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At least 19 recordsLinked to original sources
PubMed1977

The metabolism of trans-cyclohexan-1,2-diol by an Acinetobacter species.

1. Acinetobacter TD63 was one of some thirty organisms isolated by elective culture with trans-cyclohexan-1,2-diol as sole source of carbon. The great majority of these isolates displayed the same growth spectrum as Nocardia globerula CL1 and Acinetobacter NCIB 9871 being capable of utilizing trans-cyclohexan-1,2-diol, 2-hydroxycyclohexan-1-one, cyclohexanol, cyclohexanone,1-oxa-2oxocycloheptane and adipate and were assumed to use well described metabolic pathways. 2. Acinetobacter TD63 was distinctive in being incapable of growth with cyclohexanol, cyclohexanone or 1-oxa-2-oxocycloheptane and because of this it was hoped that it would display an alternative pathway for the oxidation of trans-cyclohexan-1,2-diol. 3. Studies with cell extracts have shown the presence of inducible dehydrogenase for the conversion of trans-cyclohexan-1,2-diol to 2-hydroxycyclohexan-1-one and cyclohexan-1,2-dione and of 6-oxohexanoate to adipate. These enzymes are linked into a metabolic sequence by the action of a monooxygenase of broad specificity but efficiently capable of converting 2-hydroxy-cyclohexan-1-one into the lactone 1-oxa-2-oxo-7-hydroxycycloheptane that spontaneously rearranges to yield 6-oxohexanoate. 4. An enzyme capable of attacking cyclohexan-1,2-dione (mono-enol) in the absence of an electron donor or oxygen has also been detected. Evidence has been presented indicating that this enzyme catalyses a keto-enol tautomerization between cyclohexan-1,2-dione (mono-enol) and cyclohexan-1,2-dione (mono-hydrate) and is not involved in the pathway of ring cleavage. 5. The failure of Acinetobacter TD63 to grow with cyclohexanol, cyclohexanone or 1-oxa-2-oxocycloheptane is due not to this organism possessing a distinctive metabolic sequence but to a narrow inducer specificity coupled with an inability to form a lactone hydrolase enabling it to cleave the stable 1-oxa-2-oxocycloheptane which is an intermediate in the established pathway of cyclohexanol and cyclohexanone oxidation.

Acinetobacter↗
PubMed1990

Mouse skin ornithine decarboxylase induction and tumor promotion by cyclohexane.

Cyclohexane, a frequently used solvent in industry, was assessed for its tumorigenic potential on mouse skin following multistage initiation-promotion protocols. The activity of ornithine decarboxylase (ODC), a marker of tumor promotion was found to be induced by the topical application of cyclohexane. This ODC induction was dependent on the dose of cyclohexane used and the duration of application. Effect of protein synthesis inhibitors and the modifiers of tumor promotion on the cyclohexane induced ODC activity was also studied. ODC induction was inhibited by cycloheximide and also, up to some extent, by actinomycin D. Inhibitors of stage II tumor promotion showed more effect on the ODC induction by cyclohexane as compared to the inhibitors of stage I tumor promotion. In chronic animal bioassay experiments topical application of cyclohexane to DMBA initiated mouse skin resulted in just 10% of tumor bearing animals while prior application of TPA for two weeks resulted in 45% of tumor bearing animals. Collectively, the present study demonstrates that cyclohexane is more effective as a stage II tumor promoter over mouse skin and possibly affects the biochemical events at the molecular level.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1978

Metabolism of cyclohexane carboxylic acid by Alcaligenes strain W1.

Thirty-three microorganisms capable of growth with cyclohexane carboxylate as the sole source of carbon were isolated from mud, water, and soil samples from the Aberystwyth area. Preliminary screening and whole-cell oxidation studies suggested that, with one exception, all of the strains metabolized the growth substrate by beta-oxidation of the coenzyme A ester. This single distinctive strain, able to oxidize rapidly trans-4-hydroxycyclohexane carboxylate, 4-ketocyclohexane carboxylate, p-hydroxybenzoate, and protocatechuate when grown with cyclohexane carboxylate, was classified as a strain of Alcaligenes and given the number W1. Enzymes capable of converting cyclohexane carboxylate to p-hydroxybenzoate were induced by growth with the alicyclic acid and included the first unambiguous specimen of a cyclohexane carboxylate hydroxylase. Because it is a very fragile protein, attempts to stabilize the cyclohexane carboxylate hydroxylase so that a purification procedure could be developed have consistently failed. In limited studies with crude cell extracts, we found that hydroxylation occurred at the 4 position, probably yielding the trans isomer of 4-hydroxycyclohexane carboxylate. Simultaneous measurement of oxygen consumption and reduced nicotinamide adenine dinucleotide oxidation, coupled with an assessment of reactant stoichiometry, showed the enzyme to be a mixed-function oxygenase. Mass spectral analysis enabled the conversion of cyclohexane carboxylate to p-hydroxybenzoate by cell extracts to be established unequivocally, and all of our data were consistent with the pathway: cyclohexane carboxylate --> trans-4-hydroxycyclohexane carboxylate --> 4-ketocyclohexane carboxylate --> p-hydroxybenzoate. The further metabolism of p-hydroxybenzoate proceeded by meta fission and by the oxidative branch of the 2-hydroxy-4-carboxymuconic semialde-hyde-cleaving pathway.

Alcaligenes↗
PubMed1992

Partitioning of tryptophan side-chain analogs between water and cyclohexane.

We have measured the partitioning of the tryptophan side-chain analogs 3-methylindole and N-methylindole between water and cyclohexane over the temperature range 8-55 degrees C to investigate the relative contribution of the imine-NH- to the free energy of transfer. We take advantage of the fact that the indole imine nitrogen is blocked by a methyl group in N-methylindole. Unlike previous studies, we take into account the water present in the cyclohexane phase. Free energies of partitioning were calculated using mole-fraction, volume-fraction, and Flory-Huggins-corrected volume-fraction partition coefficients [De Young, L. R., & Dill, K. A. (1990) J. Phys. Chem. 94, 801-809; Sharp, K. A., Nicholls, A., Friedman, R., & Honig, B. (1991) Biochemistry 30, 9686-9697]. These approaches account for configurational entropy changes in different ways and thus lead to different values for the calculated free energies of transfer. There is a 2-3-fold difference in the free energies calculated from our measurements, using the different units. Independent of units, the partitioning of both compounds involves identical entropy changes. However, 3-methylindole has an additional unfavorable enthalpic contribution to partitioning into cyclohexane of +1.6 kcal/mol (independent of units) which is presumably the cost of removing the indole -NH- group from water and transferring it to cyclohexane. In cyclohexane, 3-methylindole forms hydrogen bonds with water that cause water to copartition into cyclohexane with the solute. A method is described which allows the partitioning process to be examined independent of subsequent interactions with water in the solvent.

Chemical Phenomena↗
PubMed1976

Co-oligopeptides of glycine and aromatic amino acids with variable distance between the aromatic residues. IV. Spectroscopic properties of tryptophan-containing peptides in a cyclohexane phase.

L-Tryptophan, L-tryptophanylglycine, glycyl-L-tryptophan, glycyl-L-tryptophanylglycine and glycyl-L-tryptophanylglycylglycyl-L-tryptophanylglycine have been transferred from an aqueous solution (generally 0.1 M NaOH) to cyclohexane, using the quaternary ammonium salt trioctylmethyl ammonium chloride (NR+4Cl-, soluble in cyclohexane but not in water) as the transporting agent. The spectroscopic properties of L-tryptophan and tryptophan-containing peptides have been studied in the cyclohexane phase. With respect to the aqueous solutions, ultraviolet absorption spectra are characterized by a considerable red shift of the absorption maxima and by a hypochromicity of up to 10%. Fluorescence spectra generally show emission maxima which are characteristic of polar environments, accompanied by a significant enhancement of the quantum yield. CD spectra have also been investigated for all peptides and compared with those for aqueous systems reported in preceding publications. All these spectral changes cannot be attributed solely to the cyclohexane solvent effect. It is suggested that these anomalous spectral properties of the tryptophan-containing compounds in the cyclohexane-NR+4 solution are due to the influence the electrostatic field of the ion pair has on the indole chromophore. The possible implications of this finding for the spectroscopic properties of aromatic residues buried in the polar interior of proteins are discussed.

Circular Dichroism↗
PubMed1977

Epoxidation of 1,7-octadiene by Pseudomonas oleovorans: fermentation in the presence of cyclohexane.

A very efficient conversion of 1,7-octadiene to 7,8-epoxy-1-octene and 1,2-7,8-diepoxyoctane was achieved by incorporating a high concentration of cyclohexane into the conventional fermentation medium. In the presence of cyclohexane, a 90-ml% conversion of substrate to product was accomplished within 72 h, compared with an 18,5-mol% conversion in the absence of cyclohexane. Furthermore, the products were simultaneously separated and concentrated in the organic phase.

Cyclohexanes↗
PubMed1990

Effects of solvent medium on solubility. V: Enthalpic and entropic contributions to the free energy changes of di-substituted benzene derivatives in ethanol:water and ethanol:cyclohexane mixtures.

The solubility at four different temperatures in water, cyclohexane, and mixtures of water and ethanol and ethanol and cyclohexane of nine derivatives of the structure pX1-C6H4-X2, together with their heats of fusion are reported. The enthalpy and entropy of mixing (delta HM and delta SM, respectively), and also the excess free energy (delta GE) for pure solvents and several compositions of solvent mixtures were calculated. The enthalpic and entropic contribution to the free energy of transfer for water:solvent mixtures was also calculated for each compound. Solvent systems may be classified by means of the enthalpic-entropic relationships exhibited by the series in each case.

Benzene↗
PubMed1975

Effect of trans-1,4-bis(2-chlorobenzylaminomethyl) cyclohexane dihydrochloride and carbon monoxide on hepatic cholesterol biosynthesis from 4,4,-dimethyl sterols in vitro.

The drug trans-1,4-bis(2-chlorobenzylaminomethyl)cyclohexane dihydrochloride (AY-9944) almost completely inhibited the conversion of [2-14C] mevalonic acid, dihydro[14C]lanosterol, 4,4-dimethyl-5alpha-[2-3H2]cholesta-8,14-dien-3beta-ol and 4,4-dimethyl-5alpha-[2-3H2]cholest-8(14)-en-3beta-ol to 5alpha-cholest-7-en-3beta-ol and cholesterol by cell-free systems of rat liver. With the first three precursors, the inhibition was accompanied by an accumulation of radioactive 5alpha-cholesta-8,14-dien-3beta-ol, but this material could not be detected during inhibition of cholesterol biosynthesis from 4,4-dimethyl-5alpha-[2-3H2] cholest-8(14)-en-3beta-ol. Regardless of the nature of the precursor, trans-1,4-bis(2-chlorobenzylaminomethyl)cyclohexane dihydrochloride did not result in the accumulation of any delta5,7 sterols. Non-radioactive 5alpha-cholest-8(14)-en-3beta-ol inhibited the conversion of dihydro[14C]lanosterol to 4,4-dimethyl-5alpha-cholesta-8,14-dien-3beta-ol. Carbon monoxide resulted in a decrease in the rate of conversion of dihydro[14C]lanosterol to 4,4-dimethyl-5alpha-cholesta-8,14-dien-3beta-ol but had no effect on the rate of conversion of 4,4-dimethyl-5alpha-[2-3H2]cholesta-8,14-dien-3beta-ol to 5alpha-cholest-7-en-3beta-ol and cholesterol suggesting that cytochrome P-450 is involved neither in the oxidative removal of the 4-methyl groups nor in the oxidative introduction of the delta5 bond during cholesterol biosynthesis. In addition, the process of cholesterol and 5alpha-cholest-7-en-3beta-ol biosynthesis from 4,4-dimethyl-5alpha-[2-3H2]cholest-8(14)-en-3beta-ol was inhibited by carbon monoxide at a stage after the formation of 5alpha-cholest-8(14)-en-3beta-ol.

Animals↗
PubMed1990

Chemical modification by pyridoxal 5'-phosphate and cyclohexane-1,2-dione indicates that Lys-7 and Arg-10 are involved in the p2 phosphate-binding subsite of bovine pancreatic ribonuclease A.

Steric and chemical evidence had previously shown that residues Lys-7 and/or Arg-10 of bovine pancreatic RNAase A could belong to the p2 phosphate-binding subsite, adjacent to the 3' side of the main site p1. In the present work chemical modification of the enzyme with pyridoxal 5'-phosphate and cyclohexane-1,2-dione was carried out in order to identify these residues positively as part of the p2 site. The reaction with pyridoxal 5'-phosphate yields three monosubstituted derivatives, at Lys-1, Lys-7 and Lys-41. A strong decrease in the yield of derivatives at Lys-7 and Lys-41 was observed when either p1 or p2 was specifically blocked by 5'-AMP or 3'-AMP respectively. These experiments indicate that both sites are needed for the reaction of pyridoxal 5'-phosphate with RNAase A to take place. The positive charge in one of the sites interacts with the phosphate group of pyridoxal 5'-phosphate, giving the proper orientation to the carbonyl group, which then reacts with the lysine residue present in the other site. The absence of reaction between pyridoxal 5'-phosphate and an RNAase derivative that has the p2 site blocked supports this hypothesis. Labelling of Lys-7 with pyridoxal 5'-phosphate has a more pronounced effect on the kinetics with RNA than with the smaller substrate 2',3'-cyclic CMP. In addition, when the phosphate moiety of the 5'-phosphopyridoxyl group was removed with alkaline phosphatase the kinetic constants with 2',3'-cyclic CMP returned to values very similar to those of the native enzyme, whereas a higher Km and lower Vmax. were still observed for RNA. This indicates that this new derivative has recovered a free p1 site and, hence, the capability to act on 2',3'-cyclic CMP, but the presence of the pyridoxyl group bound to Lys-7 is still blocking a secondary phosphate-binding site, namely p2. Finally, reaction of cyclohexane-1,2-dione at Arg-10 is suppressed in the presence of 3'-AMP but only a 19% decrease is observed with 5'-AMP, suggesting that Arg-10 is also close to the p2 phosphate-binding subsite.

Animals↗
PubMed1978

The effect of cyclohexane derivatives on selection of bacterial groups forming activated sludge microflora.

The effect of cyclohexanol, cyclohekxanon and cyclohexylamine on the selection of bacteria in a model population composed of bacteria isolated from activated sludge was examined. The initial population consisted of both gram-positive and gram-negative bacteria. The latter, which accounted for 90-97% of the population, belonged mainly to three Pseudomonas groups and the Enterobacteriaceae, Vibrio-Aeromonas, Achromobacter-Alcaligenes and Flavobacterium groups. Seven day growth in medium containing cyclohexane derivatives caused pronounced qualitative changes in the population. The compounds favored the development of bacteria of the genus Pseudomonas and inhibited the growth of all other gram-negative bacteria. The direction of selection was independent of the type of cyclohexane derivative.

Alcaligenes↗
PubMed1975

Effects of S-8527 (1, 1-bis (4'-(1"-carboxy-1"-methylpropoxy) phenyl) cyclohexane), a new hypolipidemic compound, on platelet aggregation, adhesiveness and blood coagulation in rats.

Effects of S-8527 (1,1-bis[4'-(1"-carboxy-1"-methylpropoxy) phenyl] cyclohexane) on platelet aggregation, adhesiveness and blood coagulation were examined in rats. In animals maintained on a semisynthetic diet containing sucrose (62%) as the only carbohydrate source, platelet adhesiveness increased as compared with that in rats fed a normal chow pellet. Under these experimental conditions, oral dose of S-8527 (30-300 mg/kg) for 14 days decreased platelet adhesiveness and ADP-induced platelet aggregation, but did not decrease collagen-induced platelet aggregation. S-8527 also showed a slight but significant increase of R value of thrombelastograph. In rats which were fed a normal chow pellet oral dose of S-8527 for 14 days did not significantly affect the several tests of platelet function and blood coagulation. These results suggest that S-8527 normalizes the platelet function in a hyper-adhesive state, but does not affect the platelet function in a normal state.

Adenosine Diphosphate↗
PubMed1992

[13-week subchronic toxicity study of 1,1-bis(t-butylperoxy) 3,3,5-trimethyl cyclohexane in mice].

A 13-week subchronic toxicity study of 1,1-bis(t-butylperoxy)3,3,5-trimethyl cyclohexane (TMCH) was performed in male and female B6C3F1 mice by feeding a CRF-1 powder diet containing 0, 0.5, 1.0, 2.0 and 4.0% TMCH, to determine the maximum tolerable dose (MTD) for subsequent carcinogenicity study. Mice were randomly divided into 5 groups, each consisting of 10 males and 10 females. Eight animals of both sexes in the 4.0% TMCH group died during the early administration period. Suppression of body weight gains was marked in both sexes of the 4.0% and 2.0% TMCH groups as compared with the control group. The mean food consumption in all groups treated with TMCH was lower than that in the control group in a dose-related manner. Hematological examination revealed decreases in the number of erythrocytes, volume of hemoglobin, and values for hematocrit and mean corpuscular volume (MCV) in both sexes of the 4.0% and 2.0% TMCH groups. The relative liver weights of all groups treated with TMCH increased in a dose-related manner, whereas both absolute and relative spleen weights decreased in a dose-dependent manner. Histopathologically, swelling of the hepatocytes was found centrilobularly or diffusely in both sexes of the 1.0, 2.0 and 4.0% TMCH groups, and decrease of the hematopoietic cells in the bone marrow was observed in both sexes of the 2.0 and 4.0% TMCH groups. In addition, atrophy of red pulp and white pulp of the spleen was found in both sexes of the 2% and 4% TMCH groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1979

[Morphological differentiation of neuroblastoma by 1 methyl cyclohexane carboxylic acid (CCA) and some C1 derivatives].

We describe the induction of neuroblastoma morphological differentiation by 1 methyl cyclohexane carboxylic acid (CCA) and by some C1 derivatives of CCA. This induction proceeds in a medium which allows, in the absence of inducer, a normal growth of neuroblastoma cells and contains 7.5% fetal Calf serum. In order to establish a clear-dose response relationship and to compare the relative potencies of different drugs, the morphological changes were assessed by examining "long neurite-bearing cells".

Animals↗
PubMed1978

[On separation of isomeres, structural elucidation and pharmacological characterization of 1-(m-methoxyphenyl)-2-(dimethylaminomethyl)-cyclohexan-1-ol (author's transl)].

1-(m-Methoxyphenyl)-2-(dimethylaminomethyl)-cyclohexan-1-ol (L 201) was split into the cis- and trans-isomers and the conformations of the two isomers were determined by 13C-NMR-spectroscopy. Molecule models showed that both conformeres were similar to the geometrical structure of morphine. The adaptation of the morphine structure was better with the more active trans-isomer than with the cis-isomer. Tramadol, the trans-isomer, was separated into its optical antipodes. When tested for analgesia in the electro-stimulation test with mice, all compounds showed analgetic activity. The trans-isomer was more active than the cis-isomer and the (+)-form of the trans-isomer was more active than the (--)-form. Given by s.c. route, the (+)-transisomer E 382 was 1/3 as active as morphine. However, the Straub-tail reaction and the withdrawal jumping tests yielded more favourable results with L 201 and tramadol than with E 382.

Analgesics↗