Showing papers on "Acetone published in 1985"

Acetone, methyl ethyl ketone, ethyl acetate, acetonitrile and other polar aprotic solvents are strong inducers of aneuploidy in Saccharomyces cerevisiae.

Abstract: A diploid yeast strain D61.M was used to study induction of mitotic chromosomal malsegregation, mitotic recombination and point mutation. Several ketones (including acetone and methyl ethyl ketone) and some organic acid esters (including the methyl, ethyl and 2-methoxyethyl esters of acetic acid) and acetonitrile strongly induced aneuploidy but not recombination or point mutation. Only diethyl ketone induced low levels of recombination and point mutation in addition to aneuploidy. Related compounds were weak inducers of aneuploidy: methyl n-propyl ketone, the methyl esters of propionic and butyric acid, acetic acid esters of n- and iso-propanol and ethyl propionate. No mutagenicity was found with n-butyl and isoamyl acetate, ethyl formate, acetyl acetone (2,5-dipentanone) and dioxane. Methyl isopropyl ketone induced only some recombination and point mutation but no aneuploidy. Efficient induction was only observed with a treatment protocol in which growing cells were exposed to the chemicals during a growth period of 4 h at 28 degrees C followed by incubation in ice for more than 90 min, usually overnight for 16-17 h. Aneuploid cells could be detected in such cultures during a subsequent incubation at growth temperature if the chemical was still present. Detailed analysis showed that there was a high incidence of multiple events of chromosomal malsegregation. It is proposed that the mutagenic agents act directly on tubulin during growth so that labile microtubules are formed which dissociate in the cold. When cells are brought back to temperatures above the level critical for reassembly of tubulin and allowed to grow, faulty microtubules are formed.

Modulation of Acetone-Butanol-Ethanol Fermentation by Carbon Monoxide and Organic Acids

Abstract: Metabolic modulation of acetone-butanol-ethanol fermentation by Clostridium acetobutylicum with carbon monoxide (CO) and organic acids is described. CO, which is a known inhibitor of hydrogenase, was found to be effective in the concentration range of dissolved CO corresponding to a CO partial pressure of 0.1 to 0.2 atm. Metabolic modulation by CO was particularly effective when organic acids such as acetic and butyric acids were added to the fermentation as electron sinks. The uptake of organic acids was enhanced, and increases in butyric acid uptake by 50 to 200% over control were observed. Hydrogen production could be reduced by 50% and the ratio of solvents could be controlled by CO modulation and organic acid addition. Acetone production could be eliminated if desired. Butanol yield could be increased by 10 to 15%. Total solvent yield could be increased 1 to 3% and the electron efficiency to acetone-butanol-ethanol solvents could be increased from 73 to 78% for controls to 80 to 85% for CO- and organic acid-modulated fermentations. Based on these results, the dynamic nature of electron flow in this fermentation has been elucidated and mechanisms for metabolic control have been hypothesized.

Production of butanol by clostridium acetobutylicum in extractive fermentation system

Abstract: An extractive fermentation system was developed to prevent end-product inhibition of Clostridium acetobutylicum I AM 19012, which mainly produces butanol and acetone. Butanol exhibited greater toxicity to the microorganism than acetone, and its growth was completely inhibited above 10kg/m3 of butanol. As an extracting solvent suitable for acetone-butanol fermentation, oleyl alcohol (cis-9-octadecen-l-ol) and C-20 guerbet alcohol (branched-chain alcohol of carbon number, 20) were selected from among 29 organic compounds, based on their nontoxicity to the microorganism. These two solvents had high partition coefficients for butanol, and could be reused without deterioration. In fermentation with the solvent (solvent phase: aqueous phase = 2:5 (v/v)), the viability of the microorganism was resumed by the liquid-liquid extraction of butanol from the broth, and the amount of butanol produced was 2.6 times that in fermentation without extraction.

Production of acetone and butanol by Clostridium acetobutylicum in continuous culture with cell recycle

Abstract: To increase the solvent productivity of the acetone-butanol fermentation, a continuous culture of Clostridium acetobytylicum with cell recycling was used. At a dry cell mass concentration of 8 g l-1 and a dilution rate of D=0.64 h-1, a solvent productivity of 5.4 g l-1 h-1 was attained. To prevent degeneration of the culture, which occurs with high concentrations of solvents (acetone, butanol and ethanol), different reactor cascades were used. A two-stage cascade with cell recycling and turbidostatic cell concentration control turned out to be the best solution, the first stage of which was kept at relatively low cell and product concentrations. A solvent productivity of 3 and 2.3 g l-1 h-1, respectively, was achieved at solvent concentrations of 12 and 15 g l-1.

Effect of increased hydrogen partial pressure on the acetone-butanol fermentation by Clostridium acetobutylicum

Abstract: Elevated H2 partial pressure in the acetone-butanol fermentation increased the butanol and ethanol yields on glucose by an average of 18% and 13%, respectively, while the respective yields of acetone and of the endogenous H2 decreased by an average of 40% and 30%, and almost no effect was observed on the growth of the culture. The butanol to acetone ratio and the fraction of butanol in the total solvents were also increased with the H2 pressure. There were no major differences in the observed pattern of change with pressurization at either t=0 or t=18 h. The results demonstrate the importance of H2 partial pressure in the regulation of the C. acetobutylicum metabolism.

Influence of organic solvent mixtures on biological membranes.

Abstract: A simple experimental model was used to study the influence of organic solvents and solvent mixtures on the integrity of biological membranes. Radiolabelled membranes were prepared biosynthetically by growing Escherichia coli in the presence of 14C-oleic acid; the bulk of the radioactivity was incorporated into 14C-phosphatidylethanolamine, the predominant phospholipid species in E coli membranes. The radiolabelled bacteria were incubated at 37 degrees C in the presence of solvent, and the mixture filtrated through a Millipore 0.45 micron filter. This filtration retained radiolabel associated with the bacteria, and only radiolabel released as a result of solvent action was allowed through the filter. The radioactivity in the filtrate was then counted and expressed as a percentage of the total radioactivity. Results showed that aliphatic alcohols released membrane constituents in relation to their hydrocarbon chain length (1-propanol greater than 2-propanol greater than ethanol greater than methanol); the effects of aliphatic alcohols were potentiated by acetone, ethyl methyl ketone, ethylene glycol, and N,N'-dimethylformamide, and the effects of ethanol were potentiated by 1-butanol, benzyl alcohol, and ethylacetate. These findings point to the possibility that certain mixtures of organic solvents are more damaging to membranes than the components of the mixture would indicate, and suggest that the experimental model used might help in showing mixtures that are particularly harmful.

Method for making bisphenol

Abstract: A method of making bisphenol A from phenol and acetone is provided which allows for the use of reactor acetone feed in the rearrangement reactor. As a result, improved acetone conversion is realized and BPA productivity is enhanced.

Reductive alkylation of β-alkanolamines with carbonyl compounds and sodium borohydride

Abstract: Etude de l'alkylation d'amines primaires par reaction avec des cetones ou aldehydes en presence de tetrahydroborate de sodium

Aprotic polar solvents inducing chromosomal malsegregation in yeast interfere with the assembly of porcine brain tubulin in vitro.

Abstract: A number of aprotic solvents which had previously been found to induce mitotic aneuploidy in yeast were tested for their effects on re-assembly of twice recycled tubulin from pig brain. Some of the solvents which were strong aneuploidy-inducing mutagens in yeast slowed down tubulin assembly in vitro at concentrations lower than those required for aneuploidy induction. Ethyl acetate, methyl acetate, diethyl ketone and acetonitrile fell into this category. Other strong aneuploidy-inducing agents like acetone and 2-methoxyethyl acetate accelerated tubulin assembly. Non-genetically active methyl isopropyl ketone and isopropyl acetate both accelerated assembly, whereas methyl n-propyl ketone and n-propyl acetate were weak inducers of aneuploidy and slowed down the rate and extent of assembly. Those chemicals which slowed down the assembly rate also reduced the extent of assembly. Most chemicals which accelerated assembly also led to an increased extent of assembly, with the exception of isopropyl acetate. At the higher concentrations, however, a maximum assembly rate was reached which was followed by a slow decline. Although a perfect correlation between effects on the induction of chromosomal malsegregation and the interference with tubulin assembly in vitro was not seen, the experiments with tubulin were carried out using this class of chemicals because some of them strongly induced mitotic aneuploidy under conditions which suggested tubulin to be the prime target. The lack of a perfect coincidence might be due to species differences between the porcine brain and the yeast spindle tubulin, or the test for aneuploidy induction may have been negative because the concentrations required for an effect on yeast tubulin may be greater than the general lethal toxicity limit. Bearing this reservation in mind, the results suggest that the yeast aneuploidy test has a considerable predictive value for mammalian mutagenicity.

Squaric acid and esters: Analysis for contaminants and stability in solvents

Abstract: Two squaric acid diesters, squaric acid diethyl ester (SADEE) and squaric acid dibutyl ester (SADEE), have been suggested as replacements for 2,4-dinitrochlorobenzene in the treatment of alopecia areata and alopecia totalis. We synthesized these squaric acid diesters and examined them for the presence of carcinogenic contaminants, hexachlorobutadiene and tetrachloro-2-cyclobutene-1-one, by gas chromatography-mass spectrometry (GC-MS). The stability of SADBE to hydrolysis by water in acetone, butanol, isopropanol, and absorbent ointment with and without molecular sieves was examined. The stability of SADEE in ethanol and acetone, with and without molecular sieves, was also studied. Hydrolysis products were detected by their formation of a colored complex with ferric chloride. This complex absorbs in the visual range at 480 nm, thus affording a convenient method for determination of the concentration of free squaric acid in a solution. No contaminants were found by positive or negative ion detection in our GC-MS system. At the end of 3 weeks the extent of hydrolysis was greater in alcohols than in acetone when 10 and 100 molar excess of water were added to the solutions. In the presence of molecular sieves, hydrolysis was reduced even at 100 molar excess of added water in alcohol or acetone. However, under storage conditions without sieves, acetone solutions and alcohol solutions were equally stable over a period of 2 months. Molecular sieves reduce hydrolysis of squarate esters in the presence of a large molar excess of water, regardless of solvent.

Solvation of acetone in protic and aprotic solvents and binary solvent mixtures

Abstract: The infrared spectra of dilute solutions of acetone in a range of protic and aprotic solvents have been measured in the C—O stretch region. Band maxima are shown to correlate linearly with 13C n.m.r. shifts for the carbonyl carbon and, after suitable corrections, with solvent acceptor numbers. In mixed solvent systems involving protic and aprotic solvents, bands are gained and lost, indicative of the presence of discrete solvates. We infer that acetone in methanol is ca. 90% monohydrogen-bonded and ca. 10% non-hydrogen bonded. As basic aprotic cosolvents are added, the former species is lost and the latter gained, the efficiencies of these changes being proportional to the donor numbers (base strengths) of the cosolvents (cyanomethane, dimethyl sulphoxide, hexamethylphosphoramide and triethylamine).For systems involving water + basic aprotic cosolvents, three distinct species were detected. We suggest that the species present in pure water is acetone with two hydrogen bonds to water, that dominating in the middle range, with νmax close to that for methanolic solutions, has one hydrogen bond and the third species forms no such bonds. The overall tendency to dehydrate is again proportional to the donor number of the cosolvent except in the water-rich region, where the solvation number of the cosolvent is thought to be the overriding factor.Small shifts in the band maxima (νmax) for these discrete species with change in solvent composition are discussed in terms of secondary solvation and specific interactions between acetone and aprotic solvent molecules. The latter is particularly marked for methanol + dimethyl sulphoxide systems.Attempts are made to justify our assignments of the species detected in protic solvents to specifically hydrogen-bonded units. In particular, our suggestion that acetone is completely present as doubly hydrogen-bonded units in dilute aqueous solutions despite the evidence that the resulting hydrogen bonds are weaker than the average water–water bonds is defended.

An efficient method for the generation of N-methyl nitrones

Abstract: Formation d'oxydes d'(alkylidene methyl) amines par reaction d'aldehydes ou de cetones avec la (N-methyl N-trimethylsilyl O-trimethylsilyl) hydroxylamine

Study of rosin glycerol esters as microencapsulating materials.

Abstract: Rosin esters were prepared by heating rosin with glycerol and intermediate reaction products with different acid values were withdrawn. Salicylic acid granules were encapsulated using a 10 per cent solution of rosin esters in acetone. The coated microcapsules were evaluated for moisture absorption, flow properties and dissolution studies. The results showed that rosin and rosin-glycerol intermediates with acid values of 122, 105 and 55 had excellent moisture protection properties. Dissolution studies showed that these could be used for delayed release of drug.

Determination of aldehydes and acetone by ion chromatography

Abstract: Low molecular weight aldehydes and acetone in aqueous samples are determined by single-column ion chromatography. The aldehydes and acetone are derivatized to ..cap alpha..-hydroxyalkanesulfonates using sodium bisulfite and the sulfonates that are formed are then separated by ion chromatography and detected by using a conductivity detector. Ionic species that can interfere with chromatographing of the aldehydes and acetone are removed from the sample before the aldehydes and acetone are derivatized. Linear calibration curves are also reported for the derivatized species. 5 references, 4 figures, 1 table.

Head-space gas-chromatographic determination of 3-hydroxybutyrate in plasma after enzymic reactions, and the relationship among the three ketone bodies.

Abstract: In this sensitive, reproducible method for determination of D-3-hydroxybutyrate (3-OHB) in plasma, it is converted to acetone by use of 3-hydroxybutyrate dehydrogenase (EC 1.1.1.30)/lactate dehydrogenase (EC 1.1.1.27) coupled with acetoacetate decarboxylase (EC 4.1.1.4). The resulting acetone is detected by head-space gas chromatography. The lowest concentration of 3-OHB detectable in plasma was 2 mumol/L. The calibration curve showed a linear relationship for 3-OHB concentration from 0 to 5 mmol/L (r = 0.999). Analytical recovery of 3-OHB (50 mumol/L) was 97.9 (SD 3.8)%. The method was developed for determination of the three ketone bodies in plasma. The ratio of acetone to acetoacetate was not significantly different (p greater than 0.2) between normals (n = 31) and diabetics (n = 86). In normal subjects, the ratio of 3-OHB to acetoacetate was 1.20 (SD 0.44). In diabetic patients, the ratio correlated with the logarithm of the total ketone body concentration (r = 0.828).

Effect of temperature upon growth rate and solvent production in batch cultures of Clostridium acetobutylicum

Abstract: The effect of temperature on the solvent production byClostridiumacetobutylicum has been studied in the range 25 to 40°C. It was found that the solvent yield decreased with increasing temperature; seemingly because of a reduction in acetone production. It appeared that the yield of the other major solvent, butanol, was not affected by the temperature. Considering total solvent yield and productivity only, the optimum fermentation temperature is 35°C.

Mechanism of the acetone formation by Clostridium acetobutylicum

Abstract: The production of acetone by Clostridium acetobutylicum was favoured when acetate was added to the culture medium. In the presence of acetate an increase of the acetone concentration from 4.2 to 10.1 g per liter was noted without any change of the butanol concentration. The coenzyme A transferase and the acetoacetate carboxylase were not limiting factors since the addition of acetic acid allowed the biosynthesis of acetone to increase. The control of acetate production by the cells, which is not coupled to the butanol formation, is the key point of the acetone biosynthesis.

Simultaneous determination of ketone bodies in biological samples by gas chromatographic headspace analysis.

Abstract: A method is described on gas chromatographic headspace analysis for the determination of the physiological ketone bodies: acetone, acetoacetate and beta-hydroxybutyrate. The procedure proposed involves quantitative conversion of both acetoacetate by decarboxylation in a strong acidic medium, and beta-hydroxybutyrate by oxidation to acetoacetate and decarboxylation to acetone, which is then quantified chromatographically. The successful application of the method is illustrated by the values of ketone bodies in plasma, kidney, lung, and liver of fed and 48-hr-fasted rats.

Acetone potentiation of acute acetonitrile toxicity in rats

Abstract: The purpose of these studies was to investigate the nature and mechanism of a toxicologic interaction between acetonitrile and acetone. Results of oral dose-response studies utilizing a 1:1 (w/w) mixture of acetonitrile and acetone, or varying doses of acetonitrile administered together with a constant dose of acetone, indicated that acetone potentiated acute acetonitrile toxicity three- to fourfold in rats. The onset of severe toxicity (manifested by tremors and convulsions) was delayed in the groups dosed with both solvents compared to the groups that received acetonitrile or acetone alone. Blood cyanide (a metabolite of acetonitrile) and serum acetonitrile and acetone concentrations were measured after oral administration of 25% aqueous solutions of acetonitrile, acetone, or acetonitrile plus acetone. Concentrations of cyanide in the blood of rats given acetonitrile plus acetone remained near baseline, in contrast to the high concentrations found in rats dosed with acetonitrile alone. At 34-36 h, high blood cyanide concentrations were found in rats dosed with both of the solvents. This delayed onset of elevation of blood cyanide coincided with the occurrence of clinical signs and with the disappearance of serum acetone. In further pharmacokinetic studies, blood cyanide concentrations were measured after similar dosage regimens of acetone and acetonitrile. Peak cyanide concentrations were found to be significantly greater in rats dosed with both solvents than in rats given only acetonitrile. Administration of either sodium thiosulfate or a second dose of acetone prevented the toxicity associated with exposure to both solvents. These results suggest that the effects of acetone on acetonitrile toxicity are due to a biphasic effect on the metabolism of acetonitrile to cyanide, that is, an initial inhibition followed by a stimulation of this metabolism upon acetone elimination.

The facile synthesis of unsymmetrical ketones using acetone dimethylhydrazone

Abstract: Unsymmetrical ketones were prepared by successive alkylation of acetone dimethylhydrazone. Application of this reaction to the synthesis of dihydrojasmone is described.

Production of rebaudioside a

Abstract: PURPOSE:In treating an aqueous solution of stevioside, etc., with a specific enzyme, to produce rebaudioside A in extremely high conversion ratio while suppressing formation of by-products, by adding an organic solvent or a specific enzyme to the aqueous solution. CONSTITUTION:In converting stevioside into rebaudioside A by treating an aqueous solution containing both a beta-1,3-glucosylsaccharide compound and stevioside with an enzyme having beta-1,3-glucosyl transition activity produced by a bacterium, the aqueous solution incorporated with an organic solvent and/or a beta-1,3-glucanase of exotic type or separately treated. One or more solvents selected from acetone, ethyl acetate, methyl ethyl ketone, hexane, dimethyl sulfoxide, dioxane, thioglycol, propylene glycol, methyl phthalate, methanol and ethanol are preferable the organic solvent.