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https://www.readbyqxmd.com/read/28428773/mutation-at-g103-of-mtbftsz-altered-their-sensitivity-to-coumarins
#1
Duggirala Sridevi, Karpagam U Sudhakar, Ragamanvitha Ananthathatmula, Rakesh P Nankar, Mukesh Doble
Coumarins are natural polyphenol lactones comprising of fused rings of benzene and α-pyrone. The current study demonstrates the inhibitory effect of coumarins with various substitutions on Mycobacterium smegmatis mc(2) 155. We also demonstrate the effect of pomegranate (Punica granatum) extract containing ellagic acid, on M. smegmatis as well as their affect on MtbFtsZ (FtsZ from Mycobacterium tuberculosis). The ellagic acid extracts from pomegranate peels inhibit mycobacteria with a MIC of 25 μM and 0.3 to 3...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28427132/-influences-of-abar-gene-on-biofilm-formation-of-acinetobacter-baumannii
#2
H N Guo, J Xiang
Objective: To detect drug-resistant phenotype and abaR gene of Acinetobacter baumannii (AB) and investigate influences of abaR gene on biofilm formation of AB. Methods: From February to July 2014, 159 strains AB were collected from Department of Clinical Microbiology of Ruijin Hospital of School of Medicine of Shanghai JiaoTong University and numbered starting from 1 according time when they were collected. (1) The above-mentioned 159 strains of AB were identified by detecting gene sequence of 16S ribosomal DNA...
April 20, 2017: Zhonghua Shao Shang za Zhi, Zhonghua Shaoshang Zazhi, Chinese Journal of Burns
https://www.readbyqxmd.com/read/28427016/synthesis-and-in%C3%A2-vitro-antitumour-activity-of-crassalactone-d-its-stereoisomers-and-novel-cinnamic-ester-derivatives
#3
Ivana Kovačević, Mirjana Popsavin, Goran Benedeković, Jelena Kesić, Vesna Kojić, Dimitar Jakimov, Tatjana Srdić-Rajić, Gordana Bogdanović, Vladimir Divjaković, Velimir Popsavin
Naturally occurring styryl lactone, crassalactone D (1), unnatural 4-epi-crassalactone D (2), and the corresponding 7-epimers (3 and 4) have been synthesized starting from d-glucose. The key step of the synthesis is a new one-pot sequence that commenced with a Z-selective Wittig olefination of suitably functionalized sugar lactols with a stabilized ylide, (methoxycarbonylmethylene)-triphenylphosphorane, in dry methanol, to afford 1 or 3, in the mixtures with the corresponding 4-epimers (2 or 4, respectively)...
April 13, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28425948/characterization-of-n-acyl-homoserine-lactones-in-vibrio-tasmaniensis-lgp32-by-a-biosensor-based-uhplc-hrms-ms-method
#4
Léa Girard, Élodie Blanchet, Laurent Intertaglia, Julia Baudart, Didier Stien, Marcelino Suzuki, Philippe Lebaron, Raphaël Lami
Since the discovery of quorum sensing (QS) in the 1970s, many studies have demonstrated that Vibrio species coordinate activities such as biofilm formation, virulence, pathogenesis, and bioluminescence, through a large group of molecules called N-acyl homoserine lactones (AHLs). However, despite the extensive knowledge on the involved molecules and the biological processes controlled by QS in a few selected Vibrio strains, less is known about the overall diversity of AHLs produced by a broader range of environmental strains...
April 20, 2017: Sensors
https://www.readbyqxmd.com/read/28425531/iridium-catalysed-asymmetric-allylic-alkylation-of-benzofuran-%C3%AE-lactones-followed-by-heteroaromatic-cope-rearrangement-study-of-an-unusual-reaction-sequence
#5
Maxence Bos, Emmanuel Riguet
The iridium-catalysed asymmetric allylic alkylation of γ-lactones produces an all-carbon quaternary stereocentre substituted by an allyl and a benzofuran. The resulting 1,5-hexadienes were found to be excellent substrates for an unusual heteroaromatic Cope rearrangement. We describe here the first insight into the synthetic outcome of this intriguing reaction sequence.
April 20, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28425292/lactone-derivatives-produced-by-a-phaeoacremonium-sp-an-endophytic-fungus-from-senna-spectabilis
#6
Geraldo H Silva, Maria L Zeraik, Camila M de Oliveira, Helder L Teles, Henrique C Trevisan, Ludwig H Pfenning, Camila P Nicolli, Maria C M Young, Yvonne P Mascarenhas, Lucas M Abreu, Amanda C Saraiva, Alexandra I Medeiros, Vanderlan da S Bolzani, Angela R Araujo
Three new isoaigialones, A, B, and C (1-3), along with aigialone (4), were isolated from the crude EtOAc extract of a Phaeoacremonium sp., an endophytic fungus obtained from the leaves of Senna spectabilis. The structures of these compounds were elucidated based on the analysis of spectroscopic data. Compounds 2 and 4 were active against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum. This is the first report of metabolites produced by an Phaeoacremonium sp., associated with S...
April 20, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28424524/hqia-a-novel-quorum-quenching-enzyme-which-expands-the-ahl-lactonase-family
#7
Marta Torres, Stéphane Uroz, Rafael Salto, Laure Fauchery, Emilia Quesada, Inmaculada Llamas
The screening of a metagenomic library of 250,000 clones generated from a hypersaline soil (Spain) allowed us to identify a single positive clone which confers the ability to degrade N-acyl homoserine lactones (AHLs). The sequencing of the fosmid revealed a 42,318 bp environmental insert characterized by 46 ORFs. The subcloning of these ORFs demonstrated that a single gene (hqiA) allowed AHL degradation. Enzymatic analysis using purified HqiA and HPLC/MS revealed that this protein has lactonase activity on a broad range of AHLs...
April 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28423074/7-epi-griffonilide-a-new-lactone-from-bauhinia-pentandra-complete-1h-and-13c-chemical-shift-assignments
#8
Macia C S DE Almeida, Luciana G S Souza, Daniele A Ferreira, Francisco C L Pinto, Débora R DE Oliveira, Gilvandete M P Santiago, Francisco J Q Monte, Raimundo Braz-Filho, Telma L G DE Lemos
A new lactone, 7-epi-griffonilide (1), and six known compounds, 2, 3a - 3c, 4a and 4b, were isolated from the leaves of Bauhinia pentandra (Fabaceae). The structures elucidation of 1 and 2 were based on detailed 2D NMR techniques and spectral comparison with related compounds, leading to complete assignment of the 1H and 13C NMR spectra.
January 2017: Anais da Academia Brasileira de Ciências
https://www.readbyqxmd.com/read/28422492/a-concise-efficient-and-scalable-total-synthesis-of-thapsigargin-and-nortrilobolide-from-r-carvone
#9
Dezhi Chen, P Andrew Evans
A concise, efficient and scalable synthesis of thapsigargin and nortrilobolide from commercially available (R)-(-)-carvone was developed. Our synthetic strategy is inspired by nature's carbon-carbon bond formation sequence, which facilitates the construction of a highly functionalized sesquiterpene lactone skeleton in five steps via an enantioselective ketone alkylation and a diastereoselective pinacol cyclization. We envision that this strategy will permit the construction of other members of the family, structural analogs and provide a practical synthetic route to these important bioactive agents...
April 19, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28421764/total-synthesis-of-the-claimed-structure-of-%C3%A2-hyptinin-and-structural-revision-of-natural-hyptinin
#10
Kazuto Maeda, Toshiyuki Hamada, Satoaki Onitsuka, Hiroaki Okamura
A total synthesis of (±)-hyptinin was achieved via a convergent route using the key phosphonate, cyclic ketone, and aryl Grignard components. The (1)H and (13)C NMR spectra of natural hyptinin did not agree with those of the synthesized compound. In particular, there were considerable differences between the signals assigned to the protons and carbons surrounding the lactone carbonyl group for the natural and synthesized compounds. The NMR data strongly suggested that the naturally occurring compound, hyptinin, was a structural isomer of the synthesized compound...
April 19, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28420479/andrographolide-disrupts-meiotic-maturation-by-blocking-cytoskeletal-reorganisation-and-decreases-the-fertilisation-potential-of-mouse-oocytes
#11
Hong-Xing Liang, Sheng-Sheng Lu, Zheng Yan, Yan-Ping Kuang, Xiang-Xing Zhu, Zhi-Guang Yan, Tong Du, Wei-Ran Chai, Hui Long, Qi-Feng Lyu
Andrographolide (AG) is a diterpenoid lactone isolated from the stem and leaves of Andrographis paniculata Nees that is used for the effective treatment of infectious diseases in Asian countries. Previous studies have reported adverse effects of AG on female fertility in rodents; however, the underlying mechanisms are unknown. The aim of the present study was to investigate the effects of AG on the IVM of mouse oocytes and their fertilisation potential. Immature oocytes incubated for 6, 14 or 24h in medium containing 5, 10 or 20μM AG showed time- and dose-dependent decreases in maturation rates compared with the control group...
April 19, 2017: Reproduction, Fertility, and Development
https://www.readbyqxmd.com/read/28418185/cu-pd-synergistic-dual-catalysis-asymmetric-%C3%AE-allylation-of-an-%C3%AE-cf3-amide
#12
Akira Saito, Naoya Kumagai, Masakatsu Shibasaki
Despite the burgeoning demand for fluorine-containing chemical entities, the construction of CF3 -containing stereogenic centers has remained elusive. Herein, we report the strategic merger of Cu(I) /base-catalyzed enolization of an α-CF3 amide and Pd(0) -catalyzed allylic alkylation in an enantioselective manner to deliver chiral building blocks bearing a stereogenic carbon center connected to a CF3 , an amide carbonyl, and a manipulable allylic group. The phosphine complexes of Cu(I) and Pd(0) engage in distinct catalytic roles without ligand scrambling to render the dual catalysis operative to achieve asymmetric α-allylation of the amide...
April 18, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28418096/expression-of-toll-like-receptors-in-t-lymphocytes-stimulated-with-n-3-oxododecanoyl-l-homoserine-lactone-from-pseudomonas-aeruginosa
#13
Lei Bao, Jialin Yu, Haiying Zhong, Daochao Huang, Qi Lu
The establishment of chronic Pseudomonas aeruginosa infections is correlated with the disturbance of the host immune system. The P. aeruginosa quorum-sensing molecule N-3-(oxododecanoyl)-L-homoserine lactone (3-O-C12-HSL) has the potential to modulate the host immune system. The immune system recognizes pathogens via toll-like receptors (TLRs). We found that 3-O-C12-HSL induced TLR changes in monocytes. However, the role of T cells in P. aeruginosa infection has not been delineated. In order to understand this activity, we examined whether 3-O-C12-HSL has an effect on the immune function and the expression of TLRs in T lymphocytes...
April 18, 2017: APMIS: Acta Pathologica, Microbiologica, et Immunologica Scandinavica
https://www.readbyqxmd.com/read/28416866/rheology-and-microstructure-of-kefiran-and-whey-protein-mixed-gels
#14
Hosayn Kazazi, Faramarz Khodaiyan, Karamatollah Rezaei, Malihe Pishvaei, Mohammad Amin Mohammadifar, Sohrab Moieni
The effect of kefiran on cold-set gelation of whey protein isolate (WPI) at 25 °C was studied using rheological measurements and environmental scanning electron microscopy (ESEM). The gelation of samples was induced by the addition of glucono-δ-lactone to the dispersions. WPI concentration was maintained at 8% (w/v) and the concentration of kefiran varied from 0 to 0.08% (w/v). According to rheological measurements, the addition of kefiran into WPI dispersions resulted in a significant increase in the gel strength, the yield stress, and the shear stress values at the flowing point...
April 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28416110/structural-basis-for-kinase-mediated-macrolide-antibiotic-resistance
#15
Desiree H Fong, David L Burk, Jonathan Blanchet, Amy Y Yan, Albert M Berghuis
The macrolides are a class of antibiotic, characterized by a large macrocyclic lactone ring that can be inactivated by macrolide phosphotransferase enzymes. We present structures for MPH(2')-I and MPH(2')-II in the apo state, and in complex with GTP analogs and six different macrolides. These represent the first structures from the two main classes of macrolide phosphotransferases. The structures show that the enzymes are related to the aminoglycoside phosphotransferases, but are distinguished from them by the presence of a large interdomain linker that contributes to an expanded antibiotic binding pocket...
April 1, 2017: Structure
https://www.readbyqxmd.com/read/28415922/host-pharmacokinetics-and-drug-accumulation-of-anthelmintics-within-target-helminth-parasites-of-ruminants
#16
A Lifschitz, C Lanusse, L Alvarez
Anthelmintic drugs require effective concentrations to be attained at the site of parasite location for a certain period to assure their efficacy. The processes of absorption, distribution, metabolism and excretion (pharmacokinetic phase) directly influence drug concentrations attained at the site of action and the resultant pharmacological effect. The aim of the current review article was to provide an overview of the relationship between the pharmacokinetic features of different anthelmintic drugs, their availability in host tissues, accumulation within target helminths and resulting therapeutic efficacy...
April 17, 2017: New Zealand Veterinary Journal
https://www.readbyqxmd.com/read/28415473/preparation-of-a-novel-bioavailable-curcuminoid-formulation-cureit%C3%A2-using-polar-nonpolar-sandwich-pns-technology-and-its-characterization-and-applications
#17
Augustine Amalraj, Shintu Jude, Karthik Varma, Joby Jacob, Sreeraj Gopi, Oluwatobi S Oluwafemi, Sabu Thomas
Health benefits of curcuminoid are highly limited due to their poor aqueous solubility, very low systemic bioavailability, fast metabolic alterations and rapid elimination. In this study, a novel bioavailable curcuminoid formulation Cureit™ was prepared by using Polar-Nonpolar-Sandwich (PNS) technology with complete natural turmeric matrix (CNTM). The synthesized bioavailable curcuminoid formulation Cureit™ was characterizations by Nuclear magnetic resonance spectroscopy (NMR), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infra-red (IR), current-voltage (I-V) study, Quadrupole Time-of-Flight Mass Spectrometry (Q-TOF), differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA)...
June 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28415001/degradation-of-synthetic-fragrances-by-laccase-mediated-system
#18
Laura Vallecillos, Yumna Sadef, Francesc Borrull, Eva Pocurull, Kai Bester
Laccase mediator systems are important biodegradation agents as the rate of reaction could be enhanced in the presence of redox mediators. In the present study the commercial enzyme laccase from Trametes versicolor and the redox mediator 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) were used for the biotransformation of the synthetic fragrances 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8,-tetramethyl-2-naphthyl)ethan-1-one (Iso-E-Super, OTNE), 1,3,4,6,7,8,-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[g]-2-benzopyran (Galaxolide, HHCB), 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphtalene (Tonalide, AHTN) and the transformation product of HHCB, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[g]-2-benzopyran-1-one (Galaxolidone, HHCB-lactone) in water...
April 4, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28414904/in-silico-prediction-of-chemicals-binding-to-aromatase-with-machine-learning-methods
#19
Hanwen Du, Yingchun Cai, Hongbin Yang, Hongxiao Zhang, Yuhan Xue, Guixia Liu, Yun Tang, Weihua Li
Environmental chemicals may affect endocrine systems through multiple mechanisms, one of which is via effects on aromatase (also known as CYP19A1), an enzyme critical for maintaining the normal balance of estrogens and androgens in the body. Therefore, rapid and efficient identification of aromatase-related endocrine disrupting chemicals (EDCs) is important for toxicology and environment risk assessment. In this study, on the basis of the Tox21 10K compound library, in silico classification models for predicting aromatase binders/non-binders were constructed by machine learning methods...
April 17, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/28414449/time-dependent-ph-scanning-of-the-acid-induced-unfolding-of-human-serum-albumin-reveals-stabilization-of-the-native-form-by-palmitic-acid-binding
#20
Alessandra Del Giudice, Cedric Dicko, Luciano Galantini, Nicolae Viorel Pavel
The most abundant plasma protein, Human Serum Albumin (HSA), is known to undergo several conformational transitions in acidic environment. To avoid buffer effects and correlate global and local structural changes, we developed a continuous acidification method and simultaneously monitored the protein changes by both small-angle scattering (SAXS) and fluorescence. The progressive acidification, based on the hydrolysis of glucono-δ-lactone from pH 7 to pH 2.5, highlighted a multi-step unfolding involving the putative F form (pH 4) and an extended and flexible conformation (pH < 3...
April 17, 2017: Journal of Physical Chemistry. B
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