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At least 19 recordsLinked to original sources
PubMed1975

Airway disease caused by phenolic (phenol-formaldehyde) resin exposure.

A standardized respiratory questionnaire and pulmonary function tests, including measurement of forced vital capacity (FVC), one-second forced expiratory volume (FEV1.0), and maximum expiratory flow rate at 50% FVC (MEF50%), were administered to five groups of employees in a filter-manufacturing plant to determine the acute and chronic effects of exposure to phenolic resin fumes. Employees exposed for more than five years had lower FEV1.0/FVC and MEF50%/FVC ratios than a group that had smoked more but that had never been consistently exposed to resin fumes. The existence of chronic airway obstruction was also evident by a slight excess of chronic cough and sputum production in the exposed groups. However, in spite of the high proportions of subjects reporting acute respiratory symptoms, we found only small decreased in pulmonary function during the workday and workweek.

Adult↗
PubMed1975

The percutaneous absorption of phenolic compounds: the effect of vehicles on the penetration of phenol.

The effects of interactions between drug and skin, drug and vehicle, and vehicle and skin on the overall penetration rate of a drug through the skin may be evaluated by comparison of penetration rates through excised skin and an inert reference membrane such as polyethylene. Dimethyl sulphoxide, dimethyl formamide, ethanol and water increase the permeability of the skin but because of reduced thermodynamic activities in the vehicles low penetration rates are observed.

Animals↗
PubMed1977

Kinetic studies of the phenol sulphate-phenol sulphotransferase of Aspergillus oryzae.

Arylsulphatase II of Aspergillus oryzae exhibits both hydrolytic and sulphotransferase activities. The kinetic data suggest the formation of an intermediate covalent enzyme-sulphate complex with transfer of sulphate from donor to acceptor proceeding via a Ping Pong mechanism. The unusual kinetic behaviour when 2-hydroxy-5-nitrophenyl sulphate is the substrate is also consistent with this mechanism.

Aspergillus oryzae↗
PubMed1979

Cocarcinogenicity of phenols from Estonian shale tars (oils).

Many phenols have carcinogenic activity. The Estonian shale oils contain up to 40 vol % phenols. The promoting activity after initiation of phenols of Estonian shale oils was tested in mice with a single subthreshold dose (0.36 mg) of benzo(a)pyrene. C57Bl and CC57Br mice were used in skin painting experiments. Weak carcinogenic activity was found in the total crude water-soluble phenols recovered from the wastewater of a shale processing plant. In two-stage experiments a clear promoting action of the total crude phenols was established, whereas the fractions A and B (training reagents), obtained by selective crystallization of the total phenols exerted a considerably weaker promoting action. Epo-glue, a commercial epoxy product produced from unfractionated crude phenols, had no promoting activity, which may be due to the processing of the phenols involving polymerization. The mechanism of action of phenols is not clear. According to some data from the literature, phenol and 5-methylresorcinol reduce the resorption speed of BP in mouse skin, causing prolongation of the action fo the carcinogen.

Animals↗
PubMed2026

Nutrikinetics and bioavailability of Promunel®, a standardized poplar-type propolis phenolic extract: a double-blinded, placebo-controlled, cross-over, randomized trial.

Brown poplar-type propolis has been recognized and used for centuries to help prevent upper respiratory tract infections (URTIs). However, the scarce, incomplete information in humans on the nutrikinetics and bioavailability of its phenolic constituents, combined with a lack of standardization in its phenolic content and profile pose major challenges to develop bioactive ingredients. Thus, the aim of this study was to establish the nutrikinetics and total bioavailability (NKBA) parameters of brown poplar-type propolis phenolics in humans using the Standardized Propolis Extract (SPE) Promunel®. To achieve this, a 48 h NBKA study was conducted following a double blinded, randomized, placebo-controlled, cross-over design in healthy humans (n = 10) with two doses of SPE (1X = 400 mg or 4X = 1600 mg). Phenolic compounds were detected, identified and quantified in the extract, plasma and urine through different LC-MS/UV technologies. The SPE used is a rich (304.44 ± 15.61 µmol mg-1) and diverse source of phenolic compounds (5 sub-families). A total of 63 and 85 phenolic metabolites were identified and quantified in plasma and urine, mostly in the form of glucuronides and sulfates. In plasma, phenolic metabolites reached Cmax (1.22 ± 0.20 for 1X and 4.80 ± 0.48 µM for 4X) after 1 h of SPE intake, while urinary excretion occurred mostly during the first 3 h after. The total net bioavailability of SPE phenolic compounds at 48 h was 57.16 ± 5.71% for 1X and 43.82 ± 6.77% for 4X. Generally, the data between SPE 1X and 4X were proportional, indicating that a higher dose does not substantially modulate total net bioavailability. Overall, our data shows that brown poplar-type SPE phenolic compounds are highly bioavailable in the form of cinnamic acid and flavonoid conjugates, and that these compounds are rapidly absorbed and eliminated through the urine. Our results suggest that, for a sustained presence in circulation, brown poplar-type propolis supplements should be consumed more than once a day.

Humans↗
PubMed1978

Design of a specific oxidant for phenols.

Selective ortho-substitution of phenols can be secured, in principle, by attachment of the substituting reagent to the phenolic hydroxy group and subsequent rearrangement of this derivative by a cyclic mechanism into the orthoposition. So far, only one example of this principle (the Claisen rearrangement) is well established. For ortho-hydroxylation, a phenolic ester of selenium(IV) should have the desired properties. Diphenylseleninic anhydride, PhSE(=0)0.Sec(=0)Ph, has proved has proved to be the new reagent for the application of this mechanism. Several phenols, including models of the phenolic ring A of tetracycline, gave o-hydroxydienones, with quinones and phenylselenated species as by-products, when treated with diphenylseleninic anhydride. When the phenols were converted into their corresponding anions before treatment with the anhydridide, the o-hydroxydienones were obtained in good yield free from other products arising from reaction at the para position. When phenols were added to a warm solution of diphenylseleninic anhydride, they were oxidized to the o-quinones even when the phenols were not substituted in para position.

Anhydrides↗
PubMed1978

Pyridine interactions with phenolic groups in water: evidence for hydrogen bonding and hydrophobic association.

Pyridine interactions with phenol, substituted phenol, tyrosine and poly(Glu50,Tyr50) in aqueous solutions have been studied by ultraviolet (UV) difference spectroscopy, spectrophotometric pH titration, circular dichroism (CD) and proton magnetic resonance (PMR) spectroscopy. A red shift and spectral sharpening of the near-UV spectrum of phenol in water was noted at pyridine concentrations greater than 0.25 M. In addition, the spectrophotometric equivalence point for the phenol- or substituted phenol-phenolate equilibrium was increased about 0.5 pH units upon the addition of 1.0 M pyridine. PMR studies were consistent with the formation of a 1 : 1 phenol-pyridine hydrogen bonded complex. The equilibrium constant derived for this interaction, 0.6-0.7 M-1, is greater than the corresponding value for phenol-acetate hydrogen bonding in water. Enhancement of thepyridine hydrogen bond interaction with Tyr within poly(Glu50,Tyr50) was observed at pH greater than 12 due to a hydrophobic microenvironment produced by pyridine molecules intercalating between neighboring tyrosyl residues.

Circular Dichroism↗
PubMed2026

QTLs associated with phenolic acid accumulation and antioxidant activity in tropical maize.

Maize represents a significant source of phytochemicals, with phenolic acids standing out as one of the most extensively studied functional compound families. These bioactive molecules have gained attention for their potent antioxidant properties and potential contributions to human health improvement. To evaluate the segregation of phenolic compounds in maize and its genetic basis, this study was conducted to identify quantitative trait loci (QTLs) associated with major phenolic compounds and their antioxidant capacity. The mapping population comprised 100 recombinant inbred lines (RILs) derived from the cross between P84 and Kilima. Twelve traits were analyzed: free and cell wall-bound antioxidant capacity, total phenolic content, and contents of p-coumaric acid, ferulic acid, three isomers of di-ferulic acid, and three isomers of tri-ferulic acid. The RILs exhibited substantial diversity in phenolic compound profiles. In total, 19 QTLs were identified for nine traits, with the number of associated regions ranging from 1 to 5 and explaining between 2.95% and 37.48% of the phenotypic variation. This research provides substantial evidence for the co-localization of major QTLs for principal phenolic acids in maize with genomic regions harboring genes putatively related to their biosynthesis and biotic resistance. This is the first study to report QTLs associated with triferulic acids in maize. The identified regions co-localizing with biotic stress resistance genes represent targets for marker-assisted selection toward the improvement of phenolic acid accumulation in maize breeding programs.

QTLs↗
PubMed1978

[The influence on efficacy of formaldehyd and phenol against bacterial cells I. Effect of drying, cations and pH-value (author's transl)].

1. When cells of E. coli and Staph. aureus are dried, the efficacy of phenol is reduced but the efficacy of formaldehyde is increased. 2. A change of the aw-value by addition of salts changes the efficacy of formaldehyde as well as that of phenol. For these tests the chlorides of various alkali and alkaline earth metals were used in different concentrations. 3. The optimal efficacy of phenol and formaldehyde within the tested concentration gradientis caused by different concentrations of the ions: In low concentrations the efficacy of formaldehyde is optimally increased, the efficacy of phenol, however, attains a minimum at this concentration range. By higher concentrations of ions the efficacy of phenol is increased, that of formaldehyde is reduced. 4. The position of the cations in the periodic system also plays a role in the influence on the efficacy of the phenol and formaldehyde respectively. The cations of the lower periods from the main groups I and II favour the damage to the cells by phenol, the cations of the higher periods favour the damage by formaldehyde.

Bacteria↗
PubMedDate not supplied

[Volatile phenolic compounds in white wines].

By gas-liquid chromatography the following volatile phenols were identified in extracts and distillates of white table wines prepared with the aid of husks and pulp used in fermentation: phenol, m-cresol, guaicol, ethyl-4-phenol, vinyl-4-phenol, eugenol, tyrosol; phenol, m-cresol, guaicol, ethyl-4-phenol, vinyl-4-phenol. The amount of volatile oils grew significantly with an increase in the number of husks in the fermenting liquid and fermentation temperature.

Chromatography, Gas↗
PubMed1976

Comparison of uptake and binding of disodium cromoglycate and phenol red in rat lung.

In rat lung slices 3H-disodium cromoglycate (3H-DSCG) (0.001 mM) was taken up rapidly and 3H-DSCG tissue spaces, which equilibrated by 30 minutes, remained constant over a 4-hour incubation period. In contrast, 35S-phenol red (0.001 mM) accumulated in lung slices to a much greater extent than did DSCG, and the measured tissue spaces continued to increase over a 3-hour incubation period. In the presence of either phenol red (1 mM) or the metabolic inhibitors, iodoacetic acid (10(-4) M) and dinitrophenol (10(-4) M), 3H-DSCG uptake was significantly decreased. Accumulation of 3H-DSCG in lung slices and binding to tissue homogenates (pH 7.4) was also decreased when Ca and Mg ions were omitted from the bathing solution. Although DSCG and phenol red mutually inhibited the accumulation of one another over time in lung slices and 3H-DSCG (0.001 mM) binding to lung homogenates was decreased in the presence of 1 mM phenol red, 35S-phenol red efflux was not altered by the addition of 1 mM DSCG during the washout. Thus, it appears that, in rat lung, DSCG and phenol red share a common binding site(s) for uptake, possible on the transport "carrier." Also, there appear to be additional pulmonary binding sites for phenol red. These sites are not occupied by DSCG and their presence could account for the differences observed in the extent of accumulation of the two compounds in lung slices.

Animals↗