[Injuries to health caused by acetic acid in production of cellulose acetates].
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Acetates↗
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Brettanomyces bruxellensis: effect of oxygen on growth and acetic acid production.
The influence of the oxygen supply on the growth, acetic acid and ethanol production by Brettanomyces bruxellensis in a glucose medium was investigated with different air flow rates in the range 0-300 l h(-1 ) x (0-0.5 vvm). This study shows that growth of this yeast is stimulated by moderate aeration. The optimal oxygen supply for cellular synthesis was an oxygen transfer rate (OTR) of 43 mg O(2) l(-1) x h(-1). In this case, there was an air flow rate of 60 l h(-1) (0.1 vvm). Above this value, the maximum biomass concentration decreased. Ethanol and acetic acid production was also dependent on the level of aeration: the higher the oxygen supply, the greater the acetic acid production and the lower the ethanol production. At the highest aeration rates, we observed a strong inhibition of the ethanol yield. Over 180 l h(-1) x (0.3 vvm, OTR =105 mg O(2) l(-1) x h(-1)), glucose consumption was inhibited and a high concentration of acetic acid (6.0 g x l(-1)) was produced. The ratio of "ethanol + acetic acid" produced per mole of consumed glucose using carbon balance calculations was analyzed. It was shown that this ratio remained constant in all cases. This makes it possible to establish a stoichiometric equation between oxygen supply and metabolite production.
Acetic Acid↗
Trapping social wasps (Hymenoptera: Vespidae) with acetic acid and saturated short chain alcohols.
Nineteen compounds were evaluated in combination with a solution of acetic acid as baits for trapping the German yellowjacket, Vespula germanica (F.), the western yellowjacket Vespula pensylvanica (Sausssure), and the golden paper wasp Polistes aurifer Saussure. Compounds with three to six carbon chains or branched chains and with a hydroxy functional group were selected for testing based on their similarity to isobutanol. They were compared with isobutanol with acetic acid, which is a known wasp attractant. None of the compounds tested were superior to isobutanol when presented with acetic acid as a lure for these species of wasps. However, traps baited with either the S-(-)- or the racemic mixture of 2-methyl-1-butanol in combination with acetic acid captured similar numbers of both species of yellowjackets, compared with isobutanol with acetic acid. Polistes aurifer responded strongly to the S-(-)-enantiomer and to the racemic mixture of 2-methyl-1-butanol with acetic acid and not to the R-(+)-enantiomer with acetic acid.
Acetic Acid↗
Acetic acid suppresses the increase in disaccharidase activity that occurs during culture of caco-2 cells.
To understand how blood glucose level is lowered by oral administration of vinegar, we examined effects of acetic acid on glucose transport and disaccharidase activity in Caco-2 cells. Cells were cultured for 15 d in a medium containing 5 mmol/L of acetic acid. This chronic treatment did not affect cell growth or viability, and furthermore, apoptotic cell death was not observed. Glucose transport, evaluated with a nonmetabolizable substrate, 3-O-methyl glucose, also was not affected. However, the increase of sucrase activity observed in control cells (no acetic acid) was significantly suppressed by acetic acid (P < 0.01). Acetic acid suppressed sucrase activity in concentration- and time-dependent manners. Similar treatments (5 mmol/L and 15 d) with other organic acids such as citric, succinic, L-maric, L-lactic, L-tartaric and itaconic acids, did not suppress the increase in sucrase activity. Acetic acid treatment (5 mmol/L and 15 d) significantly decreased the activities of disaccharidases (sucrase, maltase, trehalase and lactase) and angiotensin-I-converting enzyme, whereas the activities of other hydrolases (alkaline phosphatase, aminopeptidase-N, dipeptidylpeptidase-IV and gamma-glutamyltranspeptidase) were not affected. To understand mechanisms underlying the suppression of disaccharidase activity by acetic acid, Northern and Western analyses of the sucrase-isomaltase complex were performed. Acetic acid did not affect the de novo synthesis of this complex at either the transcriptional or translational levels. The antihyperglycemic effect of acetic acid may be partially due to the suppression of disaccharidase activity. This suppression seems to occur during the post-translational processing.
Acetic Acid↗
A new perspective in the Lewis acid catalyzed ring opening of epoxides. Theoretical study of some complexes of methanol, acetic acid, dimethyl ether, diethyl ether, and ethylene oxide with boron trifluoride.
Several 1:1, 1:2, and 2:2 complexes between BF3 and CH3OH (Met), CH3COOH (AcA), (CH3)2O (DME), (CH3CH2)2O (DEE), and (CH2)2O (EOX) have been studied using ab initio (MP2) and density functional theory (DFT) (PBE, B3LYP) methods and the 6-311++G(3df,2pd) basis set. Geometrical structures and vibrational frequencies are reported, in most cases, for the first time. A detailed comparison of the vibrational frequencies for the O...BF3 vibrational modes, as well as for the nu(OH) band in the methanol and acetic acid complexes with BF3, is performed, and the theoretical frequency shifts are compared with the available experimental information. Thermochemical properties are calculated by employing counterpoise correction to alleviate the basis set superposition error. The DFT enthalpy of complexation of the 1:1 complexes results in the order of stability (AcA)2>AcA:BF3>DEE:BF3>DME:BF3>Met:BF3>EOX:BF3>(Met)2; in contrast, MP2 shows the noticeable difference that the AcA:BF3 complex is much less stable (similar to Met:BF3). The order of stability shows that, even though acetic acid prefers dimerization to complexation with BF3, the case is exactly the opposite for methanol. In both cases, the interaction of BF3 with the dimer gives rise to very stable trimers. However, in contrast to the interaction of BF3 with the methanol dimer being stronger than that with the monomer, the interaction of BF3 with the acetic acid dimer is weaker than that with the monomer. The relative strength of the complexes, discussed in the context of BF3-catalyzed ring opening of epoxides, suggests that the effect of the catalyst in a nonprotogenic solvent should be more properly ascribed to activation of the nucleophile instead of activation of the epoxide.
Acetic Acid↗
Determination of acetic acid in aqueous samples, by water-phase derivatisation, solid-phase microextraction and gas chromatography.
The direct derivatisation of acetic acid with n-hexyl chloroformate and with benzyl bromide in water was evaluated. With n-hexyl chloroformate, acetic acid did not give the n-hexyl acetate derivative, but the reaction of acetic acid with benzyl bromide in aqueous solution resulted in the formation of benzyl acetate. The derivatisation of acetic acid with benzyl bromide and the headspace solid-phase microextraction (SPME) of benzyl acetate were optimised. Under optimum conditions, the limit of detection for acetic acid was 260 nM, and the relative standard deviation of the overall procedure at 1.10(-4) M acetic acid was 15.6% (n = 10). A linear response was obtained in the 1 x 10(-4) to 5 x 10(-6) M concentration range (R2 = 0.993, n = 6). Although Carbowax-divinylbenzene (CW-DVB)-coated fibres exhibited a higher extraction capacity for benzyl acetate, polyacrylate (PA) was selected, because its mechanical stability was better than that of CW-DVB fibres. Moreover, the relative standard deviation of the SPME was better with PA (1.5%, n = 10 at 1 x 10(-5) M) than with CW-DVB-coated fibres (8.0%, n = 10 at 1 x 10(-5) M). Thus, a new analytical method for the quantitative determination of micromolar concentrations of acetic acid in the aqueous phase was developed. This method is based on water-phase derivatisation with benzyl bromide, headspace SPME with PA fibres and GC-FID. It was observed experimentally that benzyl alcohol formed by hydrolysis of the reagent affected the fibre-gas phase partitioning of benzyl acetate.
Acetic Acid↗
Effect of acetic acid added to cooking water on the dissolution of proteins and activation of protease in rice.
The effect of acetic acid on the dissolution of proteins in rice was studied to elucidate the mechanism for the textural change induced by the acid by chemical and SDS-PAGE analyses of the rice proteins in the soaking solution. More proteins were extracted with 0.2 M acetic acid (pH 2.7) than with water (pH 6.8). The effect of acetic acid on the protein dissolution increased with increasing temperature. Immunoblotting confirmed that, when rice was soaked in acetic acid, glutelin was dissolved into the soaking solution and degraded by aspartic proteinase. Aspartic proteinase degraded glutelin much more than it did albumin and globulin. It was found that the combined amount of albumin and globulin dissolved into the acetic acid solution was much larger than that of glutelin, despite the smaller amounts present of albumin and globulin than of glutelin. Metal ions were extracted more with acetic acid than with water. In addition, carboxypeptidase was activated under the acidic condition and resulted in an increase in the amount of free amino acids. The main effect of acetic acid on the dissolution of rice proteins was enhancement of the solubility of albumin, globulin, and glutelin, the effect of proteases being minor.
Acetic Acid↗
Liver perforation: a serious complication of percutaneous acetic acid injection for hepatocellular carcinoma.
A 75-year-old cirrhotic man, after undergoing percutaneous acetic acid injection therapy for hepatocellular carcinoma, presented high fever and right hypochondralgia. Computed tomography disclosed an area of low attenuation in the liver and a crescent-shaped intraperitoneal lesion adjacent to it. We diagnosed liver perforation and localized peritonitis due to the leakage of acetic acid following acetic acid injection. It is important to consider this serious complication when evaluating the indications for percutaneous acetic acid injection for hepatocellular carcinoma.
Acetic Acid↗
[The action of nicotinic acid and 3-pyridyl-acetic acid on the mechanisms of hemostasis. Modifications of the intensity of the hemorrhage].
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Acetates↗
Tolerance to cadmium in the abdominal stretch response: a comparative study of cadmium and acetic acid.
The intraperitoneal injection of cadmium (Cd) in mice produces a characteristic abdominal stretch response similar to that observed with acetic acid. Morphine, clonidine, and tripelennamine ED50 values were the same for inhibition of the response to Cd and to acetic acid. The ED50 values for aspirin and indomethacin were lower against the Cd than the acetic acid response. On repeated injections, Cd did but acetic acid did not produce tolerance to itself. Furthermore, the mice made tolerant to Cd were not cross-tolerant to acetic acid, but the acetic-acid-treated mice were cross-tolerant to Cd. These results suggest that Cd and acetic acid may produce the stretch response through different mechanisms, and the Cd-induced response might serve as a screening test for aspirin-like agents.
Abdominal Muscles↗
Putative ABC transporter responsible for acetic acid resistance in Acetobacter aceti.
Two-dimensional gel electrophoretic analysis of the membrane fraction of Acetobacter aceti revealed the presence of several proteins that were produced in response to acetic acid. A 60-kDa protein, named AatA, which was mostly induced by acetic acid, was prepared; aatA was cloned on the basis of its NH2-terminal amino acid sequence. AatA, consisting of 591 amino acids and containing ATP-binding cassette (ABC) sequences and ABC signature sequences, belonged to the ABC transporter superfamily. The aatA mutation with an insertion of the neomycin resistance gene within the aatA coding region showed reduced resistance to acetic acid, formic acid, propionic acid, and lactic acid, whereas the aatA mutation exerted no effects on resistance to various drugs, growth at low pH (adjusted with HCl), assimilation of acetic acid, or resistance to citric acid. Introduction of plasmid pABC101 containing aatA under the control of the Escherichia coli lac promoter into the aatA mutant restored the defect in acetic acid resistance. In addition, pABC101 conferred acetic acid resistance on E. coli. These findings showed that AatA was a putative ABC transporter conferring acetic acid resistance on the host cell. Southern blot analysis and subsequent nucleotide sequencing predicted the presence of aatA orthologues in a variety of acetic acid bacteria belonging to the genera Acetobacter and Gluconacetobacter. The fermentation with A. aceti containing aatA on a multicopy plasmid resulted in an increase in the final yield of acetic acid.
ATP-Binding Cassette Transporters↗
Spectroscopic evidence for complexing of acetic acid with bovine serum albumin, gramicidin, and dimethylformamide.
Acetic acid has a major effect on the absorption spectra of bovine serum albumin, gramicidin, and dimethylformamide in the region, 255 to 200 mmu. Increasing the concentration of acetic acid causes progressively decreasing absorbency accompanied by a large and progressively increasing red shift of the absorption maximum. The decrease in absorbency is interpreted in terms of a reversible complexing of acetic acid with these molecules and the red shift in terms of a non-specific solvent effect.
Acetates↗
Comparison of percutaneous acetic acid injection and percutaneous ethanol injection for small hepatocellular carcinoma.
BACKGROUND/AIMS: To assess whether ultrasound (US)-guided percutaneous acetic acid injection is more effective than percutaneous ethanol injection in the treatment of small hepatocellular carcinoma (HCC). METHODOLOGY: sixty patients with 1 to 4 HCC smaller than 3 cm entered a randomized controlled trial from August 1993 to September 1995. Thirty one and 29 patients were treated by percutaneous acetic acid injection using 50% acetic acid and percutaneous ethanol injection using absolute ethanol, respectively. There were no significant differences in clinical characteristics and biochemical data between the two groups. RESULTS: All original tumors were treated successfully by the chosen therapy. However, local recurrence occurred in 8% of the 38 tumors treated with percutaneous acetic acid injection and 37% of the 35 tumors treated with percutaneous ethanol injection P>0.001). The 1- and 2-year survival rates were 100% and 92% with percutaneous acetic acid injection and 83% and 63% with percutaneous ethanol injection (p=0.0017). Multivariate analysis of prognostic factors revealed that treatment was an independent predictor of survival. CONCLUSION: percutaneous acetic acid injection is more effective than percutaneous ethanol injection.
Acetic Acid↗
Endothelial cell repopulation after intracameral acetic acid irrigation.
A significant, but transient corneal edema followed inadvertent intracameral irrigation of acetic acid in two patients. Since postsurgical corneal edema generally indicates corneal endothelial dysfunction, the effects of acetic acid on corneal endothelium were studied in the cat where the endothelial regenerative capacity is thought to be comparable to that of humans. The anterior chambers of feline eyes were irrigated with 0.25% acetic acid or balanced salt solution in a double-masked manner. Marked corneal opacification and thickening were evident following exposure to the acetic acid but did not occur following irrigation with balanced salt solution alone. Following intracameral acetic acid irrigation, a few endothelial cells were found in the anterior chamber angle but could not be found on Descemet's membrane. Over an 8-week period gradual repopulation of Descemet's membrane by endothelial cells occurred, first in the periphery and later in the central cornea, coincident with resolution of corneal edema.
Acetates↗
Studies on uricosuric diuretics. 4. Three-dimensional structure-activity relationships and receptor mapping of (aryloxy)acetic acid diuretics.
Attempts to develop new (aryloxy)acetic acids with a better profile of diuretic and uricosuric activities as well as with fewer side effects have produced a series of compounds in which the ring system has been varied. Diuretic screening of these analogues in rats indicated that the great difference in the activity between these compounds might be ascribed to a difference in the ring system rather than that in the substituent effect and that the annulation hypothesis described before is not necessarily applicable to all of these compounds. This prompted us to study the relationship between the structure and the diuretic activity of the (aryloxy)acetic acids. An active model (receptor model) was created with the indanone moiety of R-(-)-3 and the dihydrobenzofuran-2-carboxylic acid moiety of S-(+)-4. The three-dimensional structure-activity study of known compounds 2-4, and 5a using the active model showed that the degree of fitting to the model is related to the diuretic activity of these compounds. This was also confirmed for compounds 6a, 6b, 9a, 10a, 11a, 12a, 13a, 14a, 15a, and 16a, and the relation between the structure and the diuretic activity was rationalized qualitatively. With these insights in mind, a modified receptor model was constructed. We believe that this model is useful for a prediction of the activity of compounds not yet synthesized as well as for designing new (aryloxy)acetic acid diuretics.
Acetates↗
Early detection of cervical cancer through acetic acid application--an aided visual inspection.
OBJECTIVE: To assess the sensitivity and specificity of visual inspection of cervix for detection of precancerous and early cancerous lesions of cervix. METHODS: In a Maternal and Child Health Care setting of New Delhi women underwent a detailed pelvic examination, visual inspection of cervix after 5% acetic acid application, cytology (pap smear), detailed colposcopic examination and colposcopic directed biopsy when indicated. RESULTS: Findings of aided visual inspection using 5% acetic acid and of cytology were evaluated among symptomatic 402 women against colposcopic findings and/or histologic reports. Seventy-three mild dysplasias, 50 moderate dysplasias, 45 severe dysplasias/Carcinoma in-situ and 40 early invasive cancerous cases were diagnosed histologically. The sensitivity of cytology (75.3%) was higher compared to that of acetic acid application (52.0%) for mild dysplasias. On the other hand, the sensitivity for detecting moderate dysplasias was 78% for cytology and 81.6% for acetic acid; for severe dysplasias/carcinoma in-situ it was 73.3% for cytology and 86.7% for acetic acid. For invasive cancers sensitivity for acetic acid application and cytology (95% for both modalities) was comparable. The specificity of cytology (99%) was higher compared to that of acetic acid application (94.3%). The false positive rate for cytology was 1.0% as against 5.7% for acetic acid application. The results of acetic acid application also showed a remarkable improvement in the sensitivity of unaided visual inspection for early cancerous lesion which was about 60% for early cancerous lesion and only 12% for mild dysplastic and 20% for moderate and severe dysplastic lesions in our earlier experience. It also reduced the false positive rates from 12% by unaided visual inspection to 5.7% by acetic acid application. Furthermore, cost of detection of one true lesion through acetic acid application (Rs.1689.00) was much lower as compared to the cost involved in cytology detected true lesions (Rs.2227.00). Visual inspection without acetic acid incurred Rs.6608.60 for detection of true lesion. CONCLUSION: Screening for cervical precancerous and cancerous lesions using visual inspection aided by acetic acid may be a suitable low-cost and a feasible alternative modality for control of cervical cancer in a resource poor setting.
Acetic Acid↗
[Gas-chromatographic detection of acetic acid in cadaveric specimens].
Data on Liquid Gas Chromatographic method for detection of the acetic acid after etherification in the cadaveric organs are presented. The results of quantitative acetic acid determination in the cadaveric organs by LGC method after etherification are influenced upon by its "background" values. Acetic acid concentration in the cadaveric organs of subjects who died from the cause other than acetic acid poisoning is within the limits 0.1-0.21 g (mean value 0.17 g) in 100 g of the stomach and 0.07-0.13 g (mean value 0.11 g) in 100 g of the liver. Method may be used in expert practice to determine acetic acid poisoning with due regard for its "background" concentrations in the organs.
Acetates↗
Photocatalytic oxidation and decomposition of acetic acid on titanium silicalite.
Transient reaction of adsorbed monolayers of acetic acid was used to characterize the photocatalytic properties of titanium silicalite zeolites (TS-1). The TS-1 zeolites having Si/Ti ratios of 5, 12.5, and 50 are effective catalysts at room temperature for both photocatalytic oxidation (PCO) and decomposition (PCD) of acetic acid. The rates of PCO are higher than the rates of PCD for each catalyst. Acetic acid oxidized photocatalytically in 0.2% O2 to form gas-phase CO2 and CH4 and adsorbed H2O on the TS-1 catalysts, whereas no CH4 formed on Degussa P25 TiO2. Isotope labeling showed that, on both TiO2 and TS-1 catalysts, the alpha-carbon formed CO2 whereas the beta-carbon formed CH4 and CO2. The rates of oxidation of the two carbons have different dependencies on UV intensity. The catalysts with higher Si/Ti ratios adsorbed significantly more acetic acid, and the PCO rates per gram of titanium are highest on the TS-1 catalyst with the lowest Ti content, apparently because a larger fraction of the Ti atoms are surface atoms on this catalyst. During PCD in an inert atmosphere, CO2, CH4, and C2H6 formed on TiO2 and on the catalyst with a Si/Ti ratio of 5, but C2H6 was not detected on the other catalysts. The CO2/CH4 selectivity during PCD increased with increasing Si/Ti ratio. The first step in PCO and PCD on TS-1 catalysts appears to be similar and involves formation of a CH3 radical.
Acetic Acid↗