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https://www.readbyqxmd.com/read/28231561/structural-analysis-of-rebaudioside-a-derivatives-obtained-by-lactobacillus-reuteri-180-glucansucrase-catalyzed-trans-%C3%AE-glucosylation
#1
Gerrit J Gerwig, Evelien M Te Poele, Lubbert Dijkhuizen, Johannis P Kamerling
The wild-type Gtf180-ΔN glucansucrase enzyme from Lactobacillus reuteri 180 was found to catalyze the α-glucosylation of the steviol glycoside rebaudioside A, using sucrose as glucosyl donor in a transglucosylation process. Structural analysis of the formed products by MALDI-TOF mass spectrometry, methylation analysis and NMR spectroscopy showed that rebaudioside A is specifically α-d-glucosylated at the steviol C-19 β-d-glucosyl moiety (55% conversion). The main product is a mono-(α1 → 6)-glucosylated derivative (RebA-G1)...
January 31, 2017: Carbohydrate Research
https://www.readbyqxmd.com/read/28231545/aqueous-extract-of-cortex-dictamni-protects-h9c2-cardiomyocytes-from-hypoxia-reoxygenation-induced-oxidative-stress-and-apoptosis-by-pi3k-akt-signaling-pathway
#2
Lin Li, Yunfeng Zhou, Yanlin Li, Lili Wang, Lan Sun, Lidong Zhou, Hiderori Arai, Yun Qi, Yang Xu
Ischemia-reperfusion injury is the major manifestation of ischemic heart disease, which facilitates cardiac arrhythmias, heart failure and death. Oxidative stress and apoptosis have been involved in the pathogenesis of myocardial ischemia-reperfusion injury. Modern pharmacological studies have indicated that the extracts and active compounds of Cortex Dictamni exhibit antioxidative and cardiovascular protective activities. This study was designed to investigate the protective effect of aqueous extract of Cortex Dictamni (CDAE) on regulating hypoxia/reoxygenation (H/R)-induced cardiomyocytes oxidative stress and apoptosis...
February 20, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28231530/identification-of-a-novel-low-level-impurity-in-fungicide-pyraclostrobin-by-high-performance-liquid-chromatography-tandem-mass-spectrometry
#3
Kaimin Xia, ShanShan Shen, Qun Gao, Wei Shang, Yuanjiang Pan, Jun Wu
Pyraclostrobin is one kind of new type methoxy acrylate fungicides that has been widely used in agriculture at present, with a lot of advantages including broad spectrum, high efficiency and high selectivity. In this work, a novel low-level impurity in the pyraclostrobin at about 0.2% was separated and characterized by high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS). Firstly, the impurity was speculated to possess the same skeleton structure as the main product pyraclostrobin while the methyl group on the methyl ester was substituted to be CH2CH2Cl on the basis of the on-line multi-stage mass spectrometric behaviors compared with that of pyraclostrobin...
February 17, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28231388/structural-characterization-and-antifatigue-effect-in-vivo-of-maca-lepidium-meyenii-walp-polysaccharide
#4
Weimin Tang, Lu Jin, Lianghua Xie, Juqing Huang, Nan Wang, Bingquan Chu, Xulin Dai, Yu Liu, Rui Wang, Ying Zhang
Maca (Lepidium meyenii Walp) polysaccharides (MP) with purity of 99.2% were obtained to investigate their structural characteristics and antifatigue effect in vivo. The physicochemical properties of MP were analyzed through high-performance gel filtration chromatography, IR, monosaccharide composition, methylation, GC-MS, and NMR analyses. The antifatigue effect of MP was evaluated by using a mouse weight-loaded swimming model. MP is an acidic heteropolysaccharide with an average molecular weight (Mw ) of 793...
February 23, 2017: Journal of Food Science
https://www.readbyqxmd.com/read/28231131/effects-of-matrix-composition-on-detection-threshold-estimates-for-methyl-anthranilate-and-2-aminoacetophenone
#5
Demetra M Perry, John E Hayes
Conceptually, a detection threshold represents the lowest concentration at which an individual or a group of individuals can reliably perceive a given stimulus, with a commonly used operational definition of 50% performance above chance. Estimated detection thresholds (DTs), however, are often reported in the literature with little attention given to the matrix in which the stimuli were evaluated. Here, we highlight the influence of matrix effects on DTs for two odor-active compounds commonly found in Vitis Labrusca wines...
May 17, 2016: Foods (Basel, Switzerland)
https://www.readbyqxmd.com/read/28231047/original-research-paper-characterization-and-taste-masking-evaluation-of-microparticles-with-cetirizine-dihydrochloride-and-methacrylate-based-copolymer-obtained-by-spray-drying
#6
Aleksandra Amelian, Marta Szekalska, Patrycja Ciosek, Anna Basa, Katarzyna Winnicka
Taste of a pharmaceutical formulation is an important parameter for the effectiveness of pharmacotherapy. Cetirizine dihydrochloride (CET) is a second-generation antihistamine that is commonly administered in allergy treatment. CET is characterized by extremely bitter taste and it is a great challenge to successfully mask its taste; therefore the goal of this work was to formulate and characterize the microparticles obtained by the spray drying method with CET and poly(butyl methacrylate-co-(2-dimethylaminoethyl) methacrylate-co-methyl methacrylate 1:2:1 copolymer (Eudragit E PO) as a barrier coating...
March 1, 2017: Acta Pharmaceutica
https://www.readbyqxmd.com/read/28231008/palladium-catalyzed-%C3%AE-arylation-of-cyclic-vinylogous-esters-for-the-synthesis-of-%C3%AE-arylcyclohexenones-and-total-synthesis-of-aromatic-podocarpane-diterpenoids
#7
Wen-Yi Hou, Yen-Ku Wu
Described is a method for the formal γ-arylation of cyclohexenones allowing synthesis of a remote all-carbon quaternary center. The process involves the palladium-catalyzed α-arylation of a α-substituted cyclic vinylogous ester followed by the Stork-Danheiser transposition. The synthetic utility of this protocol is featured in the total syntheses of (±)-12-hydroxy-13-methylpodocarpa-8,11,13-trien-3-one, (±)-3β,12-dihydroxy-13-methylpodocarpane-8,11,13-triene, and (±)-O-methyl nimbinone.
February 23, 2017: Organic Letters
https://www.readbyqxmd.com/read/28230869/a-combined-high-temperature-experimental-and-theoretical-kinetic-study-of-the-reaction-of-dimethyl-carbonate-with-oh-radicals
#8
Fethi Khaled, Binod Raj Giri, Milán Szőri, Tam V-T Mai, Lam K Huynh, Aamir Farooq
The reaction kinetics of dimethyl carbonate (DMC) and OH radicals were investigated behind reflected shock waves over the temperature range of 872-1295 K and at pressures near 1.5 atm. Reaction progress was monitored by detecting OH radicals at 306.69 nm using a UV laser absorption technique. The rate coefficients for the reaction of DMC with OH radicals were extracted using a detailed kinetic model developed by Glaude et al. (Proc. Combust. Inst. 2005, 30(1), 1111-1118). The experimental rate coefficients can be expressed in Arrhenius form as: kexpt'l = 5...
February 23, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28230867/ultrafast-electron-and-hole-transfer-dynamics-of-a-solar-cell-dye-containing-hole-acceptors-on-mesoporous-tio2-and-al2o3
#9
Mirko Scholz, Oliver Flender, Gerrit Boschloo, Kawon Oum, Thomas Lenzer
The stability of dye cations against recombination with conduction band electrons in mesoporous TiO2 electrodes is a key property for improving light harvesting in dye-sensitised solar cells. Using ultrafast transient broadband absorption spectroscopy, we monitor efficient intramolecular hole transfer in the solar cell dye E6 having two peripheral triarylamine acceptors. After photoexcitation, two hole transfer mechanisms are identified: a concerted mechanism for electron injection and hole transfer (2.4 ps) and a sequential mechanism with time constants of 3...
February 23, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28230864/dicer-promotes-tumorigenesis-by-translocating-to-nucleus-to-promote-sfrp1-promoter-methylation-in-cholangiocarcinoma-cells
#10
Wenlong Cheng, Yongqiang Qi, Li Tian, Bing Wang, Wenhua Huang, Yongjun Chen
Dicer, a member of the RNase III family of endoribonucleases, has an important role in regulating methylation of CpG islands in mammal cancer cells. However, the underlying mechanism of action remains unclear. In this study, we demonstrated that upregulation of Dicer in cholangiocarcinoma (CCA) cells and its translocation to nuclues to interact with heterochromatin protein 1α (HP1α). The nuclear Dicer/HP1α complex appeared to promote both H3K9 trimethylation and DNA methylation of the secreted frizzled-related protein 1 (SFRP1) promoter...
February 23, 2017: Cell Death & Disease
https://www.readbyqxmd.com/read/28230826/modifying-effects-of-5-azacytidine-on-metal-containing-proteins-profile-in-guerin-carcinoma-with-different-sensitivity-to-cytostatics
#11
V F Chekhun, Y V Lozovska, L A Naleskina, T V Borikun, A P Burlaka, I N Todor, D V Demash, T M Yalovenko, T V Zadvornyi, A O Pavlova, D M Storchay, N Yu Lukianova
AIM: To assess the influence of the treatment with 5-azacytidine (5-aza) on the profile of metal-containing proteins and factors of their regulation in Guerin carcinoma cells in vivo. MATERIALS AND METHODS: The study was conducted on Wistar rats transplanted with wild-type Guerin carcinoma (Guerin/WT) and its strains resistant to cisplatin (Guerin/CP) or doxorubicin (Guerin/Dox). Animals were distributed in 6 groups treated with 5-aza and control animals without treatment...
December 2016: Experimental Oncology
https://www.readbyqxmd.com/read/28230814/m1a%C3%A2-post-transcriptional%C3%A2-modification%C3%A2-in%C3%A2-trnas
#12
REVIEW
Stephanie Oerum, Clément Dégut, Pierre Barraud, Carine Tisné
To date, about 90 post-transcriptional modifications have been reported in tRNA expanding their chemical and functional diversity. Methylation is the most frequent post-transcriptional tRNA modification that can occur on almost all nitrogen sites of the nucleobases, on the C5 atom of pyrimidines, on the C2 and C8 atoms of adenosine and, additionally, on the oxygen of the ribose 2'-OH. The methylation on the N1 atom of adenosine to form 1-methyladenosine (m1A) has been identified at nucleotide position 9, 14, 22, 57, and 58 in different tRNAs...
February 21, 2017: Biomolecules
https://www.readbyqxmd.com/read/28230799/evaluation-of-extraction-and-degradation-methods-to-obtain-chickpeasaponin-b1-from-chickpea-cicer-arietinum-l
#13
Kun Cheng, Hua Gao, Rong-Rong Wang, Yang Liu, Yu-Xue Hou, Xiao-Hong Liu, Kun Liu, Wei Wang
The objective of this research is to implement extraction and degradation methods for the obtainment of 3-O-[α-l-rhamnopyranosyl-(1→2)-β-d-galactopyranosyl] soyasapogenol B (chickpeasaponin B1) from chickpea. The effects of microwave-assisted extraction (MAE) processing parameters-such as ethanol concentration, solvent/solid ratio, extraction temperature, microwave irradiation power, and irradiation time-were evaluated. Using 1g of material with 8 mL of 70% aqueous ethanol and an extraction time of 10 min at 70 °C under irradiation power 400W provided optimal extraction conditions...
February 21, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28230792/static-hot-air-and-infrared-rays-roasting-are-efficient-methods-for-aflatoxin-decontamination-on-hazelnuts
#14
Ilenia Siciliano, Barbara Dal Bello, Giuseppe Zeppa, Davide Spadaro, Maria Lodovica Gullino
Aflatoxins are a group of secondary metabolites produced by members of Aspergillus Section Flavi that are dangerous to humans and animals. Nuts can be potentially contaminated with aflatoxins, often over the legal threshold. Food processes, including roasting, may have different effects on mycotoxins, and high temperatures have proven to be very effective in the reduction of mycotoxins. In this work, two different roasting methods-traditional static hot air roasting and infra-red rays roasting-were applied and compared for the detoxification of hazelnuts from Italy and Turkey...
February 21, 2017: Toxins
https://www.readbyqxmd.com/read/28230711/asperger-syndrome-and-early-onset-schizophrenia-associated-with-a-novel-mecp2-deleterious-missense-variant
#15
Aurore Curie, Gaëtan Lesca, Gérald Bussy, Sabine Manificat, Valérie Arnaud, Sibylle Gonzalez, Olivier Revol, Alain Calender, Daniel Gérard, Vincent des Portes
Methyl-CpG-binding protein 2 (MECP2) deleterious variants, which are responsible for Rett syndrome in girls, are involved in a wide spectrum of developmental disabilities in males. A neuropsychiatric phenotype without intellectual disability is uncommon in patients with MECP2 deleterious variants. We report on two dizygotic twins with an MECP2-related psychiatric disorder without intellectual disability. Neuropsychological and psychiatric phenotype assessments were performed, and a genetic analysis was carried out...
February 22, 2017: Psychiatric Genetics
https://www.readbyqxmd.com/read/28230317/p-cymene-as-a-solvent-for-olefin-metathesis-matching-efficiency-and-sustainability
#16
Eduardo N Dos Santos, Artur V Granato, Alexandra G Santos
The underexploited, biorenewable, p-cymene is employed as a solvent for the metathesis of various substrates. p-cymene is a nontoxic compound that can be obtained in large amounts from side product of cellulose and citrus industry. For the cross-metathesis of estragole with methyl acrylate, this solvent prevents the consecutive double-bond isomerization of the product and gives the best yield of all solvents tested. Undesired consecutive isomerization is a major problem for many substrates in olefin metathesis, including pharmaceutical precursors, and the use of p-cymene as solvent may be a way to prevent it...
February 23, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28230294/asymmetric-total-syntheses-of-kopsia-indole-alkaloids
#17
Lingying Leng, Xiaohan Zhou, Qi Liao, Falu Wang, Hao Song, Dan Zhang, Xiao-Yu Liu, Yong Qin
The asymmetric total syntheses of a group of structurally complex Kopsia alkaloids, (-)-kopsine, (-)-isokopsine, (+)-methyl chanofruticosinate, (-)-fruticosine, and (-)-kopsanone, has been achieved. The key strategies for the construction of the molecular complexity in the targets included an asymmetric Tsuji-Trost rearrangement to set the first quaternary carbon center at C20, an intramolecular cyclopropanation by diazo decomposition to install the second and third quaternary carbon centers at C2 and C7, respectively, and a SmI2 -promoted acyloin condensation to assemble the isokopsine core...
February 23, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28230279/folate-protects-hepatocytes-of-hyperhomocysteinemia-mice-from-apoptosis-via-cystic-fibrosis-transmembrane-conductance-regulator-cftr-activated-endoplasmic-reticulum-stress
#18
Anning Yang, Yue Sun, Caiyan Mao, Songhao Yang, Min Huang, Mei Deng, Ning Ding, Xiaoling Yang, Minghao Zhang, Shaoju Jin, Yideng Jiang, Ying Huang
Folate deficiency is a known risk factor for liver injury; however, the underlying mechanism remains unclear. In this study, we employed a high homocysteine-induced liver injury model of Apolipoprotein E-deficient (ApoE(-/-) ) mice fed high-methionine diet and found that high homocysteine induced endoplasmic reticulum (ER) stress and liver cell apoptosis by downregulation of cystic fibrosis transmembrane conductance regulator (CFTR) expression; observations that were attenuated with supplementation of dietary folate...
February 23, 2017: Journal of Cellular Biochemistry
https://www.readbyqxmd.com/read/28230255/changes-in-pectin-characteristics-during-the-ripening-of-jujube-fruit
#19
Shenghua Ding, Rongrong Wang, Yang Dan, Gaoyang Li, Shiyi Ou
BACKGROUND: Pectin is relative to fruit maturation and loss of flesh firmness. In this research, changes in pectin characteristics, including pectin content, neutral sugar compositions, molecular weight (Mw ) distribution, and degree of methyl esterification (DM), in six different growth stages (S1-S6) of jujube fruit were assessed. RESULTS: The growth of jujube fruit corresponded to an increase in water-soluble pectin (WSP), and a decrease in Na2 CO3 -soluble pectin (SSP)...
February 23, 2017: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/28230192/an-endoparasitoid-wasp-influences-host-dna-methylation
#20
Sunil Kumar, Yonggyun Kim
Parasitism by endoparasitoid wasps changes the expression of various host genes, and alters host immune and developmental processes. However, it is not clearly understood how parasitism changes host gene expression in a whole genome scale. This study focused on an epigenetic control of Cotesia plutellae, an endoparasitoid wasp, against its host, Plutella xylostella. Two DNA methyltransferases (DNMT-1 and DNMT-2) are encoded in the genome of P. xylostella. In addition, methyl-binding domain proteins (MBDs) and DNA demethylation factor, ten-eleven translation protein (TET) are encoded...
February 23, 2017: Scientific Reports
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