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PubMed1994

[Synthesis and antibacterial action of new ureido- and dicarboxylic acid diamido- derivatives of acylpenicillins with and without catechol substituents].

New ureido, oxamoyl, fumaramoyl and terephthalamoyl derivatives of ampicillin or amoxicillin were synthesized by reaction of acylpenicillines with o-dihydroxy- or o-diacyloxy substituents containing aromatic amines bound over CO- or dicarboxylic groups. Corresponding compounds derived from 3,4-diacetoxyaniline showed significant increase of activity against pseudomonas and salmonella in contrast to derivatives without catechol substituents. No increase of activity was observed by corresponding derivatives of bi- and tricyclic amines. Derivatives with oxamoyl, fumaramoyl or terephthalamoyl groups were found to be more active than the corresponding ureido derivatives. Studies with mutants possessing higher membrane permeability have shown that the high activities of catechol containing derivatives are connected with the improved penetration through the outer membrane. Some new penicillin derivatives are more stable against beta-lactamases compared with azlocillin.

Bacteria↗
PubMed1996

Effects of aluminum(III) on catechol-stimulated nerve growth factor biosynthesis by cultured mouse brain astroglial cells.

The effects of aluminum and other metal ions on the synthesis of nerve growth factor (NGF) by cultured mouse brain astroglial cells have been investigated. Natural NGF formation was dependent on the AlCl3 concentration of the cell culture medium; it was stimulated at low concentrations but was inhibited at higher concentrations. Catechol-stimulated NGF formation was also inhibited at AlCl3/catechol molar ratios > 0.3, whereas ZnCl2 and CaCl2 had no effect under similar conditions. Ethylenediamine-N,N,N',N'-tetraacetate (EDTA) and citrate blocked the inhibitory effect of Al(III). These observations were explained by the complex formation between Al(III) and catechols.

Aluminum↗
PubMed1977

The effect of monoamine oxidase and catechol O-methyltransferase inhibitors on the accumulation and metabolism of [l-3H] norepinephrine by the adventitia and media of rabbit aorta.

The effects of catechol O-methyltransferase (COMT) and monoamine oxidase (MAO) inhibitors on the accumulation and metabolism of [l-3H] norepinephrine ([l-3H]NE) were studied in the isolated adventitia and media of rabbit aorta. The COMT inhibitors produced a greater inhibition of O-methylation in the isolated media than in the isolated adventitia. In addition, exposure to these drugs was associated with an increased level of [l-3H]NE and increased formation of the catechol deaminated metabolites by the isolated media but not by the isolated adventitia. The effects of these drugs on the balance of the oxidized vs. reduced forms of the deaminated metabolites was interpreted to mean that 3-methoxy-4-hydroxyphenylethylglycol is formed from normetanephrine rather than from 3,4-dihydroxyphenylethylglycol whereas 3-methoxy-4-hydroxymandelic acid is formed from 3,4-dihydroxymandelic acid. 3,4-Dihydroxyphenylethylglycol does not seem to serve as a substrate for 3-methoxy-4-hydroxyphenylethylglycol becuase it rapidly passes out of the tissue after it is formed. Parglyline and iproniazid markedly decreased deamination of [l-3H]NE and increased the tissue level of [l-3H]NE. However, these drugs produced little if any compensatory increase in O-methylation of [l-3H]NE. The effects of these drugs are compatible with the hypothesis that adrenergic nerves contain MAO and vascular smooth muscle contains MAO and COMT. Harmaline seemed to block both MAO and COMT. Based on the effects of clorgyline and deprenyl and the other MAO inhibitors tested, the isolated adventitia seems to contain primarily type A MAO and the isolated media seems to contain primarily type B MAO.

Animals↗
PubMed1998

Genetic polymorphisms in catechol-O-methyltransferase, menopausal status, and breast cancer risk.

Polymorphic catechol-O-methyltransferase (COMT) catalyzes the O-methylation of estrogen catechols. In a case-control study, we evaluated the association of the low-activity allele (COMT(Met)) with breast cancer risk. Compared to women with COMT(Val/Val), COMT(Met/Met) was associated with an increased risk among premenopausal women [odds ratio (OR), 2.1; confidence interval (CI), 1.4-4.3] but was inversely associated with postmenopausal risk (OR, 0.4; CI, 0.2-0.7). The association of risk with at least one low-activity COMT(Met) allele was strongest among the heaviest premenopausal women (OR, 5.7; CI, 1.1-30.1) and among the leanest postmenopausal women (OR, 0.3; CI, 0.1-0.7), suggesting that COMT, mediated by body mass index, may be playing differential roles in human breast carcinogenesis, dependent upon menopausal status.

Body Mass Index↗
PubMed1976

Potentiation of the effects of topical epinephrine on the pupil and intraocular pressure in the sympathetically denervated rabbit eye by a catechol-O-methyl transferase inhibitor.

Dose-response curves of increase in pupil size and decrease in intraocular pressure with topical epinephrine have been determined in the sympathetically denervated rabbit eye. Topical pretreatment with the catechol-O-methyl transferase inhibitor U-0521 potentiated the effects of epinephrine on both the pupil and pressure. These observations suggest a possible role for catechol-O-methyl transferase in the aqueous humor dynamics of the supersensitive eye. The possible use of the denervated rabbit eye as an experimental model for the glaucomatous eye in evaluating the ocular effects of adrenergic agents is discussed.

Administration, Topical↗
PubMed1983

Microbial transformations of natural antitumor agents XXII: Conversion of bouvardin to O-desmethylbouvardin and bouvardin catechol.

Bouvardin is a cyclic hexapeptide antitumor agent which undergoes two major microbial transformation reactions. Screening with 220 cultures revealed 17 different strains capable of producing O-desmethylbouvardin in good yield. O-Desmethylbouvardin was isolated and characterized from preparative scale incubations with Streptomyces rutgersensis NRRL B-1256. Four aspergilli and one streptomycete formed bouvardin catechol when O-desmethylbouvardin was used as substrate. Bouvardin catechol was isolated and characterized from a preparative scale incubation with Aspergillus ochraceous UI 398.

Antineoplastic Agents, Phytogenic↗
PubMed2003

Metabolism of benzyl alcohol via catechol ortho-pathway in methylnaphthalene-degrading Pseudomonas putida CSV86.

Pseudomonas putida CSV86 metabolizes 1- and 2-methylnaphthalene through distinct catabolic and detoxification pathways. In spite of the similarity in the steps involved in the methylnaphthalene detoxification and the toluene side-chain hydroxylation pathways, the strain failed to utilize toluene or xylenes. However, it could grow on benzyl alcohol, 2- and 4-hydroxybenzyl alcohol. Metabolic studies suggest that the benzyl alcohol metabolism proceeds via the benzaldehyde, benzoate, and catechol ortho-cleavage pathway, in contrast to the well established catechol meta-cleavage pathway. Carbon source-dependent enzyme activity studies suggest that the degradation of aromatic alcohol involves two regulons. Aromatic alcohol induces the upper regulon, which codes for aromatic alcohol- and aromatic aldehyde-dehydrogenase and converts alcohol into acid. The aromatic acid so generated induces the specific lower regulon and is metabolized via either the ortho- or the meta-cleavage pathway. CSV86 cells transform 1- and 2-methylnaphthalene to 1- and 2-hydroxymethyl naphthalene, which are further converted to the respective naphthoic acids due to the basal level expression and broad substrate specificity of the upper regulon enzymes.

Alcohol Oxidoreductases↗
PubMed1999

Catechol(amine)s as probes of lactoperoxidase catalytic site structure: spectroscopic and modeling studies.

Binding affinities to lactoperoxidase (LPO) of a homologous series of substituted catechol(amine)s [such as catechol, 4-methylcatechol, 3,4-dihydroxybenzoic acid, 3,4-dihydroxyphenylacetic acid, 3-(3,4-dihydroxyphenyl)propionic acid; dopamine, noradrenaline, adrenaline; L-3,4-dihydroxyphenylalanine] were studied by UV-visible spectroscopy and docking simulations. Dissociation constant (Kd) values were calculated by direct fitting of the experimental data and fall in a range of 3-95 mM. Thermodynamic parameters are comparable with those reported for the interaction of LPO with p-substituted phenols, suggesting a similar general mode of binding. Furthermore, the relative contributions to binding energy, described by the unimolecular constant Ku, show that interaction between protein and ligands originates from a relatively large number of groups. Docking and molecular dynamics simulations, in agreement with experimental evidence, predict that the substrate is localized into the access channel in the vicinity of heme distal pocket. This channel is characterized by a hydrophobic patch (six Phe residues) and by a charged contribution (two Glu and one His residues). All of the substrates, except caffeic acid, may approach the protein active site. Positively charged Arg372 acts as a gate above the heme distal pocket and seems to address substrate orientation in relation to the side-chain terminal group.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1981

Voltammetry in the striatum of chronic freely moving rats: detection of catechols and ascorbic acid.

Differential pulse voltammetry used in combination with an electrochemically treated carbon fiber electrode allowed to detect ascorbic acid (AA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the striatum of unanaesthetized freely moving rats. Carbon fiber electrodes were implanted under light halothane anaesthesia. When the rat recovered from anaesthesia, voltammograms were recorded every 2.5 min for about 5 h. During the last 3 h the signals corresponding to AA and DOPAC appeared stable and reproducible, allowing comparisons between control and pharmacological experiments. After the in vivo experiments, the electrodes were calibrated in AA and DOPAC solutions. Striatal AA and DOPAC levels were thus estimated to be 306 and 17.7 microM respectively. DOPAC signals were increased by haloperidol and chloral hydrate, decreased by amphetamine and suppressed by pargyline. In pargyline pretreated rats the catechol signal slightly re-appeared after amphetamine injections. This signal was attributed to dopamine (DA) and estimated to a concentration less than 50 nM DA. The AA current recorded in the striatum was not modified when dopaminergic terminals selectively degenerated. The AA signal was decreased by chloral hydrate or halothane anaesthesia and increased by amphetamine injections. This latter effect depended on the presence of dopaminergic terminals. This shows that the increasing current effect of amphetamine, previously observed by non-selective techniques, should be attributed to AA rather than DA. These results confirm that the catechol compound electrochemically detected in the striatum is the direct metabolite of the DA, i.e. DOPAC, and support the thesis of a functional relationship between AA levels and dopaminergic neurotransmission.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1986

Human neuroblastoma cell lines as models of catechol uptake.

This report compares the effect of antidepressants on the accumulation of [3H]catecholamines in two human neuroblastoma cell lines, IMR-32 and SK-N-SH, and a rat pheochromocytoma cell line, PC-12. Analysis of the catecholamine uptake system in SK-N-SH cells revealed that both [3H]dopamine and [3H]norepinephrine accumulated via a single competitive, saturable and apparently active process. Similar potencies exhibited by several inhibitors suggest that identical uptake systems exist in all 3 cell lines, with SK-N-SH cells being the most active. Although SK-N-SH and PC-12 cells have been reported to secrete dopamine in preference to other catecholamines, high intracellular concentrations of [3H]norepinephrine were measurable after incubation with [3H]dopamine. Additionally, [3H]norepinephrine/[3H]dopamine ratios increased with longer tracer incubations, in the presence of exogenous ascorbate and when including O-methylated metabolites. Moreover, accumulation of [3H]catechols was competitively inhibited by various antidepressants, with maximal inhibition to 7% of control and Kis consistent with reported noradrenergic uptake transport systems. Hence, the human neuroblastoma cell lines studied appear to serve as appropriate models of catechol reuptake processes in noradrenergic cells.

Animals↗
PubMed1996

Plasma catechols and monoamine oxidase metabolites in untreated Parkinson's and Alzheimer's diseases.

Prior studies have documented functional and pathological compromise of the peripheral sympathetic nervous system in patients with Parkinson's disease, suggesting the possibility of reduced catecholamine release into the circulation. We measured free plasma catechols in early and untreated patients with Parkinson's disease, but found no evidence of reduced concentrations, compared to control subjects or a group of patients with probable Alzheimer's disease. Rather, there was a significant elevation of plasma norepinephrine within the Parkinson's disease group. Furthermore, 6 of 15 untreated Parkinson's disease patients (40%) displayed markedly elevated plasma concentrations of the catecholamine MAO metabolites, DOPAC or DOPEG. Despite this finding, platelet MAO-B activity measured in these and all other Parkinson's disease patients fell well within the range of the control subjects, and was also statistically similar to the group with Alzheimer's type dementia. Plasma dopa levels were similar in all groups, whereas the majority of patients in the three groups had plasma free dopamine and epinephrine concentrations below the limits of detection. These trends toward increased, rather than decreased, circulating catechol concentrations suggest that peripheral sympathetic nervous system catecholamine production and release is not severely compromised in patients with early Parkinson's disease. In addition, we were unable to confirm certain previous reports of elevated MAO-B activity in patients with Parkinson's or Alzheimer's diseases.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1987

Simultaneous determination of catechols in thalamic slices with liquid chromatography/electrochemistry.

A method was developed for the simultaneous determination of dopamine (DA), epinephrine (E), norepinephrine (NE), 3,4-dihydroxyphenylacetic acid (DOPAC) and 3-methoxy-4-hydroxyphenylglycol (MHPG), as well as L-3,4-dihydroxyphenylalanine (L-DOPA) with liquid chromatography (LC) using electrochemical (EC) detection. With a ODS column and a mobile phase consisting of a sodium acetate-citrate with heptasulfonic acid, this method was applied on simultaneous determination of catechols released from thalamic slices of ddY mouse. The pretreatment of the bathing medium required only centrifugation, and the supernatant was injected directly into the LCEC system. The high potassium stimulation of catecholaminergically innervated thalamic slices led to increase in the levels of DA, NE, DOPAC and MHPG, especially of NE, but not that of L-DOPA itself. In the present study, we designed to make simultaneous determination of catechols released from thalamic slices for estimation of the physiological status of catecholaminergic neuronal activity.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1978

A radioimmunoassay method for urinary catechol estrogens.

A radioimmunoassay method for urinary catechol estrogens is described; The specific nature of the antisera allows direct analyses of acid hydrolyzed urine. A LH-20 Sephadex column chromatography can be employed for individual determinations of 2-hydroxyestrone and 2-hydroxyestradiol. The excretion of catechol estrogens during menstrual cycles ranged from 14.48 to 50.15 microgram per 24 hours, whereas, during the last trimester of pregnancies, the values ranged from 129.30 to 1758. 20 microgram per 24 hours.

Antibody Specificity↗
PubMed2006

The effect of a catecholate chelator as a redox agent in Fenton-based reactions on degradation of lignin-model substrates and on COD removal from effluent of an ECF kraft pulp mill.

We evaluated the effect of a catecholate chelator as a redox agent in Fenton-based reactions (known as chelator-mediated Fenton reaction-CMFR), in the presence of three different transition metals ions (Fe(2+), Fe(3+) and Cu(2+)) by determining the oxidative capability of CMFR towards lignin-model substrates. The potential application of mediated Fenton-based reactions as a novel process to treat pulp mill effluent was evaluated and monitored by chemical oxygen demand (COD) and total phenol removals from a combination of the effluents generated during an ECF bleaching stage. The catecholate chelator 3,4-dihydroxiphenilacetic acid (DOPAC) reduced both Fe(3+) and Cu(2+), in addition, the maximum Cu(2+) reduction activity was reached in a shorter time than for Fe(3+) reduction, however, the highest metal reduction activity was observed with Fe(3+). When DOPAC was added to Fenton-based reactions (Fe(3+)/H(2)O(2), Fe(2+)/H(2)O(2), Cu(2+)/H(2)O(2)) an increase in oxidative activities of these reactions were found as they resulted in great degradation improvement of the lignin-model substrates azure B, phenol red and syringaldazine. The same increase in oxidative capability of Fenton-based reactions in the presence of DOPAC was observed after effluent treatment, expressed by the increase in COD removal, namely, an increase in the range of about 70% in COD removal when Fe(2+) or Fe(3+) was the catalytic metal and about 25% for Cu(2+). However CMFR lead to an increase in total phenol content. As COD removal by CMFR system using Fe(3+) and Fe(2+) was not significantly different and that Fe(3+) ions promoted lesser increase in total phenol content, Fe(3+) was chosen for experimental optimization. At optimum conditions, 75% of COD and 30% of total phenol removal were achieved.

3,4-Dihydroxyphenylacetic Acid↗
PubMed2000

Caspase-dependent and -independent mechanisms in apoptosis induced by hydroquinone and catechol metabolites of remoxipride in HL-60 cells.

The hydroquinone and catechol like metabolites, NCQ344 and NCQ436 respectively, of the antipsychotic remoxipride have recently been demonstrated to induce apoptosis in myeloperoxidase (MPO)-rich human bone marrow progenitor and HL-60 cells [S.M. McGuinness, R. Johansson, J. Lundstrom, D. Ross, Induction of apoptosis by remoxipride metabolites in HL-60 and CD34+/CD19- human bone marrow progenitor cells: potential relevance to remoxipride-induced aplastic anemia, Chem. Biol. Interact. 121 (1999) 253-265]. In the present study, we determined the molecular mechanisms of apoptosis induced by these remoxipride metabolites in HL-60 cells. Our results show that apoptosis was accompanied by phosphatidylserine (PS) exposure, activation of caspases-9, -3, -7 and DNA cleavage. In HL-60 cells treated with the hydroquinone NCQ344 and catechol NCQ436, the general caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp. fluoromethyl ketone (Z-VAD.FMK) blocked DNA cleavage and activation of caspases-9, -3/-7. In addition, PS exposure was significantly but not completely inhibited by Z-VAD.FMK. These results demonstrate that although Z-VAD.FMK inhibitable caspases are necessary for maximal apoptosis induced by NCQ344 and NCQ436, additional caspase-independent processes may orchestrate changes leading to PS exposure during apoptosis induced by the remoxipride polyphenolic metabolites.

Amino Acid Chloromethyl Ketones↗
PubMed2004

Constitutive synthesis, purification, and characterization of catechol 1,2-dioxygenase from the aniline-assimilating bacterium Rhodococcus sp. AN-22.

A catechol 1,2-dioxygenase (CD) was found, which was synthesized constitutively in the aniline-assimilating bacterium Rhodococcus sp. AN-22 grown on a medium without aniline, as well as on aniline medium. The bacterium synthesized CD in its cells grown on all the 21 non-aromatic substrates examined, including four natural media such as meat and yeast extracts, one sugar, six organic acids, and 10 amino acids as carbon, energy, and nitrogen sources. When the bacterium was incubated on a medium with D-glucose, L-malate, isoleucine, leucine, etc., it synthesized more CD than that in cells grown on aniline. Two CDs, which were prepared from cells grown on aniline and L-malate, were purified separately to homogeneity and characterized. The two enzymes were apparently identical in molecular and catalytic properties including molecular mass, optimal pH, stability to heating, and substrate specificity for catechol analogues. However, they differed in the substrate specificity and resistance to sulfhydryl and chelating agents from the inducible CDs produced by other aniline-assimilating bacteria reported previously.

Journal Article↗
PubMed2001

An investigation of the chromium oxidation state of a monoanionic chromium tris(catecholate) complex by X-ray absorption and EPR spectroscopies.

The well-known monoanionic Cr tris(3,5-di-tert-butylcatecholato) complex, [Cr(DTBC)3]-, has been studied by X-ray absorption spectroscopy. The multiple-scattering fit to the XAFS gave good correlation (R = 19.8%) and good values for all of the bond lengths, angles, and Debye-Waller factors. The principal bond lengths and angles around the metal center (Cr-O, 1.96 A; O-C, 1.28 A; O-Cr-O, 81.8 degrees; Cr-O-C, 113.3 degrees) were most consistent with the XRD structure for [Cr(X4C6O2)3]- (X = Cl, Br), compared to those in other oxidation states, [Cr(DTBC)3], [Cr(Cl4C6O2)3], and [Cr(O2C6H4)3]3-. The XANES spectrum shows the main K edge at 6003.3 eV and a preedge peak at 5992.9 eV, which is approximately 8% of the intensity of the main K edge. The XANES data were compared to those for Cr-ehba complexes (ehbaH2 = 2-ethyl-2-hydroxybutanoic acid) of known oxidation states (III, IV, and V) and show, in conjunction with EPR spectroscopy and a reevaluation of XRD structures and theoretical calulations, that the complex is best described as a Cr(V) center with delocalization from the catechol ligands. The [Cr(catecholato)3]n+ (n = 1, 0) complexes have similar EPR spectroscopic and structural properties, respectively, to the 1- complex and are also best described as Cr(V) complexes. Such intermediates are important in the redox reactions of catechol(amine)s, and oxidized amino acids (e.g., DOPA), with carcinogenic Cr(VI) and may have relevance in Cr-induced cancers.

Journal Article↗