Publications by authors named "Huyen T Tran"

The development of efficient and sustainable chemical processes which use greener reagents and solvents, currently play an important role in current research. Methanol, a cheap and readily available resource from chemical industry, could be activated by transition metal catalysts. This review focuses in covering the recent five-years literature and provides a systematic summary of strategies for methanol activation and the use in organic chemistry.

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Four previously undescribed carvotacetones including one monomeric (1) and three dimeric (8, 9, 10) derivatives, together with six known compounds were isolated from the n-hexane extract of the aerial parts of Sphaeranthus africanus L. The structures of the previously undescribed compounds were elucidated as 3-angeloyloxy-5-isobutanoyloxy-7-hydroxycarvotacetone (1), 7,7'-oxybis{3-angeloyloxy-5-[(2R*,3R*)-2,3-dihydroxy-2-methylbutanoyloxy]carvotacetone} (8), (2″S*,3″R*)-7-{3-angeloyloxy-5-[(2R*,3R*)-2,3-dihydroxy-2-methylbuta-noyloxy]carvotaceton-7-yloxy}-3-angeloyloxy-5-(2,3-dihydroxy-2-methylbutanoyloxy)carvo-tacetone (9), and 7,7'-oxybis{3-angeloyloxy-5-[(2S*,3R*)-2,3-dihydroxy-2-methylbutanoyl-oxy]carvotacetone} (10). The three dimeric derivatives (8-10) showed potent anti-proliferative activity against human cancer cell lines (CCRF-CEM, MDA-MB-231, U-251, HCT-116) with IC values ranging from 0.

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Fermentation technology using endophytes is considered a potential alternative approach for producing pharmaceutical compounds like podophyllotoxin (PTOX). In this study, fungus TQN5T (VCCM 44284) was selected from endophytic fungi isolated from Dysosma versipellis in Vietnam for PTOX production through TLC. The presence of PTOX in TQN5T was further confirmed by HPLC.

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Three carvotacetones (1 - 3: ) isolated from were screened in 60 cancer cell lines at the National Cancer Institute (NCI) within the Developmental Therapeutics Program (DTP). At the concentration of 10 M, compound 1: (3,5-diangeloyloxy-7-hydroxycarvotacetone) turned out to be the most active compound against ACHN and UO-31 renal cancer cell lines with growth percent values of - 100% (all cells dead). Compound 2: (3-angeloyloxy-5-[2″,3″-epoxy-2″-methylbutanoyloxy]-7-hydroxycarvotacetone) showed strong effects in SK-MEL-5 melanoma and ACHN renal cancer cells with inhibition values of 93% and 97%, respectively.

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Acute myocarditis is one of the common complications of coronavirus disease 2019 (COVID-19) with a relatively high case fatality. Here reported is a fulminant case of a 42-year-old previously healthy woman with cardiogenic shock and refractory cardiac arrest due to COVID-19-induced myocarditis who received veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) after 120 minutes of cardiopulmonary resuscitation (CPR). This is the first adult case of cardiac arrest due to COVID-19-induced myocarditis supported by ECMO that fully recovered with normal neurological functions.

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Tobacco is an important commercial crop and a rich source of alkaloids for pharmaceutical and agricultural applications. However, its yield can be reduced by up to 70% due to virus infections, especially by a potyvirus Potato virus Y (PVY). The replication of PVY relies on host factors, and eukaryotic translation initiation factor 4Es (eIF4Es) have already been identified as recessive resistance genes against potyviruses in many plant species.

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Hairy root induction system has been applied in various plant species as an effective method to study gene expression and function due to its fast-growing and high genetic stability. Recently, these systems have shown to be an effective tool to evaluate activities of CRISPR/Cas9 systems for genome editing. In this study, mediated hairy root induction was optimized to provide an effective tool for validation of plant transformation vector, CRISPR/Cas9 construct activities as well as selection of targeted gRNAs for gene editing in cucumber ( L.

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Carvotacetones () isolated from were screened for their antimycobacterial and efflux pump (EP) inhibitory potential against the mycobacterial model strains mc 155, ATCC 23366, and BCG ATCC 35734. The minimum inhibitory concentrations (MICs) of the carvotacetones were detected through high-throughput spot culture growth inhibition (HT-SPOTi) and microbroth dilution assays. In order to assess the potential of the compounds and to accumulate ethidium bromide (EtBr) in and , a microtiter plate-based fluorometric assay was used to determine efflux activity.

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Background: Sphaeranthus africanus has been used in traditional Vietnamese medicine to treat sore throat, and to relieve pain and swelling. However, the anti-inflammatory activity of this plant had not yet been investigated. Previously, we isolated five carvotacetones (1-5) from this plant that displayed cytotoxicity against several cancer cell lines.

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Five carvotacetone derivatives, including two known ones, 3,5-diangeloyloxy-7-hydroxycarvotacetone (1) and 3-angeloyloxy-5-[2″,3″-epoxy-2″-methylbutanoyloxy]-7-hydroxycarvotacetone (2), along with three new compounds, 3-angeloyloxy-5-[3″-chloro-2″-hydroxy-2″-methylbutanoyloxy]-7-hydroxycarvotacetone (3), 5-angeloyloxy-7-hydroxy-3-tigloyloxycarvotacetone (4), and 3-angeloyloxy-5,7-dihydroxycarvotacetone (5), were isolated from the aerial parts of Sphaeranthus africanus collected in Vietnam. Bioassay-guided fractionation was monitored by the antiproliferative activity on CCRF-CEM human cancer cells. The structures of compounds 1-5 were determined on the basis of NMR spectroscopic and mass spectrometric data.

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Gene flow between species may last a long time in plants. Reticulation inevitably causes difficulties in phylogenetic reconstruction. In this study, we looked into the genetic divergence and phylogeny of 20 Lilium species based on multilocus analyses of 8 genes of chloroplast DNA (cpDNA), the internally transcribed nuclear ribosomal DNA (nrITS) spacer and 20 loci extracted from the expressed sequence tag (EST) libraries of L.

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D-Alanyl-D-alanine is an essential precursor of bacterial peptidoglycan and is synthesized by D-alanine-D-alanine ligase (DDL) with hydrolysis of ATP; this reaction makes DDL an important drug target for the development of antibacterial agents. Five crystal structures of DDL from Yersinia pestis (YpDDL) were determined at 1.7-2.

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Along with the co-chaperonin GroES, the chaperonin GroEL plays an essential role in enhancing protein folding or refolding and in protecting proteins against misfolding and aggregation in the cellular environment. The XoGroEL gene (XOO_4288) from Xanthomonas oryzae pv. oryzae was cloned and the protein was expressed, purified and crystallized.

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Introduction: The insulin-regulated aminopeptidase (IRAP) is expressed in several cell types, where it is mainly located in specialized secretory endosomes that are quickly recruited to the cell surface upon cell type-specific activation. Here we describe for the first time the expression and subcellular distribution of IRAP in macrophages.

Methods: IRAP mRNA expression, protein expression and presence at the cell surface was investigated by real-time polymerase chain reaction (PCR), Western blot and [(3)H]IVDE77 binding, respectively.

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Campylobacter jejuni is one of the major foodborne pathogens causing human infection. Peptide deformylase, a metallohydrolase, catalyzes the deformylation of N-formylated methionine in newly synthesized polypeptides in prokaryotes and some eukaryotic organelles. The deformylation process is an essential step in protein synthesis and has attracted much attention as a potential target for the development of novel antibacterial agents.

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Background: Tuberculosis-associated Immune Reconstitution Inflammatory Syndrome (TB-IRIS) is a common complication of combined antiretroviral therapy (cART) in HIV-TB co-infected patients. However, the disease mechanism is poorly understood, prognosis of TB-IRIS is currently impossible, and diagnosis is highly challenging. We analyzed whether the gene expression of monocytes could be correlated with TB-IRIS pathogenesis and could be used to classify patients predisposed to TB-IRIS.

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Objective: Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is a common complication in HIV-TB co-infected patients receiving combined antiretroviral therapy (cART). This study investigated a putative contribution of monocytes to the development of TB-IRIS.

Design: A prospective study was designed to compare gene expression between patients who developed TB-IRIS with matched non-TB-IRIS controls.

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Background: The immune system exerts a diversifying selection pressure on HIV through cellular, humoral and innate mechanisms. This pressure drives viral evolution throughout infection. A better understanding of the natural immune pressure on the virus during infection is warranted, given the clinical interest in eliciting and sustaining an immune response to HIV which can help to control the infection.

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Sustained release (SR) tablets containing solid dispersions (SD) granules of a poorly water-soluble drug were prepared to investigate the controlled pH-independent release of the drug. Losartan potassium (LST), an anti-hypertensive agent was chosen as a model drug because of its pH-dependent solubility and short elimination half-life. Poloxamer 188 was used as an SD carrier.

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Background: During HIV infection and/or antiretroviral therapy (ART), monocytes and macrophages exhibit a wide range of dysfunctions which contribute significantly to HIV pathogenesis and therapy-associated complications. Nevertheless, the molecular components which contribute to these dysfunctions remain elusive. We therefore applied a parallel approach of genome-wide microarray analysis and focused gene expression profiling on monocytes from patients in different stages of HIV infection and/or ART to further characterise these dysfunctions.

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We examined how melatonin absorption was affected by pharmaceutical excipients using the Ussing chamber technique with mounted rat gastrointestinal (GI) segments. Melatonin absorption occurs throughout the GI tract, with the greatest absorption being in the rectum and ileum and the least in the stomach. Melatonin can be classified as a low permeability drug.

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The primary objective of the study was to validate a simple and sensitive method of determining valsartan concentration in human plasma samples using high performance liquid chromatography (HPLC) combined with ultraviolet (UV) detection. Methanol appeared to be the best with a high recovery efficiency compared to other solvents such as acetonitrile, ethylacetate and methyl-tert-butyl ether. After a simple protein precipitation using methanol, the analytes were separated on a Phenomenex Luna C(18) column using 42% acetonitrile with 15 mM potassium dihydrogenphosphate in water (pH 2.

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The present work is an original evaluation of the microenvironmental pH (pH(M)) and crystallinity of an ionizable drug in order to enhance its dissolution using alkalizers in polyethylene glycol 6000 (PEG 6000) based solid dispersions (SDs). Telmisartan (TEL) was chosen as a model drug due to its poor and pH-dependent water solubility. The nine alkalizers used to modify the pH of TEL were MgO, NaOH, KOH, Na2CO3, NaHCO, bentonite, Na2HPO4, K2HPO4 and arginine.

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A statistical method is reported to determine the pairs of fragment ions in a mass spectrum that are most susceptible to control by adaptive optimization of the laser pulse shapes in the strong-field regime. The proposed method is based on covariance analysis of the mass spectral fragmentation patterns generated by a set of randomly shaped pulses. The pairs of fragment ions that have higher negative covariances possess a correspondingly higher degree of controllability in an adaptive control experiment, whereas the pairs that have higher positive covariances possess correspondingly lower controllability.

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