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Tactical substitutions

Sindhu Kancherla, Marianne Lorentzen, Victor Snieckus, Kåre Bredeli Jørgensen
A general method for the regioselective synthesis of a series of ortho-substituted chrysenyl N,N-diethyl-O-carbamates by the directed ortho metalation (DoM) strategy is reported. The starting O-carbamates were prepared from corresponding chrysenols, available by oxidative photochemical cyclization or directed remote metalation tactics. Chrysen-1-yl and chrysene-3-yl ring site selectivity of directed ortho metalation (DoM) and anionic ortho Fries rearrangement (AoF) protocols, with s-BuLi/TMEDA, followed by electrophilic quench using a selection of electrophiles, were observed leading to new chrysenyl derivatives...
March 15, 2018: Journal of Organic Chemistry
Kasireddy Harsha Vardhan Reddy, Expédite Yen-Pon, Sylvia Cohen-Kaminsky, Samir Messaoudi, Mouad Alami
A convergent total synthesis of MK-801 has been achieved. Key synthetic transformations include multi-component Barbier-type reaction to construct the α-branched amine, a selective Heck α-coupling tactic to generate the exocyclic alkene skeleton, and a late-stage intramolecular hydroamination reaction between the exocyclic alkene and the secondary protected amine. The efficacy of this method was demonstrated by the synthesis of two news analogues substituted on the aromatic rings.
February 28, 2018: Journal of Organic Chemistry
Coady Wing, Kosali Simon, Ricardo A Bello-Gomez
The difference in difference (DID) design is a quasi-experimental research design that researchers often use to study causal relationships in public health settings where randomized controlled trials (RCTs) are infeasible or unethical. However, causal inference poses many challenges in DID designs. In this article, we review key features of DID designs with an emphasis on public health policy research. Contemporary researchers should take an active approach to the design of DID studies, seeking to construct comparison groups, sensitivity analyses, and robustness checks that help validate the method's assumptions...
January 12, 2018: Annual Review of Public Health
Hugo Sarmento, Filipe Manuel Clemente, Duarte Araújo, Keith Davids, Allistair McRobert, António Figueiredo
BACKGROUND: Evolving patterns of match analysis research need to be systematically reviewed regularly since this area of work is burgeoning rapidly and studies can offer new insights to performance analysts if theoretically and coherently organized. OBJECTIVE: The purpose of this paper was to conduct a systematic review of published articles on match analysis in adult male football, identify and organize common research topics, and synthesize the emerging patterns of work between 2012 and 2016, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines...
April 2018: Sports Medicine
Rania A H Ishak, Nada M Mostafa, Amany O Kamel
The blood-brain barrier is considered the leading physiological obstacle hindering the transport of neurotherapeutics to brain cells. The application of nanotechnology coupled with surfactant coating is one of the efficacious tactics overcoming this barrier. The aim of this study was to develop lipid polymer hybrid nanoparticles (LPHNPs), composed of a polymeric core and a phospholipid shell entangled, for the first time, with PEG-based surfactants (SAA) viz. TPGS or Solutol HS 15 in comparison with the gold standard Tween 80, aiming to enhance brain delivery and escape opsonization...
November 2017: Drug Delivery
Soumen Biswas, Debashis Majee, Soumitra Guin, Sampak Samanta
An efficient, solvent-free, and eco-friendly domino reaction of 5/6-membered cyclic sulfamidate imines with a variety of β,γ-unsaturated α-ketocarbonyls in neat conditions under MW irradiation promoted by DABCO as a solid organobase has been developed for the rapid construction of a novel class of densely functionalized picolinates. This interesting metal-solvent-free tactic allows a wide range of useful functionalities on the aryl rings and delivers good to excellent yields of the aforesaid aza-heterocycles within short time spans (20-40 min)...
October 2, 2017: Journal of Organic Chemistry
Jill Theresa Messing, Jacquelyn C Campbell, Carolyn Snider
AIMS: To assess the predictive validity of the DA-5 with the addition of a strangulation item in evaluating the risk of an intimate partner violence (IPV) victim being nearly killed by an intimate partner. BACKGROUND: The DA-5 was developed as a short form of the Danger Assessment for use in healthcare settings, including emergency and urgent care settings. Analyzing data from a sample of IPV survivors who had called the police for domestic violence, the DA-5 was tested with and without an item on strangulation, a potentially fatal and medically damaging IPV tactic used commonly by dangerous abusers...
September 16, 2017: Journal of Advanced Nursing
Xiqiang Cheng, Ping Gao, Lin Sun, Ye Tian, Peng Zhan, Xinyong Liu
Highly active antiretroviral therapy (HAART) has been widely adopted to control the HIV-1 infection successfully. HIV-1 integrase (IN) inhibitors are primary drugs in HAART regimens targeting integration step in the HIV-1 life cycle. However, due to the emergence of viral resistance and cross-resistance amongst drugs, there is a pressing need for new and potent IN inhibitors. This review covers the three patents describing spirocyclic and phosphate substituted quinolizine derivatives as novel HIV-1 IN inhibitors for the discovery of new anti-HIV-1 drug candidates...
November 2017: Expert Opinion on Therapeutic Patents
Vittorio Pace, Laura Castoldi, Eugenia Mazzeo, Marta Rui, Thierry Langer, Wolfgang Holzer
β,γ-Unsaturated aldehydes with all-carbon quaternary or tertiary α-centers were rapidly assembled from ketones through a unique synthetic operation consisting of 1) C1 homologation, 2) Lewis acid mediated epoxide-aldehyde isomerization, and 3) electrophilic trapping. The synthetic equivalence of a vinyl oxirane and a β,γ-unsaturated aldehyde is the key concept of this previously undisclosed tactic. Mechanistic studies and labeling experiments suggest that an aldehyde enolate is a crucial intermediate...
October 2, 2017: Angewandte Chemie
Sabin Fatima, Tehmina Anjum
Biocontrol of plant diseases through induction of systemic resistance is an environmental friendly substitute to chemicals in crop protection measures. Different biotic and abiotic elicitors can trigger the plant for induced resistance. Present study was designed to explore the potential of Pseudomonas aeruginosa PM12 in inducing systemic resistance in tomato against Fusarium wilt. Initially the bioactive compound, responsible for ISR, was separated and identified from extracellular filtrate of P. aeruginosa PM12...
2017: Frontiers in Plant Science
Yuichiro Kobayashi, Kayako Honjo, Susumu Kitagawa, Jessica Gwyther, Ian Manners, Takashi Uemura
Thermal ring-opening polymerization of the unsymmetrically substituted [1]ferrocenophane was performed in one-dimensional nanochannels of porous coordination polymers (PCPs). In contrast to conventional thermal polymerization in bulk, formation of cyclic polymer was inhibited in the channels. In addition, the tacticity of the resulting polymer was dependent on the pore size of PCPs.
June 22, 2017: Chemical Communications: Chem Comm
Moustafa M Elsawy, Achala de Mel
Reconstructive urologists are constantly facing diverse and complex pathologies that require structural and functional restoration of urinary organs. There is always a demand for a biocompatible material to repair or substitute the urinary tract instead of using patient's autologous tissues with its associated morbidity. Biomimetic approaches are tissue-engineering tactics aiming to tailor the material physical and biological properties to behave physiologically similar to the urinary system. This review highlights the different strategies to mimic urinary tissues including modifications in structure, surface chemistry, and cellular response of a range of biological and synthetic materials...
2017: Research and Reports in Urology
The D Ngo, Mahima Krishnan, Peter Boutsalis, Gurjeet Gill, Christopher Preston
BACKGROUND: Chloris virgata is a warm season, C4 , annual grass weed affecting field crops in northern Australia that has become an emerging weed in southern Australia. Four populations with suspected resistance to glyphosate were collected in South Australia, Queensland and New South Wales, Australia and compared to one susceptible (S) population to confirm glyphosate resistance and elucidate possible mechanisms of resistance. RESULTS: Based on the rate of glyphosate required to kill 50% of treated plants (LD50 ), glyphosate resistance (GR) was confirmed in four populations of C...
December 26, 2016: Pest Management Science
Susan Z Lever, Kuo-Hsien Fan, John R Lever
INTRODUCTION: Aspects of radiopharmaceutical development are illustrated through preclinical studies of [125 I]-(E)-1-(2-(2,3-dihydrobenzofuran-5-yl)ethyl)-4-(iodoallyl)piperazine ([125 I]-E-IA-BF-PE-PIPZE), a radioligand for sigma-1 (σ1 ) receptors, coupled with examples from the recent literature. Findings are compared to those previously observed for [125 I]-(E)-1-(2-(2,3-dimethoxy-5-yl)ethyl)-4-(iodoallyl)piperazine ([125 I]-E-IA-DM-PE-PIPZE). METHODS: Syntheses of E-IA-BF-PE-PIPZE and [125 I]-E-IA-BF-PE-PIPZE were accomplished by standard methods...
January 2017: Nuclear Medicine and Biology
Thomas C Nugent, Foad Tehrani Najafian, Hussein Ali El Damrany Hussein, Ishtiaq Hussain
Site selectivity, differentiating instances of the same functional group type on one substrate, represents a forward-looking theme within chemistry: reduced dependence on protection/deprotection protocols for increased overall yield and step-efficiency. Despite these potential benefits and the expanded tactical advantages afforded to synthetic design, site selectivity remains elusive and especially so for ketone-based substrates. Herein, site-selective intermolecular mono-aldolization has been demonstrated for an array of prochiral 4-keto-substituted cyclohexanones with concomitant regio-, diastereo-, and enantiocontrol...
September 26, 2016: Chemistry: a European Journal
Evelyn Hearne, Marie Claire Van Hout
An array of dissociative novel psychoactive substances, including "methoxetamine," "3-MeO-PCP," and "methoxphenidine," have emerged as substitutes for the illicit substance "ketamine." A netographic research methodology aimed to describe online, dissociative novel psychoactive substance users' perceptions of risk, informed knowledge around use, and indigenous harm-reduction practices as advocated within online drug fora, so as to provide credible information which can be used to inform public online health education and drug prevention...
September 2016: Journal of Psychoactive Drugs
Liam D Harper, Melissa Fothergill, Daniel J West, Emma Stevenson, Mark Russell
Qualitative research investigating soccer practitioners' perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research...
2016: PloS One
Yu Feng, Jun Liu, Yazmin P Carrasco, John B MacMillan, Jef K De Brabander
We describe the isolation, structure elucidation, and total synthesis of the novel marine natural product rifsaliniketal and the total synthesis of the structurally related variants salinisporamycin and saliniketals A and B. Rifsaliniketal was previously proposed, but not observed, as a diverted metabolite from a biosynthetic precursor to rifamycin S. Decarboxylation of rifamycin provides salinisporamycin, which upon truncation with loss of the naphthoquinone ring leads to saliniketals. Our synthetic strategy hinged upon a Pt(II)-catalyzed cycloisomerization of an alkynediol to set the dioxabicyclo[3...
June 8, 2016: Journal of the American Chemical Society
Martin Pettersson, Xinjun Hou, Max Kuhn, Travis T Wager, Gregory W Kauffman, Patrick R Verhoest
Strategic replacement of one or more hydrogen atoms with fluorine atom(s) is a common tactic to improve potency at a given target and/or to modulate parameters such as metabolic stability and pKa. Molecular weight (MW) is a key parameter in design, and incorporation of fluorine is associated with a disproportionate increase in MW considering the van der Waals radius of fluorine versus hydrogen. Herein we examine a large compound data set to understand the effect of introducing fluorine on the risk of encountering P-glycoprotein mediated efflux (as measured by MDR efflux ratio), passive permeability, lipophilicity, and metabolic stability...
June 9, 2016: Journal of Medicinal Chemistry
A Nazemi, J Khajehali, T Van Leeuwen
Onion thrips, Thrips tabaci Lindeman, is the main pest of onion-growing fields in Isfahan and is mainly controlled by frequently spraying several insecticides. To investigate the resistance status and mechanisms, the susceptibility of ten field populations collected from Isfahan onion-growing regions were tested to several currently used pesticides. Resistance to the tested insecticides was observed in most populations when compared with the susceptible reference population. Enhanced detoxification, implicated by the use of inhibitors of major metabolic detoxification enzymes, was observed in the populations resistant to profenofos and chlorpyrifos...
May 2016: Pesticide Biochemistry and Physiology
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