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Qiao, Yue, Zhaohua Gao, Yong Liu, Yan Cheng, Mengxiao Yu, Lingling Zhao, Yixiang Duan y Yu Liu. "Breath Ketone Testing: A New Biomarker for Diagnosis and Therapeutic Monitoring of Diabetic Ketosis". BioMed Research International 2014 (2014): 1–5. http://dx.doi.org/10.1155/2014/869186.
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Background. Acetone,β-hydroxybutyric acid, and acetoacetic acid are three types of ketone body that may be found in the breath, blood, and urine. Detecting altered concentrations of ketones in the breath, blood, and urine is crucial for the diagnosis and treatment of diabetic ketosis. The aim of this study was to evaluate the advantages of different detection methods for ketones, and to establish whether detection of the concentration of ketones in the breath is an effective and practical technique.Methods. We measured the concentrations of acetone in the breath using gas chromatography-mass spectrometry andβ-hydroxybutyrate in fingertip blood collected from 99 patients with diabetes assigned to groups 1 (−), 2 (±), 3 (+), 4 (++), or 5 (+++) according to urinary ketone concentrations.Results. There were strong relationships between fasting blood glucose, age, and diabetic ketosis. Exhaled acetone concentration significantly correlated with concentrations of fasting blood glucose, ketones in the blood and urine, LDL-C, creatinine, and blood urea nitrogen.Conclusions. Breath testing for ketones has a high sensitivity and specificity and appears to be a noninvasive, convenient, and repeatable method for the diagnosis and therapeutic monitoring of diabetic ketosis.
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Taylor, Robert M. y Justin T. Baca. "Feasibility of Interstitial Fluid Ketone Monitoring with Microneedles". Metabolites 12, n.º 5 (10 de mayo de 2022): 424. http://dx.doi.org/10.3390/metabo12050424.
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Diabetic ketoacidosis (DKA) is one of the most dangerous and costly complications of diabetes, accounting for approximately 50% of deaths in diabetic individuals under 24 years. This results in over 130,000 hospital admissions yearly and costs the USA over USD 2.4 billion annually. Earlier diagnosis, treatment, and management of DKA are of critical importance to achieving better patient outcomes and preventing prolonged hospital admissions. Diabetic patients undergoing stress from illness or injury may not recognize early ketosis and often present advanced ketoacidosis, requiring intensive care admission. We have recently developed a microneedle-based technology to extract dermal interstitial fluid (ISF) from both animals and humans, which could enable wearable sensors to rapidly detect ketosis. Metabolite concentrations in ISF may differ in urine and blood and could likely represent local metabolic conditions in the surrounding tissue. Development of a wearable ketone detector will require an understanding of ketone concentrations and kinetics in ISF. Here, we report data that is first of its kind, with regard to the ketone concentrations present in the dermal ISF of rats, their correlation to blood, and the possible impact on the development of a wearable ISF “early warning system” to prevent morbidity from DKA. We extracted ISF, using minimally invasive microneedle arrays, from control Sprague Dawley rats and 17 h fasted rats. ISF and blood ketone levels were measured using a common glucose/ketone meter and strips. Local tissue concentrations of glucose were similar to those of blood, with an average blood to ISF glucose ratio of 0.99 ± 0.15 mg/dL. ISF ketones (0.4 ± 0.3 mM) were significantly higher (p = 4.2 × 10−9), compared with blood ketones (0.0 ± 0.0 mM). Although the fasted animals had slightly higher ISF ketones (1.3 ± 1.1 mM) compared with blood ketones (1.0 ± 1.0 mM), the difference was not significant (p = 0.3). This suggests ISF could possibly be useful as a surrogate for blood when determining ketone levels within a clinical setting.
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Basdevant, Benoit, Audrey-Anne Guilbault, Samuel Beaulieu, Antoine Jobin-Des Lauriers y Claude Y. Legault. "Iodine(III)-mediated synthesis of chiral α-substituted ketones: recent advances and mechanistic insights". Pure and Applied Chemistry 89, n.º 6 (27 de junio de 2017): 781–89. http://dx.doi.org/10.1515/pac-2016-1212.
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AbstractThe development of iodine(III)-mediated synthetic transformations has received growing interest, in particular to mediate enantioselective processes. In this class, the α-tosyloxylation of ketone derivatives using iodine(III) is a particularly powerful one, as it yields α-tosyloxy ketones – versatile chiral precursors that enable rapid access to numerous α-chiral ketones through nucleophilic displacement. Despite years of research from numerous groups, the enantioselectivities for this transformation have remained modest. Using quantum chemical calculations, we have uncovered a possible rational for the lack of selectivity. With these computational insights, we have developed an alternative experimental strategy and achieved unprecedented levels of selectivities. Applying this newfound knowledge, we have recently developed a new method to access α-halo ketones from non-ketonic precursors.
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Goffinet, Line, Thierry Barrea, Véronique Beauloye y Philippe A. Lysy. "Blood versus urine ketone monitoring in a pediatric cohort of patients with type 1 diabetes: a crossover study". Therapeutic Advances in Endocrinology and Metabolism 8, n.º 1-2 (13 de diciembre de 2016): 3–13. http://dx.doi.org/10.1177/2042018816681706.
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Background: The aim of our study was to determine the influence of routine ketone monitoring on hyperglycemic events (HE) and ketosis in youngsters with type 1 diabetes (T1D). Methods: Our single-site, controlled and randomized study was conducted on children and adolescents with T1D outside of remission phase. During two crossover periods of 6 months, patients ( n = 22) experiencing HE tested ketones alternatively with a blood ketone meter or urine ketone test strips and gave their opinion on screening methods after completion of clinical trial. Moreover, we evaluated levels of awareness of ketone production in a series of 58 patients and sometimes parents via a multiple-choice questionnaire. Results: Based on self-monitoring data, patients experienced a mean of 4.8 HE/month (range 0–9.3). Patients performed accurate ketone tests more frequently during urine (46%) than during blood-testing (29%) periods ( p < 0.05); while globally, 50% of ketone tests were inaccurate (i.e. without HE). Ketosis occurred significantly more often during urine (46.4%) than during blood (14.8%) monitoring ( p = 0.01), although no episodes of diabetic ketoacidosis (DKA) were noticed. Duration of hyperglycemia was not different whether patients measured ketones or not, suggesting that ketone monitoring did not affect correction of glycemia. Patients evaluated blood monitoring more frequently as being practical, reliable, and useful compared with urine testing. Scores in the awareness questionnaire were globally low (36.8%) without difference between patients and their parents. Conclusions: Although our study shows differences in outcomes (e.g. accurate use, detection of ketosis) of urine versus blood ketone monitoring, these did not affect the occurrence of HE. Whereas ketone monitoring is part of standardized diabetes education, its implementation in daily routine remains difficult, partly because patient awareness about mechanisms of ketosis is lacking.
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Dong, Guangbin, Hee Lim y Dong Xing. "Transition-Metal-Catalyzed Ketone α-Alkylation and Alkenylation with Simple Alkenes and Alkynes through a Dual Activation Strategy". Synlett 30, n.º 06 (21 de noviembre de 2018): 674–84. http://dx.doi.org/10.1055/s-0037-1610315.
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In this personal account, we summarize our investigations on the α-alkylation and α-alkenylation reactions of ketones with nonactivated alkenes and alkynes, respectively. The serendipitous discovery of C–H alkylation/alkenylation of cyclic 1,2-diketones provided a proof of concept for a dual activation strategy. Extension to the α-alkylation and α-alkenylation of regular ketones was achieved by using 7-azaindoline as a bifunctional ligand. Subsequently, intramolecular coupling between ketones and olefins was achieved with Rh- and Ru-based systems, respectively. Finally, branched-selective α-alkylation was achieved through an Ir-catalyzed enamide-mediated C–H alkylation.1 Introduction2 Serendipitous Discovery of α-Alkylation and α-Alkenylation of 1,2-Diketones through Enamine-Mediated C–H Activation3 Intermolecular Ketone α-Alkylation of Regular Ketones with Nonactivated Olefins4 Intermolecular Ketone α-Alkenylation of Regular Ketones with Nonactivated Alkynes5 Intramolecular Ketone α-Alkylation of Regular Ketones with Nonactivated Olefins6 Branched-Selective α-Alkylation of Regular Ketones with Nonactivated Olefins7 Conclusions and Outlook
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Ma, Shuai, Yunyun Li, Rigu Su, Jianxun Wu, Lingyuan Xie, Junshi Tang, Xusheng Wang et al. "Ketones in Low-Temperature Oxidation Products of Crude Oil". Processes 11, n.º 6 (30 de mayo de 2023): 1664. http://dx.doi.org/10.3390/pr11061664.
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Ketone compounds are oxidation products of crude oil in the in-situ combustion (ISC) process. Revealing the molecular composition of ketones can provide theoretical guidance for understanding the oxidation process of crude oil and valuable clues for studying the combustion state of crude oil in the reservoir. In this study, low-temperature oxidation (LTO) processes were simulated in thermal oxidation experiments to obtain thermally oxidized oil at different temperatures (170 °C, 220 °C, 270 °C, and 320 °C). A combination of chemical derivatization and positive-ion electrospray (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to analyze the molecular composition of different kinds of ketones (fatty ketones, naphthenic ketones, and aromatic ketones) in the oxidized oils at different temperatures. The results showed that the concentration of aliphatic ketones and aliphatic cyclic ketones in the product oils decreased with the increase in temperature, while aromatic ketones increased with the increase in temperature. At the same oxidation temperature, the content of ketones follows this order: fatty ketones < cycloalkanes < aromatic ketones. The concentrations of ketones reached their maximum value at 170 °C and decreased at high temperatures due to over-oxidation. It was also found that nitrogen-containing compounds are more easily oxidized to ketone compounds than their hydrocarbon counterparts in the LTO process.
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Januś, E. y D. Borkowska. "Occurrence of ketone bodies in the urine of cows during the first three months after calving and their association with milk yield". Archives Animal Breeding 56, n.º 1 (10 de octubre de 2013): 581–88. http://dx.doi.org/10.7482/0003-9438-56-057.
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Abstract. The aim of the study was to assess the effect of lactation number, month after calving, body condition at calving, milk yield and feeding season on the frequency and intensity of occurrence of ketone bodies in the urine during the first trimester after calving of Polish Holstein-Friesian cows cows with average annual milk yield of about 7,000 kg. It was also evaluated how the presence of ketone bodies in the urine of cows was associated with their milk production and the course of lactation. 479 urine samples were collected from the cows. The samples were tested using KRULAB test strips. The influence of the presence of ketone bodies on milk yield in 150 lactations and in 1,797 milk samples was also evaluated. It was found that 36.2 % of urine samples contained ketone bodies that could indicate various forms of ketosis. The frequency and intensity of the occurrence of ketone bodies in the urine was significantly influenced by the cows' body condition at calving, milk yield during standard lactation, the day the urine samples were collected and feeding season. The presence of ketones in the urine had little effect on milk yield in standard and complete lactations. Cows whose urine contained ketone bodies had significantly higher daily milk yield up to the sixth month of lactation. This could indicate that cows with high production potential are more susceptible to ketosis. The occurrence of ketones in the urine had a negative effect on the lactation curves of the cows tested.
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Bentourkia, M'hamed, Sébastien Tremblay, Fabien Pifferi, Jacques Rousseau, Roger Lecomte y Stephen Cunnane. "PET study of 11C-acetoacetate kinetics in rat brain during dietary treatments affecting ketosis". American Journal of Physiology-Endocrinology and Metabolism 296, n.º 4 (abril de 2009): E796—E801. http://dx.doi.org/10.1152/ajpendo.90644.2008.
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Normally, the brain's fuel is glucose, but during fasting it increasingly relies on ketones (β-hydroxybutyrate, acetoacetate, and acetone) produced in liver mitochondria from fatty acid β-oxidation. Although moderately raised blood ketones produced on a very high fat ketogenic diet have important clinical effects on the brain, including reducing seizures, ketone metabolism by the brain is still poorly understood. The aim of the present work was to assess brain uptake of carbon-11-labeled acetoacetate (11C-acetoacetate) by positron emission tomography (PET) imaging in the intact, living rat. To vary plasma ketones, we used three dietary conditions: high carbohydrate control diet (low plasma ketones), fat-rich ketogenic diet (raised plasma ketones), and 48-h fasting (raised plasma ketones). 11C-acetoacetate metabolism was measured in the brain, heart, and tissue in the mouth area. Using 11C-acetoacetate and small animal PET imaging, we have noninvasively quantified an approximately seven- to eightfold enhanced brain uptake of ketones on a ketogenic diet or during fasting. This opens up an opportunity to study brain ketone metabolism in humans.
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Babu, Kaki Raveendra, Xin He y Silong Xu. "Lewis Base Catalysis Based on Homoconjugate Addition: Rearrangement of Electron-Deficient Cyclopropanes and Their Derivatives". Synlett 31, n.º 02 (20 de noviembre de 2019): 117–24. http://dx.doi.org/10.1055/s-0039-1690753.
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Cyclopropane is one of the most reactive functionalities owing to its intrinsic ring strain. Transition-metal catalysis and Lewis acid catalysis have been extensively used in ring openings of cyclopropanes; however, Lewis base-catalyzed activation of cyclopropanes remains largely unexplored. Upon nucleophilic attack with Lewis bases, cyclopropanes undergo ring cleavage in a manner known as homoconjugate addition to form zwitterionic intermediates, which have significant potential for reaction development but have garnered little attention. Here, we present a brief overview of this area, with an emphasis on our recent efforts on Lewis base-catalyzed rearrangement reactions of electron-deficient cyclopropanes using the homoconjugate addition process.1 Introduction2 DABCO-Catalyzed Cloke–Wilson Rearrangement of Cyclopropyl Ketones3 Hydroxylamine-Mediated Tandem Cloke–Wilson/Boulton–Katritzky Reaction of Cyclopropyl Ketones4 Phosphine-Catalyzed Rearrangement of Vinylcyclopropyl Ketones To Form Cycloheptenones5 Phosphine-Catalyzed Rearrangement of Alkylidenecyclopropyl Ketones To Form Polysubstituted Furans and Dienones6 Conclusion and Outlook
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Wood, Thomas R., Brianna J. Stubbs y Sandra E. Juul. "Exogenous Ketone Bodies as Promising Neuroprotective Agents for Developmental Brain Injury". Developmental Neuroscience 40, n.º 5-6 (2018): 451–62. http://dx.doi.org/10.1159/000499563.
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Ketone bodies are a promising area of neuroprotection research that may be ideally suited to the injured newborn. During normal development, the human infant is in significant ketosis for at least the first week of life. Ketone uptake and metabolism is upregulated in the both the fetus and neonate, with ketone bodies providing at least 10% of cerebral metabolic energy requirements, as well as being the preferred precursors for the synthesis of fatty acids and cholesterol. At the same time, ketone bodies have been shown to have multiple neuroprotective effects, including being anticonvulsant, decreasing oxidative stress and inflammation, and epigenetically upregulating the production of neurotrophic factors. While ketogenic diets and exogenous ketosis are largely being investigated in the setting of adult brain injury, the adaptation of the neonate to ketosis suggests that developmental brain injury may be the area most suited to the use of ketones for neuroprotection. Here, we describe the mechanisms by which ketone bodies exert their neuroprotective effects, and how these may translate to benefits within each of the phases of neonatal asphyxial brain injury.
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Fan, Lulu, Shinobu Takizawa, Yoshiki Takeuchi, Kazuhiro Takenaka y Hiroaki Sasai. "Pd-catalyzed enantioselective intramolecular α-arylation of α-substituted cyclic ketones: facile synthesis of functionalized chiral spirobicycles". Organic & Biomolecular Chemistry 13, n.º 17 (2015): 4837–40. http://dx.doi.org/10.1039/c5ob00382b.
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Synthesis of chiral spirocyclic ketones was accomplishedviathe Pd-catalyzed intramolecular α-arylation of α-substituted cyclic ketones. The obtained spirocyclic ketone could be converted into an acid–base organocatalyst.
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Courchesne-Loyer, Alexandre, Etienne Croteau, Christian-Alexandre Castellano, Valérie St-Pierre, Marie Hennebelle y Stephen C. Cunnane. "Inverse relationship between brain glucose and ketone metabolism in adults during short-term moderate dietary ketosis: A dual tracer quantitative positron emission tomography study". Journal of Cerebral Blood Flow & Metabolism 37, n.º 7 (1 de octubre de 2016): 2485–93. http://dx.doi.org/10.1177/0271678x16669366.
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Ketones (principally β-hydroxybutyrate and acetoacetate (AcAc)) are an important alternative fuel to glucose for the human brain, but their utilisation by the brain remains poorly understood. Our objective was to use positron emission tomography (PET) to assess the impact of diet-induced moderate ketosis on cerebral metabolic rate of acetoacetate (CMRa) and glucose (CMRglc) in healthy adults. Ten participants (35 ± 15 y) received a very high fat ketogenic diet (KD) (4.5:1; lipid:protein plus carbohydrates) for four days. CMRa and CMRglc were quantified by PET before and after the KD with the tracers, 11C-AcAc and 18F-fluorodeoxyglucose (18F-FDG), respectively. During the KD, plasma ketones increased 8-fold ( p = 0.005) while plasma glucose decreased by 24% ( p = 0.005). CMRa increased 6-fold ( p = 0.005), whereas CMRglc decreased by 20% ( p = 0.014) on the KD. Plasma ketones were positively correlated with CMRa (r = 0.93; p < 0.0001). After four days on the KD, CMRa represented 17% of whole brain energy requirements in healthy adults with a 2-fold difference across brain regions (12–24%). The CMR of ketones (AcAc and β-hydroxybutyrate combined) while on the KD was estimated to represent about 33% of brain energy requirements or approximately double the CMRa. Whether increased ketone availability raises CMR of ketones to the same extent in older people as observed here or in conditions in which chronic brain glucose hypometabolism is present remains to be determined.
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Newport, Mary. "Review of Strategies to Overcome Brain Insulin Resistance Through Mild Nutritional Ketosis for Alzheimer's and Mild Cognitive Impairment". Current Developments in Nutrition 5, Supplement_2 (junio de 2021): 912. http://dx.doi.org/10.1093/cdn/nzab049_025.
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Abstract Objectives Insulin resistance with abnormal glucose uptake in the brain and inflammation are key pathologies in Alzheimer's disease (AD), related dementias, and in some people with mild cognitive impairment (MCI). Mild nutritional ketosis could provide therapeutic benefit since ketones are an alternative fuel to glucose through production of adenosine triphosphate via the Kreb's cycle and have anti-inflammatory effects. Methods Ketone uptake is normal in brain regions affected by abnormal glucose uptake in AD (Castellano, et al. J Alzheim Dis 2015). Ketones are anti-inflammatory and lessen beta amyloid plaques and tau tangles in animal models (Kashiwaya et al. PNAS 2000; Wu et al. FASEB 2020). Strategies to achieve mild nutritional ketosis (blood betahydroxybutyrate levels 0.5–2 mmol/L) include: (1) Intermittent fasting ≥ 10–14 hours. (2) MCT oil ≥ 18 gm/day. (3) Ketogenic diet (KD) (carbohydrates ≤ 50 grams per day and fat ≥ 50% of calories.) (4) Exogenous ketone salts and esters. Results Clinical trials and case studies have reported positive results using medium-chain triglyceride (MCT) oil, coconut oil (source of MCT oil), KD, or ketone ester in people with mild cognitive impairment and AD. KD improves biomarkers of insulin resistance in people with type 2 diabetes (Feinman et al. Nutrition 2015). Two people with mild AD had improved insulin-resistance biomarkers and normalization of MoCA cognitive test after 10 weeks of KD (Stoykovich and Gibas Alzheimers Dement 2019; Morrill and Gibas Diabetes Metab Syndr 2019). A study of 65 people with MCI taking MCT oil 30 gm/day for 6 months vs. placebo documented increased brain energy from ketones and cognitive improvement, without change in lipid profile or serious adverse effects (Fortier et al. Alzheimers Dement 2020). A study of 53 people with mild to moderate AD taking MCT oil 6 gm 3 x daily for 30 days reported improved cognition and lipid metabolomics (Xu et al. Clin Nutr 2020). Conclusions Given the lack any new FDA-approved drug for more than 15 years to treat or improve cognition in people with Alzheimer's, accumulating evidence suggests that adopting strategies to achieve mild nutritional ketosis could provide a safe and reasonable therapeutic approach to improve symptoms and a strategy for prevention. Funding Sources None.
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Mekonnen, Habtamu Gelaw, Debasis Sahoo, Samaresh Jana y Sanjoy Kumar Maji. "Exploration of Mesyl Chloride in a One Pot Conversion of Carboxylic Acids to Ketones". Current Organocatalysis 7, n.º 3 (30 de noviembre de 2020): 242–47. http://dx.doi.org/10.2174/2213337207999200611160509.
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Background: Due to the ubiquitous nature of the ketone functionality, it is considered an important functional group in organic chemistry. Hence, the synthesis of ketones from readily available starting materials is an important chemical transformation in organic synthesis. Consequently, several research efforts have been reported in the literature for the transformation of carboxylic acids to ketones in a one-pot synthesis. However, some of the procedures have limitations, such as long reaction times, harsh reaction conditions, and usage of expensive metal catalysts. Thus, a simple and convenient one-pot conversion of carboxylic acids to ketones remains desirable. Objective: We intended to develop a simple and convenient one-pot methodology for the synthesis of ketones from carboxylic acids. Our objective was to build up a carboxylic acid-based chemical template where various types of organometallic reagents can interact to produce the desired ketone. Methods: In this procedure, a carboxylic acid was converted to a mixed anhydride using mesyl chloride in the presence of a base. This mixed anhydride was then reacted with a suitable organometallic reagent at -20°C to obtain the desired ketone. The reaction was performed in a one-pot fashion. Results: Under the optimized reaction conditions, various aromatic and heteroaromatic carboxylic acids were converted to the corresponding ketones using organolithium and organomagnesium reagents with short reaction times. Moderate to good yields of the desired ketones were observed in many of these transformations. Conclusion: A simple and convenient one-pot method for the conversion of carboxylic acids to ketones has been reported. Specifically, various aromatic and `heteroaromatic carboxylic acids have been converted to the corresponding ketones in moderate to good yields. Organomagnesium and organolithium reagents were used as nucleophiles for this reaction.
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Ayyappan, Prathapan, Tricia D. Larsen, Tyler C. T. Gandy, Eli J. Louwagie y Michelle L. Baack. "Impact of Prenatal Exposure to Maternal Diabetes and High-Fat Diet on Postnatal Myocardial Ketone Body Metabolism in Rats". International Journal of Molecular Sciences 24, n.º 4 (12 de febrero de 2023): 3684. http://dx.doi.org/10.3390/ijms24043684.
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Infants exposed to diabetic pregnancy are at higher risk of cardiomyopathy at birth and early onset cardiovascular disease (CVD) as adults. Using a rat model, we showed how fetal exposure to maternal diabetes causes cardiac disease through fuel-mediated mitochondrial dysfunction, and that a maternal high-fat diet (HFD) exaggerates the risk. Diabetic pregnancy increases circulating maternal ketones which can have a cardioprotective effect, but whether diabetes-mediated complex I dysfunction impairs myocardial metabolism of ketones postnatally remains unknown. The objective of this study was to determine whether neonatal rat cardiomyocytes (NRCM) from diabetes- and HFD-exposed offspring oxidize ketones as an alternative fuel source. To test our hypothesis, we developed a novel ketone stress test (KST) using extracellular flux analyses to compare real-time ß-hydroxybutyrate (βHOB) metabolism in NRCM. We also compared myocardial expression of genes responsible for ketone and lipid metabolism. NRCM had a dose-dependent increase in respiration with increasing concentrations of βHOB, demonstrating that both control and combination exposed NRCM can metabolize ketones postnatally. Ketone treatment also enhanced the glycolytic capacity of combination exposed NRCM with a dose-dependent increase in the glucose-mediated proton efflux rate (PER) from CO2 (aerobic glycolysis) alongside a decreased reliance on PER from lactate (anaerobic glycolysis). Expression of genes responsible for ketone body metabolism was higher in combination exposed males. Findings demonstrate that myocardial ketone body metabolism is preserved and improves fuel flexibility in NRCM from diabetes- and HFD-exposed offspring, which suggests that ketones might serve a protective role in neonatal cardiomyopathy due to maternal diabetes.
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Thiyagarajan, Subramanian y Chidambaram Gunanathan. "Ruthenium-Catalyzed Direct Cross-Coupling of Secondary Alcohols to β-Disubstituted Ketones". Synlett 30, n.º 18 (13 de agosto de 2019): 2027–34. http://dx.doi.org/10.1055/s-0037-1611912.
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The β-disubstituted ketone functionality is prevalent in biologically active compounds and in pharmaceuticals. A ruthenium-catalyzed direct synthesis of β-disubstituted ketones by cross-coupling of two different secondary alcohols is reported. This new protocol was applied to the synthesis of variety of β-disubstituted ketones from various cyclic, acyclic, symmetrical, and unsymmetrical secondary alcohols. An amine–amide metal–ligand cooperation in a Ru catalyst facilitates the activation and formation of covalent bonds in selective sequences to provide the products. Kinetic and deuterium-labeling experiments suggested that aliphatic alcohols oxidize faster than benzylic secondary alcohols. A plausible mechanism is proposed on the basis of mechanistic and kinetic studies. Water and H2 are the only byproducts from this selective cross-coupling of secondary alcohols.1 Introduction2 Catalytic Self- or Cross-Coupling of Alcohols and Selectivity Challenges3 Recent Developments in the Synthesis of β-Disubstituted Ketones4 Scope of Ruthenium-Catalyzed Cross-Couplings of Secondary Alcohols5 Mechanistic Studies and Proposed Mechanism6 Conclusion
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Nelson, Thomas, Gillian Gresham, Amelia Welborn, L. J. Amaral, Brandon Noorvash, Laura Lockshon, Mourad Tighiouart et al. "QOLP-20. DIETARY, ACTIVITY, AND QUALITY OF LIFE METRICS IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA IMPLEMENTING A KETOGENIC DIET: RESULTS OF A PHASE 1 CLINICAL TRIAL". Neuro-Oncology 23, Supplement_6 (2 de noviembre de 2021): vi187. http://dx.doi.org/10.1093/neuonc/noab196.741.
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Abstract BACKGROUND Emerging evidence suggests that a ketogenic diet (KD) may limit neoplastic growth, but limited data exist regarding the effect of KD on daily activity, cognition, and health-related quality-of-life (HRQOL) for patients with glioblastoma. METHODS Newly diagnosed GBM patients participating in a single-arm phase 1 trial of a 16-week KD plus standard-of-care measured BID blood glucose and ketone levels (Keto-Mojo), captured continuous activity data (Fitbit), and completed quality-of-life (QLQ30) surveys and Montreal Cognitive Assessments (MoCA) at baseline, Week 8, and study end (up to 16 weeks). NCT03451799. RESULTS All patients (n = 14; 57% female; median age 55 years) maintained blood ketones above 0.3 mM > 50% of study duration (mean per-patient days in ketosis = 87%). Mean glucose (mg/dl) and ketone levels decreased through the study – Weeks 1/2: glucose 94.9 (SD:16.5), ketones 1.44 (SD:5.82); Weeks 3/4: glucose 94.1 (SD:12.9), ketones 1.34 (SD:0.9); Final two weeks: glucose 92.3 (SD:13.3), ketones 1.13 (SD:0.7). On average, patients walked 6,836 steps/day (SD:5,129), spending 14.3 hours sedentary (SD:6.45) and 43.6 minutes (SD:60.4) in high-intensity activity. Sleep duration was 6.8 hours (SD:2.26). Patients (n = 9) with OS > 14.6 mo from diagnosis demonstrated greater minutes of high-intensity activity (58.2 vs 20.7, p = 0.001), downtrending glucose (p = 0.001), and higher ketone levels (1.40 vs 1.11, p = 0.026). Activity data corroborated the tolerability of KD with stable-to-increased activity by study end. MoCA scores were stable from baseline (mean 23.4/30, SD:4.16) to study end (mean 24.8/30, SD:7.12; p = 0.38). When viewed as a composite score, HRQOL was stable-to-improving in 10/14 patients at Week 8 and EOS. CONCLUSION The use of wearable technology and at-home testing allowed for remote monitoring of activity and diet adherence. Good adherence and stable HRQOL and activity levels were observed in this phase 1 trial.
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Sk, Md Raja y Modhu Sudan Maji. "Cobalt(iii)-catalyzed ketone-directed C–H vinylation using vinyl acetate". Organic Chemistry Frontiers 7, n.º 1 (2020): 19–24. http://dx.doi.org/10.1039/c9qo01164a.
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Weakly coordinating, ketone-directed C–H vinylation using vinyl acetate is reported here for a wide range of aromatic ketones such as acetophenones, diaryl ketones, chromones and chalcones under cost-effective and air-stable cobalt(iii)-catalysis.
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Mujica-Parodi, Lilianne R., Anar Amgalan, Syed Fahad Sultan, Botond Antal, Xiaofei Sun, Steven Skiena, Andrew Lithen et al. "Diet modulates brain network stability, a biomarker for brain aging, in young adults". Proceedings of the National Academy of Sciences 117, n.º 11 (3 de marzo de 2020): 6170–77. http://dx.doi.org/10.1073/pnas.1913042117.
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Epidemiological studies suggest that insulin resistance accelerates progression of age-based cognitive impairment, which neuroimaging has linked to brain glucose hypometabolism. As cellular inputs, ketones increase Gibbs free energy change for ATP by 27% compared to glucose. Here we test whether dietary changes are capable of modulating sustained functional communication between brain regions (network stability) by changing their predominant dietary fuel from glucose to ketones. We first established network stability as a biomarker for brain aging using two large-scale (n= 292, ages 20 to 85 y;n= 636, ages 18 to 88 y) 3 T functional MRI (fMRI) datasets. To determine whether diet can influence brain network stability, we additionally scanned 42 adults, age < 50 y, using ultrahigh-field (7 T) ultrafast (802 ms) fMRI optimized for single-participant-level detection sensitivity. One cohort was scanned under standard diet, overnight fasting, and ketogenic diet conditions. To isolate the impact of fuel type, an independent overnight fasted cohort was scanned before and after administration of a calorie-matched glucose and exogenous ketone ester (d-β-hydroxybutyrate) bolus. Across the life span, brain network destabilization correlated with decreased brain activity and cognitive acuity. Effects emerged at 47 y, with the most rapid degeneration occurring at 60 y. Networks were destabilized by glucose and stabilized by ketones, irrespective of whether ketosis was achieved with a ketogenic diet or exogenous ketone ester. Together, our results suggest that brain network destabilization may reflect early signs of hypometabolism, associated with dementia. Dietary interventions resulting in ketone utilization increase available energy and thus may show potential in protecting the aging brain.
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Soejana, Firman Arief, Erliza Hambali y Obie Farobie. "Synthesis of Ketones from Palm Fatty Acids Over Layered Double Hydroxide Mg/Al/Cu Catalyst". IOP Conference Series: Earth and Environmental Science 1187, n.º 1 (1 de mayo de 2023): 012047. http://dx.doi.org/10.1088/1755-1315/1187/1/012047.
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Abstract The synthesis of ketones from C18:1 fatty acid using the fatty acid decarboxylation method has been carried out to increase the added value of oil palm derivative products. One of the derivative products of palm oil is Crude Palm Oil, which can be converted into fatty acids through the triglyceride hydrolysis process. Currently, palm oil fatty acids are the most potential environmentally friendly raw material in Indonesia. This research aims to synthesize ketones from palm oil fatty acids under different fatty acid types and catalyst concentrations. Ketone compounds were synthesized using a base catalyst of solid layered double hydroxide based on Mg/Al/Cu environmentally friendly because it does not produce by-products that can become pollutants. The ketone product was analyzed using the Fehling test, Tollens test, and FTIR. The results showed that the success of ketone synthesis using the fatty acid decarboxylation method into ketones through the Fehling test that red brick precipitate did not form and the Tollens test also indicated no silver mirror formation. Meanwhile, the results of the FTIR test showed the presence of ketone compounds at peak frequencies of 1697–1710 cm-1. This study confirms that ketones produced from fatty acids have the potential to be environmentally friendly raw materials for diesel fuel, lubricants, and surfactants.
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Manikyamba, Prerepa. "Structural effects in the oxidation of ketones by acid iodate". Collection of Czechoslovak Chemical Communications 56, n.º 6 (1991): 1279–86. http://dx.doi.org/10.1135/cccc19911279.
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The kinetics of oxidation of aliphatic, alicyclic and aryl alkyl ketones by acid iodate has been studied in aqueous methanol medium. The reaction exhibits first order dependence each on [iodate] and [ketone]. The reaction is acid catalysed and a medium of low dielectric constant is favourable for the oxidation process. The oxidation rates are slower than the enolisation rates of the ketones. The mechanism proposed involves rate limiting attack of IO+2 on the enol form of the ketone leading to the formation of an intermediate carbonium ion which undergoes solvolysis, ultimately leading to the formation of a methoxy derivative. The order of reactivity of these structurally different ketones is discussed in terms of stability of the enol formed from the ketone and of the stability of the carbonium ion formed due to attack of the oxidant species in the slow step.
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Dörr, Aurélie A. y William D. Lubell. "Homoallylic ketones and pyrroles by way of copper-catalyzed cascade additions of alkyl-substituted vinyl Grignard reagents to esters". Canadian Journal of Chemistry 85, n.º 11 (1 de noviembre de 2007): 1006–17. http://dx.doi.org/10.1139/v07-114.
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Exploring the scope of the copper-catalyzed cascade addition of vinyl Grignard reagents to carboxylic esters, a set of substituted homoallylic ketones (γ,δ-unsaturated ketones) have been synthesized in 11%–94% yields from treatment of methyl 4-methoxybenzoate and methyl N-Boc-β-alaninate with different methyl-, dimethyl-, and phenyl-substituted vinyl Grignard reagents in the presence of catalytic amounts of CuCN in THF. The respective 2,4-di-, 2,3,5-tri-, and 2,3,4,5-tetrasubstituted pyrroles were obtained in 47%–93% yields from the homoallylic ketones by a sequence featuring ozonolysis followed by Paal–Knorr condensation with ammonium formate.Key words: copper-catalyzed cascade addition, homoallylic ketone, alkyl-substituted vinyl Grignard reagents, ozonolysis, pyrrole, γ,δ-unsaturated ketone.
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Selvaraj, Senthil, Daniel P. Kelly y Kenneth B. Margulies. "Implications of Altered Ketone Metabolism and Therapeutic Ketosis in Heart Failure". Circulation 141, n.º 22 (2 de junio de 2020): 1800–1812. http://dx.doi.org/10.1161/circulationaha.119.045033.
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Despite existing therapy, patients with heart failure (HF) experience substantial morbidity and mortality, highlighting the urgent need to identify novel pathophysiological mechanisms and therapies, as well. Traditional models for pharmacological intervention have targeted neurohormonal axes and hemodynamic disturbances in HF. However, several studies have now highlighted the potential for ketone metabolic modulation as a promising treatment paradigm. During the pathophysiological progression of HF, the failing heart reduces fatty acid and glucose oxidation, with associated increases in ketone metabolism. Recent studies indicate that enhanced myocardial ketone use is adaptive in HF, and limited data demonstrate beneficial effects of exogenous ketone therapy in studies of animal models and humans with HF. This review will summarize current evidence supporting a salutary role for ketones in HF including (1) normal myocardial ketone use, (2) alterations in ketone metabolism in the failing heart, (3) effects of therapeutic ketosis in animals and humans with HF, and (4) the potential significance of ketosis associated with sodium-glucose cotransporter 2 inhibitors. Although a number of important questions remain regarding the use of therapeutic ketosis and mechanism of action in HF, current evidence suggests potential benefit, in particular, in HF with reduced ejection fraction, with theoretical rationale for its use in HF with preserved ejection fraction. Although it is early in its study and development, therapeutic ketosis across the spectrum of HF holds significant promise.
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Shen, Zican, Chen Li, Brandon Q. Mercado y Jonathan A. Ellman. "Cobalt(III)-Catalyzed Diastereoselective Three-Component C–H Bond Addition to Butadiene and Activated Ketones". Synthesis 52, n.º 08 (7 de noviembre de 2019): 1239–46. http://dx.doi.org/10.1055/s-0039-1690741.
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A highly diastereoselective three-component C–H bond addition across butadiene and activated ketones is described. This transformation provides homoallylic tertiary alcohols through the formation of two C–C σ-bonds and with complete selectivity for an E-alkene isomer. The reaction exhibits good scope with respect to activated ketone inputs, including highly strained cyclic and electron-deficient cyclic and acyclic ketones. Additionally, high diastereoselectivities were achieved for alcohols prepared from unsymmetrical ketones.
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Guerin, B. y L. J. Johnston. "Laser flash photolysis studies of 2,4,6-trialkylphenyl ketones". Canadian Journal of Chemistry 67, n.º 3 (1 de marzo de 1989): 473–80. http://dx.doi.org/10.1139/v89-074.
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2,4,6-Triisopropylbenzophenone (3), 2,4,6–trimethylbenzophenone (4), and 2,4,6-trimethylacetophenone (5) have been examined by laser flash photolysis. Relatively long-lived triplets compared to similar mono-alkyl substituted ketones have been observed for each (280 ns, >2 μs and 220 ns in acetronitrile for 3, 4 and 5, respectively). Photoenol intermediates with λmax 360 nm and 380 nm were also observed from ketones 3 and 5, respectively. Ketone 3 yielded a mixture of approximately equal amounts of Z and E enols in hexane. The Z enol had a lifetime of ~4 μs while the E enol did not decay appreciably during 100 μs. Biradical intermediates were not observed from any of the three ketones. Quenching rate constants for several energy transfer and hydrogen donor substrates are reported. For example, ketones 3 and 4 react with 1,4-cyclohexadiene with rate constants of 2.8 × 107 and 3.7 × 107 M−1 s−1, respectively, to yield ketyl radicals with λmax ~480 nm. Keywords: photoenolization, trialkyl phenyl ketone, flash photolysis, triplets.
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Maya, Kadek, Iswari Pauzi y Siti Zaetun. "Effect of Carbohydrate Diet Program on Urine Ketone Positivity with A Long Time on A Diet of One until Three Years". THRIVE Health Science Journal 1, n.º 1 (5 de marzo de 2024): 24–29. http://dx.doi.org/10.56566/thrive.v1i1.165.
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Carbohydrate diet is a diet pattern that reduces carbohydrate consumption. Therefore, the body will use fat as an alternative energy source. The continuous use of fat causes the accumulation of fatty acids so it is often the cause of ketone positivity in the urine. Objective: Find out the effect of a carbohydrate diet program on the positivity of urine ketones. Method this research is an analytic observational study with a cross-sectional approach. The sample used was urine from respondents who had been on a carbohydrate diet for 1 year, 2 years, and 3 years, then urine ketones were examined using the dipstick method. Data analysis was carried out using the Chi-Square test with a confidence value (α = 0.05). Result: The sample in this study amounted to 45 samples, with a total of 23 samples of positive ketones and 22 samples of negative ketones. The results of the Chi-Square test obtained an Asymp.sig value of 0.009 <0.05 (α) which indicates that the carbohydrate diet program has a significant effect on the positivity of urine ketones. The carbohydrate diet program affects urine ketone levels.
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Rukh, Mah, Aqsa Naeem, Syed Bilal Hussain y Muhammad Imran Qadir. "To Evaluate the Link Between Ketones in Urine and Perfume Allergy". Mediterranean Journal of Basic and Applied Sciences 06, n.º 03 (2022): 55–57. http://dx.doi.org/10.46382/mjbas.2022.6307.
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This study presents the relation between perfume allergy and presence of ketones in urine. When glucose level is low in our body or we don’t have enough insulin to absorb glucose then our body compensate by start breaking fats to provide energy and ketone are produced as a byproduct. The normal value of ketone in urine is less than 0.06mmol/L. Ketones are normally present in blood and urine but an increased value shows acidosis that can be fatal. Some people love scents. Perfumes contain certain chemicals that can cause allergy. The most common one is contact allergic dermatitis. The most common symptoms of perfume allergy are headache, difficulty in breathing, wheezing, chest tightening, asthma and stuffy nose. The present study shows that 25% males have Ketones in urine and are also allergic to perfumes while 2.25% females have ketone in urine and also allergic to perfumes.
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Falkenhain, Kaja, Ali Daraei, Scott Forbes y Jonathan Little. "Effects of Exogenous Ketones on Blood β-OHB and Glucose: A Systematic Review and Meta-Analysis". Current Developments in Nutrition 6, Supplement_1 (junio de 2022): 440. http://dx.doi.org/10.1093/cdn/nzac057.006.
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Abstract Objectives Exogenous ketone (monoester or salt) supplements are increasingly being employed for a variety of research purposes and marketed amongst the general public for their ability to raise blood beta-hydroxybutyrate (β-OHB). Emerging research suggests a blood glucose-lowering effect of exogenous ketones. Here, we systematically review and meta-analyze the available evidence of trials reporting on exogenous ketones and blood glucose. Methods We searched 6 electronic databases on December 13, 2021 for trials of any length that reported on the use of exogenous ketones compared to a placebo. We pooled raw mean differences (MD) in (i) blood β-OHB and (ii) blood glucose using random-effects models, and explored differences in the effects of ketone salts compared to ketone monoesters. Publication bias and risk of bias were examined using funnel plots and Cochrane's risk-of-bias tool, respectively. Results Twenty-eight trials including a total of 332 participants met inclusion criteria. There was no evidence for publication bias. Four trials were judged to be at low risk of bias with some concern for risk of bias in the remaining trials. Compared to placebo, consumption of exogenous ketones raised blood β-OHB (MD = 1.98 mM; 95% CI: 1.52 mM, 2.45 mM; P < 0.001) and decreased blood glucose (MD = −0.47 mM; 95% CI: −0.57 mM, −0.36 mM; P < 0.001) across the post-supplementation period of up to 300 minutes. Across both analyses, significantly greater effects were found following ingestion of ketone monoesters compared to ketone salts (P < 0.001). Conclusions Consumption of exogenous ketone supplements leads to acutely increased blood β-OHB and decreased blood glucose. Ketone monoesters exert a more potent β-OHB-raising and glucose-lowering effect as compared to ketone salts. Funding Sources Michael Smith Foundation for Health Research (MSFHR) Scholar Award.
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Veneti, Stavroula, Maria G. Grammatikopoulou, Evangelia Kintiraki, Gesthimani Mintziori y Dimitrios G. Goulis. "Ketone Bodies in Diabetes Mellitus: Friend or Foe?" Nutrients 15, n.º 20 (16 de octubre de 2023): 4383. http://dx.doi.org/10.3390/nu15204383.
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In glucose-deprived conditions, ketone bodies are produced by the liver mitochondria, through the catabolism of fatty acids, and are used peripherally, as an alternative energy source. Ketones are produced in the body under normal conditions, including during pregnancy and the neonatal period, when following a ketogenic diet (KD), fasting, or exercising. Additionally, ketone synthesis is also augmented under pathological conditions, including cases of diabetic ketoacidosis (DKA), alcoholism, and several metabolic disorders. Nonetheless, diet is the main regulator of total body ketone concentrations. The KDs are mimicking the fasting state, altering the default metabolism towards the use of ketones as the primary fuel source. Recently, KD has gained recognition as a medical nutrition therapy for a plethora of metabolic conditions, including obesity and diabetes mellitus (DM). The present review aims to discuss the role of ketones, KDs, ketonemia, and ketonuria in DM, presenting all the available new evidence in a comprehensive manner.
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Li, Wan-Di, Jia-Shuo Zhang, Lin-Yan Zhang, Zhong-Wen Liu, Juan Fan y Xian-Ying Shi. "Rhodium-Catalyzed Alkylation of Aromatic Ketones with Allylic Alcohols and α,β-Unsaturated Ketones". Catalysts 13, n.º 8 (26 de julio de 2023): 1157. http://dx.doi.org/10.3390/catal13081157.
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The direct transition-metal-catalyzed addition of C–H bonds to unsaturated C=X (X=C, O, and N) bonds via C–H bond activation has been recognized as a powerful tool for the construction of C–C bonds (in terms of atom and step economy). Herein, the direct rhodium-catalyzed C–H bond addition of aromatic ketones to allylic alcohols and α,β-unsaturated ketones that affords β-aryl carbonyl compounds is described, in which a ketone carbonyl acts as a weakly coordinating directing group. It was found that the type of alkyl in aromatic ketones is crucial for the success of the reaction. This transformation provides a convenient and efficient methodology for the synthesis of 2-alkyl aromatic ketones in moderate-to-excellent yields.
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Noori, Farid, Sousan Mohammadi Kebar, Yousef Mohammadi-Kebar, Maryam Ghavami y Khatereh Isazadehfar. "Comparison of urinary and plasma ketone using urinary nitroprusside strip in patients with diabetic ketoacidosis". International Journal of Research in Medical Sciences 11, n.º 10 (29 de septiembre de 2023): 3597–601. http://dx.doi.org/10.18203/2320-6012.ijrms20233007.
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Background: Diabetic ketoacidosis is one of the most important and serious acute complications of diabetes and one of the medical emergencies that has been the most common cause of death in patients with diabetes. Prompt diagnosis and therapeutic intervention play an important role in reducing complications and mortality. The aim of this study was to compare urinary and plasma ketones using urinary nitroprusside strip in patients with diabetic ketoacidosis. Methods: In this cross-sectional study, 38 diabetic ketoacidosis patients were included in this study during the years 2017 and 2018 in the emergency department of Imam Khomeini hospital in Ardabil city. To test for plasma ketones, 2 cc of venous blood samples were taken and transferred to the laboratory for plasma isolation. The resulting plasma was examined with a urine dipstick and the discoloration was recorded. This was repeated at 0, 6 and 12 o'clock for serum ketones. All patients received their treatment according to the treatment protocol of diabetic ketoacidosis and urine ketone, PH and bicarbonate and BE patients were measured routinely. Results: Serum ketones were positive in all patients and 34 patients had positive urinary ketones. In this study, serum ketone levels were significantly correlated with blood acidity at baseline and with bicarbonate and basal arterial gas deficit at all three stages. However, urinary ketones had a significant correlation with blood acidity at baseline and at 12 hours, with bicarbonate at baseline and with arterial gas deficiency at 12 hours. Conclusions: The results showed that examination of plasma ketones with dipstick can be a useful, rapid and accurate clinical trial for the diagnosis of diabetic ketoacidosis in patients with diabetes.
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Yin, Junxiang, Pengcheng Han, Zhiwei Tang, Qingwei Liu y Jiong Shi. "Sirtuin 3 Mediates Neuroprotection of Ketones against Ischemic Stroke". Journal of Cerebral Blood Flow & Metabolism 35, n.º 11 (10 de junio de 2015): 1783–89. http://dx.doi.org/10.1038/jcbfm.2015.123.
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Stroke is one of the leading causes of death. Growing evidence indicates that ketone bodies have beneficial effects in treating stroke, but their underlying mechanism remains unclear. Our previous study showed ketone bodies reduced reactive oxygen species by using NADH as an electron donor, thus increasing the NAD+/NADH ratio. In this study, we investigated whether mitochondrial NAD+-dependent Sirtuin 3 (SIRT3) could mediate the neuroprotective effects of ketone bodies after ischemic stroke. We injected mice with either normal saline or ketones (beta-hydroxybutyrate and acetoacetate) at 30 minutes after ischemia induced by transient middle cerebral artery (MCA) occlusion. We found that ketone treatment enhanced mitochondria function, reduced oxidative stress, and therefore reduced infarct volume. This led to improved neurologic function after ischemia, including the neurologic score and the performance in Rotarod and open field tests. We further showed that ketones' effects were achieved by upregulating NAD+-dependent SIRT3 and its downstream substrates forkhead box O3a (FoxO3a) and superoxide dismutase 2 (SOD2) in the penumbra region since knocking down SIRT3 in vitro diminished ketones' beneficial effects. These results provide us a foundation to develop novel therapeutics targeting this SIRT3-FoxO3a-SOD2 pathway.
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Csako, G. "False-positive results for ketone with the drug mesna and other free-sulfhydryl compounds." Clinical Chemistry 33, n.º 2 (1 de febrero de 1987): 289–92. http://dx.doi.org/10.1093/clinchem/33.2.289.
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Abstract All free-sulfhydryl compounds tested produced false-positive reactions in the Legal test for ketones. The color developed in the ketone pad of urine dipsticks [N-Multistix SG, Multistix 10 SG (Ames), and Chemstrip 9 (Boehringer-Mannheim)] was misinterpreted for ketone bodies, both by visual and automated reading. In contrast to the reaction with true ketones, a drop of glacial acetic acid added onto the ketone pad of dipsticks discharged the false-positive red color. A red-violet also developed instantly with free -SH compounds in the Acetest tablet assay (Ames), but quickly faded. In general, the presence of acidic groups such as -COOH and -SO3H in the structure appeared to increase the nitroprusside reactivity of free -SH compounds, whereas the presence of a -NH2 group appeared to decrease it. Currently, false-positive ketone reactions ascribable to a free -SH group are most likely to be seen for urine containing mesna. The false-positive test for ketones caused by free -SH compounds can be recognized and ruled out by proper procedures. On the other hand, this chromogenic reaction with free thiols might be used for monitoring urinary excretion of mesna.
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Klinot, Jiří, Jan Sejbal y Alois Vystrčil. "Triterpenoid 2,3-ketols, diols and their acetates: Preparation and conformation of the ring A". Collection of Czechoslovak Chemical Communications 54, n.º 2 (1989): 400–412. http://dx.doi.org/10.1135/cccc19890400.
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19β,28-Epoxy-18α-oleanane derivatives I-III were converted into hydroxy ketones IV, VIII and X, acetoxy ketones V, VII, IX and XI, diols and their mono- and diacetates XII-XXV. Seven of the eight possible isomeric 2,3-diol monoacetates were obtained. Conformation of the ring A in these compounds has been derived from the 1H NMR and IR spectra. In 2β-acetoxy-3-ketone VII, 3α-hydroxy- and 3α-acetoxy-2-ketones VIII and IX, and in 2β,3α-diol monoacetates XVIII and XIX the ring A exists predominantly in a boat conformation.
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Tamas, Corina, Flaviu Tamas, Attila Kovecsi, Georgiana Serban, Cristian Boeriu y Adrian Balasa. "The Role of Ketone Bodies in Treatment Individualization of Glioblastoma Patients". Brain Sciences 13, n.º 9 (11 de septiembre de 2023): 1307. http://dx.doi.org/10.3390/brainsci13091307.
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Glioblastoma is the most common and aggressive primary brain tumor in adults. According to the 2021 WHO CNS, glioblastoma is assigned to the IDH wild-type classification, fulfilling the specific characteristic histopathology. We have conducted a prospective observational study to identify the glucose levels, ketone bodies, and the glucose-ketone index in three groups of subjects: two tumoral groups of patients with histopathological confirmation of glioblastoma (9 male patients, 7 female patients, mean age 55.6 years old) or grade 4 astrocytoma (4 male patients, 2 female patients, mean age 48.1 years old) and a control group (13 male patients, 9 female patients, mean age 53.9 years old) consisting of subjects with no personal pathological history. There were statistically significant differences between the mean values of glycemia (p value = 0.0003), ketones (p value = 0.0061), and glucose-ketone index (p value = 0.008) between the groups of patients. Mortality at 3 months in glioblastoma patients was 0% if the ketone levels were below 0.2 mM and 100% if ketones were over 0.5 mM. Patients with grade 4 astrocytoma and the control subjects all presented with ketone values of less than 0.2 mM and 0.0% mortality. In conclusion, highlighting new biomarkers which are more feasible to determine such as ketones or glucose-ketone index represents an essential step toward personalized medicine and survival prolongation in patients suffering from glioblastoma and grade 4 astrocytoma.
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Cannon, Sophie M. y Trevor E. Angell. "LBODP035 When Is Ketosis Just Ketosis?" Journal of the Endocrine Society 6, Supplement_1 (1 de noviembre de 2022): A265—A266. http://dx.doi.org/10.1210/jendso/bvac150.545.
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Abstract Background Little is known about the impact of over-the-counter ketone supplementation, used by patients to promote weight loss, on ketosis and serum ketone values. Recent literature suggests that acute ingestion of exogenous ketones leads to increased blood beta-hydroxybutyrate and decreased blood glucose1. Clinical Case A 61-year-old man with a history of type 2 diabetes mellitus, atrial fibrillation, hypertension, and hyperlipidemia presented as a transfer to the neurocritical care ICU from an outside hospital for subarachnoid hemorrhage secondary to intracranial saccular aneurysm. His admission hemoglobin A1c was 9.9% (ref 4.4-5.6), blood glucose was 205 mg/dL (ref 70-99), beta-hydroxybutyrate was markedly elevated at 26.2 mg/dL (ref 0-3), and urinalysis showed 80mg/dL ketones (ref 0). Serum toxicology screen was notable for detectable acetone 8mg/dL (ref: none detected). His lactate was 2 mmol/L (ref 0.5-1.9), Cr 0.99mg/dL (0.67-1.17), and HCO3 22 mmol/L (ref 22-27). Arterial blood gas showed pH of 7.37 (ref 7.38-7.47), and an anion gap metabolic acidosis (AGMA) of 15 mmol/L (ref <12). Given the patient's profound ketosis, hyperglycemia, and mild AGMA, the patient was started on an insulin drip for presumed diabetic ketoacidosis (DKA). After 4 hours, the patient's anion gap had decreased to 12mmcol/L. The following day, he was transitioned to basal/bolus insulin, and underwent embolization of his cerebral aneurysm. After further recovery, Endocrinology was consulted for insulin recommendations. The patient denied any prior history of DKA or use of any SGLT2-inhibitors, and denied decreased oral intake or vomiting prior to admission. He did report taking ketone supplements, "Keto Strong: Ketogenic Weight Management – Advanced Formulation," two tabs (700mg "proprietary keto blend") BID for 2-3 years with ingredients listed as: sodium beta-hydroxybutyrate, calcium beta-hydroxybutyrate, magnesium beta-hydroxybutyrate, medium chain triglyceride oil, L-arginine, alpha-ketoglutaric acid, and 7-keto-dehydroepiandrosterone. Given a lack of acidosis, mild hyperglycemia, and mild lactic acidosis without risk factors for euglycemic DKA, it was suspected his profound ketosis out of proportion to clinical picture was secondary to ketone supplementation with a misdiagnosis of DKA. Conclusion This is one of the first cases to report profound ketosis in a hospitalized patient likely secondary to exogenous ketone supplementation. Ketosis secondary to nutritional supplementation should be considered once more common etiologies are ruled out. Additional research is needed to determine the role of exogenous ketone use on metabolism and glycemic control. References: Falkenhain, Kaja et al. "Effects of Exogenous Ketone Supplementation on Blood Glucose: A Systematic Review and Meta-Analysis." Advances in nutrition (Bethesda, Md.), nmac036. 5 Apr. 2022 Presentation: No date and time listed
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Elias, Natalia Olga, Adriana Campos Martinez, Mariana Dicugno, Julieta Souto y Marina Ines Curria. "LBODP019 Vitamin D Levels In A Population With Type 2 Diabetes". Journal of the Endocrine Society 6, Supplement_1 (1 de noviembre de 2022): A263. http://dx.doi.org/10.1210/jendso/bvac150.540.
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Abstract Background Little is known about the impact of over-the-counter ketone supplementation, used by patients to promote weight loss, on ketosis and serum ketone values. Recent literature suggests that acute ingestion of exogenous ketones leads to increased blood beta-hydroxybutyrate and decreased blood glucose1. Clinical Case A 61-year-old man with a history of type 2 diabetes mellitus, atrial fibrillation, hypertension, and hyperlipidemia presented as a transfer to the neurocritical care ICU from an outside hospital for subarachnoid hemorrhage secondary to intracranial saccular aneurysm. His admission hemoglobin A1c was 9.9% (ref 4.4-5.6), blood glucose was 205 mg/dL (ref 70-99), beta-hydroxybutyrate was markedly elevated at 26.2 mg/dL (ref 0-3), and urinalysis showed 80mg/dL ketones (ref 0). Serum toxicology screen was notable for detectable acetone 8mg/dL (ref: none detected). His lactate was 2 mmol/L (ref 0.5-1.9), Cr 0.99mg/dL (0.67-1.17), and HCO3 22 mmol/L (ref 22-27). Arterial blood gas showed pH of 7.37 (ref 7.38-7.47), and an anion gap metabolic acidosis (AGMA) of 15 mmol/L (ref <12). Given the patient's profound ketosis, hyperglycemia, and mild AGMA, the patient was started on an insulin drip for presumed diabetic ketoacidosis (DKA). After 4 hours, the patient's anion gap had decreased to 12mmcol/L. The following day, he was transitioned to basal/bolus insulin, and underwent embolization of his cerebral aneurysm. After further recovery, Endocrinology was consulted for insulin recommendations. The patient denied any prior history of DKA or use of any SGLT2-inhibitors, and denied decreased oral intake or vomiting prior to admission. He did report taking ketone supplements, "Keto Strong: Ketogenic Weight Management – Advanced Formulation," two tabs (700mg "proprietary keto blend") BID for 2-3 years with ingredients listed as: sodium beta-hydroxybutyrate, calcium beta-hydroxybutyrate, magnesium beta-hydroxybutyrate, medium chain triglyceride oil, L-arginine, alpha-ketoglutaric acid, and 7-keto-dehydroepiandrosterone. Given a lack of acidosis, mild hyperglycemia, and mild lactic acidosis without risk factors for euglycemic DKA, it was suspected his profound ketosis out of proportion to clinical picture was secondary to ketone supplementation with a misdiagnosis of DKA. Conclusion This is one of the first cases to report profound ketosis in a hospitalized patient likely secondary to exogenous ketone supplementation. Ketosis secondary to nutritional supplementation should be considered once more common etiologies are ruled out. Additional research is needed to determine the role of exogenous ketone use on metabolism and glycemic control. References: Falkenhain, Kaja et al. "Effects of Exogenous Ketone Supplementation on Blood Glucose: A Systematic Review and Meta-Analysis." Advances in nutrition (Bethesda, Md.), nmac036. 5 Apr. 2022 Presentation: No date and time listed
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Rittig, Nikolaj, Mads Svart, Henrik Holm Thomsen, Esben Thyssen Vestergaard, Jens Frederik Rehfeld, Bolette Hartmann, Jens Juul Holst, Mogens Johannsen, Niels Møller y Niels Jessen. "Oral D/L-3-Hydroxybutyrate Stimulates Cholecystokinin and Insulin Secretion and Slows Gastric Emptying in Healthy Males". Journal of Clinical Endocrinology & Metabolism 105, n.º 10 (27 de julio de 2020): e3597-e3605. http://dx.doi.org/10.1210/clinem/dgaa483.
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Abstract Background D-3-hydroxybutyrate (D-3-OHB) is a ketone body that serves as an alternative nutritional fuel but also as an important signaling metabolite. Oral ketone supplements containing D/L-3-OHB are becoming a popular approach to achieve ketosis. Aim To explore the gut-derived effects of ketone supplements. Methods Eight healthy lean male volunteers were investigated on 2 separate occasions: An acetaminophen test was performed to evaluate gastric emptying and blood samples were obtained consecutively throughout the study period. Results We show that oral consumption of D/L-3-OHB stimulates cholecystokinin release (P = 0.02), elevates insulin (P = 0.03) and C-peptide (P < 0.001) concentrations, and slows gastric emptying (P = 0.01) compared with matched intravenous D/L-3-OHB administration. Measures of appetite and plasma concentrations of glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) were unaffected by interventions. Conclusion Our findings show that D/L-3-OHB exert incretin effects and indicate luminal sensing in the gut endothelium. This adds to our understanding of ketones as signaling metabolites and displays the important difference between physiological ketosis and oral ketone supplements.
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Jensen, Nicole Jacqueline, Helena Zander Wodschow, Malin Nilsson y Jørgen Rungby. "Effects of Ketone Bodies on Brain Metabolism and Function in Neurodegenerative Diseases". International Journal of Molecular Sciences 21, n.º 22 (20 de noviembre de 2020): 8767. http://dx.doi.org/10.3390/ijms21228767.
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Under normal physiological conditions the brain primarily utilizes glucose for ATP generation. However, in situations where glucose is sparse, e.g., during prolonged fasting, ketone bodies become an important energy source for the brain. The brain’s utilization of ketones seems to depend mainly on the concentration in the blood, thus many dietary approaches such as ketogenic diets, ingestion of ketogenic medium-chain fatty acids or exogenous ketones, facilitate significant changes in the brain’s metabolism. Therefore, these approaches may ameliorate the energy crisis in neurodegenerative diseases, which are characterized by a deterioration of the brain’s glucose metabolism, providing a therapeutic advantage in these diseases. Most clinical studies examining the neuroprotective role of ketone bodies have been conducted in patients with Alzheimer’s disease, where brain imaging studies support the notion of enhancing brain energy metabolism with ketones. Likewise, a few studies show modest functional improvements in patients with Parkinson’s disease and cognitive benefits in patients with—or at risk of—Alzheimer’s disease after ketogenic interventions. Here, we summarize current knowledge on how ketogenic interventions support brain metabolism and discuss the therapeutic role of ketones in neurodegenerative disease, emphasizing clinical data.
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Durnin, Sheena, Jennifer Jones, Emer Ryan, Ruth Howard, Sean Walsh, Ian Dawkins, Carol Blackburn, Sinead M. O'Donnell y Michael J. Barrett. "The utility of ketones at triage: a prospective cohort study". Archives of Disease in Childhood 105, n.º 12 (3 de julio de 2020): 1157–61. http://dx.doi.org/10.1136/archdischild-2019-318425.
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ObjectiveTo establish the relationship between serum point-of-care (POC) ketones at triage and moderate-to-severe dehydration based on the validated Gorelick Scales.Design, setting and patientsProspective unblinded study from April 2016 to February 2017 in a paediatric emergency department. Patients aged 1 month to 5 years, with vomiting and/or diarrhoea and/or decreased intake with signs of moderate or severe dehydration or clinical concern for hypoglycaemia were eligible.Main outcome measuresThe primary outcome was to describe the relationship between triage POC ketones to the two Gorelick Scales. Secondary outcomes were to examine the response of ketone levels to fluid/glucose administration and patient disposition.ResultsOne-hundred and ninety-eight patients were included; median age 1.8 years. The median triage ketones were 4.6 (IQR 2.8–5.6) mmol/L. A weak correlation was identified between triage ketones and the 10-point Gorelick Scale (Spearman’s ρ=0.217, p=0.002), however no correlation between triage ketones and the 4-point Gorelick Scale was identified. Those admitted had median triage ketones of 5.2 (IQR 4–6) mmol/L and repeat ketones of 4.6 (IQR 3.3–5.7) mmol/L compared with 4.2 (IQR 2.4–5.3) mmol/L and 2.9 (IQR 1.6–4.2) mmol/L in those discharged home.ConclusionNo correlation between triage POC ketones and the 4-point Gorelick Scale was established. POC ketones at triage have poor accuracy for predicting hospital admission. The elevated profile of POC ketones in non-diabetic children with acute illness suggests a potential target of tailored treatments for further research.
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Plakhotnyuk, I., Yu Ordin y B. Ivasenko. "Reproductive recovery in cows with subclinical ketosis". Naukovij vìsnik veterinarnoï medicini, n.º 2(160) (24 de noviembre de 2020): 21–27. http://dx.doi.org/10.33245/2310-4902-2020-160-2-21-27.
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The development of ketosis in high productive cows is accompanied by damage to various organs and systems of the body.Therefore, even with successful treatment, animals have long-term consequences leading to a decrease in milk production, metritis, steroidogenesis disorders, impaired development of follicles and yellow bodies, and infertility. It is because the problem remains poorly understood, which is associated with the special features of the restoration of reproductive function in cows with ketosis. Our research was carried out on 208 cows of Holstein and Ukrainian black-and-white dairy breeds at the age of 2–6 years, with various fatness and productivity of 6–10 thousand kg of milk per lactation. The concentration of β-ketones was determined on the 5th and 10th days after delivery using a CareSens Dual ketometer. After detecting 1.1 and more mmol/l ketone bodiesin the blood of cows, the animal was considered sick and treatment was started according to the farm scheme. After identifying the stage of the reproductive cycle, insemination was carried out using payets. The pregnancy was diagnosed with an ultrasonic device Kaixin KX 5200 on the 35-40 day after insemination. After the research, it was found that on the fifth day after giving birth, an increased content of β-ketones in the blood was found in 42,8%, and on the tenth day – in 21,4% of cows. Of these, in 18,3% of animals the disease was re-detectedon the tenth day after calving. The emergence of subclinical ketosis after parturition is accompanied by decrease(3,6days)of the period from calving to recovery of reproductive cyclicity and the number of pregnant animals(32,7%, p <0.001), and by increase of 17,6 (p <0.001) days in the duration of infertility and insemination index(by 1,3). Re-development of latent ketosis in cows complicated the course of the disease. After a diseaserelapse there was a decrease by 15,1 days (p <0.001) in the impedance period and by 66,7% (p <0.001) of fertility and an increase by 29,4 days(p <0.001) in the service period and by 11,7 the number of sperm doses used for one successful insemination. Key words: ketosis, cow, fertility, insemination index, ketometer, β-ketones, blood, reproductive cycle.
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Kabalka, George W., Su Yu y Nan-Sheng Li. "Selective hydroboration of alkenes and alkynes in the presence of aldehydes and ketones". Canadian Journal of Chemistry 76, n.º 6 (1 de junio de 1998): 800–805. http://dx.doi.org/10.1139/v98-042.
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The reactions of terminal alkenes in the presence of ketones or aldehydes with a variety of borane reagents have been investigated. It was found that the selective hydroboration of a terminal alkene in the presence of a ketone or an aldehyde is most efficient when dicyclohexylborane is used as the hydroborating agent. The hydroboration of olefinic ketones and olefinic aldehydes with dicyclohexylborane generates the corresponding hydroxyaldehydes and hydroxyketones in good yields after oxidation with sodium perborate. The hydroboration of alkynyl ketones and alkynyl aldehydes with dicyclohexylborane yields the corresponding olefinic carbonyl compounds after protonation, or dicarbonyl compounds after oxidation.Key words: hydroboration, reduction, dicyclohexylborane, hydroxyaldehyde, hydroxyketone.
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Goldberg, Emily, Yun-Hee Youm, Kim Nguyen, Emad Alnemri y Vishwa Dixit. "Ketone body beta-hydroxy butyrate deactivates NLRP3 inflammasome in myeloid cells (CAM1P.153)". Journal of Immunology 194, n.º 1_Supplement (1 de mayo de 2015): 48.10. http://dx.doi.org/10.4049/jimmunol.194.supp.48.10.
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Abstract The NLRP3 inflammasome is a major regulator of sterile inflammation. It is now known that many age-related diseases are NLRP3-dependent, including metabolic disease, cognitive decline, bone loss, and thymic demise. Therefore, decreasing inflammasome activation during aging may prevent many chronic diseases known to limit healthspan. Calorie restriction and prolonged fasting reduce inflammation. During fasting, the body uses fat for energy, leading to an increase in ketone body production as a byproduct of fatty acid oxidation. We tested the hypothesis that switching the substrates from glucose to ketones could inhibit inflammasome activation in myeloid lineage cells, macrophages and neutrophils. Here we present novel data that ketone body beta-hydroxy butyrate (BHB) inhibits NLRP3-dependent IL-1β secretion. Notably, related short chain fatty acid, butyrate does not impact the inflammasome and oxidation of ketones for energetic utilization was not required for inflammasome deactivation in myeloid cells. Instead, ketones directly inhibit inflammasome complex assembly by blocking ASC oligomerization and prionization. BHB also inhibits NLRP3 dependent inflammasome activation in vivo and in neutrophils of aged mice. Therefore, ketones may represent an anti-inflammatory intervention to prevent chronic inflammation during aging that is normally associated with functional decline and death in the elderly.
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Stephenson, W. Kirk y Richard Fuchs. "Enthalpies of interaction of ketones with organic solvents". Canadian Journal of Chemistry 63, n.º 2 (1 de febrero de 1985): 336–41. http://dx.doi.org/10.1139/v85-057.
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Enthalpies of solution (ΔHS) of a series of ketones (acetone, 2-butanone, 2-heptanone, 2-nonanone, 5-nonanone, 2,2,4,4-tetramethyl-3-pentanone, cyclohexanone) and alkane model compounds (n-heptane, n-nonane, 2,2,4,4-tetramethylpentane, cyclohexane) have been determined in 17 organic solvents (n-heptane, cyclohexane, CCl4, α,α,α,-trifluorotoluene, 1,2-dichloroethane, triethylamine, butyl ether, ethyl acetate, DMF, DMSO, benzene, toluene, mesitylene, 1-octanol, methanol, t-butyl alcohol, 2,2,2-trifluoroethanol), and combined with heats of vaporization to give enthalpies of transfer from vapor to solvent (ΔH(v → S)). These values have been used to evaluate ketone–solvent polar interactions (ΔΔH(v → S) = ΔH(v → S)(ketone) − ΔH(v → S)(alkane)). The linear relationships between ΔΔH(v → S) and solvent dipolarity-polarizability (Taft-Kamlet π* parameters) are derived. Based on the deviations from these correlations, ketone–CF3CH2OH enthalpies of hydrogen bond formation have been evaluated. The other alcohol solvents show no evidence of exothermic H-bond formation with ketones.
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Porper, Keren, Leor Zach, Yael Shpatz, Bruria Ben-Zeev, Michal Tzadok, Elisheva Jan, Alisa Talianski et al. "Dietary-Induced Ketogenesis: Adults Are Not Children". Nutrients 13, n.º 9 (2 de septiembre de 2021): 3093. http://dx.doi.org/10.3390/nu13093093.
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There is increasing interest in the use of a ketogenic diet for various adult disorders; however, the ability of adults to generate ketones is unknown. Our goal was to challenge the hypothesis that there would be no difference between adults and children regarding their ability to enter ketosis. Methods: Two populations were studied, both treated with identical very low-carbohydrate high-fat diets: a retrospective series of children with epilepsy or/and metabolic disorders (2009–2016) and a prospective clinical trial of adults with glioblastoma. Dietary intake was assessed based upon written food diaries and 24-h dietary recall. Ketogenic ratio was calculated according to [grams of fat consumed]/[grams of carbohydrate and protein consumed]. Ketone levels (β-hydroxybutyrate) were measured in blood and/or urine. Results: A total of 168 encounters amongst 28 individuals were analyzed. Amongst both children and adults, ketone levels correlated with nutritional ketogenic ratio; however, the absolute ketone levels in adults were approximately one quarter of those seen in children. This difference was highly significant in a multivariate linear regression model, p < 0.0001. Conclusions: For diets with comparable ketogenic ratios, adults have lower blood ketone levels than children; consequently, high levels of nutritional ketosis are unobtainable in adults.
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Maya, Dyah Astining, Iswari Pauzi, Siti Zaetun y Yudha Anggit Jiwantoro. "Effects of Carbohydrate Diet Programs on Urine Ketones Positiveness with Long Time on a Diet 1 Year, 2 Years and 3 Years". Jurnal Analis Medika Biosains (JAMBS) 10, n.º 1 (5 de abril de 2023): 42. http://dx.doi.org/10.32807/jambs.v10i1.303.
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Carbohydrate diet is a diet pattern that reduces carbohydrate consumption. Therefore, the body will use fat as an alternative energy source. The continuous use of fat causes the accumulation of fatty acids so that it often causes ketone positivity in the urine. Objective : Find out the effect of a carbohydrate diet program on the positivity of urine ketones. Method : This research is an analytic observational study with a cross sectional approach. The sample used was urine from respondents who had been on a carbohydrate diet for 1 year, 2 years and 3 years, then urine ketones were examined using the dipstick method. Data analysis was carried out using the Chi-Square test with a confidence value (α = 0.05). Result : The sample in this study amounted to 45 samples, with a total of 23 samples of positive ketones and 22 samples of negative ketones. The results of the Chi Square test obtained an Asymp. sig value of 0.009 <0.05 (α) which indicates that the carbohydrate diet program has a significant effect on the positivity of urine ketones.
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Pan, Jullie W., Douglas L. Rothman, Kevin L. Behar, Daniel T. Stein y Hoby P. Hetherington. "Human Brain β-Hydroxybutyrate and Lactate Increase in Fasting-Induced Ketosis". Journal of Cerebral Blood Flow & Metabolism 20, n.º 10 (octubre de 2000): 1502–7. http://dx.doi.org/10.1097/00004647-200010000-00012.
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Ketones are known to constitute an important fraction of fuel for consumption by the brain, with brain ketone content generally thought to be low. However, the recent observation of 1-mmol/L levels of brain β-hydroxybutyrate (BHB) in children on the ketogenic diet suggests otherwise. The authors report the measurement of brain BHB and lactate in the occipital lobe of healthy adults using high field (4-T) magnetic resonance spectroscopy, measured in the nonfasted state and after 2-and 3-day fasting-induced ketosis. A 9-mL voxel located in the calcarine fissure was studied, detecting the BHB and lactate upfield resonances using a 1H homonuclear editing sequence. Plasma BHB levels also were measured. The mean brain BHB concentration increased from a nonfasted level of 0.05 ± 0.05 to 0.60 ± 0.26 mmol/L (after second day of fasting), increasing further to 0.98 ± 0.16 mmol/L (after the third day of fasting). The mean nonfasted brain lactate was 0.69 ± 0.17 mmol/L, increasing to 1.47 ± 0.22 mmol/L after the third day. The plasma and brain BHB levels correlated well ( r = 0.86) with a brain–plasma slope of 0.26. These data show that brain BHB rises significantly with 2-and 3-day fasting-induced ketosis. The lactate increase likely results from ketones displacing lactate oxidation without altering glucose phosphorylation and glycolysis.
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Wang, Ming Feng, En Chen Jiang, Lei Ming Xiong, Xi Wei Xu, Chuang Zhao, Gang Wang y Qian Ma. "Components Characteristics of Wood Vinegar from Rice Husk Continuous Pyrolysis and Catalytic Cracking". Applied Mechanics and Materials 291-294 (febrero de 2013): 368–74. http://dx.doi.org/10.4028/www.scientific.net/amm.291-294.368.
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Wood vinegar is one of the major products of biomass pyrolysis, and it contains a large number of beneficial ingredients. We investigated the components of fresh and preserved wood vinegar gained from rice husk continuous pyrolysis and catalytic cracking. The main ingredients of fresh pyrolysis wood vinegar are acids, phenols and ketones. The species of ketones are more than any other compounds, but the content of each single component is very low. After a year’s preservation, the content of acids and alcohols increases, while phenols decreases. For the catalytic cracking wood vinegar, the content of acids is low, while the content of phenols and ketones is high. The content of acids, phenols and alcohols increases remarkably, and the content of ketones decreases sharply after a year. N in the wood vinegar exists in the form of amino, nitroso and cyclization. Ketol and unsaturated ketones could be generated by condensation reaction of ketones, and alcohols from the reduction reaction or addition reaction of ketones, caused the increase of alcohols and enol ketone. Phenol could be generated by dealkylation reaction of alkylphenol, and alkyl broke into small molecule alcohols and carboxylic acids, caused an increment of acids and alcohols. Acids and alcohols with longer carbon chain, which may be the by-products of some reactions or products of condensation reactions, are detected in the preserved wood vinegar.
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Wang, Guorong. "Analysis of Ketogenic Metabolic Interventions for Obesity". SHS Web of Conferences 144 (2022): 01010. http://dx.doi.org/10.1051/shsconf/202214401010.
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According to statistics and surveys by the World Health Organization, the obesity ratio of people in the world nearly tripled since 1975; in 2016, more than 1.9 billion adults aged 18 and older were overweight. Obesity and overweight are defined as abnormal or excessive fat accumulation that presents a risk to health. Obesity prevention and intervention is a serious health problem facing humanity. This article is an analysis of interventions for obesity from the perspective of ketogenic metabolism, by supplementing exogenous ketones or increasing endogenous ketone levels. By analyzing experimental data on the metabolic mechanisms of ketones, exogenous ketones esters on body weight, food intake and satiety hormones, this paper concludes that exogenous ketones have a positive effect on interventions in obesity. A study of the literature revealed that the involvement of ketogenesis in the process of fat metabolism is still a very vague concept.
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Médici, Rosario, Hanna Stammes, Stender Kwakernaak, Linda G. Otten y Ulf Hanefeld. "Assessing the stereoselectivity of Serratia marcescens CECT 977 2,3-butanediol dehydrogenase". Catalysis Science & Technology 7, n.º 9 (2017): 1831–37. http://dx.doi.org/10.1039/c7cy00169j.
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