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1.
New Phytol ; 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39103987

RESUMEN

Plant phenology, the timing of recurrent biological events, shows key and complex response to climate warming, with consequences for ecosystem functions and services. A key challenge for predicting plant phenology under future climates is to determine whether the phenological changes will persist with more intensive and long-term warming. Here, we conducted a meta-analysis of 103 experimental warming studies around the globe to investigate the responses of four phenophases - leaf-out, first flowering, last flowering, and leaf coloring. We showed that warming advanced leaf-out and flowering but delayed leaf coloring across herbaceous and woody plants. As the magnitude of warming increased, the response of most plant phenophases gradually leveled off for herbaceous plants, while phenology responded in proportion to warming in woody plants. We also found that the experimental effects of warming on plant phenology diminished over time across all phenophases. Specifically, the rate of changes in first flowering for herbaceous species, as well as leaf-out and leaf coloring for woody species, decreased as the experimental duration extended. Together, these results suggest that the real-world impact of global warming on plant phenology will diminish over time as temperatures continue to increase.

2.
Adv Pharmacol Pharm Sci ; 2023: 6737062, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38075389

RESUMEN

Pexidartinib offered a new therapeutic option for adult patients with symptomatic tenosynovial giant cell tumor (TGCT) who were refractory to surgical treatment and had severe morbidity or functional limitations. Meanwhile, the metabolism of pexidartinib was mainly mediated through the oxidation of cytochrome P450 (CYP) 3A and glucuronidation by uridine glucuronosyltransferase (UGT) 1A4 and attention shall be paid to CYP450-based drug-drug interactions during therapeutic dosing. This study aimed to examine the changes in the pharmacokinetics of pexidartinib by silymarin and compound glycyrrhizin on pexidartinib in vivo in rats by high-performance liquid chromatography (HPLC)-UV approach and to detect its expression in CYP3A4 and CYP2C9 using the western blot. The findings of chromatography experiments revealed that silybinin as well as compound glycyrrhizin increased the exposure of pexidartinib in rats and had a significant inhibitory effect on the metabolism of pexidartinib. The results of immunoblotting assays suggested that silybinin as well as compound glycyrrhizin inhibited the protein expression of CYP3A4 and CYP2C9 in rats. Therefore, the combination of pexidartinib with silybinin and compound glycyrrhizin should be monitored to avoid clinical adverse effects.

3.
Nat Commun ; 14(1): 6086, 2023 09 29.
Artículo en Inglés | MEDLINE | ID: mdl-37773240

RESUMEN

Post-translational modifications (PTMs) couple feed-fast cycles to diurnal rhythms. However, it remains largely uncharacterized whether and how meal timing organizes diurnal rhythms beyond the transcriptome. Here, we systematically profile the daily rhythms of the proteome, four PTMs (phosphorylation, ubiquitylation, succinylation and N-glycosylation) and the lipidome in the liver from young female mice subjected to either day/sleep time-restricted feeding (DRF) or night/wake time-restricted feeding (NRF). We detect robust daily rhythms among different layers of omics with phosphorylation the most nutrient-responsive and succinylation the least. Integrative analyses reveal that clock regulation of fatty acid metabolism represents a key diurnal feature that is reset by meal timing, as indicated by the rhythmic phosphorylation of the circadian repressor PERIOD2 at Ser971 (PER2-pSer971). We confirm that PER2-pSer971 is activated by nutrient availability in vivo. Together, this dataset represents a comprehensive resource detailing the proteomic and lipidomic responses by the liver to alterations in meal timing.


Asunto(s)
Relojes Circadianos , Multiómica , Femenino , Ratones , Animales , Proteómica , Ritmo Circadiano/fisiología , Sueño , Hígado/metabolismo , Relojes Circadianos/fisiología
4.
Nat Metab ; 5(7): 1236-1251, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37365376

RESUMEN

Physical endurance and energy conservation are essential for survival in the wild. However, it remains unknown whether and how meal timing regulates physical endurance and muscle diurnal rhythms. Here, we show that day/sleep time-restricted feeding (DRF) enhances running endurance by 100% throughout the circadian cycle in both male and female mice, compared to either ad libitum feeding or night/wake time-restricted feeding. Ablation of the circadian clock in the whole body or the muscle abolished the exercise regulatory effect of DRF. Multi-omics analysis revealed that DRF robustly entrains diurnal rhythms of a mitochondrial oxidative metabolism-centric network, compared to night/wake time-restricted feeding. Remarkably, muscle-specific knockdown of the myocyte lipid droplet protein perilipin-5 completely mimics DRF in enhancing endurance, enhancing oxidative bioenergetics and outputting rhythmicity to circulating energy substrates, including acylcarnitine. Together, our work identifies a potent dietary regimen to enhance running endurance without prior exercise, as well as providing a multi-omics atlas of muscle circadian biology regulated by meal timing.


Asunto(s)
Relojes Circadianos , Carrera , Femenino , Ratones , Masculino , Animales , Ritmo Circadiano/fisiología , Relojes Circadianos/fisiología
5.
Ecol Lett ; 26(8): 1370-1381, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37278184

RESUMEN

Shifts in plant phenology influence ecosystem structures and functions, yet how multiple global change drivers interact to affect phenology remains elusive. We conducted a meta-analysis of 242 published articles to assess interactions between warming (W) and other global change drivers including nitrogen addition (N), increased precipitation (IP), decreased precipitation (DP) and elevated CO2 (eCO2 ) on multiple phenophases in experimental studies. We show that leaf out and first flowering were most strongly affected by warming, while warming and decreased precipitation were the most pronounced drivers for leaf colouring. Moreover, interactions between warming and other global change drivers were common and both synergistic and antagonistic interactions were observed: interactions W + IP and W + eCO2 were frequently synergistic, whereas interactions W + N and W + DP were mostly antagonistic. These findings demonstrate that global change drivers often affect plant phenology interactively. Incorporating the multitude of interactions into models is crucial for accurately predicting plant responses to global changes.


Asunto(s)
Clima , Ecosistema , Plantas , Hojas de la Planta/fisiología , Reproducción , Cambio Climático
6.
F1000Res ; 11: 1087, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36531263

RESUMEN

Background: Meal timing resets circadian clocks in peripheral tissues, such as the liver, in seven days without affecting the phase of the central clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus. Anterior hypothalamus plays an essential role in energy metabolism, circadian rhythm, and stress response. However, it remains to be elucidated whether and how anterior hypothalamus adapts its circadian rhythms to meal timing. Methods: Here, we applied transcriptomics to profile rhythmic transcripts in the anterior hypothalamus of nocturnal female mice subjected to day- (DRF) or night (NRF)-time restricted feeding for seven days. Results: This global profiling identified 128 and 3,518 rhythmic transcripts in DRF and NRF, respectively. NRF entrained diurnal rhythms among 990 biological processes, including 'Electron transport chain' and 'Hippo signaling' that reached peak time in the late sleep and late active phase, respectively. By contrast, DRF entrained only 20 rhythmic pathways, including 'Cellular amino acid catabolic process', all of which were restricted to the late active phase. The rhythmic transcripts found in both DRF and NRF tissues were largely resistant to phase entrainment by meal timing, which were matched to the action of the circadian clock. Remarkably, DRF for 36 days partially reversed the circadian clock compared to NRF. Conclusions: Collectively, our work generates a useful dataset to explore anterior hypothalamic circadian biology and sheds light on potential rhythmic processes influenced by meal timing in the brain (www.circametdb.org.cn).


Asunto(s)
Relojes Circadianos , Núcleo Supraquiasmático , Femenino , Animales , Ratones , Núcleo Supraquiasmático/metabolismo , Relojes Circadianos/fisiología , Ritmo Circadiano/fisiología , Hipotálamo , Hígado
7.
Sheng Li Xue Bao ; 74(5): 726-736, 2022 Oct 25.
Artículo en Chino | MEDLINE | ID: mdl-36319096

RESUMEN

The central circadian clock and feeding rhythm coordinately reset peripheral circadian clocks. Emerging evidence suggests that feeding rhythm resets peripheral circadian clocks in a tissue-specific manner. This study aimed to determine whether and how feeding rhythm regulates circadian rhythms of the circadian clock and metabolic genes in brown adipose tissue (BAT). We applied different regimens of time-restricted feeding (TRF) in wildtype and Per1/2 deficient C57BL/6 mice, and quantified the effects of sex, treatment duration, constant light, and circadian clock on circadian rhythms of the BAT circadian clock and metabolic genes by RT-qPCR; Representative circadian clock genes are Bmal1, Nr1d1, Dbp, and Per2, and representative metabolic genes are uncoupling protein 1 (Ucp1), 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (Pfkfb3) that controls the flux through glycolysis, pyruvate dehydrogenase kinase isozyme 4 (Pdk4) gating the tricarboxylic acid cycle, and carnitine palmitoyltransferase 1A (Cpt1a) that controls mitochondrial fatty acid oxidation. The results showed that, daytime-restricted feeding (DRF) moderately shifted the phase of the BAT circadian clock in female mice within 7 or 36 d, and resulted in the loss of circadian rhythm in Dbp and Per2 transcripts in males. DRF induced de novo oscillation of the Ucp1 transcript, and shifted the phase of representative metabolic genes, such as Pfkfb3, Pdk4, and Cpt1a, more than 7 h. Constant light is known to disrupt the synchrony of the central circadian clock. The results showed that constant light promoted phase entrainment of the circadian clock by DRF in BAT, but abolished the oscillation of the metabolic genes (except for Pdk4). Despite combined treatment with Per1/2 deficiency and constant darkness, DRF was sufficient to drive circadian rhythms of Bmal1 and Dbp, but not those of Nr1d1, Ucp1, Pfkfb3, and Cpt1a. Overall, the circadian clock of BAT has weak adaptation to altered feeding rhythms and sex differences. The central circadian clock antagonizes DRF in the entrainment of the BAT circadian clock, whereas DRF resets circadian rhythms of metabolic genes, such as Ucp1, Pfkfb3, and Cpt1a, in a circadian clock-dependent manner.


Asunto(s)
Relojes Circadianos , Femenino , Masculino , Animales , Ratones , Ratones Endogámicos C57BL , Tejido Adiposo Pardo , Factores de Transcripción ARNTL , Ritmo Circadiano
8.
J Mol Cell Biol ; 14(8)2022 12 26.
Artículo en Inglés | MEDLINE | ID: mdl-36107452

RESUMEN

Comparative gene identification-58 (CGI-58), also known as α/ß hydrolase domain containing 5, is the co-activator of adipose triglyceride lipase that hydrolyzes triglycerides stored in the cytosolic lipid droplets. Mutations in CGI-58 gene cause Chanarin-Dorfman syndrome (CDS), an autosomal recessive neutral lipid storage disease with ichthyosis. The liver pathology of CDS manifests as steatosis and steatohepatitis, which currently has no effective treatments. Perilipin-3 (Plin3) is a member of the Perilipin-ADRP-TIP47 protein family that is essential for lipid droplet biogenesis. The objective of this study was to test a hypothesis that deletion of a major lipid droplet protein alleviates fatty liver pathogenesis caused by CGI-58 deficiency in hepatocytes. Adult CGI-58-floxed mice were injected with adeno-associated vectors simultaneously expressing the Cre recombinase and microRNA against Plin3 under the control of a hepatocyte-specific promoter, followed by high-fat diet feeding for 6 weeks. Liver and blood samples were then collected from these animals for histological and biochemical analysis. Plin3 knockdown in hepatocytes prevented steatosis, steatohepatitis, and necroptosis caused by hepatocyte CGI-58 deficiency. Our work is the first to show that inhibiting Plin3 in hepatocytes is sufficient to mitigate hepatocyte CGI-58 deficiency-induced hepatic steatosis and steatohepatitis in mice.


Asunto(s)
1-Acilglicerol-3-Fosfato O-Aciltransferasa , Hígado Graso , Ratones , Animales , Perilipina-3 , 1-Acilglicerol-3-Fosfato O-Aciltransferasa/genética , 1-Acilglicerol-3-Fosfato O-Aciltransferasa/metabolismo , Hígado Graso/genética , Hígado Graso/metabolismo , Hepatocitos/metabolismo , Triglicéridos/metabolismo
9.
World J Surg Oncol ; 19(1): 284, 2021 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-34537053

RESUMEN

BACKGROUND: To determine the potential of the combination of DCE-MRI imaging method with DWI and serum CA125 and CA199 levels in the evaluation of the efficacy of neoadjuvant chemotherapy in breast cancer patients. METHODS: Sixty-five breast cancer patients who received neoadjuvant chemotherapy in our hospital from April 2016 to April 2017 were selected as research subjects. The patients received 4 courses of neoadjuvant chemotherapy. Lesions were monitored using DCE-MRI and DWI, while ELISA was used to measure the serum expression levels of the tumour markers CA125 and CA199. The patients were divided into the remission group and ineffective group based on pathological diagnosis. RESULTS: There were significant differences in Kep, Ktrans, ADCmin, ADCmean, tumour volume, and serum levels of CA125 and CA199 in patients in the remission group, before and after neoadjuvant chemotherapy, and there were significant differences in post-chemotherapy values of these indexes between the remission group and the ineffective group (p < 0.01). CONCLUSION: Combination of DCE-MRI diagnostic imaging with DWI can directly reflect the lesions in breast cancer patients after neoadjuvant chemotherapy. Serum levels of CA125 and CA199 levels are useful for evaluation of the impact of neoadjuvant chemotherapy on breast cancer patients, including risk of cancer cell metastasis and changes in some small lesions.


Asunto(s)
Neoplasias de la Mama , Terapia Neoadyuvante , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/tratamiento farmacológico , Medios de Contraste , Imagen de Difusión por Resonancia Magnética , Femenino , Humanos , Imagen por Resonancia Magnética , Pronóstico , Resultado del Tratamiento
10.
STAR Protoc ; 2(3): 100701, 2021 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-34382024

RESUMEN

Inverted feeding is a paradigm to study synchronization of circadian clocks by feeding rhythm in tissues more directly. Here, we provide a protocol for performing inverted feeding in mice and analyzing circadian rhythmicity in mouse tissues. We describe setting up inverted feeding and performing tissue dissection, followed by RNA extraction and gene expression analysis, and lastly R software-based analysis of circadian rhythmicity. This protocol can be combined with the use of CircaMetDB database for mechanistic studies of inverted feeding. For complete details on the use and execution of this protocol, please refer to Xin et al. (2021).


Asunto(s)
Ritmo Circadiano/fisiología , Biología Computacional/métodos , Animales , Relojes Circadianos/genética , Ritmo Circadiano/genética , Conducta Alimentaria/fisiología , Metabolismo/fisiología , Ratones , Proteínas Circadianas Period/genética
11.
Mol Divers ; 25(2): 861-876, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-32172491

RESUMEN

In the present investigation, a series of dihydrotriazine derivatives-bearing 5-aryloxypyrazole moieties were synthesized and their structures were confirmed by different spectral tools. The biological evaluation in vitro revealed that some of the target compounds exerted good antibacterial and antifungal activity in comparison with the reference drugs. Among these novel hybrids, compound 10d showed the most potent activity with minimum inhibitory concentration values (MIC) of 0.5 µg/mL against S. aureus 4220, MRSA 3506 and E. coli 1924 strain. The cytotoxic activity of the compounds 6d, 6m, 10d and 10g was assessed in MCF-7 and HeLa cells. Growth kinetics study showed significant inhibition of bacterial growth when treated with different conc. of 10d. In vitro enzyme study implied that compound 10d exerted its antibacterial activity through DHFR inhibition. Moreover, significant inhibition of biofilm formation was observed in bacterial cells treated with MIC conc. of 10d as visualized by SEM micrographs. Twenty-nine target compounds were designed, synthesized and evaluated in terms of their antibacterial and antifungal activities.


Asunto(s)
Antibacterianos , Triazinas , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Supervivencia Celular/efectos de los fármacos , Células HeLa , Humanos , Células MCF-7 , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Relación Estructura-Actividad , Tetrahidrofolato Deshidrogenasa/química , Triazinas/síntesis química , Triazinas/química , Triazinas/farmacología
12.
Mol Divers ; 23(4): 997-1010, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30953296

RESUMEN

A Rh(I)/Sc(III) co-catalyzed synthesis of highly valuable functionalized 1,4-diketone derivatives in good yields and with an excellent diastereoselectivity. The established method provides a rapid approach to structurally diverse 1,4-diketone scaffold in a very mild and rapid fashion from simple starting materials. Moreover, the protocol could be easily scaled up to gram-scale synthesis. An attempt to develop an asymmetric version of the Rh(I)/guanidine system was also explored, resulting in a moderate enantioselectivity (71% ee).


Asunto(s)
Cetonas/química , Rodio/química , Escandio/química , Compuestos de Amonio/química , Compuestos de Anilina/química , Catálisis , Indoles/química
13.
Life Sci ; 200: 81-86, 2018 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-29551577

RESUMEN

AIMS: To investigate whether intrauterine organochlorine pesticide (OCP)-dichlorodiphenyltrichloroethane (DDT) exposure could lead to epigenetic alterations by DNA methylation with possible important lifetime health consequences for offspring. MAIN METHODS: We used Illumina Infinium HumanMethylation 450 K BeadChip to explore the pattern of genome-wide DNA methylation containing >485,000 gene sites in cord blood of 24 subjects in a 12 mother-newborn pairs birth cohort. Based on the genome-wide DNA methylation data, we chose one potential gene, BRCA1, to verify the results in another group comprising 126 subjects. KEY FINDINGS: We identified 1,131 significantly different CpG sites which included 690 hypermethylation sites and 441 hypomethylation sites in the DNA methylation level between case and control group. The identified sites were located in 598 unique genes. In subsequent validation studies, we found that the DNA methylation level of the identified CpGs of BRCA1 increased with increased exposure to dichlorodiphenyltrichloroethane (DDT) and the level of gene expression in the identified CpGs of BRCA1 decreased with increased exposure to dichlorodiphenyltrichloroethane (DDT). SIGNIFICANCE: The results indicated that epigenetic processes played a possible role in the development of fetuses affected by maternal OCP-DDT exposure. Early prenatal exposure to DDT may affect fetal BRCA1 gene methylation, and increased exposure leads to a higher DNA methylation level and lower gene expression level.


Asunto(s)
Islas de CpG , Metilación de ADN/efectos de los fármacos , Diclorodifenildicloroetano/toxicidad , Feto/metabolismo , Insecticidas/toxicidad , Exposición Materna/efectos adversos , Adulto , Proteína BRCA1/biosíntesis , Femenino , Feto/patología , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Estudio de Asociación del Genoma Completo , Humanos , Recién Nacido , Masculino , Embarazo
14.
Chem Sci ; 8(6): 4312-4317, 2017 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-29081965

RESUMEN

Metal-associated carbenes from diazo compounds promote many useful chemistry transformations in modern organic chemistry. However, compared to α-aryldiazoacetate-derived carbenes (ArDCs), the synthetic application of α-alkyldiazoacetate-derived carbenes (AlDCs) is greatly limited due to intramolecular α-H transfer (elimination) that results in alkenes as the main by-products. An intriguing α-alkyldiazoacetate-involved three-component reaction has been developed following DFT calculation inspiration to provide ß-hydroxyl α-alkyl-α-amino acid derivatives in good yields. The intramolecular α-H shift of an α-alkyldiazoacetate-derived carbene was successfully suppressed by the association of a Rh(i) complex to form the corresponding active ammonium ylide, which was trapped before the fast 1,2-H transfer process. A Rh(i)-chiral diene complex was identified as an effective catalyst to give an asymmetric version of the reaction with good enantioselectivity. This reaction provides insight into extending the efficient transformation of α-alkyldiazoacetate-derived carbenes and their synthetic application.

15.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 48(3): 410-417, 2017 May.
Artículo en Chino | MEDLINE | ID: mdl-28616916

RESUMEN

OBJECTIVES: To determine the associations of single nucleotide polymorphism (SNP) in leptin (LEP) genes and environmental factors with cholesterol gallstone in southeast Han populations. METHODS: A 1:2 matched case-control study was conducted involving 200 patients with cholesterol gallstone. Genotyping of the SNP was examined on the LightCycler480 PCR platform using in-house high resolution melting (HRM) approaches. Detection correctness was validated through direct sequencing. Multifactor dimensionality reduction (MDR) analysis was applied to examine the effects of potential gene-environment interactions. RESULTS: Three genotypes of LEP G2548A were obtained by HRM genotyping, including 52 cases of GG wild type, 192 cases of GA mutant heterozygosity and 356 cases of AA mutation homozygous type. The genotype distribution of the SNP locus in the control group was in line with the Hardy-Weinberg genetic balance (P>0.05). The AA genotype carriers of LEP G2548A had significantly higher serum leptin than the GA/GG genotype carriers (H=6.83, P<0.05). The conditional logistic regression revealed that high serum leptin [odds ratio (OR)=5.012, 95% confidence interval (CI): 3.248-7.734], AA genotype of LEP G2548A site (OR=2.292, 95%CI: 1.012-5.193), family history of gallstones (OR=2.984, 95%CI: 1.329-6.700), high SBP (OR=1.927, 95%CI: 1.140-3.255) and smoking (OR=1.717, 95%CI: 1.006-2.928) were predictors of cholesterol gallstone. However, regular drinking of strong tea (OR=0.552, 95%CI: 0.336-0.907) and exercise (OR=0.591, 95%CI: 0.395-0.882) were protecting factors for cholesterol gallstone. The results of MDR analysis indicated that tea drinking, genotype of LEP G2548A site and serum leptin formed the optimal gene-environment interaction model. CONCLUSIONS: Individuals who drink less tea, carry AA genotype and have high serum leptin are more susceptible to cholesterol gallstone.


Asunto(s)
Cálculos Biliares/genética , Leptina/genética , Polimorfismo de Nucleótido Simple , Estudios de Casos y Controles , Colesterol , Predisposición Genética a la Enfermedad , Genotipo , Humanos
16.
Sci Adv ; 3(3): e1602467, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28345053

RESUMEN

Multicomponent reactions (MCRs) represent an ideal organic synthesis tool for the rapid construction of complex molecules due to their step and atom economy. Compared to two-component reactions, the development of new MCRs has been greatly limited during the 170 years since the first MCR was reported. Theoretically, the trapping of an active intermediate generated from two components by a third component could change the traditional two-component reaction pathway, leading to the discovery of MCRs. We report an example of the trapping of α-imino enols generated in situ from 1-sulfonyl-1,2,3-triazoles via α-imino metal carbene species by vinylimine ions using C(2)-substituted indoles and paraformaldehyde as precursors in the presence of a rhodium(II) catalyst. The traditional enol-ketone transformation pathway was suspended by the trapping procedure and efficiently switched to an MCR pathway to produce α-amino-ß-indole ketones in moderate to good yields. Unexpectedly, the resulting products and the theoretical density functional theory (DFT) calculation results indicated that the enolic carbon had a stronger nucleophilicity than the well-known traditional enamic carbon in the trapping process. The reaction mechanism was investigated using control experiments and detailed DFT calculations, and the synthetic application of the products was also illustrated. The developed strategy provides a mild and rapid access to α-amino-ß-indole ketones and suggests a rationale for the discovery of MCRs by trapping an active intermediate with a third component in a traditional two-component reaction pathway.

17.
Org Lett ; 19(6): 1290-1293, 2017 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-28248513

RESUMEN

A Ru(II)/iminium cocatalyzed asymmetric formal [3 + 1 + 1] cycloaddition reaction of diazoacetophenones, anilines, and enals is disclosed to construct multisubstituted pyrrolidines in one step with excellent diastereoselectivity and enantioselectivity. The reaction mechanism was postulated as a successful trapping of Ru(II)-associated ammonium ylides via a selective 1,4-addition to chiral amine activated enals followed by a tandem aza-aldol process. The control experiments and theoretical density functional theory investigation revealed that the reversible NaOAc-facilitated aza-aldol process led to the diastereomeric conversion to provide a stable product.

18.
Chem Commun (Camb) ; 53(19): 2854-2857, 2017 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-28217767

RESUMEN

An iron catalyzed three-component reaction of alkyl diazoesters, isatins and ammonia is reported. This reaction provided convenient access to non-protected ß-hydroxy-α-aminoesters with adjacent quaternary stereocenters. This transformation is achieved via trapping of ammonium ylide which is generated from a diazocompound and ammonia under mild reaction conditions. Poly-functional group unprotected amines are obtained exclusively with up to 77% yield and 62 : 38 dr.

19.
Zhonghua Yu Fang Yi Xue Za Zhi ; 49(11): 998-1004, 2015 Nov.
Artículo en Chino | MEDLINE | ID: mdl-26833012

RESUMEN

OBJECTIVE: To investigate the levels and influencing factors of phthalate internal exposure in pregnant women (gestation age ≤ 16 weeks). METHODS: During April to June in 2013, 1 020 pregnant women (gestation age ≤ 16 weeks) who had established the maternal care manual were recruited in maternal and child health hospital of Siming District, Xiamen city. Participators were asked to complete a questionnaire to obtain information on socio-demographic characteristics, lifestyle behaviors, and antenatal examination and to provide a urine sample. Finally, 998 pregnant women who provided a urine sample and completed the questionnaire were enrolled. Adopting systematic sampling method, 100 ones were selected randomly among 998 pregnant women. High performance liquid chromatography-electrospray ionization-tandern mass was used to determine the concentration of five phthalate monoesters in each urine, including mono-n-methyl phthalate (MMP), mono-ethyl phthalate (MEP), mono-butyl phthalate (MBP), mono-benzyl phthalate (MBzP), mono-ethylhexyl phthalate (MEHP). Based on the measurements and questionnaire data, multivariate logistic regression was used to analyze the association between the phthalate monoester levels and potential influential factors. RESULTS: The detection rates of MMP, MEP, MBP, MBzP and MEHP in 100 pregnant urine samples were 94%, 93%, 87%, 83%, 99%, respectively. And the urinary median uncorrected concentrations of MMP, MEP, MBP, MBzP and MEHP in 100 urine samples were 20.56, 17.62, 10.15, 2.03, and 5.12 ng/ml, respectively. Specific gravity-corrected concentration were 20.81, 20.36, 12.88, 2.58, 5.00 ng/ml, respectively. The results of multivariate logistic regression analysis indicated that: education degree was negatively associated with urinary concentration of MMP, MEP, MBP, MBzP and MEHP, OR (95% CI) were 0.495 (0.253-0.966), 0.380 (0.191-0.755), 0.379 (0.186-0.774), 0.401 (0.196-0.819), 0.373(0.183-0.762), respectively. Participants who had hair permed and dyed during pregnancy had higher urinary level of MBP and MBzP, OR (95% CI) were 12.867 (1.240-133.525), 15.982 (1.367-186.911), respectively; Participants who use cosmetics during pregnancy had higher urinary level of MEP and MBP, OR (95% CI) were 2.977 (1.012-8.757), 4.440 (1.485-13.272), respectively; plastic bottled water consumption was positively associated with urinary concentrations of MEP and MEHP, OR (95% CI) were 3.780 (1.417-10.083), 2.699 (1.039-7.010), respectively; annual household income was negatively associated with urinary concentration of MMP, OR (95% CI) was 0.597 (0.372-0.959); individuals who took medications during pregnancy had higher urinary level of MEHP than non-takers, OR (95% CI) was 4.853 (1.084-21.732). CONCLUSION: Pregnant women whose gestation age was less than 16 weeks are generally exposed to phthalate. Phthalate internal exposure levels are significantly associated with most measured factors and the influencing factors with different phthalates internal exposure levels are different.


Asunto(s)
Exposición Materna , Ácidos Ftálicos/orina , Cromatografía Líquida de Alta Presión , Dibutil Ftalato/orina , Femenino , Humanos , Estilo de Vida , Embarazo , Encuestas y Cuestionarios , Espectrometría de Masas en Tándem
20.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 2): m231-2, 2010 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-21579687

RESUMEN

The asymmetric unit of the title compound, [Mn(C(8)H(7)N(3))(3)](2)[PMo(12)O(40)]·6H(2)O, consists of a complex [Mn(C(8)H(7)N(3))(3)](2+) cation, half of a mixed-valent Mo(V,VI) α-Keggin-type [PMo(12)O(40)](4-) heteropolyanion, and three uncoordinated water mol-ecules. The Mn(2+) cation is surrounded by six N atoms from three chelating 3-(2-pyrid-yl)-1H-pyrazole ligands in a distorted octa-hedral coordination. In the heteropolyanion, two O atoms of the central PO(4) group ( symmetry) are equally disordered about an inversion centre. N-H⋯O and O-H⋯O hydrogen bonding between the cations, anions and the uncoordinated water mol-ecules leads to a consolidation of the structure.

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