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https://www.readbyqxmd.com/read/28330200/use-of-ca-alginate-immobilized-pseudomonas-aeruginosa-for-repeated-batch-and-continuous-degradation-of-endosulfan
#1
Vijayalakshmi Pradeep, Usha Malavalli Subbaiah
The current investigation is taken up with the aim of studying repeated batch and continuous degradation of Endosulfan, using Ca-alginate immobilized cells of Pseudomonas aeruginosa isolated from an agricultural soil. The work involves the study of genes and enzymes involved in the degradation of the pesticide and was carried out with an objective of reducing the toxicity of Endosulfan by degrading it to less toxic metabolites. The long-term stability of Endosulfan degradation was studied during its repeated batch degradation, carried out over a period of 35 days...
December 2016: 3 Biotech
https://www.readbyqxmd.com/read/28326068/negative-regulation-of-violacein-biosynthesis-in-chromobacterium-violaceum
#2
Giulia Devescovi, Milan Kojic, Sonia Covaceuszach, Miguel Cámara, Paul Williams, Iris Bertani, Sujatha Subramoni, Vittorio Venturi
In Chromobacteium violaceum, the purple pigment violacein is under positive regulation by the N-acylhomoserine lactone CviI/R quorum sensing system and negative regulation by an uncharacterized putative repressor. In this study we report that the biosynthesis of violacein is negatively controlled by a novel repressor protein, VioS. The violacein operon is regulated negatively by VioS and positively by the CviI/R system in both C. violaceum and in a heterologous Escherichia coli genetic background. VioS does not regulate the CviI/R system and apart from violacein, VioS, and quorum sensing regulate other phenotypes antagonistically...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28324654/a-general-strategy-for-visible-light-decaging-based-on-the-quinone-trimethyl-lock
#3
David P Walton, Dennis A Dougherty
Visible-light triggered quinone trimethyl locks are reported as a general design for long-wavelength photoremovable protecting groups for alcohols and amines. Intramolecular photoreduction unmasks a reactive phenol that undergoes fast lactonization to release alcohols and amines. Model substrates are released in quantitative yield along with well-defined, colorless hydroquinone byproducts. Substituent modifications of the quinone core allow absorption from 400 to 600 nm.
March 24, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28323149/the-effect-of-tobramycin-incorporated-with-bismuth-ethanedithiol-loaded-on-niosomes-on-the-quorum-sensing-and-biofilm-formation-of-pseudomonas-aeruginosa
#4
Faeze Mahdiun, Shahla Mansouri, Payam Khazaeli, Rasoul Mirzaei
Pseudomonas aeruginosa is an opportunistic pathogen, enable of causing infections especially in immunocompromised patients. Recently many isolates developed multiple drug resistance, resulting in treatment failure in serious infections. In this study, the effect of tobramycin incorporated with bismuth-ethanedithiol loaded on niosomes on the quorum sensing and biofilm production by P. aeruginosa was evaluated. Thin layer hydration method with cholesterol (30%), Span 40 and Tween 40 were used to make niosomes...
March 18, 2017: Microbial Pathogenesis
https://www.readbyqxmd.com/read/28322839/derivatives-of-furanditerpenes-from-pterodon-genus-pharmacological-studies-disclose-their-potential-as-chronic-pain-relief-in-mice
#5
Humberto M Spindola, Rogério Grando, Mariana C Figueiredo, Rosana Basting, N C A Queiroz, Ângelo de Fátima, João E de Carvalho, Zaijie J Wang, M A Foglio
Pterodon genus fruits are commercially available at the Brazilian medicinal market used in folk medicine due to their anti-inflammatory, analgesic, and anti-rheumatic effects. Previous studies demonstrated that furanditerpenes possessing vouacapan skeleton, isolated from Pterodon genus, possess expressive antinociceptive activities, with promising moiety for the development of new analgesic products. The antinociceptive properties of compounds 6α,7β- 6α-hidroxivouacapan-7β-17β-lactone (HVL) and 6α-oxovouacapan-7β-17β-lactone (OVL), semi-synthetic analogues of furanditerpenes previously reported as analgesic agents were evaluated on animal experimental models (Spindola et al...
March 16, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28320391/quantification-of-resistant-alleles-in-the-%C3%AE-tubulin-gene-of-field-strains-of-gastrointestinal-nematodes-and-their-relation-with-the-faecal-egg-count-reduction-test
#6
Myriam Esteban-Ballesteros, Francisco A Rojo-Vázquez, Philip J Skuce, Lynsey Melville, Camino González-Lanza, María Martínez-Valladares
BACKGROUND: Benzimidazole (BZ) resistance in gastrointestinal nematodes is associated with a single nucleotide polymorphism (SNP) at codons 167, 198 and 200 in the isotype 1 of beta-tubulin gene although in some species these SNPs have also been associated with resistance to macrocyclic lactones. In the present study we compared the levels of resistance in Teladorsagia circumcincta and Trichostrongylus colubriformis by means of the faecal egg reduction test (FECRT) and the percentage of resistant alleles obtained after pyrosequencing...
March 20, 2017: BMC Veterinary Research
https://www.readbyqxmd.com/read/28316820/crystal-structure-of-5-o-benzoyl-2-3-o-iso-propyl-idene-d-ribono-1-4-lactone
#7
Adailton J Bortoluzzi, Gustavo P Silveira, Marcus M Sá
In the title compound, C15H16O6, obtained from the acyl-ation reaction between 2,3-O-iso-propyl-idene-d-ribono-1,4-lactone and benzoyl chloride, the known absolute configuration for the lactone moiety of the ester substituent has been confirmed. The five-membered rings of the bicyclic lactone-dioxolane moiety both show envelope conformations and form a dihedral angle of 19.82 (7)° between the lactone ring and the benzene ring. In the crystal, mol-ecules of the acyl-ated sugar are linked by very weak inter-molecular C-H⋯O inter-actions, forming a three-dimensional network...
March 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28316802/crystal-structure-of-erioflorin-isolated-from-podanthus-mitiqui-l
#8
Cristian Paz, Leandro Ortiz, Uwe Schilde
The title compound, erioflorin, C19H24O6 [systematic name: (1aR,3S,4Z,5aR,8aR,9R,10aR)-1a,2,3,5a,7,8,8a,9,10,10a-deca-hydro-3-hy-droxy-4,10a-dimethyl-8-methyl-idene-7-oxooxireno[5,6]cyclo-deca-[1,2-b]furan-9-yl methacrylate], is a tricyclic germacrane sesquiterpene lactone, which was isolated from Podanthus mitiqui (L.). The compound crystallizes in the space group P212121, and its mol-ecular structure consists of a methacrylic ester of a ten-membered ring sesquiterpenoid annelated with an epoxide and a butyrolactone...
March 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28316144/characterization-of-the-multiple-molecular-mechanisms-underlying-rsal-control-of-phenazine-1-carboxylic-acid-biosynthesis-in-the-rhizosphere-bacterium-pseudomonas-aeruginosa-pa1201
#9
Shuang Sun, Bo Chen, Zi-Jing Jin, Lian Zhou, Yun-Ling Fang, Chitti Thawai, Giordano Rampioni, Ya-Wen He
Phenazines are important secondary metabolites that have been found to affect a broad spectrum of organisms. Two almost identical gene clusters phz1 and phz2 are responsible for phenazines biosynthesis in the rhizobacterium Pseudomonas aeruginosa PA1201. Here we show that the transcriptional regulator RsaL is a potent repressor of phenazine-1-carboxylic acid (PCA) biosynthesis. RsaL negatively regulates phz1 expression and positively regulates phz2 expression via multiple mechanisms. First, RsaL binds to a 25-bp DNA region within the phz1 promoter to directly repress phz1 expression...
March 18, 2017: Molecular Microbiology
https://www.readbyqxmd.com/read/28315464/a-novel-nanosuspension-of-andrographolide-preparation-characterization-and-passive-liver-target-evaluation-in-rats
#10
Ligang Guo, Le Kang, Xinrong Liu, Xiangyun Lin, Donghua Di, Yong Wu, Dexian Kong, Yihui Deng, Yanzhi Song
Andrographolide (Andro) is an excellent anti-inflammatory bicyclic diterpene γ-lactone. However, the poor solubility limits its application as injection for the treatment of acute inflammation. To meet the clinical needs for emergency, the Andro nanosuspensions injection was first prepared by the wet milling technique. The Andro nanosuspensions were composed of 3% Andro, 5% poloxamer 188 as the non-ionic stabilizer, 0.05% sodium deoxycholate or 0.1% sodium tauroursodeoxy cholate as the ionic stabilizer, and prepared by 350rpm speed and 12cycles of grinding with 0...
March 14, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28314243/parthenolide-attenuates-cerebral-ischemia-reperfusion-injury-via-akt-gsk-3%C3%AE-pathway-in-pc12-cells
#11
Jun-Feng Zhang, Li Zhang, Li-Li Shi, Zhao-Hua Zhao, Hao Xu, Fei Liang, Hong-Bo Li, Yan Zhao, Xi Xu, Ke Yang, Ying-Fang Tian
Parthenolide (PN), a sesquiterpene lactone isolated from the herbal medicine feverfew (Tanacetum parthenium), was reported to possess neuroprotective activity. However, the neuroprotective effect of PN against cerebral ischemia/reperfusion (I/R) injury remains unclear. Therefore, the aim of the present study was to explore the neuroprotective effects of PN against oxygen-glucose deprivation (OGD)-induced apoptosis in PC12 cells and the underlying mechanisms. Our results demonstrated that PN ameliorated OGD/R-evoked neuronal injury and oxidative stress in PC12 cells...
March 13, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28304168/a-total-synthesis-of-%C3%A2-3-o-demethylmacronine-through-rearrangement-of-a-precursor-embodying-the-haemanthidine-alkaloid-framework
#12
Xiang Ma, Nadia Yuqian Gao, Martin G Banwell, Paul D Carr, Anthony C Willis
A total synthesis of the racemic modification, (±)-2, of the tazettine-type alkaloid 3-O-demethylmacronine is described. The key steps are an intramolecular Alder-ene (IMAE) reaction and a lactam-to-lactone rearrangement of tetracycle 13, a compound that embodies the haemanthidine alkaloid framework.
March 17, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28303956/inhibitory-role-of-acyl-homoserine-lactones-in-hemolytic-activity-and-viability-of-streptococcus-pyogenes-m6-s165
#13
Sunil D Saroj, Linda Holmer, Júlia M Berengueras, Ann-Beth Jonsson
Streptococcus pyogenes an adapted human pathogen asymptomatically colonizes the nasopharynx, among other polymicrobial communities. However, information on the events leading to the colonization and expression of virulence markers subject to interspecies and host-bacteria interactions are limited. The interference of acyl homoserine lactones (AHLs) with the hemolytic activity and viability of S. pyogenes M6 S165 was examined. AHLs, with fatty acid side chains ≥12 carbon atoms, inhibited hemolytic activity by downregulating the expression of the sag operon involved in the production of streptolysin S...
March 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28303526/a-herbivore-tag-and-trace-system-reveals-contact-and-density-dependent-repellence-of-a-root-toxin
#14
Zoe Bont, Carla Arce, Meret Huber, Wei Huang, Adrien Mestrot, Craig J Sturrock, Matthias Erb
Foraging behavior of root feeding organisms strongly affects plant-environment-interactions and ecosystem processes. However, the impact of plant chemistry on root herbivore movement in the soil is poorly understood. Here, we apply a simple technique to trace the movement of soil-dwelling insects in their habitats without disturbing or restricting their interactions with host plants. We tagged the root feeding larvae of Melolontha melolontha with a copper ring and repeatedly located their position in relation to their preferred host plant, Taraxacum officinale, using a commercial metal detector...
March 16, 2017: Journal of Chemical Ecology
https://www.readbyqxmd.com/read/28303270/high-level-potential-energy-surface-and-mechanism-of-al-ch3-2och3-promoted-lactone-polymerization-initiation-and-propagation
#15
Stefan Vogt-Geisse, Ricardo A Mata, Alejandro Toro-Labbé
Despite increasing experimental interest in aliphatic polyesters as biodegradable and bioassimilable polymers a theoretical description of ring-opening polymerization (ROP) is not yet fully established. We report a detailed theoretical account of the mechanism of the ROP of three lactones (glycolide, 1,5-dioxepan-2-one and ε-caprolactone) using dimethylaluminium methoxide (Al(CH3)2OCH3) as the initiator. Both the initiation and propagation steps of the ROP are investigated using a composite method consisting of explicitly correlated Moller-Plesset (DF-MP2-F12) and explicitly correlated local coupled cluster methods (DF-LCCSD(T)-F12), for an accurate and definitive determination of the transition state and intermediate electronic energies...
March 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28300289/dehydrocostus-lactone-suppresses-proliferation-of-human-chronic-myeloid-leukemia-cells-through-bcr-abl-jak-stat-signaling-pathways
#16
Hong Cai, Xiaosong Qin, Chunhui Yang
This study evaluates the anticancer effects of dehydrocostus lactone, a plant-derived sesquiterpene lactone, on human chronic myeloid leukemia cells. Dehydrocostus lactone significantly inhibits cell proliferation by inducing cells to undergo cell cycle arrest, apoptosis and differentiation. Dehydrocostus lactone suppresses the expression of cyclin B1, cyclin A, cyclin E, cyclin-dependent kinase 2 (CDK2), and cyclin-dependent kinase 1 (CDK2) and increases p21 expression, resulting in S-G2/M phase arrest in K562 cells...
March 16, 2017: Journal of Cellular Biochemistry
https://www.readbyqxmd.com/read/28300280/rapamycin-attenuates-baff-extended-proliferation-and-survival-via-disruption-of-mtorc1-2-signaling-in-normal-and-neoplastic-b-lymphoid-cells
#17
Qingyu Zeng, Shanshan Qin, Hai Zhang, Beibei Liu, Jiamin Qin, Xiaoxue Wang, Ruijie Zhang, Chunxiao Liu, Xiaoqing Dong, Shuangquan Zhang, Shile Huang, Long Chen
B cell activating factor from the TNF family (BAFF) stimulates B-cell proliferation and survival, but excessive BAFF promotes the development of aggressive B cells leading to malignant and autoimmune diseases. Recently, we have reported that rapamycin, a macrocyclic lactone, attenuates human soluble BAFF (hsBAFF)-stimulated B-cell proliferation/survival by suppressing mTOR-mediated PP2A-Erk1/2 signaling pathway. Here, we show that the inhibitory effect of rapamycin on hsBAFF-promoted B cell proliferation/survival is also related to blocking hsBAFF-stimulated phosphorylation of Akt, S6K1 and 4E-BP1, as well as expression of survivin in normal and B-lymphoid (Raji and Daudi) cells...
March 16, 2017: Journal of Cellular Physiology
https://www.readbyqxmd.com/read/28297775/-effect-of-calcium-independent-phospholipase-a-2-inhibitor-in-reducing-hepatocyte-lipoapoptosis-and-improving-insulin-resistance
#18
H B Shi, J F Fu, Y Huang, L R Liu
Objective: To investigate the effect of calcium-independent phospholipase A(2) (iPLA(2)) inhibitor in reducing hepatocyte lipoapoptosis and improving insulin resistance. Methods: A total of 28 male Sprague-Dawley rats were randomly divided into the following three groups: 12 rats in group I (normal control group) were given normal diet for 18 weeks; 8 rats in group II (non-alcoholic fatty liver disease model group) were given high-fat diet for 18 weeks; 8 rats in group III (iPLA(2) inhibitor group) were given high-fat diet for 18 weeks and intraperitoneal injection of the iPLA(2) inhibitor bromoenol lactone 150 μg/kg once every other day since week 15 (14 times of injection in total)...
January 20, 2017: Zhonghua Gan Zang Bing za Zhi, Zhonghua Ganzangbing Zazhi, Chinese Journal of Hepatology
https://www.readbyqxmd.com/read/28297640/signal-destruction-tunes-the-zone-of-activation-in-spatially-distributed-signaling-networks
#19
Kalinga Pavan Silva, Prithiviraj Chellamuthu, James Q Boedicker
Diverse microbial communities coordinate group behaviors through signal exchange, such as the exchange of acyl-homoserine lactones (AHLs) by Gram-negative bacteria. Cellular communication is prone to interference by neighboring microbes. One mechanism of interference is signal destruction through the production of an enzyme that cleaves the signaling molecule. Here we examine the ability of one such interference enzyme, AiiA, to modulate signal propagation in a spatially distributed system of bacteria. We have developed an experimental assay to measure signal transduction and implement a theoretical model of signaling dynamics to predict how the system responds to interference...
March 14, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28295941/construction-of-fused-pyrrolidines-and-%C3%AE-lactones-by-carbene-catalyzed-c-n-c-c-and-c-o-bond-formations
#20
Xingxing Wu, Lin Hao, Yuexia Zhang, Maiti Rakesh, Rambabu N Reddi, Song Yang, Bao-An Song, Yonggui Robin Chi
A carbene-catalyzed intermolecular C-N bond formation, which initiates a highly selective cascade reaction for the synthesis of pyrrolidine fused β-lactones, is disclosed. The nitrogen-containing bicyclic β-lactone products are obtained with good yields and excellent stereoselectivities. Synthetic transformations of the reaction products into useful functional molecules, such as amino catalysts, can be efficiently realized under mild reaction conditions. Mechanistically, this study provides insights into modulating the reactivities of heteroatoms, such as nitrogen atoms, in challenging carbene-catalyzed asymmetric carbon-heteroatom bond-forming reactions...
March 15, 2017: Angewandte Chemie
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