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1.
Zhongguo Zhong Yao Za Zhi ; 49(7): 1834-1847, 2024 Apr.
Artículo en Chino | MEDLINE | ID: mdl-38812196

RESUMEN

This study compared the therapeutic difference effects of the raw and scorched rhubarb for the treatment of ulcerative colitis(UC) and explored their difference in chemical components and mechanisms by using ultra-high performance liquid chromatography-quadrupole-electrostatic field orbitrap high-resolution mass spectrometry(UPLC-QE-Orbitrap-MS) and network pharmacology. The UC therapeutic effects of Shaoyao Decoction with the raw rhubarb or the scorched rhubarb were evaluated by dextran sulfate sodium(DSS)-induced mouse model. The results showed that Shaoyao Decoction with either the raw rhubarb or the scorched rhubarb could relieve the UC symptoms of mice to different extents, while the scorched rhubarb-based formula showed advantages in reducing hemorrhagic diarrhea and inflammation levels. UPLC-QE-Orbitrap-MS was used to identify a total of 78 small molecules in the water decoction of the raw and scorched rhubarb. Multivariate statistical methods were used to screen components increasing significantly after the scorching process. The seven compounds included five free anthraquinones, gallic acid, and 5-hydroxymethylfurfural(HMF). Meanwhile, the nine compounds decreasing scorching were mainly combined anthraquinones and catechins-related compounds. Network pharmacology and molecular docking suggested that free anthraquinones, gallic acid, and 5-HMF may act on core targets such as B-cell lymphoma-2(BCL2), epidermal growth factor receptor(EGFR), tumor necrosis factor(TNF), and caspase-3(CASP3) and influence the signaling pathways such as phosphoinositide-3-kinase/protein kinase B(PI3K/Akt), hypoxia inducible factor-1(HIF-1), TNF, and mitogen-activated protein kinase(MAPK), so as to regulate the inflammation response, oxidative stress, and cell apoptosis to relieve UC symptoms. This study compared the therapeutic effects and chemical components of the raw and scorched rhubarb, providing the clinical reference for using rhubarb to treat UC.


Asunto(s)
Colitis Ulcerosa , Medicamentos Herbarios Chinos , Espectrometría de Masas , Farmacología en Red , Rheum , Rheum/química , Animales , Colitis Ulcerosa/tratamiento farmacológico , Ratones , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacología , Cromatografía Líquida de Alta Presión/métodos , Masculino , Humanos
2.
Anal Chem ; 96(14): 5499-5508, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38547315

RESUMEN

Characterizing the profiles of proteome and metabolome at the single-cell level is of great significance in single-cell multiomic studies. Herein, we proposed a novel strategy called one-shot single-cell proteome and metabolome analysis (scPMA) to acquire the proteome and metabolome information in a single-cell individual in one injection of LC-MS/MS analysis. Based on the scPMA strategy, a total workflow was developed to achieve the single-cell capture, nanoliter-scale sample pretreatment, one-shot LC injection and separation of the enzyme-digested peptides and metabolites, and dual-zone MS/MS detection for proteome and metabolome profiling. Benefiting from the scPMA strategy, we realized dual-omic analysis of single tumor cells, including A549, HeLa, and HepG2 cells with 816, 578, and 293 protein groups and 72, 91, and 148 metabolites quantified on average. A single-cell perspective experiment for investigating the doxorubicin-induced antitumor effects in both the proteome and metabolome aspects was also performed.


Asunto(s)
Proteoma , Espectrometría de Masas en Tándem , Humanos , Proteoma/metabolismo , Cromatografía Liquida , Metaboloma , Células HeLa
3.
Nat Commun ; 15(1): 1279, 2024 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-38341466

RESUMEN

The shotgun proteomic analysis is currently the most promising single-cell protein sequencing technology, however its identification level of ~1000 proteins per cell is still insufficient for practical applications. Here, we develop a pick-up single-cell proteomic analysis (PiSPA) workflow to achieve a deep identification capable of quantifying up to 3000 protein groups in a mammalian cell using the label-free quantitative method. The PiSPA workflow is specially established for single-cell samples mainly based on a nanoliter-scale microfluidic liquid handling robot, capable of achieving single-cell capture, pretreatment and injection under the pick-up operation strategy. Using this customized workflow with remarkable improvement in protein identification, 2449-3500, 2278-3257 and 1621-2904 protein groups are quantified in single A549 cells (n = 37), HeLa cells (n = 44) and U2OS cells (n = 27) under the DIA (MBR) mode, respectively. Benefiting from the flexible cell picking-up ability, we study HeLa cell migration at the single cell proteome level, demonstrating the potential in practical biological research from single-cell insight.


Asunto(s)
Proteoma , Proteómica , Animales , Humanos , Células HeLa , Proteómica/métodos , Proteoma/metabolismo , Análisis de la Célula Individual , Flujo de Trabajo , Mamíferos/metabolismo
4.
Cell Rep ; 42(11): 113455, 2023 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-37976159

RESUMEN

Although single-cell multi-omics technologies are undergoing rapid development, simultaneous transcriptome and proteome analysis of a single-cell individual still faces great challenges. Here, we developed a single-cell simultaneous transcriptome and proteome (scSTAP) analysis platform based on microfluidics, high-throughput sequencing, and mass spectrometry technology to achieve deep and joint quantitative analysis of transcriptome and proteome at the single-cell level, providing an important resource for understanding the relationship between transcription and translation in cells. This platform was applied to analyze single mouse oocytes at different meiotic maturation stages, reaching an average quantification depth of 19,948 genes and 2,663 protein groups in single mouse oocytes. In particular, we analyzed the correlation of individual RNA and protein pairs, as well as the meiosis regulatory network with unprecedented depth, and identified 30 transcript-protein pairs as specific oocyte maturational signatures, which could be productive for exploring transcriptional and translational regulatory features during oocyte meiosis.


Asunto(s)
Proteoma , Transcriptoma , Animales , Ratones , Transcriptoma/genética , Proteoma/metabolismo , Oocitos/metabolismo , Oogénesis/genética , Perfilación de la Expresión Génica , Meiosis
5.
Food Chem X ; 19: 100826, 2023 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-37780250

RESUMEN

This study aims to analysis the structures of polysaccharides isolated from Pteridium revolutum and their antioxidant and antiglycated activities. Three novel water-soluble heteropolysaccharides, named PRP0, PRP1, and PRP2, were isolated from P. revolutum. The average molecular weight was determined by high performance gel permeation chromatography analysis as 1.04 × 106, 8.39 × 105, and 7.37 × 105 Da, respectively. Their structures were characterized using physicochemical and spectroscopic methods. The antioxidant and antiglycated activities were assayed in vitro. PRP0, PRP1, and PRP2 consist of l-Ara, l-Rha, d-Man, d-Xyl, d-Fuc, d-Gal, and d-Glc in different proportions. PRP1 mainly has a backbone of (1 â†’ 3,6)-linked d-Man and (1 â†’ 3)-linked d-Gal on main chain. PRP2 is mainly composed of (1 â†’ 2,4)-linked d-Man and (1 â†’ 3)-linked d-Gal on main chain. All polysaccharides have strong scavenging power on 2,2-difenil-1-picril-hidrazil and hydroxyl radicals and significantly antiglycated activity in Bovine serum albumin-Glucose model, which showing that the polysaccharides have potential application value on the functional food.

6.
Am J Chin Med ; 51(7): 1845-1864, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37667863

RESUMEN

Sleep deprivation (SD) has become a universal social problem. There is a causal relationship between SD and energy metabolism disorder. Phytochemicals have been demonstrated to have excellent sleep-promoting effects, and studies have shown that ginsenoside Rg5 (Rg5) exerts sedative and hypnotic effects. The present study aimed to investigate the role of Rg5 in regulating energy metabolism and explore the potential mechanism of improving sleep. Sleep-deprived rats were randomly divided into a control group (Ctrl), SD model group (SD), Rg5 group (GRg5), and melatonin group (MT). Sleep-deprived model rats were generated by housing rats in an SD box for 4 weeks. The Ctrl and SD groups were given equal volumes of saline. The Rg5 groups were given 25[Formula: see text]mg/kg Rg5 or 50[Formula: see text]mg/kg Rg5, and the MT group was given 0.27[Formula: see text]g/kg MT. A Western blot analysis and ELISA were used to detect the metabolic levels, mitochondrial functional proteins, AMPK pathway proteins, clock-related proteins, adenosine receptors, and neurotransmitter receptors. The results showed that Rg5 corrected abnormal glucose and lipid metabolism as well as improved ATP levels. In addition, Rg5 alleviated mitochondrial structural damage and improved the expression of proteins involved in mitochondrial biosynthesis, fission, and fusion. Moreover, Rg5 improved the expression of AMPK/PGC-1/Nrf-1 pathway proteins, regulated mitochondrial biological functions, and affected the rhythm characteristics of circadian clock-related proteins. Further, Rg5 improved the expression of A1R and A[Formula: see text]R as well as regulated the expression levels of GABAA1[Formula: see text] and mGluR5 to improve sleep in SD rats.

7.
ACS Appl Mater Interfaces ; 15(20): 24408-24415, 2023 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-37186773

RESUMEN

As one of the most widely used energetic materials to date, trinitrotoluene (TNT) suffers from several generally known drawbacks such as high toxicity, oil permeability, and poor mechanical properties, which are driving researchers to explore new high-performance energetic melt-castable materials for replacing TNT. However, it still remains a great challenge to discover a promising TNT alternative due to the multidimensional requirements for practical applications. Herein, we reported a new promising energetic melt-castable molecule, 4-methoxy-1-methyl-3,5-dinitro-1H-pyrazole (named as DMDNP). Besides a reasonable melting point (Tm: 94.8 °C), good thermostability (Td: 293.2 °C), and excellent chemical compatibility, DMDNP exhibits some obvious advantages over TNT including more environmentally friendly synthesis, high yield, low toxicity, low volume shrinkage, low mechanical and electrostatic sensitivities, etc., demonstrating well-balanced properties and great promise as a TNT replacement.

8.
Zhongguo Zhong Yao Za Zhi ; 47(19): 5203-5208, 2022 Oct.
Artículo en Chino | MEDLINE | ID: mdl-36472026

RESUMEN

The present study comprehensively compared the content of chondroitin sulfate in Cervi Cornu Pantotrichum(CCP) and Cervi Cornu(CC) of different specifications and explored the feasibility of chondroitin sulfate as an indicator to distinguish between CCP and CC. Twenty-two batches of CCP of different specifications(two-branched velvet antler and three-branched velvet antler) from 15 habitats, CC from 6 habitats, and 60 batches of CCP slices prepared from different parts(wax slices, powder slices, gauze slices, and bone slices) were collected. High-performance liquid chromatography(HPLC) was used to determine chondroitin sulfate content in CCP and CC of different specifications. Cluster analysis was used to classify CCP slices of different specifications. The results showed that CCP contained abundant chondroitin sulfate. The average content of chondroitin sulfate was 2.35 mg·g~(-1) in two-branched velvet antler and 1.79 mg·g~(-1) in three-branched velvet antler, significantly higher than 0.11 mg·g~(-1) in CC. Chondroitin sulfate content in wax slices, powder slices, gauze slices, and bone slices were 7.81, 8.39, 1.33, and 0.54 mg·g~(-1), respectively. Cluster analysis showed that gauze slices and bone slices could be clustered into one category and distinguished from wax slices and powder slices. CCP slices prepared from different parts could be separated well through chondroitin sulfate content. Based on the five principles of Q-marker selection, chondroitin sulfate can be used as a potential Q-marker for the identification of CCP and CC, as well as a potential quality indicator for CCP slices of different specifications(wax slices, powder slices, gauze slices, and bone slices). This research provides data support for CCP quality evaluation.


Asunto(s)
Cuernos de Venado , Cornus , Ciervos , Gastrópodos , Animales , Sulfatos de Condroitina , Polvos
9.
Front Microbiol ; 13: 1055055, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36569047

RESUMEN

Ophiocordyceps sinensis is widely utilized due to its pharmaceutical value. Mycelial protein forms a key active component of O. sinensis and determines the medicinal potential of fungus. Here, we describe the development of an optimized fermentation medium to obtain more mycelial soluble protein from O. sinensis using response surface methodology (RSM) and investigate the increased mycelial protein content using transcriptomics. The maximum mycelial protein content of 2.11% was obtained using a medium consisting of 20% beef broth, 0.10% peptone, 2% glucose, 0.15% yeast extract, 0.20% KH2PO4, and 0.02% MgSO4. Transcriptome analysis identified 790 differentially expressed genes (DEGs), including 592 up-regulated genes and 198 down-regulated genes, optimisation resulted in more up-regulated genes. The main DEGs were enriched in metabolic pathways, ABC transporters, starch and sucrose metabolism, tyrosine metabolism, and glutathione metabolism. In addition, some DEGs associated with mycelial protein enhancement such as tyrosinase (TYR), glutathione S-transferase (GST), glutamine synthetase (glnA), and ß-glucosidase may contribute to increased mycelial protein content. Real-time quantitative PCR (RT-qPCR) was used to confirm gene expression and the results support the accuracy of RNA-Seq and DEG analysis. This study provides an optimized fermentation method for enhancing the mycelial protein content of O. sinensis and a reference for the effective development of O. sinensis protein.

10.
J Colloid Interface Sci ; 628(Pt A): 426-436, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-35932679

RESUMEN

Strongly hydrogen-bonded compounds such as 1,3,5-triamino-2,4,6­trinitrobenzene (TATB, an important insensitive high explosive) have excellent stability, but poor solubilities to limit their recrystallization, purification and recycling. In this study, core-shell clusters based on symmetrical tetra-n-alkylammonium [TTA]+ are designed to provide an inner cavity to incorporate TATB, and thus the clusters can separate TATB from original hydrogen-bonded networks to increase largely the solubility. Based on this design, deep eutectic solvents (DESs) based on [TTA]+ cations are first developed to yield self-assembled core-shell clusters for solubilizing TATB. Ninety-nine DESs based on [TTA]+ were prepared by combining with halide ions and hydrogen bond donors, and TATB's solubility increases with the formation of core-shell clusters. Tetrabutyl ammonium ([TBA]+ )-based DES (CS-1) displays excellent dissolution toward TATB. Room-temperature solubility of TATB in CS-1 with 32.88 mg/mL is about 10 times higher than recently reported ionic liquids and approximately 470 times higher than DMSO. Compared to traditional solvents, CS-1 shows economical and high dissolution ability toward TATB. The dissolution mechanism is demonstrated by experimental characterizations and theoretical calculations. After forming Zundel-type complexes between TATB and F-, the complexes as the core are surrounded by [TBA]+ as the shell to yield core-shell clusters through self-assembly of electrostatic interaction.

11.
Front Nutr ; 9: 833859, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35445056

RESUMEN

The mechanism by which ginsenosides from Panax quinquefolium L. transform into rare saponins by different processing methods and their antitumour effects have yet to be fully elucidated. Our study aimed to detect the effect of amino acids and processing methods on the conversion of ginsenosides in American ginseng to rare ginsenosides, using 8 monomeric ginsenosides as substrates to discuss the reaction pathway and mechanism. S180 tumour-bearing mice were established to study the antitumour effects of American ginseng total saponins (AGS-Q) or American ginseng total saponins after transformation (AGS-H) synergistic CTX. The results showed that aspartic acid was the best catalyst, and the thermal extraction method had the best effect. Under the optimal conditions, including a reaction temperature of 110°C, an aspartic acid concentration of 5%, a reaction time of 2.5 h and a liquid-solid ratio of 30 mL/g, the highest conversion of Rk1 and Rg5 was 6.58 ± 0.11 mg/g and 3.74 ± 0.05 mg/g, respectively. In the reaction pathway, the diol group saponins participated in the transformation process, and the triol group saponins basically did not participate in the transformation process. AGS-Q or AGS-H synergistic CTX, or AGS-H synergistic CTX/2 could significantly increase the tumour inhibition rate, spleen index and white blood cell count, had a significant upregulation effect on IL-2 and IL-10 immune cytokines; significantly restored the ratio of CD4+/CD8+; and significantly inhibited the level of CD4+CD25+. AGS-Q or AGS-H synergistic with CTX or CTX/2 can significantly upregulate the expression of Bax and cleaved-Caspase-3 and inhibit the expression of antiapoptotic protein Bcl-2. AGS synergistic CTX in the treatment of S180 tumour-bearing mice can improve the efficacy and reduce toxicity.

12.
Food Chem ; 379: 132146, 2022 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-35078058

RESUMEN

Sediment is a key issue in the production and marketing of plant beverages, as is ginseng beverages. The formation of sediment in ginseng beverages is a gradual process. This work describes the formation of sediment from different parts of ginseng and describes the color and clarity of the liquid and the amount and morphology of the sediment. The results showed there are significant differences in the sediment formation speed, morphology and transmittance for the aqueous extracts prepared from different parts of ginseng. The amounts of sediment generated from the different parts of ginseng is as follows: main root > rhizome > fibrous root. Free amino acids, Ba, Ca, Ni, and Sr concentrations are significantly and positively correlated with the transmittance. The total saponins, Al, Fe, and Mn concentrations are significantly and negatively correlated with the transmittance. There are obvious crystals and more Ca in the fibrous root sediment. We analyzed and compared the chemical components in the sediment and extract. The results show that the main components of the sediment are carbohydrates and protein. According to the partition coefficient the contents of protein, ginsenosides (Rb1, Rb2, Rb3, Rf) and some ions (Al, Fe, Ca, and Na) contribute more to the formation of the sediment than the other investigated components.


Asunto(s)
Ginsenósidos , Panax , Saponinas , Cromatografía Líquida de Alta Presión , Ginsenósidos/análisis , Raíces de Plantas/química , Rizoma/química
13.
Environ Sci Pollut Res Int ; 29(8): 12100-12114, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34558054

RESUMEN

The outbreak of COVID-19 has caused increasing public attention to laboratory-acquired infections (LAIs), especially for a mobile Bio-Safety Level 4 Lab (BSL-4) with high potential of exposure. In this paper, the distribution and removal mechanism of bioaerosols in the biosafety laboratory were studied. A simulation model of airflow distribution in the opening and closing state of air-tight door was established and verified. The results showed that the airflow entrainment velocity during the opening of the door was approximately 0.12 m/s. It increased the probability of vortex generation in the laboratory. The deposition rate of particles was doubled when the air-tight door opening is compared with air-tight door closing. Besides, nearly 80% of the particles deposited on the surface of the wall and ceiling, increasing the possibility of LAIs. The findings of this paper could provide new scientific methods for high-level biosafety laboratories to avoid cross-infection. Moreover, future work regarding air-tight door rotation speed regulation and control should be emphasized.


Asunto(s)
COVID-19 , Laboratorios , Simulación por Computador , Contención de Riesgos Biológicos , Humanos , SARS-CoV-2
14.
J AOAC Int ; 105(1): 129-141, 2022 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-34519786

RESUMEN

BACKGROUND: At present, plant growth regulators (PGRs) are widely used in agricultural and forestry production. PGRs, like traditional pesticides, have certain toxicities. Naively excessively applying them will cause the acute and chronic poisoning of humans and animals and potentially harm human health. OBJECTIVE: In order to assess, prevent, and control the residues of PGRs in fruits and vegetables, a set of quick, easy, cheap, effective, rugged, and safe (QuEChERS) analytical methods that simultaneously detect multiple PGR residues are urgently needed for quality and safety inspection of agricultural product. METHODS: In this study, grapes (representative of fruits) and cabbages (representative of vegetables) were used as the detected objects. The 30 commercial product residues of PGRs were detected in both with an ultra-high performance liquid chromatography (UHPLC)-tandem mass spectrometry (MS/MS) method, based on optimized chromatographic, MS, and preparation conditions (extraction solvent and cleanup conditions). Grape and cabbage samples were extracted with acetonitrile containing 5% (v/v) acetic acid, dehydrated using a salt package, purified using the QuEChERS method, ionized using electrospray ionization under positive and negative ion switching mode, detected using multi-reaction monitoring, and quantification using an external standard method of matrix matching standard curve. RESULTS: Methanol was selected as the strong elution phase. A methanol-0.1% formic acid-5 mmol/L ammonium acetate solution was selected as the best mobile phase. The optimal extraction solvent was acetonitrile containing 5% acetic acid. Primary secondary amine cleanup could met the determination requirements of PGR residues. The developed method for determination of 30 commercial products of PGR, such as betaine, showed excellent linearity in 1-500, 10-1000, ∼500, ∼2000, and 100-10 000 µg/kg (R ≥ 0.98). At the 0.001 (0.01), 0.05, 0.20, and 1.00 mg/kg additive concentrations, the average addition standard recovery of 30 commercial products of PGR were 61-132% with the relative standard deviations of 1-14% and the LOQs were confirmed to be 1.0-100 µg/kg through the actual addition values of samples. CONCLUSION: The set of optimized QuEChERS UHPLC-MS/MS methods simultaneously detect residues of PGRs in fruits and vegetables with one-time sample preparation for high-throughput, rapid quantitative screening, and confirmation. The methods cover a wide range of PGRs with simple and convenient preparation and small amounts of solvent, and can provide technical support for the supervision of PGR residues in fruits and vegetables. HIGHLIGHTS: The optimizations of extraction solvent screening, different ratios of various purification packages in the QuEChERS method, and UPLC-MS conditions were conducted and the precision, sensitivity, and recovery rates of the methods were investigated in order to establish a QuEChERS UPLC-MS/MS method for simultaneously detecting 30 kinds of PGR residues in fruits and vegetables. The methods allow high-throughput determination of multiple PGR residues in fruits and vegetables and can also provide technical references for related compound residue detection of other matrixes.


Asunto(s)
Brassica , Residuos de Plaguicidas , Vitis , Animales , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Humanos , Residuos de Plaguicidas/análisis , Reguladores del Crecimiento de las Plantas , Extracción en Fase Sólida , Espectrometría de Masas en Tándem
15.
Foods ; 10(11)2021 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-34828995

RESUMEN

Sediment is a key issue in the beverage industry. This study confirmed that reversible and irreversible sediments were formed during low-temperature storage of ginseng extract. The first 30 days of storage are the critical period for sediment formation. As the time of storage extends, the chemical composition changes. The composition interaction model verified that the cross-linking of protein-pectin, protein-oxalic acid and Ca2+-pectin was the main cause of the turbidity of ginseng extract. Based on the characterization of irreversible sediment (IRS), there are typical structures of proteins, polysaccharides and calcium oxalate dihydrate (COD) crystals. Glucose, galacturonic acid, aspartate, glutamic acid, leucine, Ca, K, Al, Mg, Na and Fe are the main monomer components. Effective regulation of these ingredients will greatly help the quality of ginseng beverages.

16.
Chin Herb Med ; 13(2): 290, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36121403

RESUMEN

[This corrects the article DOI: 10.1016/j.chmed.2019.05.001.].

17.
Talanta ; 221: 121613, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33076143

RESUMEN

Herein, we developed a simple approach for quantitative metering of nanoliter-scale liquids in parallel based on a capillary array and applied it in high throughput screening protein crystallization conditions. The quantitative metering of liquids was achieved by using capillary force to spontaneously introduce the liquids into short capillaries with fixed length and inner diameter, and the nanoliter-scale droplets were generated by using a pneumatic pump to deliver liquids out from the capillary channels. We adopted measures of sharpening the capillary tips and performing a hydrophobic treatment on the tip surface to significantly reduce the capillary residues during the liquid aspirating and dispensing process, and thus improved the precision to 0.2%-3.5% relative standard deviations (RSD, n = 3) in metering droplets in the range of 280 pL-90 nL. We evaluated the performance of the system in metering liquids of different surface tensions and viscosity. On the basis of this approach, we built a capillary array system with 12 capillaries, by which parallel generation of 12 nL droplets of 12 samples could be achieved in 40 s with a relative standard deviation (RSD) of 1.2%. We applied the system in the screening of lysozyme crystallization conditions of 48 precipitants with 7.5 nL precipitant and 7.5 nL protein solutions in each crystallization droplet reactor, to demonstrate its potentials in large-scale high-throughput screening and analysis with different samples.

19.
Chem Commun (Camb) ; 56(44): 5909-5912, 2020 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-32342091

RESUMEN

A three-component reaction between one molecule of phosphorus ylides (P-ylides) and two molecules of isocyanates for the rapid assembly of 2-amino-3-carboxylate-4-quinolones is described. The mechanism may involve the addition of a P-ylide to an isocyanate followed by 1,3-H shift to form a carbamoyl stabilized P-ylide. The intermediate then reacts with another aryl isocyanate via Wittig/ketenimine-ketene rearrangement/6π-electrocyclization/1,3-H shift to finally afford the 4-quinolones.

20.
Angew Chem Int Ed Engl ; 58(31): 10698-10702, 2019 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-31091339

RESUMEN

We report a phosphine-catalyzed ring opening of electron-deficient alkylidenecyclopropanes (ACPs) to generate allylic phosphonium zwitterions that resemble the well-studied phosphine-allene adducts but exhibit distinct properties. The potent reactivity of these intermediates has been demonstrated in three types of substrate-controlled phosphine-catalyzed rearrangements of alkylidenecyclopropylketones, which chemoselectively afford tri- and tetrasubstituted furans, and trisubstituted dienones in good yields.

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