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PubMed1999

Synthesis of phenoxyacetic acid derivatives as highly potent antagonists of gastrin/cholecystokinin-B receptors. III.

In order to improve the biological characteristics of DA-3934 (5), a novel gastrin/cholecystokinin (CCK)-B receptor antagonist, phenoxyacetic acid derivatives replacing the N-methyl-N-phenylcarbamoylmethyl moiety of 5 with various alkyl chains have been synthesized and their biological activity evaluated. The relationship between the structure of these compounds and their human gastrin receptor binding affinity showed that there should be the optimal size among the various N-alkyl chains. Also a significant increase in the receptor binding affinity was achieved by several compounds. Among those compounds, 2-[3-[3- [N-cyclohexylmethyl-N-[2-(N-methyl- N-phenylcarbamoylmethoxy)phenyl]carbamoylmethyl]ureido]pheny l]acetic acid (22c) and (+/-)-2-[3-[3-[N-[2-(N-methyl-N- phenylcarbamoylmethoxy)phenyl]-N-(3-methylpentyl)carbamoy lmethyl]ureido] phenyl]acetic acid (22h) exhibited high affinity for human gastrin receptors and were also more potent inhibitors in a pentagastrin-induced gastric acid secretion model than the parent compound, 5. The ED50 values of these compounds when administered intraduodenally to rats were 0.12 and 0.63 mg/kg, respectively.

Acetates↗
PubMedDate not supplied

Phenoxyacetic acid herbicides and chlorophenols and the etiology of lymphoma and soft-tissue neoplasms.

The phenoxyacetic acid herbicides and the chlorophenols are compounds of economic importance. The herbicide 2,4-D is widely used in agriculture, industry, and the home. Recently, concern has arisen over their safety as a result of studies linking these compounds with soft-tissue sarcomas and non-Hodgkin's lymphomas. We reviewed the available literature in order to advise a provincial government regulatory body and investigated methodologic issues by examining the pattern of reported cases in Alberta. We conclude that, taking into account the serious limitations on methodology in the available data, the evidence for a causal association is strongest for non-Hodgkin's lymphomas and probably reflects either a weak effect or, possibly, a confounding exposure associated with the use of 2,4-D. Given the worst-case assumptions, however, the potency of 2,4-D as a carcinogen is probably weak. Its intrinsic toxicity is less than that of alternative herbicides and the hazard posed by its use is probably much less than either the use of chemical alternatives or manual cleaning of vegetation, which carry a high risk of occupational injuries.

Chlorophenols↗
PubMedDate not supplied

[The specific effects of new phenoxyacetic acid derivatives at the cellular membrane level].

Substances ASFA-2 and ASFA-4, new derivatives of phenoxyacetic acid, induce, in normal conditions, the hyperpolarization of the striated muscle fibre membrane, inhibition the depolarization due to the absence of external Ca2+, the restoration of membrane potential of the liver cells poisoned with ally alcohol and the change of redox potential of the environment. It results that these substances have important pharmacological properties--influence upon the membrane potential and cellular excitability, membrane stabilization, redox modulation and hepatic protection--that can be useful in therapy.

1-Propanol↗
PubMed1979

Hydrophobic binding of phenoxyacetic and phenylacetic acids to horseradish peroxidase and human serum albumin: structure-activity relationships.

Studies of protein binding in homologous series of drugs are of great interest for drug research. Apparent binding constants of phenoxyacetic and phenylacetic acids to horseradish peroxidase and to human serum albumin are evaluated by NMR studies and an optical method. These constants are good parameters to describe hydrophobic interactions, and the results are in a good agreement with our protein binding model described previously.

Chemical Phenomena↗
PubMed1979

Prenatal effects of 2,4,5-T, 2,4,5-trichlorophenol, and phenoxyacetic acid in mice.

The herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and two structurally related compounds, phenoxyacetic acid and 2,4,5-trichlorophenol, were suspended in a 1:1 solution of honey:water and administered by gavage to pregnant mice on one of gestation days 8-15 (copulation plug day = day 1) or on three consecutive days (7-9, 10-12, or 13-15). Doses were 800-900 mg/kg for single and 250-300 mg/kg/day for multiple treatments. With the exception of 2,4,5-trichlorophenol treatment on day 14, only 2,4,5-T treatment significantly increased prenatal mortality, and only 2,4,5-T was associated with decreased fetal weight when comparisons were made with the solvent controls. Although low incidences were seen in all treatment groups, only 2,4,5-T significantly increased cleft palate or other gross malformations. Significant skeletal, visceral or histopathological defects were not observed. These results indicate that both the carboxyl group and chlorination of the aromatic ring are essential for an unambiguous teratogenic response.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1982

Quantitative structure-activity studies. 2nd Communication: De novo calculations on antilipemic activity of 4-(4-chlorobenzyl)phenoxyacetic acid esters.

Quantitative structure-activity studies are carried out on antilipemic activity of 4-(4-chlorobenzyl)phenoxyacetic acid esters (1). Fujita-Ban group contributions are calculated for a variety of substituents. It is observed that when R1 is pyrid-3-ylmethyl, it has maximum contribution to activity and minimum toxic effects expressed in terms of liver growth. It is further noted that alkyl group substitution at position alpha to the carboxylic group leads to higher toxicities.

Animals↗
PubMedDate not supplied

[Cytogenetic study of the mutagenic properties of the repellents dimethyl phthalate and phenoxyacetic acid N,N-diethylamide].

Animal experiments ascertained that the repellent N,N-diethylamide of phenoxyacetic acid (P-203) increases the frequency of chromosomal aberration in the bone marrow cells of mice following its intraperitoneal introduction and also in the cells of a regenerating liver of rats after its repeated skin application. Dimethylphthalate displayed a mutagenic action only with respect to the rats' hepatocytes when applied repeatedly to the skin.

Administration, Topical↗
PubMed1999

Genotoxicity studies on the phenoxyacetates 2,4-D and 4-CPA in the Drosophila wing spot test.

The phenoxyacetates 2,4-D and 4-CPA were evaluated for genotoxicity using the Drosophila melanogaster wing spot test, which assesses for somatic mutation and recombination events. Third-instar larvae trans-heterozygous for two recessive mutations affecting the expression of wing trichomes, multiple wing hairs (mwh), and flare (flr) were treated by chronic feeding with different concentrations of the two chemicals. Feeding lasted until pupation of the surviving larvae and the genotoxic effects induced were evaluated in adults for the appearance of wing-blade cell clones with the mwh, flr, or mwh-flr phenotypes. Exposure to 2,4-D, at the highest concentration evaluated (10 mM), induced a weak but significant increase in the frequency of two of the categories of recorded spots: large single and total spots; in contrast, the 4-CPA treatments failed to induce any significant increase in the frequency of evaluated spots. When the heterozygous larvae for mwh and the multiple inverted TM3 balancer chromosome were treated with the chemicals, no increases were detected, either after the 2,4-D nor the 4-CPA treatments.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2001

Penicillin productivity and glutathione-dependent detoxification of phenylacetic and phenoxyacetic acids in Penicillium chrysogenum.

Both toxicity and penicillin productivity of the hydroxylated derivatives of phenylacetic acid (PA) and phenoxyacetic acid (POA) were highly dependent on the position of hydroxylation on the aromatic ring in Penicillium chrysogenum. Hydroxylation at position 2 diminished penicillin production but the compounds retained most of their toxicity. On the other hand, hydroxylation at position 4 resulted in barely toxic derivatives with still significant penicillin productivity. 3-Hydroxy-PA was a weak side-chain precursor with considerably reduced toxicity. The activity of the glutathione-dependent detoxification pathway correlated well with the toxicity of the compounds but there was no correlation between acidity, toxicity and penicillin productivity.

Acetates↗
PubMedDate not supplied

Allergenicity testing of supermethrin, phenoxyacetic acid and DNCB using in vivo and in vitro modifications of the local lymph node assays, maximization and epicutaneous testing.

The purpose of this study was to compare two methods of testing for allergenicity: in vivo and in vitro modifications of local lymph node assays (LLNA) in mice and the maximization and epicutaneous skin tests in guinea pigs as per the Organization for Economic Cooperation and Development (1981). Two pesticides-the synthetic pyrethroid insecticide supermethrin (SM) and the herbicide phenoxyacetic acid (PAA)-were evaluated using this testing battery. 1-Chloro-2,4-dinitrobenzene (DNCB) was selected as a reference allergen for the local lymph node assay. In vitro modification of LLNA proliferative response per standard cell count in lymphocyte cultures derived from treated Balb/c mice did not differ from control mice. Results of the in vivo modification showed that treatment with 50% PAA and 50% SM resulted in a lower proliferation response of lymphocytes in lymph nodes compared with control animals. The vigour of the proliferative response varied more in in vivo modification of LLNA. Stimulation indices were <3, so PAA and SM did not indicate classification as allergens. Lymphocyte proliferation in 1% DNCB-activated lymph nodes was approximately fivefold higher than in those derived from control mice. Proliferation response in vitro calculated as stimulation index was higher in DNCB-treated mice than those observed in vivo, but differences were not dramatic. Auricular lymph node weight and cellularity in mice treated with PAA and SM were similar to controls. The DNCB stimulation index for lymph node cellularity was 5.5. Lymph node weight was three times higher in comparison with controls. In the maximization test in guinea pigs SM and PAA acid resulted in 40% and 50% of animals demonstrating sensitization, respectively. Epicutaneous administration resulted in weaker reaction. Both SM and PAA are mildly strong sensitizers by this battery.

Acetates↗
PubMed1996

Erythroid progenitor proliferation is stimulated by phenoxyacetic and phenylalkyl acids.

Short-chain fatty acids, such as butyrate and propionate, are under investigation as therapeutic stimulants of fetal hemoglobin production in the beta-hemoglobin disorders. Significant limitations to these fatty acids and derivatives as optimal therapeutics are their rapid metabolism in vivo and their induction of cell growth arrest in the G1 phase of the cell cycle. This antiproliferative activity is related to their inhibition of metabolic transport pumps which are essential for cell proliferation. Other small carbon compounds, the phenylalkyl acids, phenoxyacetic acids, and phenylacetic acids, which are structurally resistant to oxidative metabolism, are shown here to induce fetal globin production in human erythroid cultures at concentrations of 0.2 mM, lower than those required for most other fatty acids. Certain of these compounds were found not to inhibit cellular neutral amino acid transport function in erythroid cells, nor to inhibit erythroid colony (Bfu-e) growth. Certain of these compounds even stimulated human Bfu-e proliferation in vitro beyond that induced by optimal concentrations of hematopoietic growth factors. The combination of increased fetal globin chain production by these compounds and their stimulatory effects on erythropoiesis result in an increase in Hb F-expressing erythroid cells in culture several-fold greater than that achieved by the butyrates. These new compounds thus have the potential to provide superior therapy for the beta-hemoglobinopathies and other anemias.

Biological Transport↗
PubMed1981

Chlorinated phenoxyacetic acids and chlorophenols in the modified Allium test.

The chlorinated phenoxyacetic acids 2-methyl-4-chlorophenoxyacetic acid (MCPA), 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and 2,4,5-T butoxyethyl ester and the chlorophenols 2,4-dichlorophenol and 2,4,5-trichlorophenol were tested for genotoxicity in the modified Allium test, which is based on exposure to the test chemicals of growing onions. The mean length of growing roots were measured and chromosome damage was recorded. Of the substances tested, MCPA was the most toxic and the chlorophenoxyacetic acids were more toxic than the chlorophenols. The lower threshold values for growth retardation were below 0.1 ppm for the acids, approx. at 0.1 ppm for the ester and less than 5 ppm for the phenols. Though a monocotyledon, Allium cepa was sensitive enough to respond to even low concentrations of these dicotyledon-selecting pesticides.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed2005

Liquid-liquid-liquid microextraction with automated movement of the acceptor and the donor phase for the extraction of phenoxyacetic acids prior to liquid chromatography detection.

A simple liquid-liquid-liquid microextraction with automated movement of the acceptor and the donor phase (LLLME/AMADP) technique is described for the quantitative determination of five phenoxyacetic acids in water using a disposable and ready to use hollow fiber. The target compounds were extracted from the acidified sample solution (donor phase) into the organic solvent residing in the pores of the hollow fiber and then back extracted into the alkaline solution (acceptor phase) inside the lumen of the hollow fiber. The fiber was held by a conventional 10-microl syringe. The acceptor phase was sandwiched between the plunger and a small volume of the organic solvent (microcap). The acceptor solution was repeatedly moved in and out of the hollow fiber assisted by a programmable syringe pump. This repeated movement provides a fresh acceptor phase to come in-contact with the organic phase and thus enhancing extraction kinetics leading to high enrichment of the analytes. The microcap separates the aqueous acceptor phase and the donor phase in addition of being partially responsible for mass transfer of the analytes from donor solution (moving in and out of the hollow fiber from the open end of the fiber) to the acceptor solution. Separation and quantitative analyses were then performed using liquid chromatography (LC) with ultraviolet (UV) detection at 280 nm. Various parameters affecting the extraction efficiency viz. type of organic solvent used for immobilization in the pores of the hollow fiber, extraction time, stirring speed, effect of sodium chloride, and concentration of donor and acceptor phases were studied. Repeatability (RSD, 3.2-7.4%), correlation coefficient (0.996-0.999), detection limit (0.2-2.8 ng ml(-1)) and enrichment factors (129-240) were also investigated. Relative recovery (87-101%) and absolute recoveries (4.6-13%) have also been calculated. The developed method was applied for the analysis of river water.

Acetates↗
PubMed2006

Substituent and solvent effects on electronic spectra of some substituted phenoxyacetic acids.

The effects of substituents and solvents have been studied through the absorption spectra of nearly 19 para- and ortho-substituted phenoxyacetic acids in the range of 200-400 nm. The effects of substituent on the absorption spectra of compounds under present investigation are interpreted by correlation of absorption frequencies with simple and extended Hammett equations. Effect of solvent polarity and hydrogen bonding on the absorption spectra are interpreted by means of Kamlet equation and the results are discussed.

Absorption↗
PubMed2000

Phenoxyacetic acid residue incorporation in cell walls of soybean (Glycine max.).

The metabolism of [(14)C] phenoxyacetic acid (POA) and the formation of bound residues were studied in soybean leaves and stems. POA was metabolized to 4-HO-POA and to 4-HO-POA glucoside, and a significant fraction of the radioactivity was incorporated in the cell walls (CW). An extraction procedure of CW polymers was developed to specifically isolate the radioactivity associated with each of them. In leaves, the radioactivity showed a preferential distribution into the hemicelluloses and lignins, while pectins and lignins were the most radioactive CW polymers in stems. The identified bound metabolites were 4-HO-POA, POA, and phenolic residues. The latter and POA were essentially incorporated into the lignin fractions and were linked to the benzylic carbons of lignin monomers. 4-HO-POA, the major bound residue, was more evenly distributed in CW polymers. It was esterified to noncellulosic polysaccharides and lignins, but in the latter, contrary to other POA residues, it was mainly linked at the gamma-carbon of propanoid side-chains of lignin monomers. That type of linkage suggested an enzymatic incorporation of 4-HO-POA in CW, contrary to others residues which have an opportunistic lignin incorporation. That incorporation of 4-HO-POA in CW polymers looks like that of endogenous hydroxycinnamic acids.

Acetates↗
PubMed2005

Phenoxyacetic acid herbicide exposure for women on Ontario farms.

Women living and working on farms would be expected to have higher exposure to pesticides than the general nonoccupationally exposed population. Urinary concentrations of the herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and (4-chloro-2-methyl) phenoxyacetic acid (MCPA) were measured in 125 women living on farms in Ontario where these herbicides had recently been used for the first time that growing season. The women collected a spot urine void prior to the start of herbicide handling by spouses, followed by 2 consecutive 24-h urine samples. The pesticide applicator provided questionnaire data on pesticides that were used on the farm. Approximately 80% of the women had no detectable level of either herbicide in their urine. Geometric mean urinary concentrations of 2,4-D and MCPA in the d-2 samples were 0.7 microg/L. The responses to the questions on herbicide use on the farm were compared with urinary levels of the herbicide and the sensitivity for MCPA was determined to be 95-100%; however, the false positive rate for exposure was 70%. For 2,4-D, the sensitivity and specificity were approximately 70%, with a false positive rate of 30%. A simple question on whether the herbicide was used recently can accurately identify people who are likely not exposed; however, further research is required to be able to more validly predict those individuals who are exposed. Based on our study, it was concluded that exposure estimates based on questionnaire data alone may be fraught with uncertainties, which may differ depending on the particular pesticide of interest.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2001

Sodium phenoxyacetate hemihydrate.

The structure of the hemihydrate of sodium phenoxyacetate, Na(+) x C(8)H(7)O(3)(-) x 0.5H(2)O, has been redetermined at low temperature (160 K). The structure consists of ribbons containing octahedral NaO(6) units, and half of the Na(2)O(2) squares within the ribbon are bridged by water molecules which lie across twofold rotation axes in C2/c. The phenyl substituents lie on the outside of the ribbon.

Journal Article↗
PubMed1991

4-[2-(o-carboxybenzamido)ethyl]phenoxyacetic acid dihydrate.

C18H17NO6.2H2O, Mr = 379.386, monoclinic, P21/c, a = 7.161 (5), b = 12.997 (2), c = 20.290 (3) A, beta = 99.22 (2) degrees, V = 1861.4 A3, Z = 4, Dx = 1.354 g cm-3, Cu K alpha radiation, lambda = 1.5418 A, mu = 9.2 cm-1, F(000) = 800, T = 293 K, final R(F) = 0.051 for 2262 observed reflections. The structure was solved by direct methods and compared to the previously determined structure of the analogous drug molecule, bezafibrate. The structural characteristics of the two compounds are then correlated to their relative activities as allosteric effectors of hemoglobin. The molecule adopts a synplanar-antiplanar conformation unlike other phenoxyacetic acids.

Bezafibrate↗