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At least 19 recordsLinked to original sources

The effect of 5-(n-alk(en)yl)resorcinols on membranes. I. Characterization of the permeability increase induced by 5-(n-heptadecenyl)resorcinol.

The influence of 5-(n-heptadecenyl)resorcinol, one of the main rye grain resorcinol derivatives, on the erythrocyte membrane permeability for nonelectrolytes differing in molecular size was studied turbidimetrically at various concentrations of the resorcinol derivative studied. The alkenylresorcinol induced increased permeability of the erythrocyte membrane for all the solutes studied (glycerol, m-erythritol, D-glucose, sucrose and polyethylene glycol 1000). At a given concentration of 5-(n-heptadecenyl)resorcinol the highest permeability increases were obtained for the smallest solutes. The membrane lipid to alkenylresorcinol ratio necessary for initiation of the increase of the erythrocyte membrane permeability for the solutes studied varied from 273 to 82 for glycerol and polyethylene glycol 1000, respectively, indicating that this strong membrane perturbing action may be primarily responsible for the biological effect of phenolic lipids.

Cell Membrane Permeability

Metabolism of resorcinylic compounds by bacteria: alternative pathways for resorcinol catabolism in Pseudomonas putida.

Two strains of Pseudomonas putida isolated by enrichment cultures with orcinol as the sole source of carbon were both found to grow with resorcinol. Data are presented which show that one strain (ORC) catabolizes resorcinol by a metabolic pathway, genetically and mechanistically distinct from the orcinol pathway, via hydroxyquinol and ortho oxygenative cleavage to give maleylacetate, but that the other strain (O1) yields mutants that utilize resorcinol. One mutant strain, designated O1OC, was shown to be constitutive for the enzymes of the orcinol pathway. After growth of this strain on resorcinol, two enzymes of the resorcinol pathway are also induced, namely hydroxyquinol 1,2-oxygenase and maleylacetate reductase. Thus hydroxyquniol, formed from resorcinol, undergoes both ortho and meta diol cleavage reactions with the subsequent formation of both pyruvate and maleylacetate. Evidence was not obtained for the expression of resorcinol hydroxylase in strain O1OC; the activity of orcinol hydroxylase appears to be recruited for this hydroxylation reaction. P. putida ORC, on the other hand, possesses individual hydroxylases for orcinol and resorcinol, which are specifically induced by growth on their respective substrates. The spectral changes associated with the enzymic and nonenzymic oxidation of hydroxyquinol are described. Maleylacetate was identified as the product of hydroxyquinol oxidation by partially purified extracts obtained from P. putida ORC grown with resorcinol. Its further metabolism was reduced nicotinamide adenine dinucleotide dependent.

Catechols

A strictly anaerobic nitrate-reducing bacterium growing with resorcinol and other aromatic compounds.

With resorcinol as sole source of energy and organic carbon, two stains of gram-negative, nitrate-reducing bacteria were isolated under strictly anaerobic conditions. Strain LuBRes1 was facultatively anaerobic and catalase- and superoxide dismutase-positive. This strain was affiliated with Alcaligenes denitrificans on the basis of substrate utilization spectrum and peritrichous flagellation. Strain LuFRes1 could grow only under anaerobic conditions with oxidized nitrogen compounds as electron acceptor. Cells were catalase-negative but superoxide dismutase-positive. Since this strain was apparently an obligate nitrate reducer, it could not be grouped with any existing genus. Resorcinol was completely oxidized to CO2 by both strains. Neither an enzyme activity reducing or hydrolyzing the resorcinol molecule, nor an acyl-CoA-synthetase activating resorcylic acids or benzoate was detected in cell-free extracts of cells grown with resorcinol. In dense cell suspensions, both strains produced a compound which was identified as 5-oxo-2-hexenoic acid by mass spectrometric analysis. This would indicate a direct, hydrolytic cleavage of the resorcinol nucleus without initial reduction.

Bacteria, Anaerobic

The benzenediols: catechol, resorcinol and hydroquinone--a review of the industrial toxicology and current industrial exposure limits.

A review of the published industrial toxicology for the benzenediols, catechol, resorcinol and hydroquinone was made to evaluate their proposed or established occupational exposure levels. Acute animal toxicity data for catecholand resorcinol are presented, along with that for phenol because of its analogous signs of illness and intoxication. The comparative acute toxicity data for catechol and phenol are anomalous, but suggest a TLV for catechol similar to that of phenol. The comparative acute toxicity data for resorcinol and phenol clearly show that resorcinol is significantly less toxic than phenol which has a 5 ppm TLV. These data, along with production plant exposures as high as 9.6 ppm without reported effects, suggest an industrial exposure level (TLV) for resorcinol of at least 10 ppm, perhaps 20 ppm or higher. The established 2 mg/M3 TLV for hydroquinone appears to be proper.

Administration, Oral

Modification by catechol and resorcinol of upper digestive tract carcinogenesis in rats treated with methyl-N-amylnitrosamine.

Modifying effects of the environmental contaminant catechol, and its isomers resorcinol and hydroquinone, on methyl-N-amylnitrosamine (MNAN)-induced carcinogenesis were studied in male F344 rats. Groups of 15 rats were given three i.p. injections of 25 mg/kg of body weight of MNAN within the initial 2-wk period, and commencing 1 wk thereafter they were administered 0.8% catechol, 0.8% resorcinol, or 0.8% hydroquinone in powdered basal diet or were given basal diet alone for 49 wk. Additional groups of 10 to 15 rats were similarly treated without prior carcinogen exposure. Histological examination after sacrifice at wk 52 revealed that the incidences of tongue papillomas and esophageal squamous cell carcinomas in the groups given MNAN followed by catechol (57.1% and 64.3%) or resorcinol (50% and 58.8%) were significantly higher than those in the carcinogen only controls (9.1, and 0%, respectively). Hydroquinone also enhanced the development of esophageal squamous cell carcinomas but was less active than catechol or resorcinol. The incidence of alveolar hyperplasia in the lungs of the group given MNAN followed by catechol (0%) was, in contrast, significantly reduced as compared to the control value (54.5%). Hydroquinone and resorcinol showed a similar but non-significant tendency. These results indicated that the environmental contaminant, catechol and its isomers, may play a role in the development of human upper gastrointestinal cancer, in addition to exerting modifying effects in other organs.

Animals

[Multiple effects of resorcinol on thyroid function (author's transl)].

In rats, I.V. injected resorcinol led to a decrease in thyroid radioiodine uptake and labelled iodothyronine/iodotyrosine ratio with no changes in the percent of thyroidal labelled iodide or radioiodine release. When thyroid lobes were incubated in vitro with radioiodine, resorcinol concentrations from 10(-3)M to 10(-6)M gave an increase in the percent of thyroidal labelled iodide and iodotyrosine/iodothyronine ratio. In animals fed 5% resorcinol for 2 weeks we observed an increase in thyroid weight, a decrease in plasma T4, no change in the percent of free T4, a decrease in T4 half life and no significant changes in T3 half life. Thyroidal labelled MIT/DIT and T3/T4 atios increased. Resorcinol, given in diet during 5 days to rats which had a low thyroidal thyroglobulin content after PTU administration for 2 weeks, gave, in comparison with rats fed PTU only, an increase in thyroidal thyroglobulin/DNA ratio and a decrease in thyroidal radioiodine release contrasting with an increase in plasma TSH. These differences did not exist when resorcinol was given for one month.

Administration, Oral

Quantitative determination of resorcinol in presence of phenol.

A simple and accurate method for the quantitative determination of resorcinol in the presence of phenol is reported. The method is based on the formation of indophenol by reacting resorcinol with 2, 6-dibromoquinone-4-chlorimide. The concentration of indophenol can be measured spectrophotometrically. This method is recommended for the determination of resorcinol in resorcinol-phenol-boric acid solution and carbol-fuchsin solution. The decomposition products of resorcinol and phenol, e.g., colored quinones, do not interfere with the assay procedure.

Colorimetry

[Effects of peeling agents (resorcinol, crystalline sulfur, salicylic acid) on the epidermis of guinea pig (author's transl)].

The mode of action of "classical peeling agents" such as resorcinol, crystalline sulfur, and salicylic acid on the epidermis is almost unknown. There are only a few experimental data available. Therefore the effects of resorcinol, crystalline sulfur, and salicylic acid were studied. A 1% and 3% concentration of these chemicals in vaselinum flavum or Unguentum Cordes was applied to the ears and flanks of adult male guinea pigs up to 14 days. Prior to biopsies at various time intervals, 3H-thymidine was injected intradermally. Specimens were paraffin embedded and routinely processed for autoradiographical analysis. The following parameters were assessed: Labelling index (L.I. in %); number of labelled basal cells per unit length of basement membrane; papillomatosis-index; and acanthosis-factor (projection histoplanimetry). The data were statistically analysed. The peeling agents induced a concentration-dependent increase of the L.I., acanthosis, and papillomatosis. Crystalline sulfur caused the most pronounced effect, followed by resorcinol. In contrast salicylic acid caused only a minute acanthosis factor and a slight increase in labelling. The correlation coefficient r of epidermal thickness to the L.I. for all concentrations and peeling agents used reaches the high figure of 0.978 for the ear. The 1% and 3% salicylic acid has a lower acanthosis factor than vaselinum flavum by itself. Preliminary autoradiographical studies in humans with 1% and 10% salicylic acid confirm these data. Salicylic acid counteracts acanthosis. These experiments show that crystalline sulfur and resorcinol have a potent effect on cell proliferation and acanthosis. They peel via proliferation hyperkeratosis. The mode of peeling by salicylic acid must be different, as cell proliferation and acanthosis are barely enhanced. The clinically known "keratolytic" effect of salicylic acid may be due to a direct action on the intercellular cement substance of the horny cells.

Animals

Metabolism of phenol and resorcinol in Trichosporon cutaneum.

Trichosporon cutaneum was grown with phenol or resorcinol as the carbon source. The formation of beta-ketoadipate from phenol, catechol, and resorcinol was shown by a manometric method using antipyrine and also by its isolation and crystallization. Metabolism of phenol begins with o-hydroxylation. This is followed by ortho-ring fission, lactonization to muconolactone, and delactonization to beta-ketoadipate. No meta-ring fission could be demonstrated. Metabolism of resorcinol begins with o-hydroxylation to 1,2,4-benzenetriol, which undergoes ortho-ring fission yielding maleylacetate. Isolating this product leads to its decarboxylation and isomerization to trans-acetylacrylic acid. Maleylacetate is reduced by crude extracts to beta-ketoadipate with either reduced nicotinamide adenine dinucleotide or reduced nicotinamide adenine dinucleotide phosphate as a cosubstrate. The enzyme catalyzing this reaction was separated from catechol 1,2-oxygenase, phenol hydroxylase, and muconate lactonizing enzyme on a diethyl-aminoethyl-Sephadex A50 column. As a result it was purified some 50-fold, as was the muconate-lactonizing enzyme. Methyl-, fluoro-, and chlorophenols are converted to a varying extent by crude extracts and by purified enzymes. None of these derivatives is converted to maleylacetate, beta-ketoadipate, or their derivatives. Cells grown on resorcinol contain enzymes that participate in the degradation of phenol and vice versa.

Adipates

[5-Alkyl(C19-C25) resorcinols as regulators of succinate and NAD-dependent substrate oxidation by mitochondria].

The effect of 5-n-alkyl(C19-C25) resorcinols isolated from Azotobacter chroococcum on the oxidation of succinate and NAD-dependent substrates (glutamate, alpha-ketoglutarate, malate, pyruvate) by rat liver mitochondria was studied, using the polarographic technique. With succinate, the above resorcinol lipids activated to some extent the 2,4-dinitrophenol-decoupled mitochondrial respiration, but markedly suppressed it (up to 95%) in the presence of NAD-dependent substrates. The activating and inhibiting effects correlated with the resorcinol lipid/mitochondrial proteins ratio and were observed, when the lipid concentration in the incubation mixture ranged from 2.4.10(-4) to 6.0.10(-4) M. The most striking inhibiting effect was observed with alpha-ketoglutarate as substrate. The results obtained suggest that 5-n-alkyl(C19-C25) resorcinols should be regarded as rotenone type regulators of cell respiration.

Animals

[Synchronous fluorescent determination of phenol and resorcinol using linear regression of multiwavelength data].

A method for simultaneous determination of phenol and resorcinol in mixtures using fluorimetry is developed by combining synchronous fluorescence technique with linear regression of multiwavelength data. The effect of solution pH and other mental variables was examined and the optimal condition for determination of phenol and resorcinol was established. The proposed method was applied to fluorescent assay of resorcinol based on preparation with recoveries of 97.18 ( +/- 2.42)% and 98.15 (+/- 2.70)% for phenol and resorcinol, respectively.

Phenols

Structure activity relationships of resorcinol substituted ring systems.

Dopamine receptor agonist activity was evaluated using resorcinol derivatives of the following ring systems: dopamine, aminotetralin, indan, benzocycloheptane, octahydrobenzo(f)quinoline and octahydrobenzo[g]quinoline. The compounds were evaluated for biological activity using in vitro binding assays, anesthetized cat blood pressure and heart rate, cat cardioaccelerator nerve preparation and rotations of rats with unilateral denervation of the caudate nucleus. Resorcinol substitutions were chosen because one hydroxyl group corresponded to the alpha-conformer of dopamine and the second hydroxyl group corresponded to the beta-conformer of dopamine. Dopamine receptor activity was found primarily with derivatives of aminotetralin and octahydrobenzo[f]quinoline while the other ring systems yielded compounds which were quite inactive. The active resorcinol derivatives were found in the same ring systems where catechol substitution was active in ring positions corresponding to either the alpha- or beta-conformer of dopamine. Likewise in those ring systems where catechol substitution corresponding to the beta-conformer of dopamine were quite inactive, resorcinol substitution in these series was not favorable for activity. The ring systems requirements for alpha- and beta-adrenoceptor agonist activity did not follow the same structural pattern as found for dopamine receptor agonist activity.

Animals

Comparative metabolism and excretion of resorcinol in male and female F344 rats.

Following oral administration, resorcinol was readily absorbed from the gastrointestinal tract, rapidly metabolized, and excreted by male and female rats. In both sexes, most of the dose of resorcinol (greater than 90%) was excreted in the urine within 24 hr after oral administration of 112 mg/kg, indicating little potential for bioaccumulation in animal tissues. Less than 3% of an oral dose was excreted in feces. An analysis of bile indicated that at least 50% of the dose excreted in bile undergoes enterohepatic circulation to be eventually excreted in urine. Little (less than 5%) of the parent compound was excreted in urine; most of the dose was in the form of three major and one minor metabolite. The relative amounts of metabolites excreted changed only slightly with time and dose administered. Approximately 70% of the total radioactivity in the urine of both sexes was in the form of a glucuronide conjugate. Female rats excreted a greater portion of the dose as a sulfate conjugate than males. Males excreted more of a diconjugate containing both sulfate and glucuronide groups. Repeated exposure to up to five daily doses resulted in no apparent alteration of the pattern of resorcinol absorption, metabolism, and excretion observed after a single dose.

Animals

Bacterial metabolism of resorcinylic compounds: purification and properties of orcinol hydroxylase and resorcinol hydroxylase from Pseudomonas putida ORC.

The hydroxylase activities observed in extracts of Pseudomonas putida ORC after growth on orcinol and resorcinol as sole source of carbon have been purified to homogeneity. Both enzymes were shown to be flavoproteins and to contain approximately 1 mol of FAD for each polypeptide chain, S20,W values for each enzyme are 4.1 +/- 0.1 and are independent of the presence of their aromatic substrates. Molecular weight determinations under native (approximately 68000) and denaturing (approximately 70000) conditions indicated that they are monomeric. The visible absorption spectra identical but the circular dichroic spectra of the two proteins can be distinguished. Although each protein catalyzes the NAD(P)H and O2-dependent hydroxylation of both orcinol and resorcinol, the efficiency of the transformations of the substrates by the two enzymes is radically different; furthermore resorcinol hydroxylase is much more versatile in the aromatic compounds it can utilize as substrates and effectors. Other properties of the enzymes which clearly establish their own identity include their serological characteristics and amino acid composition; the latter property is particularly evident when the quantities of valine and alanine residues are compared. The synthesis of each enzyme is also under different regulatory constraints, being controlled by the substrate used for growth.

Amino Acids

Modulation of the activities of membrane enzymes by cereal grain resorcinolic lipids.

Resorcinolic lipids, amphiphilic compounds from cereal grains show strong effects upon the activity of membrane enzymes. The concentrations for 50% inhibition of erythrocyte membrane acetylcholinesterase were in the range of 18-90 microM and were dependent on the length of the aliphatic side chain of the homologue and on the modification of hydroxyl groups in the benzene ring. Sulfonation of OH groups resulted in a drastic decrease of the inhibitory potency. The effect of resorcinolic lipids on the activity of Ca2+(calmodulin)-ATPase was the opposite. Up to concentrations of 50 microM alk(en)ylresorcinols stimulated the activity of this enzyme and only slight inhibition (approx. 30%) was observed above 100 microM. The results suggest that the effect of resorcinolic lipids might depend on their ability to alter the bilayer properties. Most probably these compounds decrease the mobility of membrane phospholipid molecules.

Acetylcholinesterase

The effect of resorcinolic lipids on phospholipid hydrolysis by phospholipase A2.

The effects of resorcinolic lipids (5-n-alk(en)ylresorcinols) isolated from cereal grains on the phospholipase A2 catalyzed hydrolysis of phospholipid vesicles were examined. Studied compounds inhibited the apparent enzyme activity at the molar fraction in the membrane as low as 0.025, which is equivalent to the concentration of 3 microM. This effect was visualized by dramatic increase (over ten-fold) of the latency period of the reaction progress. This makes resorcinolic lipids one of the most potent inhibitors of phospholipase A2 among already studied compounds. Highest inhibitory activities were shown for dienoic and monoenoic homologs of 17 carbon atoms in the aliphatic chain. Both saturation of the chain and the increase of its length reduced inhibitory properties of resorcinolic lipids. The data suggest that the compounds studied in this paper like other known amphiphilic inhibitors of phospholipase A2 owe most of their effects to the ability to modify the quality of the substrate interface. These are the alteration of the enzyme binding, velocity of the formation and redistribution of the products. However part of the effect seems to be attributed to direct interaction and modification of enzyme properties by alk(en)ylresorcinols.

Alkylation

The effect of 5-(n-alk(en)yl)resorcinols on membranes. II. Dependence of the aliphatic chain length and unsaturation.

The effect of chain length and unsaturation on the haemolytic properties of cereal resorcinolic lipids, (5-n-alk(en)ylresorcinols), was studied using isolated saturated, monoenoic and dienoic homologues. The haemolytic activities of the homologues studied were proportional to the degree of the side chain unsaturation and inversely proportional to the chain length. At temperatures close to physiological of animal organisms the most active were mono- and di-enoic homologues of 5-n-heptadecyl and 5-n-nonadecyl resorcinols. The results might point to the importance of short-chain cereal resorcinolic lipids in animal and human nutrition.

Erythrocyte Membrane