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11,889 result(s) for "ketones"
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Preparation and Transformations of Acetophenone-Derived Enamino Ketones, BFsub.2-β-Ketoiminates, and BFsub.2-β-Diketonates
A series of differently substituted β-enaminones 2a,b, 4a–i, 8a–d, and 9–13, their BF[sub.2]-β-ketoiminate complexes 5a–d, and BF[sub.2]-β-diketonate complexes 6a–d were prepared as model substrates for photochemical transformations. The attempted photochemical transformations of enaminones 2, 4, 8 and BF[sub.2]-β-ketoiminate complexes 5 failed. On the other hand, irradiation of mixtures of BF[sub.2]-β-diketonate complexes 6a–d and cycloalkanes with UV-A light (365 nm) gave the corresponding De Mayo reaction products 7a–f in 9–30% yields. The photochemical ring-expansion of acetyl tetralone-derived BF[sub.2]-complex 6d gave novel diannulated cyclooctane derivatives 7e and 7f, which would be difficult to obtain using conventional cyclization methods.
The ketogenic diet for the treatment of childhood epilepsy: a randomised controlled trial
The ketogenic diet has been widely and successfully used to treat children with drug-resistant epilepsy since the 1920s. The aim of this study was to test the efficacy of the ketogenic diet in a randomised controlled trial. 145 children aged between 2 and 16 years who had at least daily seizures (or more than seven seizures per week), had failed to respond to at least two antiepileptic drugs, and had not been treated previously with the ketogenic diet participated in a randomised controlled trial of its efficacy to control seizures. Enrolment for the trial ran between December, 2001, and July, 2006. Children were seen at one of two hospital centres or a residential centre for young people with epilepsy. Children were randomly assigned to receive a ketogenic diet, either immediately or after a 3-month delay, with no other changes to treatment (control group). Neither the family nor investigators were blinded to the group assignment. Early withdrawals were recorded, and seizure frequency on the diet was assessed after 3 months and compared with that of the controls. The primary endpoint was a reduction in seizures; analysis was intention to treat. Tolerability of the diet was assessed by questionnaire at 3 months. The trial is registered with ClinicalTrials.gov, number NCT00564915. 73 children were assigned to the ketogenic diet and 72 children to the control group. Data from 103 children were available for analysis: 54 on the ketogenic diet and 49 controls. Of those who did not complete the trial, 16 children did not receive their intervention, 16 did not provide adequate data, and ten withdrew from the treatment before the 3-month review, six because of intolerance. After 3 months, the mean percentage of baseline seizures was significantly lower in the diet group than in the controls (62·0% vs 136·9%, 75% decrease, 95% CI 42.4–107.4%; p<0·0001). 28 children (38%) in the diet group had greater than 50% seizure reduction compared with four (6%) controls (p<0·0001), and five children (7%) in the diet group had greater than 90% seizure reduction compared with no controls (p=0·0582). There was no significant difference in the efficacy of the treatment between symptomatic generalised or symptomatic focal syndromes. The most frequent side-effects reported at 3-month review were constipation, vomiting, lack of energy, and hunger. The results from this trial of the ketogenic diet support its use in children with treatment-intractable epilepsy. HSA Charitable Trust; Smiths Charity; Scientific Hospital Supplies; Milk Development Council.
Eribulin versus dacarbazine in previously treated patients with advanced liposarcoma or leiomyosarcoma: a randomised, open-label, multicentre, phase 3 trial
A non-randomised, phase 2 study showed activity and tolerability of eribulin in advanced or metastatic soft-tissue sarcoma. In this phase 3 study, we aimed to compare overall survival in patients with advanced or metastatic soft-tissue sarcoma who received eribulin with that in patients who received dacarbazine (an active control). We did this randomised, open-label, phase 3 study across 110 study sites in 22 countries. We enrolled patients aged 18 years or older with intermediate-grade or high-grade advanced liposarcoma or leiomyosarcoma who had received at least two previous systemic regimens for advanced disease (including an anthracycline). Using an interactive voice and web response system, an independent statistician randomly assigned (1:1) patients to receive eribulin mesilate (1·4 mg/m2 intravenously on days 1 and 8) or dacarbazine (850 mg/m2, 1000 mg/m2, or 1200 mg/m2 [dose dependent on centre and clinician] intravenously on day 1) every 21 days until disease progression. Randomisation was stratified by disease type, geographical region, and number of previous regimens for advanced soft-tissue sarcoma and in blocks of six. Patients and investigators were not masked to treatment assignment. The primary endpoint was overall survival in the intention-to-treat population. The study is registered with ClinicalTrials.gov, number NCT01327885, and is closed to recruitment, but treatment and follow-up continue. Between March 10, 2011 and May 22, 2013, we randomly assigned patients to eribulin (n=228) or dacarbazine (n=224). Overall survival was significantly improved in patients assigned to eribulin compared with those assigned to dacarbazine (median 13·5 months [95% CI 10·9–15·6] vs 11·5 months [9·6–13·0]; hazard ratio 0·77 [95% CI 0·62–0·95]; p=0·0169). Treatment-emergent adverse events occurred in 224 (99%) of 226 patients who received eribulin and 218 (97%) of 224 who received dacarbazine. Grade 3 or higher adverse events were more common in patients who received eribulin (152 [67%]) than in those who received dacarbazine (126 [56%]), as were deaths (10 [4%] vs 3 [1%]); one death (in the eribulin group) was considered treatment-related by the investigators. Overall survival was improved in patients assigned to eribulin compared with those assigned to an active control, suggesting that eribulin could be a treatment option for advanced soft-tissue sarcoma. Eisai.
1,2-Oxidative Trifluoromethylation of Olefin with Ag and Osub.2: Synthesis of α-Trifluoromethyl Ketones
A novel and efficient 1,2-oxidative trifluoromethylation of olefins employing Ag(O[sub.2]CCF[sub.2]SO[sub.2]F) as a trifluoromethyl source is described with O[sub.2] as the oxidant, which provides access to a variety of valuable α-trifluoromethyl-substituted ketones. The broad substrate scope, feasibility of large-scale operation, and derivatization reactions of α-trifluoromethyl ketones demonstrate the promising utility of this protocol.
Activity of eribulin mesylate in patients with soft-tissue sarcoma: a phase 2 study in four independent histological subtypes
Eribulin inhibits microtubule dynamics via a mechanism distinct from that of other tubulin-targeting drugs, inducing cell-cycle arrest and tumour regression in preclinical models. We assessed the activity and safety of eribulin in four strata of patients with different types of soft-tissue sarcoma. In this non-randomised multicentre phase 2 study, patients were included if they had progressive or high-grade soft-tissue sarcoma and had received no more than one previous combination chemotherapy or up to two single drugs for advanced disease. They were stratified by the type of soft-tissue sarcoma they had. Eribulin was given intravenously at a concentration of 1·4 mg/m2 over 2–5 min at days 1 and 8 every 3 weeks to primarily assess progression-free survival at 12 weeks (RECIST 1.0), which we evaluated in all patients who started treatment. Safety analyses were done in all patients who started treatment. This trial is registered at ClinicalTrials.gov, number NCT00413192. Of 128 patients included, 37 had adipocytic sarcoma, 40 had leiomyosarcoma, 19 had synovial sarcoma, and 32 had other sarcomas. 12 (31·6%) of 38 patients with leiomyosarcoma evaluable for the primary endpoint, 15 (46·9%) of 32 patients with adipocytic sarcoma, four (21·1%) of 19 with synovial sarcoma, and five (19·2%) of 26 in other sarcomas were progression-free at 12 weeks. The most common grade 3–4 adverse events were neutropenia (66 [52%] of 127 patients evaluable for safety), leucopenia (44 [35%]), anaemia (nine [7%]), fatigue (nine [7%]), febrile neutropenia (eight [6%]), abnormal alanine aminotransferase concentrations (six [5%]), mucositis (four [3%]), and sensory neuropathy (four [3%]). Eribulin deserves further study in this setting, based on progression-free survival at 12 weeks in leiomyosarcoma and adipocytic sarcoma. Eisai Limited, Hatfield, UK.
Eribulin monotherapy versus treatment of physician's choice in patients with metastatic breast cancer (EMBRACE): a phase 3 open-label randomised study
Treatments with survival benefit are greatly needed for women with heavily pretreated metastatic breast cancer. Eribulin mesilate is a non-taxane microtubule dynamics inhibitor with a novel mode of action. We aimed to compare overall survival of heavily pretreated patients receiving eribulin versus currently available treatments. In this phase 3 open-label study, women with locally recurrent or metastatic breast cancer were randomly allocated (2:1) to eribulin mesilate (1·4 mg/m 2 administered intravenously during 2–5 min on days 1 and 8 of a 21-day cycle) or treatment of physician's choice (TPC). Patients had received between two and five previous chemotherapy regimens (two or more for advanced disease), including an anthracycline and a taxane, unless contraindicated. Randomisation was stratified by geographical region, previous capecitabine treatment, and human epidermal growth factor receptor 2 status. Patients and investigators were not masked to treatment allocation. The primary endpoint was overall survival in the intention-to-treat population. This study is registered at ClinicalTrials.gov, number NCT00388726. 762 women were randomly allocated to treatment groups (508 eribulin, 254 TPC). Overall survival was significantly improved in women assigned to eribulin (median 13·1 months, 95% CI 11·8–14·3) compared with TPC (10·6 months, 9·3–12·5; hazard ratio 0·81, 95% CI 0·66–0·99; p=0·041). The most common adverse events in both groups were asthenia or fatigue (270 [54%] of 503 patients on eribulin and 98 [40%] of 247 patients on TPC at all grades) and neutropenia (260 [52%] patients receiving eribulin and 73 [30%] of those on TPC at all grades). Peripheral neuropathy was the most common adverse event leading to discontinuation from eribulin, occurring in 24 (5%) of 503 patients. Eribulin showed a significant and clinically meaningful improvement in overall survival compared with TPC in women with heavily pretreated metastatic breast cancer. This finding challenges the notion that improved overall survival is an unrealistic expectation during evaluation of new anticancer therapies in the refractory setting. Eisai.
Multifunctional Biomass-Based Ionic Liquids/CuCl-Catalyzed COsub.2-Promoted Hydration of Propargylic Alcohols: A Green Synthesis of α-Hydroxy Ketones
α-Hydroxy ketones are a class of vital organic skeletons that generally exist in a variety of natural products and high-value chemicals. However, the traditional synthetic route for their production involves toxic Hg salts and corrosive H[sub.2]SO[sub.4] as catalysts, resulting in harsh conditions and the undesired side reaction of Meyer–Schuster rearrangement. In this study, CO[sub.2]-promoted hydration of propargylic alcohols was achieved for the synthesis of various α-hydroxy ketones. Notably, this process was catalyzed using an environmentally friendly and cost-effective biomass-based ionic liquids/CuCl system, which effectively eliminated the side reaction. The ionic liquids utilized in this system are derived from natural biomass materials, which exhibited recyclability and catalytic activity under 1 bar of CO[sub.2] pressure without volatile organic solvents or additives. Evaluation of the green metrics revealed the superiority of this CuCl/ionic liquid system in terms of environmental sustainability. Further mechanistic investigation attributed the excellent performance to the ionic liquid component, which exhibited multifunctionality in activating substrates, CO[sub.2] and the Cu component.
IN/I,IN/I′-Diaryldihydrophenazines as a Sustainable and Cost-Effective Alternative to Precious Metal Complexes in the Photoredox-Catalyzed Alkylation of Aryl Alkyl Ketones
An inexpensive and highly efficient metal-free alternative to commonly used Ru- and Ir-based catalysts was proposed. It was shown that the new 2,7-di-tert-butyl-5,10-bis(4-trifluoromethylphenyl)-5,10-dihydrophenazine outcompeted the iridium phenylpyridyl complex in photoredox activity in the alkylation of silyl enol ethers yielding aryl alkyl ketones. The reaction occurred under visible light irradiation at room temperature and was also applicable to drug derivatives (ibuprofen and naproxen). In-depth photophysical, electrochemical, and quantum chemical studies showed that the aforementioned N,N-diaryldihydrophenazine exhibited enhanced properties that were essential for the photoredox catalysis (a long-lived triplet excited state, strong reducing ability, high stability of the radical cations formed in single-electron-transfer event, and chemical inertness of the catalyst with respect to reactants). Importantly, the substituted N,N′-diaryldihydrophenazines could be obtained directly from diaryl amines; a facile, easily handled and scaled-up one-pot synthetic procedure was elaborated.
Effectiveness of Exogenous Ketone Salts in Enhancing Circulating Acetoacetate Levels—A Pilot Study in Healthy Adults
Background/Objectives: Ketone salt (KS) containing a racemic beta-hydroxybutyrate mixture is commonly used as an alternative fuel source as it may lead to improved health and/or performance. We postulate that KS will raise acetoacetate levels and represent the effectiveness of exogenous KS as an energy source. We conducted a pilot study to quantify changes in the circulating acetoacetate following KS and to determine if any changes in acetoacetate were associated with the changes in circulating beta-hydroxybutyrate. Methods: Thirteen adults (21.6 ± 4.3 years old; seven males/six females) completed this randomized, triple-blinded, placebo-controlled, cross-over design study. Participants consumed either KS or flavor-matched placebo with a one-week washout period between supplements. Blood samples were taken before and 30 min after consuming each supplement, and plasma acetoacetate and beta-hydroxybutyrate levels were measured by gas chromatography/mass spectrometry. Results: The consumption of KS resulted in a significant increase in acetoacetate from baseline. The increase in acetoacetate after the KS supplement was significantly greater than that following the consumption of a placebo (↑ 0.57 ± 0.44 mM vs. ↑ 0.07 ± 0.23 mM, p = 0.009, d = 0.86), and significantly and strongly related to the change in blood beta-hydroxybutyrate (r = 0.757, p < 0.001). Conclusions: Our findings indicate that KS markedly increases plasma ketone body interconversion, presumably to supply peripheral tissues for ATP generation.