), ERF, related to ABI3/VP (RAV), and Soloist. All identified CsAP2/ERF genes presented relatively stable expression levels in the four tea plant cultivars. Many groups also showed cultivar specificity. Five CsAP2/ERF genes from each AP2/ERF subfamily (DREB, ERF, AP2, and RAV) were related to temperature stresses; these results indicated that AP2/ERF TFs may play important roles in abnormal temperature stress response in C. sinensis.
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Camellia sinensis/genética , Resposta ao Choque Térmico , Proteínas de Plantas/genética , Fator de Transcrição AP-2/genética , Transcriptoma , Sequência de Aminoácidos , Camellia sinensis/fisiologia , Regulação da Expressão Gênica de Plantas , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Elementos de Resposta , Fator de Transcrição AP-2/química , Fator de Transcrição AP-2/metabolismoRESUMO
Catalytic asymmetric sulfenylation and selenenylation of 3-pyrrolyl-oxindoles for the synthesis of 3,3-disubstituted oxindoles bearing two different heteroatoms at the C3 position have been achieved with commercially available cinchonidine as catalyst. A wide range of optically active 3-thio-3-pyrrolyl-oxindoles and 3-seleno-3-pyrrolyl-oxindoles could be smoothly obtained under mild conditions with satisfactory results. The promising applicability of the protocol was also demonstrated by large-scale production.
Assuntos
Compostos Heterocíclicos/síntese química , Indóis/síntese química , Pirróis/síntese química , Compostos de Selênio/química , Compostos de Sulfidrila/química , Catálise , Alcaloides de Cinchona/química , Compostos Heterocíclicos/química , Indóis/química , Estrutura Molecular , Oxindóis , Pirróis/química , EstereoisomerismoRESUMO
Enantioselective Michael/cyclization cascade reactions of 3-hydroxyoxindoles/3-aminooxindoles with α,ß-unsaturated acyl phosphonates by using a cinchonine derived squaramide as the catalyst were developed. A broad range of spirocyclic oxindole-γ-lactones/lactams could be obtained in moderate to excellent yields (up to 98%) with good to excellent diastereo- and enantioselectivities (up to >99:1 dr and 97% ee) under mild conditions. This work represents the first example about the α,ß-unsaturated acyl phosphonates for the asymmetric construction of spirocyclic oxindoles.
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An efficient method for the preparation of 3-sulfonylated 3,3-disubstituted oxindole derivatives has been developed. The protocol involves a base-catalyzed addition of sulfinate salts to 3-halooxindoles, affording a wide range of 3-sulfonylated 3,3-disubstituted oxindoles in good to excellent yields under mild conditions. A preliminary trial of asymmetric catalytic version was conducted and gave promising enantioselectivity. The mechanism for the reaction was tentatively explored with the help of mass spectrometric analysis.
Assuntos
Hidrocarbonetos Halogenados/química , Indóis/química , Ácidos Sulfínicos/química , Indóis/síntese química , Estrutura Molecular , Oxindóis , Sais/químicaRESUMO
RATIONALE: Sesquiterpene pyridine alkaloids are a large group of highly oxygenated sesquiterpenoids that have attracted attention in the fields of medicine because of their significant biological activities. METHODS: Reference compounds including 14 sesquiterpene pyridine alkaloids and one dihydroagarofuran ester were analyzed by collision-induced dissociation tandem mass spectrometry (CID-MS/MS). A high-performance liquid chromatography/electrospray ionization (HPLC/ESI)-MS/MS method at two collision energies was adopted to investigate the botanical extracts of Tripterygium wilfordii. RESULTS: For 15 reference compounds, in the high mass range, the product ions were formed by the loss of side chains or H2 O. In the low mass range, the high-abundance product ions at m/z 206, 204, or 194 were the characteristic ions of the pyridine moiety. The characteristic product ion at m/z 310 was formed through an ion-neutral complex intermediate. Fifty-four sesquiterpenoid derivatives, including 50 sesquiterpene pyridine alkaloids, were identified or tentatively characterized in botanical extracts of T. wilfordii based on their elemental constituents, characteristic fragmentation patterns, and the major product ion profiles of the reference compounds ascertained with HPLC/ESI-MS/MS at two collision energies. It seems that isocratic energy was appropriate for the untargeted analysis of compounds with molecular weights exceeding 800 Da, whereas a linear gradient energy vs molecular weight was suitable for those compounds with molecular weights below 800 Da. CONCLUSIONS: The HPLC/ESI-MS/MS method, combining characteristic fragmentation patterns and the profiles of the product ions generated at different collision energies, is an effective technique for characterizing untargeted compounds.
Assuntos
Alcaloides/análise , Piridinas/análise , Sesquiterpenos/análise , Tripterygium/química , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodosRESUMO
A series of diarylmethylamine compounds were analyzed using electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOF-MS). [M](+)Ë and [M - H](+) were both observed, but showed different abundances. A possible mechanism for the formation of [M](+)Ë and [M - H](+) was proposed to explicate the rule for the ratio change of I([M](+)Ë)/I([M-H](+)). The [M](+)Ë has two structures, which can interconvert into each other in the gas phase. The substituted groups on the benzene rings play a crucial role in the transfer between the two structures. Electron withdrawing groups can prevent the formation of carbocations, thus nitro-containing diarylmethylamines remained mainly as structure I and were detected as [M](+)Ë. On the contrary, electron donating groups help to stabilize carbocations. This makes structure I transfer to structure II, and structure II prefers to further generate [M - H](+) by loss of an H radical. Nuclear magnetic resonance and D-labelled MS experiments indicate that the 1-C-H bond has strong activity.
Assuntos
Técnicas de Química Analítica/métodos , Radicais Livres/química , Metilaminas/análise , Espectrometria de Massas por Ionização por Electrospray , Cátions/química , Metilaminas/química , Estrutura MolecularRESUMO
UNLABELLED: Phenylketonuria (PKU) is caused by variants in the phenylalanine hydroxylase (PAH) gene. We systematically investigated all 13 exons of the PAH gene and their flanking introns in 31 unrelated patients and their parents using next-generation sequencing (NGS). A total of 33 different variants were identified in 58 of 62 mutant PAH alleles. The prevalent variants with a relative frequency of 5 % or more were c.721C > T, c.1068C > A, c.611A > G, c.1197A > T, c.728G > A, c.331C > T, and c.442-1G > A. One novel variant was identified in this study-c.699C > G. We studied genotype-phenotype correlations using the Guldberg arbitrary value (AV) system, which revealed a consistency rate of 38 % (8/21) among the 21 predicted phenotypes. The genotype-based prediction of BH4 responsiveness was also evaluated, and 14 patients (45.2 %) were predicted to be BH4 responsive. CONCLUSION: This study presents the spectrum of PAH variants in Jiangsu province. The information obtained from the genotype-based prediction of BH4 responsiveness might be used for the rational selection of candidates for BH4 testing. WHAT IS KNOWN: ⢠Phenylketonuria (PKU) is caused by variants in the phenylalanine hydroxylase (PAH) gene. ⢠The spectrum of PAH variants in different Chinese populations has been reported. What is new: ⢠This is the first report on the spectrum of PAH variants in Jiangsu province. ⢠This study identified one novel PAH variant-c.699C>G-and and tries to show a genotype-phenotype relationship also regarding BH4-responsiveness.