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https://www.readbyqxmd.com/read/29149072/different-inhibitory-potencies-of-oseltamivir-carboxylate-zanamivir-and-several-tannins-on-bacterial-and-viral-neuraminidases-as-assessed-in-a-cell-free-fluorescence-based-enzyme-inhibition-assay
#1
Stefanie Quosdorf, Anja Schuetz, Herbert Kolodziej
Neuraminidaseis a key enzyme in the life cycle of influenza viruses and is present in some bacterial pathogens. We here assess the inhibitory potency of plant tannins versus clinically used inhibitors on both a viral and a bacterial model neuraminidase by applying the 2'-(4-methylumbelliferyl)-α-d-N-acetylneuraminic acid (MUNANA)-based activity assay. A range of flavan-3-ols, ellagitannins and chemically defined proanthocyanidin fractions was evaluated in comparison to oseltamivir carboxylate and zanamivir for their inhibitory activities against viral influenza A (H1N1) and bacterial Vibrio cholerae neuraminidase (VCNA)...
November 17, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29148797/nigegladines-a-c-three-thymoquinone-dimers-from-nigella-glandulifera
#2
Jie Tian, Chao Han, Wen-Hua Guo, Yong Yin, Xiao-Bing Wang, Hong-Bin Sun, He-Quan Yao, Yong Yang, Chen Wang, Chang Liu, Ming-Hua Yang, Ling-Yi Kong
Nigegladines A-C (1-3), three thymoquinone dimers, were isolated from the seeds of Nigella glandulifera. Racemic 1 possesses a unique tricyclo[5.4.0.1(2,6)]dodecane carbon skeleton, and compounds 2 and 3 are two unusual diterpenoid alkaloids with indole cores. Their structures were determined by extensive spectroscopic analyses, and that of 1 was confirmed by single-crystal X-ray diffraction. Both (+)-1 and (-)-1 exhibited significant protective effects against hypoxia/reoxygenation-induced H9c2 myocardial cell injury...
November 17, 2017: Organic Letters
https://www.readbyqxmd.com/read/29148767/role-of-the-benzodioxole-group-in-the-interactions-between-the-natural-alkaloids-chelerythrine-and-coptisine-and-the-human-telomeric-g-quadruplex-dna-a-multiapproach-investigation
#3
F Papi, M Ferraroni, R Rigo, S Da Ros, C Bazzicalupi, C Sissi, P Gratteri
The binding properties toward the human telomeric G-quadruplex of the two natural alkaloids coptisine and chelerythrine were studied using spectroscopic techniques, molecular modeling, and X-ray diffraction analysis. The results were compared with reported data for the parent compounds berberine and sanguinarine. Spectroscopic studies showed modest, but different rearrangements of the DNA-ligand complexes, which can be explained considering particular stereochemical features for these alkaloids, in spite of the similarity of their skeletons...
November 17, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/29147541/dearomatization-of-electron-poor-six-membered-n-heterocycles-through-3-2-annulation-with-aminocyclopropanes
#4
Johannes Preindl, Shyamal Chakrabarty, Jérôme Waser
Many abundant and highly bioactive natural alkaloids contain an indolizidine skeleton. A simple, high yielding method to synthesize this scaffold from N-heterocycles was developed. A wide range of pyridines, quinolines and isoquinolines reacted with donor-acceptor (DA)-aminocyclopropanes via an ytterbium(iii) catalyzed [3 + 2] annulation reaction to give tetrahydroindolizine derivatives. The products were obtained with high diastereoselectivities (dr > 20 : 1) as anti-isomers. Additionally, the formed aminals could be easily converted into secondary and tertiary amines through iminium formation followed by reduction or nucleophile addition...
October 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/29145965/increased-cytokine-levels-and-histological-changes-in-cartilage-synovial-cells-and-synovial-fluid-after-malleolar-fractures
#5
Alexandre L Godoy-Santos, Lucas Ranzoni, Walcy R Teodoro, Vera Capelozzi, Pedro Giglio, Tulio Diniz Fernandes, Stefan Rammelt
BACKGROUND: Malleolar fractures are among the most common fractures in the human skeleton with a high risk of later development of post-traumatic osteoarthritis (OA). The acute ankle injury initiates a sequence of events potentially leading to progressive articular surface damage resulting from inflammatory changes in cartilage, synovial tissue and synovial fluid. We hypothesised that in the acute phase of ankle fracture, these changes occur at the same time in the different tissues. METHODS: Specimens of chondral tissue, synovial tissue and synovial fluid were collected from 16 patients with acute articular ankle fracture (study group)...
October 2017: Injury
https://www.readbyqxmd.com/read/29145251/renal-osteodystrophy-presenting-as-a-metabolic-superscan-on-f-18-fdg-pet-ct-a-case-report
#6
Ismaheel Lawal, Alfred Ankrah, Kehinde Ololade, Moshe Modiselle, Mike Sathekge
RATIONALE: F-18 Fluoro Deoxyglucose positron emission tomography and computed tomography (F-18 FDG PET/CT) is a useful modality in the evaluation of patients with malignancies. Increased incidence of lympho-proliferative disorders has been reported in individuals with long-standing end-stage renal disorders treated with renal replacement therapy. PATIENT CONCERNS: A 30-year-old male on peritoneal dialysis on account of end-stage renal disease. He had acute rejection of an earlier transplanted renal allograft...
November 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/29143836/synthesis-and-properties-of-7-helicene-and-7-helicene-like-compounds-with-a-cyclopenta-1-2-b-4-3-b-dithiophene-or-dithieno-2-3-b-3-2-d-heterole-skeleton
#7
K Uematsu, K Noguchi, K Nakano
A series of [7]helicene and [7]helicene-like compounds composed of a cyclopenta[1,2-b:4,3-b']dithiophene or dithieno[2,3-b:3',2'-d]heterole moiety and two naphthalene moieties were successfully synthesized from a common synthetic intermediate, 1,1'-binaphtho[2,1-b]thiophene. Their helical structures were confirmed by X-ray crystallographic analysis. The photophysical properties of them and their benzene analogues were investigated via absorption and fluorescence spectroscopy and theoretical calculations to correlate the effect of the five-membered rings in their π-conjugated skeleton...
November 16, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29143561/beyond-lip-service-towards-human-rights-driven-our-speech-language-pathology-guidelines-for-south-african-speech-language-pathologists
#8
Michelle Pascoe, Daleen Klop, Thandeka Mdlalo, Mikateko Ndhambi
Developed with a strong awareness of past injustices, South Africa's progressive constitution emphasises a full spectrum of human rights. While the constitution celebrates many languages and cultures, speech-language pathologists (SLPs) face challenges in translating these values into practice with a diverse clientele. Similarly, Article 19 of the Universal Declaration of Human Rights focuses on freedom of expression in one's language of choice, but is often perceived as a "Cinderella" right (i.e. one that is frequently neglected)...
November 16, 2017: International Journal of Speech-language Pathology
https://www.readbyqxmd.com/read/29143525/sweritranslactones-a-c-unusual-skeleton-secoiridoid-dimers-via-4-2-cycloaddition-from-swertiamarin
#9
Lu Liu, Guan-Ling Xu, Xiao-Xia Ma, Afsar Khan, Wen-Hong Tan, Zhu-Ya Yang, Zhi-Hong Zhou
Skeleton-diversity-oriented chemical conversion from pure natural products is a valuable method to obtain natural product-like compounds, especially those with novel architecture. The application of phytochemical methods to iridoids yielded three novel secoiridoid dimers: sweritranslactones A-C (1-3). These molecules possess a 6/6/6/6/6/6-fused hexacyclic skeleton and were obtained from swertiamarin, one of the major constituents of the genus Swertia, via a [4+2] cycloaddition and intramolecular nucleophilic addition in aqueous conditions...
November 16, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29143443/multiscale-characterisation-of-cortical-bone-composition-microstructure-and-nanomechanical-properties-in-experimentally-induced-osteoporosis
#10
Furqan A Shah, Adrian Stoica, Carina Cardemil, Anders Palmquist
Cortical bone plays a vital role in determining overall bone strength. We investigate the structural, compositional, and nanomechanical properties of cortical bone following ovariectomy (OVX) of 12 week old Sprague Dawley rats, since this animal model is frequently employed to evaluate the performance of implantable biomaterials in compromised bone healing conditions. Morphological parameters and material properties of bone in the geometrical centre of the femoral cortex were investigated four and eight weeks post-OVX and in unoperated controls (Ctrl), using X-ray micro-computed tomography, backscattered electron scanning electron microscopy, Raman spectroscopy, and nanoindentation...
November 16, 2017: Journal of Biomedical Materials Research. Part A
https://www.readbyqxmd.com/read/29143030/quantitative-chemoproteomic-profiling-reveals-multiple-target-interactions-of-spongiolactone-derivatives-in-leukemia-cells
#11
M H Wright, Y Tao, J Drechsel, J Krysiak, S Chamni, A Weigert-Munoz, N L Harvey, D Romo, S A Sieber
The spongiolactones are marine natural products with an unusual rearranged spongiane skeleton and a fused β-lactone ring. These compounds have potential anticancer properties but their mode of action has yet to be explored. Here we employ activity-based protein profiling to identify the targets of a more potent spongiolactone derivative in live cancer cells, and compare these to the targets of a simpler β-lactone. These hits provide the first insights into the covalent mechanism of action of this natural product class...
November 16, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/29142340/clinical-pearls-etiologies-of-superscan-appearance-on-fluorine-18-fludeoxyglucose-positron-emission-tomography-computed-tomography
#12
REVIEW
John Joseph Manov, Patrick J Roth, Russ Kuker
The term "superscan" usually refers to a characteristic pattern on skeletal scintigraphy consisting of symmetrically intense and diffuse radiotracer uptake in the skeleton with absent or diminished visualization of the genitourinary system and soft tissues. Superscans and superscan-like appearances have also been described on fluorine-18-fludeoxyglucose positron emission tomography-computed tomography (18-F-FDG PET/CT). We review reported cases of 18-F-FDG PET/CT superscans and propose criteria for differentiating pathologic superscans from physiologic causes...
October 2017: Indian Journal of Nuclear Medicine: IJNM: the Official Journal of the Society of Nuclear Medicine, India
https://www.readbyqxmd.com/read/29140718/pem-fitter-a-coarse-grained-method-to-validate-protein-candidate-models
#13
Kamal Al Nasr, Christopher Jones, Feras Yousef, Ruba Jebril
The volumetric images produced by Cryo-Electron Microscopy (cryo-EM) technique are used to model macromolecular assemblies and machines. De novo protein modeling uses these images to computationally model the structure of the molecules. Many candidate conformations are usually generated during the intermediate step. Conventionally, each of these candidates is evaluated by time-consuming approaches such as potential energy. We introduce an initial version of a geometrical screening method that uses the skeleton of the cryo-EM images to evaluate candidate structures...
November 15, 2017: Journal of Computational Biology: a Journal of Computational Molecular Cell Biology
https://www.readbyqxmd.com/read/29140690/new-sesquiterpenoids-from-eugenia-jambolana-seeds-and-their-anti-microbial-activities
#14
Feifei Liu, Chengbin Liu, Wei Liu, Zhanjun Ding, Hang Ma, Navindra P Seeram, Li Xu, Yu Mu, Xueshi Huang, Liya Li
Twenty four sesquiterpenoids, 1-24, including 11 new sesquiterpenoids, jambolanins A-K, and two new norsesquiterpenoids, jambolanes A and B, along with six known triterpenoids, were isolated from the seeds of Eugenia jambolana fruit. Their structures were elucidated on the basis of NMR and MS spectrometry data analysis. Among the isolates, compound 13 possessed a rare 6,7-seco-guaiene skeleton, and compounds 14 and 15 were norsesquiterpenoids containing a spiro[4.4]nonane skeleton. Antimicrobial assay evaluation revealed that sesquiterpenoids, 4, 5/6, 17, 19, 21, 23, and 24 inhibited the growth of the Gram-positive bacterium, Staphylococcus aureus...
November 15, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/29140674/triptycene-based-microporous-cyanate-resins-for-adsorption-separations-of-benzene-cyclohexane-and-carbon-dioxide-gas
#15
Gaoyang Deng, Zhonggang Wang
Triptycene-based cyanate monomers 2,6,14-tricyanatotriptycene (TPC) and 2,6,14-tris(4-cyanatophenyl)triptycene (TPPC) that contain different numbers of benzene rings per molecule were synthesized, from which two microporous cyanate resins PCN-TPC and PCN-TPPC were prepared. Of interest is the observation that the two polymers have very similar porosity parameters, but PCN-TPPC uptakes considerably higher benzene (77.8 wt %) than PCN-TPC (17.6 wt %) at room temperature since the higher concentration of phenyl groups in PCN-TPPC enhances the π-π interaction with benzene molecules...
November 15, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29140370/mandibular-bone-structure-analysis-using-cone-beam-computed-tomography-vs-primary-implant-stability-an-ex-vivo-study
#16
Ruben Pauwels, Somchai Sessirisombat, Soontra Panmekiate
PURPOSE: To evaluate the relationship between mandibular bone structure parameters measured on preimplant cone beam computed tomography (CBCT) images and primary implant stability. MATERIALS AND METHODS: Twenty-one hemimandibles were scanned on the 3D Accuitomo 170 CBCT. Next, an implant was placed in each hemimandible, after which insertion torque and implant stability quotient (ISQ) measurements were acquired. The following measurements were performed on the preimplant CBCT scans: bone surface, bone volume, fractal dimension, connectivity, trabecular thickness and spacing, and skeleton analysis...
November 2017: International Journal of Oral & Maxillofacial Implants
https://www.readbyqxmd.com/read/29140075/strictosidine-synthase-triggered-enantioselective-synthesis-of-n-substituted-s-3-14-18-19-tetrahydroangustines-as-novel-topoisomerase-i-inhibitors
#17
Yunrui Cai, Huajian Zhu, Zaccary Alperstein, Wenjun Yu, Artem Cherkasov, Hongbin Zou
Monoterpenoid indole alkaloids (MIAs) comprise an important class of molecules for drug discovery, and these have variant carbon skeletons with prominent bioactivities. For instance, in spite of limitations to their use, camptothecins are the only clinically approved Topoisomerase I (Top1) inhibitors. The enzyme STR1, which is key for MIA biosynthesis, was applied to the enantioselective preparation of three N-substituted (S)-3,14,18,19-tetrahydroangustine (THA) derivatives. These non-camptothecin MIAs were shown to have moderate in vitro HepG2 cytotoxicity and Top1 inhibition activities...
November 15, 2017: ACS Chemical Biology
https://www.readbyqxmd.com/read/29138481/quadoctomycin-a-48-membered-macrolide-antibiotic-from-streptomyces-sp-mm168-141f8
#18
Ryuichi Sawa, Yumiko Kubota, Maya Umekita, Masaki Hatano, Chigusa Hayashi, Masayuki Igarashi
Drug-resistant bacteria are still emerging, and screening of new skeletal antibiotics is important. During our continuous screening for antimicrobial agents, we discovered a new antimicrobial, named quadoctomycin, from solid culture of Streptomyces sp. MM168-141F8. The substance was purified by solvent extraction, silica gel chromatography and HPLC. Structural elucidation of quadoctomycin was performed by MS and NMR analyses and chemical degradation. Quadoctomycin possesses a 48-membered polyol macrolide skeleton in which an α-D-mannoside is connected to C-22 by an O-glycosidic linkage...
November 15, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/29136008/automated-tracking-and-quantification-of-angiogenic-vessel-formation-in-3d-microfluidic-devices
#19
Mengmeng Wang, Lee-Ling Sharon Ong, Justin Dauwels, H Harry Asada
Angiogenesis, the growth of new blood vessels from pre-existing vessels, is a critical step in cancer invasion. Better understanding of the angiogenic mechanisms is required to develop effective antiangiogenic therapies for cancer treatment. We culture angiogenic vessels in 3D microfluidic devices under different Sphingosin-1-phosphate (S1P) conditions and develop an automated vessel formation tracking system (AVFTS) to track the angiogenic vessel formation and extract quantitative vessel information from the experimental time-lapse phase contrast images...
2017: PloS One
https://www.readbyqxmd.com/read/29135263/photoredox-divergent-1-2-difunctionalization-of-alkenes-with-gem-dibromides
#20
Jian Cheng, Yixiang Cheng, Jin Xie, Chengjian Zhu
The redox neutral photocatalytic divergent radical 1,2-difunctionalization of a wide array of structurally varied alkenes with gem-dibromides is presented. On the basis of the electronic effect of alkenes, predictable 1,2-carboxygenation and 1,2-carbohalogenation of alkenes are readily available regardless of steric effect. This protocol affords a practical approach to the biologically important furan skeleton. It is distinguished by good regioselectivity, good functional group compatibility, and late-stage modification and thus signifies an important step forward to divergent radical difunctionalization of alkenes...
November 14, 2017: Organic Letters
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