95 research outputs found

    Ethyl 6-methyl-4-[2-(4,4,5,5-tetra­methyl-1,3,2-dioxaborolan-2-yl)thio­phen-3-yl]-2-thioxo-1,2,3,4-tetra­hydro­pyrimidine-5-carboxyl­ate

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    A new Biginelli compound, C18H25BN2O4S2, containing a boronate ester group was synthesized from a lithium bromide-catalysed reaction. The compound crystallizes with two independent mol­ecules in the asymmetric unit that differ mainly in the conformation of the ester functionality. The crystal structure is stabilized by inter­molecular N—H⋯O and N—H⋯S hydrogen bonds involving the 3,4-dihydro­pyrimidine-2(1H)-thione NH groups as donors and the carbonyl O and thio­phene S atoms as acceptors

    Synthesis and Biological Activity of Arylspiroborate Salts Derived from Caffeic Acid Phenethyl Ester

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    Two novel boron compounds containing caffeic acid phenethyl ester (CAPE) derivatives have been prepared and characterized fully. These new compounds and CAPE have been investigated for potential antioxidant and antimicrobial properties and their ability to inhibit 5-lipoxygenase and whether chelation to boron improves their biological activity. Sodium salt 4 was generally more active than ammonium salt 5 in the biological assays and surpassed the radical scavenging ability of CAPE. Compounds 4 and 5 were more active than CAPE and Zileuton in human polymorphonuclear leukocytes. These results clearly show the effectiveness of the synthesized salts as transporter of CAPE

    Adjunctive rifampicin for Staphylococcus aureus bacteraemia (ARREST): a multicentre, randomised, double-blind, placebo-controlled trial.

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    BACKGROUND: Staphylococcus aureus bacteraemia is a common cause of severe community-acquired and hospital-acquired infection worldwide. We tested the hypothesis that adjunctive rifampicin would reduce bacteriologically confirmed treatment failure or disease recurrence, or death, by enhancing early S aureus killing, sterilising infected foci and blood faster, and reducing risks of dissemination and metastatic infection. METHODS: In this multicentre, randomised, double-blind, placebo-controlled trial, adults (≥18 years) with S aureus bacteraemia who had received ≤96 h of active antibiotic therapy were recruited from 29 UK hospitals. Patients were randomly assigned (1:1) via a computer-generated sequential randomisation list to receive 2 weeks of adjunctive rifampicin (600 mg or 900 mg per day according to weight, oral or intravenous) versus identical placebo, together with standard antibiotic therapy. Randomisation was stratified by centre. Patients, investigators, and those caring for the patients were masked to group allocation. The primary outcome was time to bacteriologically confirmed treatment failure or disease recurrence, or death (all-cause), from randomisation to 12 weeks, adjudicated by an independent review committee masked to the treatment. Analysis was intention to treat. This trial was registered, number ISRCTN37666216, and is closed to new participants. FINDINGS: Between Dec 10, 2012, and Oct 25, 2016, 758 eligible participants were randomly assigned: 370 to rifampicin and 388 to placebo. 485 (64%) participants had community-acquired S aureus infections, and 132 (17%) had nosocomial S aureus infections. 47 (6%) had meticillin-resistant infections. 301 (40%) participants had an initial deep infection focus. Standard antibiotics were given for 29 (IQR 18-45) days; 619 (82%) participants received flucloxacillin. By week 12, 62 (17%) of participants who received rifampicin versus 71 (18%) who received placebo experienced treatment failure or disease recurrence, or died (absolute risk difference -1·4%, 95% CI -7·0 to 4·3; hazard ratio 0·96, 0·68-1·35, p=0·81). From randomisation to 12 weeks, no evidence of differences in serious (p=0·17) or grade 3-4 (p=0·36) adverse events were observed; however, 63 (17%) participants in the rifampicin group versus 39 (10%) in the placebo group had antibiotic or trial drug-modifying adverse events (p=0·004), and 24 (6%) versus six (2%) had drug interactions (p=0·0005). INTERPRETATION: Adjunctive rifampicin provided no overall benefit over standard antibiotic therapy in adults with S aureus bacteraemia. FUNDING: UK National Institute for Health Research Health Technology Assessment

    Effects of fluoxetine on functional outcomes after acute stroke (FOCUS): a pragmatic, double-blind, randomised, controlled trial

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    Background Results of small trials indicate that fluoxetine might improve functional outcomes after stroke. The FOCUS trial aimed to provide a precise estimate of these effects. Methods FOCUS was a pragmatic, multicentre, parallel group, double-blind, randomised, placebo-controlled trial done at 103 hospitals in the UK. Patients were eligible if they were aged 18 years or older, had a clinical stroke diagnosis, were enrolled and randomly assigned between 2 days and 15 days after onset, and had focal neurological deficits. Patients were randomly allocated fluoxetine 20 mg or matching placebo orally once daily for 6 months via a web-based system by use of a minimisation algorithm. The primary outcome was functional status, measured with the modified Rankin Scale (mRS), at 6 months. Patients, carers, health-care staff, and the trial team were masked to treatment allocation. Functional status was assessed at 6 months and 12 months after randomisation. Patients were analysed according to their treatment allocation. This trial is registered with the ISRCTN registry, number ISRCTN83290762. Findings Between Sept 10, 2012, and March 31, 2017, 3127 patients were recruited. 1564 patients were allocated fluoxetine and 1563 allocated placebo. mRS data at 6 months were available for 1553 (99·3%) patients in each treatment group. The distribution across mRS categories at 6 months was similar in the fluoxetine and placebo groups (common odds ratio adjusted for minimisation variables 0·951 [95% CI 0·839–1·079]; p=0·439). Patients allocated fluoxetine were less likely than those allocated placebo to develop new depression by 6 months (210 [13·43%] patients vs 269 [17·21%]; difference 3·78% [95% CI 1·26–6·30]; p=0·0033), but they had more bone fractures (45 [2·88%] vs 23 [1·47%]; difference 1·41% [95% CI 0·38–2·43]; p=0·0070). There were no significant differences in any other event at 6 or 12 months. Interpretation Fluoxetine 20 mg given daily for 6 months after acute stroke does not seem to improve functional outcomes. Although the treatment reduced the occurrence of depression, it increased the frequency of bone fractures. These results do not support the routine use of fluoxetine either for the prevention of post-stroke depression or to promote recovery of function. Funding UK Stroke Association and NIHR Health Technology Assessment Programme

    Hot peppers for a healthier future: boron-containing capsaicinoids

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    Synthesis and Reactivity of Novel Boranes Derived from Bulky Salicylaldimines: The Molecular Structure of a Maltolato Compound

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    Reductive amination of salicylaldehyde or 3,5-di-tert-butylsalicylaldehyde and 1-adamantylamine using NaBH4 gave the corresponding aminoalcohols in high yields. Subsequent addition of one equivalent of H3B·SMe2 to the aminoalcohols, with loss of two equivalents of dihydrogen, resulted in the formation of adamantanyl oxazaborinanes (1a,b). The molecular structure of 1b was studied by a single crystal X-ray diffraction study. Crystals were obtained from a saturated Et2O solution and belong to the triclinic space group Pī with unit cell parameters a = 9.1267(4) Å; b = 11.676(2) Å; c = 12.240(3) Å; α = 66.840(3)°; β = 78.529(3)°; and γ = 67.354(3)°. The molecular structure of the addition product (2a) arising from maltol and 1a was also confirmed by single crystal X-ray diffraction. Crystals were obtained from a saturated 1:2 mixture of toluene/Et2O and belong to the orthorhombic space group Pna2(1) with unit cell parameters a = 18.519(6) Å; b = 17.315(5) Å; and c = 12.680(4) Å. The asymmetric unit contains two molecules that differ slightly in some of the dihedral angles

    Synthesis and Molecular Structure of Ph<sub>3</sub>GeBO<sub>2</sub>C<sub>2</sub>Me<sub>4</sub>

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    This open access article is also available from the publisher, J-STAGE, at http://doi.org/10.2116/xraystruct.32.35The germanium-boron compound, Ph3GeBpin (pin = 1,2-O2C2Me4), was isolated and the molecular structure was determined by a single crystal X-ray diffraction study at 188 K. The compound crystallizes in a orthorhombic system, space group Pca2(1) and Z = 8 with cell parameters of a = 16.669(4) Å, b = 9.933(2) Å, c = 26.907(6) Å, V = 4455.0(17) Å3. The R1 [I > 2σ(I)] and wR2 (all data) values are 0.0463 and 0.1196, respectively, for all 9468 independent reflections. The molecular structure analysis reveals the boron atom lies in a roughly trigonal environment that contains one pinacolato group and a single B-Ge bond distance of 2.073(10) Å.Thanks are gratefully extended to the Natural Sciences and Engineering Research Council of Canada, the Canada Research Chairs Program, and Mount Allison University for financial support

    Fluorinated Aryl Boronates as Building Blocks in Organic Synthesis

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    Organoboron compounds are well known building blocks for many organic reactions. However, under basic conditions, polyfluorinated aryl boronic acid derivatives suffer from instability issues that are accelerated in compounds containing an ortho‐fluorine group, which result in the formation of the corresponding protodeboronation products. Therefore, a considerable amount of research has focused on novel methodologies to synthesize these valuable compounds while avoiding the protodeboronation issue. This review summarizes the latest developments in the synthesis of fluorinated aryl boronic acid derivatives and their applications in cross‐coupling reactions and other transformations. imag

    Synthesis, characterization, and reactivity of a novel thallium arylspiroboronate ester

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    Addition of 3,5-di-tert-butylcatechol (butcat) to solutions of H 3B·SMe2 gave the novel diboron species B 2(butcat)3 (2) in moderate to high yields. Compound 2 reacts with Tl(acac) to give butcatB(acac) (4) and Tl(Bbutcat2) (5). Attempts to abstract the chlorides from [(dppb)Rh(μ-Cl)]2 (where dppb = 1,4-bis(diphenylphosphino)buthane) using 5 led to the unusual dimer [(dppb)Rh(μ-Cl)2(μ-Tl)Rh(dppb)][Bbutcat2] (6), which contains an unsymmetrical Rh-Tl-Rh bridge

    Preliminary investigations into the synthesis and antimicrobial activities of boron-containing capsaicinoids

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    This preliminary study reports on the synthesis of two new boron-capsaicin derivatives containing either a short or long chain aliphatic tail group using an iridium catalyzed hydroboration reaction with pinacolborane. The boronate ester groups reside on the terminal position of the tail group and are necessary for the bioactivity of these compounds. Indeed, both compounds showed considerable activity against two Gram-positive bacteria, including Vancomycin-resistant Enterococcus. Vancomycin is considered the last resort medication for the treatment of septicemia and new antibacterial agents that can treat sepsis are of paramount importance. The more lipophilic boron compound with the longer aliphatic chain also showed antifungal activity against Saccharomyces cerevisiae.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
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