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Query: CAS:61191-21-7 (2-butanone)
 604 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An enzymatic test device, QED (quantitative ethanol detector), intended for on-the-spot analysis of ethanol not equal to saliva was evaluated in laboratory experiments. Tests were made in vitro with known-strength aqueous ethanol standards and also in vivo after healthy volunteers drank a moderate dose of alcohol (0.80 g/kg), either on an empty stomach or after breakfast. Acetone, methanol, 2-butanone, and ethylene glycol did not react with the QED when tested in vitro. However, n-propanol (100 mg/dL) gave an apparent ethanol response of 60 mg/dL; the secondary alcohol, 2-propanol (100 mg/dL), gave a response of 20 mg/dL, but a longer time was needed to reach an endpoint. When ethanol solutions of 50, 100, and 140 mg/dL were analyzed, the QED gave readings of 50 +/- 2 (+/- standard deviation [SD]), 102 +/- 3, and 136 +/- 5, corresponding to recoveries of 100, 102, and 97%, respectively. The analytical precision, expressed as coefficients of variation, ranged from 3.2-4.0%. The mean difference between the QED test result and venous blood ethanol was 4.4 +/- 0.91 mg/dL (+/- standard error [SE]), and the 95% limits of agreement (LOA) were -18 and 26 mg/dL. The QED saliva test also compared well with breath-alcohol readings; the mean difference was 3.3 +/- 0.71 mg/dL, and the 95% LOA were now slightly narrower: -12 and 19 mg/dL. The QED device proved useful for quickly analyzing alcohol in saliva, and the results agreed well with the concentrations of ethanol in venous blood and end-expired breath.
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PMID:Measuring ethanol in saliva with the QED enzymatic test device: comparison of results with blood- and breath-alcohol concentrations. 756 95

We developed an isotope-dilution method for measuring methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) in whole human blood using a purge-and-trap gas chromatographic-mass spectrometric method. The labeled analogues for MTBE and TBA were [2H12]methyl tert-butyl ether and [2H9]-tert-butyl alcohol, respectively. Volatiles were removed from the blood by direct helium purging of the liquid; were trapped on a Tenax trap; and were desorbed, cryofocused, and chromatographed on a DB-624 capillary column that was connected directly to the ion source of a mass spectrometer. Detection was by mass analysis using a double-focusing magnetic-sector mass spectrometer operating in the full-scan mode at the medium mass resolution of 3000. For the isotope-dilution method, the minimum detection limits in blood (5-10 mL) are 0.01 microgram/L for MTBE and 0.06 microgram/L for TBA. The isotope-dilution method proved to be a big improvement in recovery, reproducibility, and sensitivity over our previous analytical method, which used the labeled ketone, [4-2H3]-2-butanone, as the internal standard for both MTBE and TBA. The isotope-dilution method has sufficient sensitivity for monitoring blood levels of MTBE and TBA in populations exposed to oxygenated fuels containing MTBE.
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PMID:Measurement of methyl tert-butyl ether and tert-butyl alcohol in human blood by purge-and-trap gas chromatography-mass spectrometry using an isotope-dilution method. 756 98

This noninvasive method for collection and analysis of a wide range of aldehydes and ketones in human breath may enable assessment of lipid peroxidation and metabolic status in vivo. Breath samples are drawn through silica cartridges impregnated with 2,4-dinitrophenylhydrazine, which traps carbonyls as their hydrazone derivatives. The hydrazone derivatives are eluted from the cartridges with acetonitrile, separated by reversed-phase HPLC, and quantified spectrophotometrically. Using this method, we have measured formaldehyde, acetaldehyde, acetone, propanal, 2-butanone, butanal, pentanal, and hexanal. Recoveries of carbonyls added to Douglas bags were > 90%, except for 2-butanone, which was 86.2%. The overall CVs for sampling plus analyzing duplicate aliquots of breath were < 11%. The results indicate that this protocol can be used to monitor changes of carbonyl production by analyzing expired air, which may, with further study, indicate physiological and pathological status.
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PMID:Protocol for collection and HPLC analysis of volatile carbonyl compounds in breath. 760 Jun 83

It was found that (+/-)ethyl 2-[2-(3-hydroxypropyl)-4-oxocyclohexylidene]-propionate (1), (+/-)ethyl 2-[2-(3-hydroxypropyl)-4,5-dimethoxyphenyl]propionate (2) and (+/-)3-[2-(3-hydroxypropyl)-4,5-dimethoxyphenyl]-2-butanone (3) had excellent antiulcer activities. In order to study structure-activity relationships, (+/-)2-[(3-hydroxypropyl)phenyl]cyclopentanone derivatives (4, 5) and (+/-)2-[(3-hydroxypropyl)phenyl]cyclopentanol derivatives (6, 7) were synthesized and tested for antiulcer activities. As a result, (+/-)2-[2-(3-hydroxypropyl)-4-methoxy-5-(2- piperidinoethoxy)phenyl]cyclopentanone (5k) exhibited potent antiulcer activities.
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PMID:[Studies on antiulcer agents. III. Synthesis and antiulcer activity of phenylpropanol derivatives]. 760 97

It was found that (+/-)ethyl 2-[2-(3-hydroxypropyl)-4-oxocyclohexylidene-propionate (1), (+/-)ethyl 2-[2-(3-hydroxypropyl)-4,5-dimethoxyphenyl]propionate (2), (+/-)3-[2-(3-hydroxypropyl)-4,5-dimethoxyphenyl]-2-butanone (3) and (+/-)2-[2-(3-hydroxypropyl)-4-methoxy-5-(2- piperidinoethoxy)phenyl]cyclopentanone (4) had potent antiulcer activities. In order to study structure-activity relationships, (+/-)3-[(3-hydroxypropyl)phenoxy]-2-butanone derivatives (5, 6) were synthesized and tested for antiulcer activities. Among them, (+/-)3-[2-(3-hydroxypropyl)-4-methoxy-5-[3-(4- methylpiperidino)propoxy]phenoxy]-2-butanone.3/2 oxalate (6k) was selected as a preferred antiulcer agent.
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PMID:[Studies on antiulcer agents. IV. Synthesis and antiulcer activity of phenylpropanol derivatives]. 760 98

The lumazine synthase/riboflavin synthase complex of Bacillus subtilis consists of an icosahedral capsid of 60 beta subunits surrounding a core of three alpha subunits. The beta subunits catalyze the condensation of 5-amino-6-ribityl-amino-2,4(1H,3H)-pyrimidinedione (PYR) with 3,4-dihydroxy-2-butanone 4-phosphate (DHB) yielding 6,7-dimethyl-8-ribityllumazine. This intermediate is converted to riboflavin by the alpha subunits via an unusual dismutation. The second product of this reaction is PYR, which is also a substrate of the beta subunits and can be recycled in the catalytic process. Sigmoidal kinetics would be expected for the formation of riboflavin from PYR and DHB and are indeed observed with mixtures of artifactual beta 60 capsids and alpha subunit trimers. In contrast, the formation of riboflavin from PYR and DHB by the native alpha 3 beta 60 is characterized by a finite initial rate, which is similar to the rate of lumazine formation. Most notably, the rate of riboflavin formation has its maximum value at t = 0 and decreases dramatically after the consumption of PYR and DHB despite the presence of transiently formed lumazine. These data suggest that a significant fraction of DHB is converted to riboflavin by substrate channeling, which is conducive to an improved overall catalytic rate of riboflavin formation at low substrate concentrations. The channel is leaky, and the intermediate lumazine is therefore transiently accumulated in the bulk solution. The partitioning factor relating the direct formation of riboflavin via substrate channeling and the formation of transient 6,7-dimethyl-8-ribityl-lumazine increases at low concentrations of the substrates PYR and DHB and has a maximum value at pH 7.5. Channeling appears to result from the compartmentalization of the alpha subunits inside the icosahedral beta subunit capsid whose catalytic sites are located close to the inner capsid surface.
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PMID:Substrate channeling in the lumazine synthase/riboflavin synthase complex of Bacillus subtilis. 762 91

A series of esters and several amides were shown to undergo oxidative cleavage with the formation of carbonyl products in the presence of purified isoforms of liver microsomal cytochrome P450 (P450) in a reconstituted enzyme system. The reaction also requires NADPH and NADPH-cytochrome P450 reductase and is stimulated by phosphatidylcholine. Kinetic constants were determined in experiments in which the predicted aldehyde product was identified and quantitated by gas chromatography. A relationship was seen with P450 2E1 between the structures of the esters and the Vmax values, with the rates decreasing in the series of methyl formate to methyl valerate, and similarly in the series of methyl, ethyl, propyl, butyl, and amyl acetates. Furthermore, a clear correlation exists between the Km values of the ethyl esters examined and the log of the octanol/water partition coefficients of these substrates. With P450 2E1, the Km decreases significantly between one and four carbon atoms in the chain length of the acyl component of the ester but is unaffected by a further increase in length. However, no correlation was found between the Km value and the chain length of the alcohol moiety of the esters. Similarly, with P450 2B4 a large decrease in Km occurs between one and five carbons in the acyl component of the ethyl esters but is unaffected by a further increase in chain length. The observed correlation is presumed to arise from hydrophobic interactions between the access channel to the active site of P450 and the acyl side chain of the esters. P450 1A2 is also active in ester cleavage, and the three cytochromes examined with esters are active in the conversion of N-alkyl amides to aldehydes, as are P450s 2C3, 1A1, and 3A6. Studies on 2-butyl acetate oxidation by P450 2B4 in the presence of 18O2 showed 88% 18O incorporation into the product, 2-butanone. This is consistent with a mechanism that involves hydroxylation at the alpha-carbon of the alcohol component of the ester to yield an unstable geminal hydroxy ester, as proposed earlier by F. P. Guengerich et al. (1988, J. Biol. Chem. 263, 8176-8183) for several dihydropyridine carboxylic esters. Our results further indicate that such an intermediate decomposes by a nonhydrolytic mechanism and also rule out the possibility of transient ester hydrolysis with subsequent oxidation of the alcohol formed. In addition, they establish that oxidative cleavage is a widespread reaction among P450 cytochromes and commonly used esters and amides.
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PMID:Oxidative cleavage of esters and amides to carbonyl products by cytochrome P450. 773 61

The post-column chemiluminescent reaction of six anticholinergic alkaloid compounds with tris(2,2'-bipyridine)ruthenium(III) (Ru(bpy)3(3+)) is applied to microbore high-performance liquid chromatography (HPLC). At flow rates less than 200 microL/min, the capillary mixing cell in which Ru(bpy)3(3+) and the analyte are mixed directly allows for good light detection. In contrast, a diminished signal occurs at these low flow rates with conventional post-column mixing in a tee. Optimal chemiluminescent pH conditions for atropine, scopolamine, dicyclomine, cyclopentolate, cyclobenzaprine, and procyclidine are determined at moderately basic conditions (pH 7 to 9). 2-Butanone is found to be compatible with the chemiluminescent reaction, whereas tetrahydrofuran and propionitrile cause an increase in background noise and a chemiluminescent signal loss. As 2-butanone is more nonpolar than acetonitrile, it assists in the elution of these hydrophobic anticholinergic compounds. Five anticholinergic compounds are resolved successfully with a PRP-1 polymeric column and a slightly basic mobile phase, but a C8 silica column is better suited for the more hydrophobic compounds (cyclobenzaprine, procyclidine, and dicyclomine).
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PMID:Microbore liquid chromatography of tertiary amine anticholinergic pharmaceuticals with tris(2,2'-bipyridine)ruthenium(III) chemiluminescence detection. 775 95

The kinetic mechanism of yeast alcohol dehydrogenase (EC 1.1.1.1) activity with the redox pair 2-propanol/acetone has been probed in detail by the application of initial rate studies in the absence and in the presence of products, and a dead-end inhibitor pyrazole. An overall steady-state random Bi Bi mechanism in both directions, with the formation of both abortive ternary complexes, enzyme.NADH.2-propanol and enzyme.NAD+.acetone has been observed. A complete list of steady-state kinetic constants are also reported for the redox pair (S)-(+)-2-butanol/2-butanone.
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PMID:Kinetic mechanism of yeast alcohol dehydrogenase activity with secondary alcohols and ketones. 785 38

It was found that gamma-irigermanal, obtained from the methanol extract of root of Iris germanica, exhibited a potent antiulcer activity. Therefore, this compound was selected as a lead-compound, and related compounds were synthesized and tested for antiulcer activities. It was found that (+/-) ethyl 2-[2-(3-hydroxypropyl)-4-oxocyclohexylidene]- propionate (1) had excellent antiulcer activities. Then phenylpropanol derivatives, obtained by changing from cyclohexane ring of 1 to benzene ring, were synthesized and tested for antiulcer activities in order to study structure activity relationships. As a result, (+/-) ethyl 2-[2-(3-hydroxypropyl)-4,5-dimethoxy-phenyl]propionate (2b) and (+/-) 3-[2-(3-hydroxypropyl)-4,5-dimethoxyphenyl]-2-butanone (5) were shown to have antiulcer activities.
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PMID:[Studies on antiulcer agents. II. Synthesis and antiulcer activity of phenylpropanol derivatives]. 786 39


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