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At least 19 recordsLinked to original sources
PubMed1987

In vitro effects of short-chain aliphatic alcohols, benzyl alcohol and chlorpromazine on the transport of precursors of monoamines across the human erythrocyte membrane.

In previous papers we reported a deficit of tyrosine (TYR) and tryptophan (TRP) transport across the erythrocyte membrane in depressed patients. To investigate further the transport mechanism of both monoamine precursors, we tested in healthy subjects the role played by membrane fluidity, using different fluidizing agents such as alcohols and the neuroleptic chlorpromazine. We found that the transport of both amino acids depended on the length of the chain of each alcohol tested (number of carbon atoms = C). No inhibition was observed after methanol (C1) preincubation, in contrast to benzyl alcohol (C6), which produced an inhibition of about 80% of amino acid basal transport. In a condition of incubation by suspension of cells in an artificial medium, we observed a dose response of these transports with ethanol used at doses of 0.1-1.3 M. Finally we found in this study that the effect of ethanol on membrane fluidity, and therefore on inhibition of basal amino acid transport, was totally reversible after having washed the suspended cells, suggesting a superficial, noncovalent ethanol binding on such biological membranes.

Adult↗
PubMed1982

The activity of dopamine-stimulated adenylate cyclase from rat brain stratum is modulated by temperature and the bilayer-fluidizing agent, benzyl alcohol.

Benzyl alcohol achieved a marked activation of the adenylate cyclase activity in a partially purified membrane preparation from rat brain striata, although inhibition resulted at high concentrations. The degree of activation observed depended on the ligand used to stimulate the enzyme, with that observed in the presence of guanosine 5'-[beta,gamma-imido]triphosphate (p[NH]ppG) (5.8-fold)>dopamine+p[NH]ppG (5-fold)> GTP (3-fold)>dopamine+high GTP (2.25-fold)>dopamine (+low GTP)=basal (+low GTP) (1.7-fold). The differences in the concentration-dependence of both the activation and inhibition of dopamine-stimulated and basal activities of the enzyme meant that increasing benzyl alcohol concentrations caused a net elevation in the fold-stimulation of the basal activity by dopamine. Arrhenius plots of p[NH]ppG-, GTP-, fluoride-, dopamine-plus-high GTP- and dopamine-plus-p[NH]ppG-stimulated activities all exhibited a single break occurring at around 22 degrees C. This break point was decreased to around 13 degrees C when 50mm-benzyl alcohol was added to the assays. In the presence of dopamine (+low GTP), Arrhenius plots exhibited two distinct breaks, one at around 21 degrees C and the other at around 11 degrees C. When benzyl alcohol (50mm) was added to these assays of dopamine (+low GTP)-stimulated activity, a single break at around 14 degrees C was observed. For the basal activity the Arrhenius plot exhibited a single break at around 15 degrees C both in the presence and in the absence of 50mm-benzyl alcohol. It is suggested that the enzyme is activated by productive collisions between independent mobile entities and that the activity of the enzyme may be regulated by changes in membrane fluidity. The breaks in the Arrhenius plots of all of the ligand-stimulated activities, but not the basal activity, are attributed to lipid-phase separations occurring in either the inner or the outer halves of the bilayer.

Adenylyl Cyclases↗
PubMed1984

Inhibition of autophagy by benzyl alcohol.

Benzyl alcohol caused a rather complete and selective inhibition of the methylamine sensitive (i.e., the putative lysosomal) pathway of protein degradation in isolated rat hepatocytes. The effect was found to be entirely reversible within 30 min of removing the agent. A morphometric examination of electron micrographs revealed that the inhibition of lysosomal protein degradation coincided with a block in the formation of autophagic vacuoles. The number of acidic vacuoles (i.e., vacuoles induced to swell by adding methylamine) was not drastically reduced.

Animals↗
PubMed2005

Orientation and dynamics of benzyl alcohol and benzyl alkyl ethers dissolved in nematic lyotropic liquid crystals. 2H NMR and molecular dynamics simulations.

Most drugs have to cross cell membranes to reach their final target. A better understanding of the distribution, interactions, and dynamics of biologically active molecules in model bilayers is of fundamental importance in understanding drug functioning and design. 2H NMR quadrupole splittings (delta nu(Q)) and longitudinal relaxation times (T1) from the aromatic ring of benzyl alcohol-d5 (C0), a commonly used anesthetic, and a series of linear alkyl benzyl-d5 ethers with chain lengths from 1 to 12 carbon atoms (C1-C12), were measured. The molecules were dissolved in a nematic discotic lyotropic liquid crystal solution made of tetradecyltrimethylammonium chloride (TTAC)/decanol (DeOH)/NaCl/H2O. Values of delta nu(Q) and T1 from 1,1-dideuteriodecanol (15% enriched) and DHO (H2O with 0.2% D2O) were also measured. Delta nu(Q) of DeOH and DHO remained constant throughout the series. The value of delta nu(Q) of the para position of the ring (delta nu(p)) in C1 is 30% smaller than the delta nu(p) of C0. This is attributed to the existence of an H-bond between the alcohol hydroxyl proton and the solvent, which influences the average orientation of the ring. The relaxation data show that T1o,m is always longer than T1p and both decrease with the increase in alkyl chain length. Molecular dynamics simulations of the experimentally studied systems were performed. The aggregate was represented as a bilayer. The distribution, average orientation, and order parameters of the aromatic ring of the guest molecules in the bilayer were examined. Rotational correlation functions of all the C-D bonds and the OH bond from H2O were evaluated, allowing an estimate of the correlation times and T1. According to these results all spins relax in extreme narrowing conditions, except DeOH. Experimental and calculated T1 values differ at most by a factor of 3. However, the order of magnitude and the observed trends are well reproduced by the calculations. The aromatic ring of C0 possesses a unique average orientation in the bilayer. For the ether series, the orientation is modified and the C2 symmetry axis of the aromatic ring is exchanging between two orientations averaging the quadrupole splittings from the ortho and meta positions. The simulation supports the existence of an H-bond between C0 and the solvent not found in the ethers, which should be responsible for the observed differences.

Benzyl Alcohol↗
PubMed1984

Variation of transition-state structure as a function of the nucleotide in reactions catalyzed by dehydrogenases. 1. Liver alcohol dehydrogenase with benzyl alcohol and yeast aldehyde dehydrogenase with benzaldehyde.

Primary intrinsic deuterium and 13C isotope effects have been determined for liver (LADH) and yeast (YADH) alcohol dehydrogenases with benzyl alcohol as substrate and for yeast aldehyde dehydrogenase (ALDH) with benzaldehyde as substrate. These values have also been determined for LADH as a function of changing nucleotide substrate. As the redox potential of the nucleotide changes from -0.320 V with NAD to -0.258 V with acetylpyridine-NAD, the product of primary and secondary deuterium isotope effects rises from 4 toward 6.5, while the primary 13C isotope effect drops from 1.025 to 1.012, suggesting a trend from a late transition state with NAD to one that is more symmetrical. The values of Dk (again the product of primary and secondary isotope effects) and 13k for YADH with NAD are 7 and 1.023, suggesting for this very slow reaction a more stretched, and thus symmetrical, transition state. With ALDH and NAD, the primary 13C isotope effect on the hydride transfer step lies in the range 1.3-1.6%, and the alpha-secondary deuterium isotope effect on the same step is at least 1.22, but 13C isotope effects on formation of the thiohemiacetal intermediate and on the addition of water to the thio ester intermediate are less than 1%. On the basis of the relatively large 13C isotope effects, we conclude that carbon motion is involved in the hydride transfer steps of dehydrogenase reactions.

Alcohol Dehydrogenase↗
PubMed1991

Comparison of benzyl alcohol dehydrogenases and benzaldehyde dehydrogenases from the benzyl alcohol and mandelate pathways in Acinetobacter calcoaceticus and from the TOL-plasmid-encoded toluene pathway in Pseudomonas putida. N-terminal amino acid sequences, amino acid compositions and immunological cross-reactions.

1. N-Terminal sequences were determined for benzyl alcohol dehydrogenase, benzaldehyde dehydrogenase I and benzaldehyde dehydrogenase II from Acinetobacter calcoaceticus N.C.I.B. 8250, benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase encoded by the TOL plasmid pWW53 in Pseudomonas putida MT53 and yeast K(+)-activated aldehyde dehydrogenase. Comprehensive details of the sequence determinations have been deposited as Supplementary Publication SUP 50161 (5 pages) at the British Library Document Supply Centre, Boston Spa. Wetherby. West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1991) 273. 5. The extent of sequence similarity suggests that the benzyl alcohol dehydrogenases are related to each other and also to established members of the family of long-chain Zn2(+)-dependent alcohol dehydrogenases. Benzaldehyde dehydrogenase II from Acinetobacter appears to be related to the Pseudomonas TOL-plasmid-encoded benzaldehyde dehydrogenase. The yeast K(+)-activated aldehyde dehydrogenase has similarity of sequence with the mammalian liver cytoplasmic class of aldehyde dehydrogenases but not with any of the Acinetobacter or Pseudomonas enzymes. 2. Antisera were raised in rabbits against the three Acinetobacter enzymes and both of the Pseudomonas enzymes, and the extents of the cross-reactions were determined by immunoprecipitation assays with native antigens and by immunoblotting with SDS-denatured antigens. Cross-reactions were detected between the alcohol dehydrogenases and also among the aldehyde dehydrogenases. This confirms the interpretation of the N-terminal sequence comparisons and also indicates that benzaldehyde dehydrogenase I from Acinetobacter may be related to the other two benzaldehyde dehydrogenases. 3. The amino acid compositions of the Acinetobacter and the Pseudomonas enzymes were determined and the numbers of amino acid residues per subunit were calculated to be: benzyl alcohol dehydrogenase and TOL-plasmid-encoded benzyl alcohol dehydrogenase, 381; benzaldehyde dehydrogenase I and benzaldehyde dehydrogenase II, 525; TOL-plasmid-encoded benzaldehyde dehydrogenase, 538.

Acinetobacter↗
PubMed1999

Allylic or benzylic stabilization is essential for catalysis by bacterial benzyl alcohol dehydrogenases.

Benzyl alcohol dehydrogenase from Acinetobacter calcoaceticus (AC-BADH) and TOL plasmid-encoded benzyl alcohol dehydrogenase from Pseudomonas putida (TOL-BADH) have previously been shown to oxidize a variety of aromatic alcohols but not aliphatic substrates. Here, we have expressed the genes for AC-BADH and TOL-BADH in Escherichia coli, purified the resulting over-expressed enzymes, and shown that each is an effective catalyst of both benzylic and allylic alcohol oxidation, but not of oxidation of nonallylic analogs. Enzyme specificity (kcat/Km) for both enzymes was higher with an aliphatic, allylic alcohol (3-methyl-2-buten-1-ol) than with benzyl alcohol. These results suggest that bacterial benzyl alcohol dehydrogenases use the resonance stabilization provided by allylic and benzylic alcohols to promote catalysis.

Acinetobacter calcoaceticus↗
PubMed2000

Enantioresolution by the chiral phthalic acid method: absolute configurations of substituted benzylic alcohols.

Substituted benzylic alcohols were enantioresolved by the chiral phthalic acid method as follows; 1) esterification of racemic alcohols with chiral phthalic acid, 2) separation of a diastereomeric mixture of the esters formed by HPLC on silica gel, and 3) recovery of enantiopure alcohols from the separated esters. The absolute configurations of chiral phthalic acid esters of benzylic alcohols were unambiguously determined by the X-ray crystallography using the campharsultam moiety as the internal standard of absolute configuration.

Benzyl Alcohols↗
PubMed1979

Selective catalytic reduction of 7-methyl-6-dehydrotestosterone acetate to 7 beta-methyltestosterone acetate by benzyl alcohol.

Using benzyl alcohol as a hydrogen donor in the presence of Pd on charcoal, 7-methyl-6-dehydrotestosterone acetate was selectively reduced to 7 beta-methyltestosterone acetate in 90% yield. The addition of hydrogen atoms to the 6, 7 double bond proceeded from the less hindered alpha-face of the steroid molecule, giving rise to the 7 beta-methyl product. Gas chromatograph analysis indicated small amounts of the 7 alpha-methyl epimer, 7 beta-methyl-5 alpha-dihydrotestosterone acetate and the 5 beta-epimer. The 6,7 double bond was hydrogenated in preference to 4,5 double bond, although both are trisubstituted.

Benzyl Alcohols↗
PubMedDate not supplied

Studies on the stimulation of cAMP metabolism by heparin solutions containing benzyl alcohol.

Heparin solutions containing benzyl alcohol as a preservative increase intracellular cAMP concentrations in human lymphocytes by as much as 5 fold. Similar changes but of a lesser magnitude were also observed in human polymorphonuclear leukocytes and platelets and rabbit alveolar macrophages. Further analysis demonstrated that benzyl alcohol used as a preservative was responsible for this finding and that heparin per se had no effect on cAMP metabolism. The cAMP response to benzyl alcohol was a time- and dose-dependent process. In human peripheral blood lymphocytes, cAMP levels increased in a linear fashion over a benzyl alcohol concentration range from 0.015-0.30% (v/v). The increased cAMP concentrations in lymphocytes as measured by radioimmunoassay were not due to formation of a cross-reacting adenosine-alcohol adduct since the immunoreactive material produced was destroyed by phosphodiesterase and co-migrated with 3H-cAMP in thin layer chromatographic studies. Concentrations of benzyl alcohol which affect cAMP metabolism are commonly present in biologic studies employing heparin solutions. In view of these findings certain previously described effects of heparin may need to be reinterpreted and in the future heparin solutions containing benzyl alcohol should not be used when studying biologic processes known to be influenced by alterations in cAMP metabolism.

Animals↗
PubMedDate not supplied

Antiarrhythmic effect of solvents: propylene glycol, benzyl alcohol.

Propylene glycol and benzyl alcohol, the main constituents of most solvent vehicles, display a pronounced antiarrhythmic-antifibrillatory effects, when injected intravenously into animals (dogs, rats) with spontaneous or drug-induced arrhythmias. The antiarrhythmic dose for propylene glycol amounts to 0.2-0.3 ml/kg of a 70 per cent solution and, for benzyl alcohol to 0.2-0.4 ml/kg of a 4 per cent solution in physiologic saline, respectively. Similar effects were also obtained by the combined injection of propylene glycol + benzyl alcohol, in proportions which correspond to the formulae of numerous commercial "solvents" (vehicles): 2 to 20 per cent solutions of benzyl alcohol in 70 per cent propylene glycol (0.05-0.2 ml/kg). The mechanisms which might be responsible for the antiarrhythmic activity of solvents are discussed: lengthening of the effective refractory period, local and general anaesthetic effects, changes of osmolarity. The intravenous injection of propylene glycol and/or benzyl alcohol, in high doses, produces intravascular haemolysis. Clinical investigations are recommended as to the potential, beneficial or toxic effects of drug solvents, especially upon the cardiocirculatory system.

Animals↗
PubMed1986

Toxicity of benzyl alcohol in adult and neonatal mice.

Benzyl alcohol, a bacteriostatic agent found in many parenteral preparations, has been implicated as the agent responsible for precipitating "the gasping syndrome" in premature neonates. To investigate this toxicity, benzyl alcohol was administered intraperitoneally to adult (23-28 g) and neonatal (2-7 g) CD-1 male mice. Gross behavioral changes were monitored. Low doses (less than 800 mg/kg) produced minimal toxic effects within an initial 4-h observation period. At the end of this time, the LD50 was determined to be 1000 mg/kg for both age groups. When mortality in the adult group was observed after 7 d following a single treatment with benzyl alcohol, the LD50 on day 7 was determined to be 650 mg/kg. Rapid absorption and conversion of benzyl alcohol to its primary metabolite, benzaldehyde, occurred within both experimental groups; the plasma levels of each were comparable in both neonatal and mature animals when determined by GC. In an attempt to alter the toxicity of benzyl alcohol, pyrazole and disulfiram were used to inhibit the activities of alcohol dehydrogenase and aldehyde dehydrogenase, respectively. Treatment with pyrazole, before benzyl alcohol exposure, resulted in an increase in benzyl alcohol levels to 203% of control values and a marked increase in toxicity. Although pretreatment with disulfiram led to benzaldehyde levels which were 368% of control values, toxicity was unchanged. These data imply that the acute toxicity of benzyl alcohol, which includes sedation, dyspnea, and loss of motor function, is due to the alcohol itself and not to its metabolite, benzaldehyde.

Aging↗
PubMed2001

Final report on the safety assessment of Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate.

Benzyl Alcohol is an aromatic alcohol used in a wide variety of cosmetic formulations as a fragrance component, preservative, solvent, and viscosity-decreasing agent. Benzoic Acid is an aromatic acid used in a wide variety of cosmetics as a pH adjuster and preservative. Sodium Benzoate is the sodium salt of Benzoic Acid used as a preservative, also in a wide range of cosmetic product types. Benzyl Alcohol is metabolized to Benzoic Acid, which reacts with glycine and excreted as hippuric acid in the human body. Acceptable daily intakes were established by the World Health Organization at 5 mg/kg for Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate. Benzoic Acid and Sodium Benzoate are generally recognized as safe in foods according to the U.S. Food and Drug Administration. No adverse effects of Benzyl Alcohol were seen in chronic exposure animal studies using rats and mice. Effects of Benzoic Acid and Sodium Benzoate in chronic exposure animal studies were limited to reduced feed intake and reduced growth. Some differences between control and Benzyl Alcohol-treated populations were noted in one reproductive toxicity study using mice, but these were limited to lower maternal body weights and decreased mean litter weights. Another study also noted that fetal weight was decreased compared to controls, but a third study showed no differences between control and Benzyl Alcohol-treated groups. Benzoic Acid was associated with an increased number of resorptions and malformations in hamsters, but there were no reproductive or developmental toxicty findings in studies using mice and rats exposed to Sodium Benzoate, and, likewise, Benzoic Acid was negative in two rat studies. Genotoxicity tests for these ingredients were mostly negative, but there were some assays that were positive. Carcinogenicity studies, however, were negative. Clinical data indicated that these ingredients can produce nonimmunologic contact urticaria and nonimmunologic immediate contact reactions, characterized by the appearance of wheals, erythema, and pruritus. In one study, 5% Benzyl Alcohol elicited a reaction, and in another study, 2% Benzoic Acid did likewise. Benzyl Alcohol, however, was not a sensitizer at 10%, nor was Benzoic Acid a sensitizer at 2%. Recognizing that the nonimmunologic reactions are strictly cutaneous, likely involving a cholinergic mechanism, it was concluded that these ingredients could be used safely at concentrations up to 5%, but that manufacturers should consider the nonimmunologic phenomena when using these ingredients in cosmetic formulations designed for infants and children. Additionally, Benzyl Alcohol was considered safe up to 10% for use in hair dyes. The limited body exposure, the duration of use, and the frequency of use were considered in concluding that the nonimmunologic reactions would not be a concern. Because of the wide variety of product types in which these ingredients may be used, it is likely that inhalation may be a route of exposure. The available safety tests are not considered sufficient to support the safety of these ingredients in formulations where inhalation is a route of exposure. Inhalation toxicity data are needed to complete the safety assessment of these ingredients where inhalation can occur.

Animals↗
PubMed1990

Purification and characterisation of TOL plasmid-encoded benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase of Pseudomonas putida.

Benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase, two enzymes of the xylene degradative pathway encoded by the plasmid TOL of a Gram-negative bacterium Pseudomonas putida, were purified and characterized. Benzyl alcohol dehydrogenase catalyses the oxidation of benzyl alcohol to benzaldehyde with the concomitant reduction of NAD+; the reaction is reversible. Benzaldehyde dehydrogenase catalyses the oxidation of benzaldehyde to benzoic acid with the concomitant reduction of NAD+; the reaction is irreversible. Benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase also catalyse the oxidation of many substituted benzyl alcohols and benzaldehydes, respectively, though they were not capable of oxidizing aliphatic alcohols and aldehydes. The apparent Km value of benzyl alcohol dehydrogenase for benzyl alcohol was 220 microM, while that of benzaldehyde dehydrogenase for benzaldehyde was 460 microM. Neither enzyme contained a prosthetic group such as FAD or FMN, and both enzymes were inactivated by SH-blocking agents such as N-ethylmaleimide. Both enzymes were dimers of identical subunits; the monomer of benzyl alcohol dehydrogenase has a mass of 42 kDa whereas that of the monomer of benzaldehyde dehydrogenase was 57 kDa. Both enzymes transfer hydride to the pro-R side of the prochiral C4 of the pyridine ring of NAD+.

Alcohol Oxidoreductases↗