Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.15.1 (ACE)
 18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The influence of halogenated antibacterials on membrane structure and function was investigated using the human erythrocyte membrane as a model. Measurements of hemolysis in isotonic solution, altered membrane permeability, and stabilization against hypotonic hemolysis resulting from exposure of erythrocytes to halogenated antibacterials served as criteria of membrane-related effects. The hemolytic potency of the compounds studied differed widely, decreasing in the order hexachlorophene (HCP) greater than 2,2'-methylenebis(3,5-dichlorophenol) (3,5-TCP) greater than 2,2'-methylenebis(3,4-dichlorophenol) (3,4-TCP) approximately equal to 2,2'-methylenebis(4,6-dichlorophenol) (4,6-TCP) greater than 2,2'-methylenebis(4-chlorophenol) (DCP) greater than 3,4'-tribromosalicylanilide (TBS) approximately equal to 3,3',4',5-tetrachlorosalicylanilide (TCSA). Each of the antibacterials tested stabilized the erythrocyte against hypotonic hemolysis, although there were marked differences in the concentrations required to afford maximum stabilization as well as in the extent of protection. The observed order of protective effectiveness was HCP greater than 3,4-TCP greater than 4,6-TCP greater than DCP approximately equal to TCS greater than TBS. As shown by measurements of the first-order rate constant for K+ efflux, the permeability of the erythrocyte membrane to K+ was increased upon exposure to the antibacterials, with the effect of HCP greater than 3,4-TCP greater than 4,6-TCP approximately equal to 3,4-TCP greater than DCP approximately equal to TCS greater than TBS. These results indicate that halogenated antibacterials are capable of perturbing mammalian membranes, a feature which may account in part for their mammalian toxicity.
 ...
PMID:Effects of halogenated antibacterials on the erythrocyte membrane. 69 71

The 2-(2,4-dichlorphenoxy)propionic acid (2,4-DP)-degrading bacterial strain MH was isolated after numerous subcultivations of a mixed culture obtained by soil-column enrichment and finally identified as Flavobacterium sp. Growth of this strain was supported by 2,4-DP (maximum specific growth rate 0.2 h-1) as well as by 2,4-dichlorophenoxyacetic acid (2,4-D), 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB), and 2-(4-chloro-2-methylphenoxy)propionic acid (MCPP) as sole sources of carbon and energy under aerobic conditions. 2,4-DP-Grown cells (10(8] of strain MH degraded 2,4-dichlorophenoxyalkanoic acids, 2,4-dichlorophenol (2,4-DCP), and 4-chlorophenol at rates in the range of 30 nmol/h. Preliminary investigations indicate that cleavage of 2,4-DP results in 2,4-DCP, which is further mineralized via ortho-hydroxylation and ortho-cleavage of the resulting 3,5-dichlorocatechol.
 ...
PMID:Isolation and characterization of a 2-(2,4-dichlorophenoxy) propionic acid-degrading soil bacterium. 136 57

2,4-Dichlorophenol (2,4-DCP) was anaerobically degraded in freshwater lake sediments. From observed intermediates in incubated sediment samples and from enrichment cultures, the following sequence of transformations was postulated. 2,4-DCP is dechlorinated to 4-chlorophenol (4-CP), 4-CP is dechlorinated to phenol, phenol is carboxylated to benzoate, and benzoate is degraded via acetate to methane and CO2; at least five different organisms are involved sequentially. The rate-limiting step was the transformation of 4-CP to phenol. Sediment-free enrichment cultures were obtained which catalyzed only the dechlorination of 2,4-DCP, the carboxylation of phenol, and the degradation of benzoate, respectively. Whereas the dechlorination of 2,4-DCP was not inhibited by H2, the dechlorination of 4-CP, and the transformation of phenol and benzoate were. Low concentrations of 4-CP inhibited phenol and benzoate degradation. Transformation rates and maximum concentrations allowing degradation were determined in both freshly collected sediments and in adapted samples: at 31 degrees C, which was the optimal temperature for the dechlorination, the average adaptation time for 2,4-DCP, 4-CP, phenol, and benzoate transformations were 7, 37, 11 and 2 days, respectively. The maximal observed transformation rates for these compounds in acclimated sediments were 300, 78, 2, 130, and 2,080 micromol/liter(-1)/day(-1), respectively. The highest concentrations which still allowed the transformation of the compound in acclimated sediments were 3.1 m/M 2,4-DCP, 3.1 mM 4-CP, 13 mM phenol, and greater than 52 mM benzoate. The corresponding values were lower for sediments which had not been adapted for the transformation steps.
 ...
PMID:Sequential anaerobic degradation of 2,4-dichlorophenol in freshwater sediments. 211 Nov 12

Anaerobic degradation of 2,4-dichlorophenol (2,4-DCP) between 5 and 72 degrees C was investigated. Anaerobic sediment slurries prepared from local freshwater pond sediments were partitioned into anaerobic tubes or serum vials, which then were incubated separately at the various temperatures. Reductive 2,4-DCP dechlorination occurred only in the temperature range between 5 and 50 degrees C, although methane was formed up to 60 degrees C. In sediment samples from two sites and at all tested temperatures from 5 to 50 degrees C, 2,4-DCP was transformed to 4-chlorophenol (4-CP). The 4-CP intermediate was subsequently degraded after an extended lag period in the temperature range from 15 to 40 degrees C. Adaptation periods for 2,4-DCP transformation decreased between 5 and 25 degrees C, were essentially constant between 25 and 35 degrees C, and increased in the tubes incubated at temperatures between 35 and 40 degrees C. The degradation rates increased exponentially between 15 and 30 degrees C, had a second peak at 35 degrees C, and decreased to about 5% of the peak activity by 40 degrees C. In tubes from one sediment sample, incubated at temperatures above 40 degrees C, an increase in the degradation rate was observed following the minimum at 40 degrees C. This suggests that at least two different organisms were involved in the transformation of 2,4-DCP to 4-CP. Storage of the original sediment slurries for 2 months at 12 degrees C resulted in increased adaptation times, but did not affect the degradation rates.
 ...
PMID:Anaerobic biodegradation of 2,4-dichlorophenol in freshwater lake sediments at different temperatures. 271 77

Chlorinated bisphenol antibacterial and antifungal agents are potent inhibitors of torula yeast glucose-6-phosphate dehydrogenase (G6PD). Several compounds were tested, including hexachlorophene [HCP; 2,2'-methylenebis(3,4,6-trichlorophenol)]; 2,2'-oxybis(tetrachlorophenol); 2',4-dihydroxy-2,3,3',5,5',6-hexachlorodiphenylmethane; 2,2'-methylenebis(3,4-dichlorophenol) (3,4-TCP); bithionol [2,2'-thiobis(4,6-dichlorophenol)]; 2,2'-methylenebis(3,5-dichlorophenol); 2,2'-dihydroxy-3,3',5,6,6'-pentachlorodiphenylmethane; 2,2'-methylenebis(4-chlorophenol) (DCP); 2,2'-methylenebis(4,6-dichlorophenol); and the related uncoupler 2,4-dinitrophenol. The relative inhibitory activity of the chlorinated bisphenols tended to increase with degree of chlorination of the aromatic rings. the concentrations of the bisphenols that caused 50% inhibition ranged from 2.5 micrometers for 2,2'-oxybis(tetrachlorophenol) to 40 micrometers for 2,2'-methylenebis(4,6-dichlorophenol) under comparable assay conditions. More detailed kinetic analysis showed that, as with HCP, the inhibition of G6PD by 3,4-TCP and DCP followed noncompetitive kinetics. Calculations from the kinetic data gave apparent inhibition constant (Ki) values for 3,4-TCP of 267 micrometers with G6P and 308 micrometers with NADP, and for DCP of 697 micrometers with both G6P and NADP.
 ...
PMID:Effects of chlorinated bisphenols on torula yeast glucose-6-phosphate dehydrogenase. 680 84

The degradation of 2,4-Dichlorophenol (from now on 2,4-DCP) has been carried out on Nafion-Fe (1.78%) in the presence of H2O2 under visible light irradiation. A solution containing 2,4-DCP (TOC 72 mg C/L)) is seen to be mineralized in approximately 1 h in the presence of H2O2 (10 mM) under solar simulated visible light (80 mW cm-2) at pH values between 2.8 and 11. Homogeneous photo-assisted Fenton reactions were capable of mediating 2,4-DCP degradation only up to pH 5.4. The degradation kinetics of 2,4-DCP on Nafion-Fe membranes was more favorable than the one observed during Fenton photo-assisted processes at pH 2.8. The degradation of 2,4-DCP was investigated as a function of the substrate, oxidant concentration and applied light intensity. The Nafion-Fe was seen to be effective over many cycles during the photo-catalytic degradation of 2,4-DCP showing an efficient and stable performance during 2,4-DCP degradation without leaching out Fe(3+)-ions into the solution. Evidence is presented that the degradation at the surface of the Nafion-Fe membrane seems to be controlled by mass transfer and not by chemical reaction of the species in solution. The approach used to degrade 2,4-DCP is shown to be valid for other chloro-carbons like 4-chlorophenol, 2,3-chlorophenol and 2,4,5-trichlorophenol.
 ...
PMID:Degradation of 2,4-dichlorophenol by immobilized iron catalysts. 1133 46

Uncatalyzed, and palladium-catalyzed Fe(0) and Mg(0) systems were examined for their efficiencies of dechlorination of 2.86 mM 4-chlorophenol (4-CP), 2.52 mM 2,6-dichlorophenol (2,6-DCP), 3.03 mM 2,4,6-trichlorophenol (2,4,6-TCP), and 2.48 mM pentachlorophenol (PCP) in 50/50 (v/v) 2-propanol/water under room temperature and pressure conditions. Previous investigators have found that PCP is extremely recalcitrant under these conditions. In this investigation, complete dechlorination of 5.0 ml of 2.48 mM PCP was observed for 1.0 g of 2659 ppm Pd/Mg (20 mesh) after 48 h. The only detectable products were cyclohexanol and cyclohexanone at 25% yield. No other chlorinated or otherwise products were observed by mass spectral analysis. It is hypothesized that volatile low molecular weight species were formed from the Pd/Mg dechlorination of PCP. Under conditions of equal surface area (0.0786 m2), the approximate order of PCP dechlorination power of these systems followed as 2659 ppm Pd/Mg>319 ppm Pd/Mg>Mg approximately 4856 ppm Pd/Fe>Fe. Degradation of the other chlorinated phenols by all metallic systems was more facile than PCP.
 ...
PMID:Dechlorination of chlorinated phenols by catalyzed and uncatalyzed Fe(0) and Mg(0) particles. 1177 95

In this paper we studied the sorption capacity of paper mill sludges for phenols. Phenol, 2-chlorophenol (2-CP), 3-chlorophenol 3-CP). 4-chlorophenol (4-CP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), 2.4-dichlorophenol (2,4-DCP), 3,4-dichlorophenol (3,4-DCP) 3,5-dichlorophenol (3,5-DCP) and 2,4,5-trichlorophenol (2,4,5-TCP) were chosen for the sorption tests. Kinetic experiments showed that substituted-phenol sorption on papermill sludge was rapid (equilibrium was reached after 3 h); conversely, the time taken by the phenol to reach equilibrium conditions was 260 h. Experimental data showed that particle diffusion was involved in the sorption process but was not the only rate-limiting mechanism; several other mechanisms were involved. The adsorption isotherms showed the following order of retention capacity of papermill sludge: 2-NP = 4-NP < < 2-CP < phenol < 4-CP < or = 3-CP < 2,4 DCP<3,4 DCP=2,4,5 TCP<3,5 DCP. In all cases the experimental data showed a good fit with the Hill equation. which is mathemratically equivalent to the Langmuir-Freundlich model obtained by assuming that the surface is homogeneous, and that the adsorption is a cooperative process influenced by adsorbate-adsorbate interactions.
 ...
PMID:Adsorption of phenols by papermill sludges. 1200 28

The effects of 2,4-dichlorophenol (2,4-DCP) on both acclimated and unacclimated activated sludge were investigated in batch reactors. The IC(50) values on the basis of maximum specific growth rate ( micro(m)), percent chemical oxygen demand (COD) removal efficiency and sludge activity were found to be 72, 60 and 47 mg l(-1), respectively, for unacclimated culture. The percent COD removal efficiencies of unacclimated culture were affected adversely, even at low concentrations, whereas culture acclimated to 75 mg 2,4-DCP l(-1) could tolerate about 200 mg 2,4-DCP l(-1)on the basis of COD removal efficiency. Although yield coefficient values of unacclimated culture increased surprisingly to very high values with the addition of 2,4-DCP, a linear decrease with respect to 2,4-DCP concentrations was observed for acclimated culture. Although no removal was observed with unacclimated culture, almost complete removal of 2,4-DCP up to a concentration of 148.7 mg l(-1) was observed with acclimated culture. It was showed that the culture could use 2,4-DCP as sole organic carbon source, although higher removal efficiencies in the presence of a readily degradable substrate were observed. Culture acclimated to 4-chlorophenol used 2,4-DCP as sole organic carbon source better than those acclimated to 2,4-DCP.
 ...
PMID:Effects of 2,4-dichlorophenol on activated sludge. 1211 Nov 71

Presence of 2,4-dichlorophenol (2,4-DCP) in extracts of fed and nonfed adult female Dermacentor variabilis (Say) by gas chromatography and mass spectroscopy (GC/MS) is reported. 2,4-DCP was detected as part of a mixture with 2,6-dichlorophenol, which is the attractant sex pheromone in this species in a 1:9 ratio, respectively. Extracts did not contain the monochlorinated phenols, 2-chlorophenol and 4-chlorophenol. None of these chlorophenols were detected in eggs. 2,4-DCP is comparable in efficacy to 2,6-DCP as an attractant sex pheromone, prompting attraction, arrestment and feeding posture behavior by fed males. It is also present in the female adult.
 ...
PMID:Identification of 2,4-dichlorophenol in females of the American dog tick, Dermacentor variabilis (Acari: Ixodidae), and its possible role as a component of the attractant sex pheromone. 1249 99


1 2 3 4 5 6 7 Next >>