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At least 595 records · Page 33Linked to original sources
PubMed2004

A technique for the identification and direct analysis of hexahydro-1,3,5-tris(2-hydroxyethyl)-s-triazine in metalworking fluids using electrospray-mass spectrometry.

Hexahydro-1,3,5-tris(2-hydroxyethyl)-s-triazine is a widely used biocide in metalworking fluids that resists direct quantification in many analytical methods due to instability. It can be detected in electrospray-mass spectrometry (ES-MS) due to the formation of a charged and relatively stable adduct with the sodium ion. This adduct produces a distinct ion spectrum via collision-induced fragmentation, which should promote specific detection of the analyte in complex matrices. ES-MS detection of the analyte added to, or already present in, metalworking fluid samples at microg mL(-1) levels is demonstrated. Parameters affecting the formation and detection of the sodium adduct, including choice of solvent, alkalinity, and sodium ion level are explored. Linearity of response in flow injection mode is demonstrated.

Anti-Infective Agents↗
PubMed2005

Identification of the F1F0 mitochondrial ATPase as a target for modulating skin pigmentation by screening a tagged triazine library in zebrafish.

A triazine-based combinatorial library of small molecules was screened in zebrafish to identify compounds that produced interesting phenotypes. One compound (of 1536 screened) induced a dramatic increase in the pigmentation of early stage zebrafish embryos. This compound, PPA, was also found to increase pigmentation in cultured mammalian melanocytes. The cellular target was identified as the mitochondrial F1F0-ATP synthase (ATPase) by affinity chromatography. Oligomycin, a small molecule known to inhibit the mitochondrial ATPase, competed with PPA for its cellular target in melanocytes. In addition, PPA was shown to alter the membrane potential of mitochondria, consistent with inhibition of the mitochondrial ATPase. Thus, PPA has been successfully used as a chemical probe in a forward chemical genetic approach to establish a link between the phenotype and the protein. The results attest to the power of screening small molecule libraries in zebrafish as a means of identifying mammalian targets and suggest the mitochondrial ATPase as a target for modulating pigmentation in both melanocytes and melanoma cells.

Amino Acid Sequence↗
PubMed2006

Theoretical modeling of the valence UV spectra of 1,2,3-triazine and uracil in solution.

Assessment of the perturbed matrix method (PMM) ability in reproducing valence UV absorption spectra is carried out on two model systems: 1,2,3-triazine in methanol solution and uracil in water solution. Results show that even using the simplest definition of the quantum center, i.e. the portion of the system explicitly treated quantum mechanically, PMM provides rather good results. This paper further confirms the possibility of using PMM as a theoretical-computational tool, complementary to other methodologies, for addressing the electronic properties in molecular systems of high complexity.

Mathematics↗
PubMed2006

Episulfonium ion-mediated cyclic peptide and triazine synthesis.

The product of an episulfonium ion-mediated cyclotrimerisation, previously reported as being a 15-membered ring trilactam, has now been shown to be a 1,3,5-triazine. Smaller medium-ring bilactams have, however, been synthesised from linear precursors using the sulfur-based methodology.

Peptides, Cyclic↗
PubMed1982

The degradative pathway of the s-triazine melamine. The steps to ring cleavage.

1. The degradative pathway of melamine (1,3,5-triazine-2,4,6-triamine) was examined in Pseudomonas sp. strain A. 2. The bacterium grew with melamine, ammeline, ammelide, cyanuric acid or NH+4 as sole source of nitrogen, and each substrate was entirely metabolized. Utilization of ammeline, ammelide, cyanuric acid or NH+4 was concomitant with growth. But with melamine as substrate, a transient intermediate was detected, which was identified as ammeline by three methods. 3. Enzymes from strain A were separated by chromatography on DEAE-cellulose, and four activities were examined. 4. Melamine was converted stoichiometrically into equimolar amounts of ammeline and NH+4. 5. Ammeline was converted stoichiometrically into equimolar amounts of ammelide and NH+4; ammelide was identified by four methods. 6. Ammelide was converted stoichiometrically into equimolar amounts of cyanuric acid and NH+4; cyanuric acid was identified by four methods. 7. Cyanuric acid was converted by an enzyme preparation into an unidentified product with negligible release of NH+4. 8. The specific activities of the degradative enzymes (greater than or equal to 0.3 mkat/kg of protein) were high enough to explain the growth rate of the organism. 9. The bacterium converted 0.4 mM-melamine anaerobically into 2.3 mM-NH+4. 10. Two other pseudomonads and two strains of Klebsiella pneumoniae were also examined, with similar results. 11. The degradative pathway of melamine appears to be hydrolytic, and proceeds by three successive deaminations to cyanuric acid, which is further metabolized.

Chemical Phenomena↗
PubMed1984

Specific inhibition of L-type pyruvate kinase by the triazine dye Procion Blue MX-R.

Incubation of the triazine dye Procion Blue MX-R with L- and M-type pyruvate kinase resulted in rapid time- and dye-concentration-dependent loss of activity. L-type pyruvate kinase was protected only by a low concentration of Mg2+; this was not the case with the M-type enzyme. Modification of the L-type form resulted in the incorporation of 1.54 +/- 0.057 mol of dye/mol of enzyme subunit in the absence of Mg2+, but only 0.73 +/- 0.024 mol of dye/mol of enzyme subunit in the presence of Mg2+. Tryptic peptide mapping of L-type pyruvate kinase modified in the presence and in the absence of Mg2+ further indicated that there were two sites modified in the enzyme, one of which was protected by Mg2+. The pKa of the nucleophile involved in the modification was calculated to be 7.1, implicating the possible involvement of a histidine residue. L-type enzyme was bound to Sepharose-immobilized Procion Blue MX-R specifically in the presence of Mg2+, whereas binding of the M-type enzyme was Mg2+-independent. The specific interaction of L-type pyruvate kinase with the dye was exploited in the large-scale purification of the enzyme and in the isolation of the phosphorylated enzyme.

Affinity Labels↗
PubMedDate not supplied

Potent and selective aromatase inhibitor: in vitro and in vivo studies with s-triazine derivative SEF19.

We found a potent aromatase inhibitor through the screening of agents for estrogen-dependent breast cancer. SEF19 (2-(imidazol-1-yl)-4,6-dimorphorino-1,3,5-triazine) decreased 50% of human placental aromatase activity in vitro at the concentration of 5.3 nM. In order to clarify the selectivity of SEF19 for enzyme inhibition, we determined the effect of SEF19 on the activities of four steroidogenic cytochrome P450 enzymes in porcine adrenal gland, P450SCC(side-chain cleavage of cholesterol), P450(11 beta) (11 beta-hydroxylase), P450(17 alpha)(17 alpha-hydroxylase/C17,20 lyase) and P450C21 (21-hydroxylase). SEF19 failed to inhibit the activities of porcine adrenal P450SCC, P450(17 alpha) and P450C21 up to the concentration of 100 microM and showed some inhibition on P450(11 beta) activity at 100 microM, while SEF19 completely nullified the aromatase activity at 1 microM. We also determined the potency of SEF19 for the suppression of aromatase activity in vivo. SEF19 suppressed dose-dependently the uterine hypertrophy of immature rats caused by administration of androstenedione (30 mg/kg, s.c.). The ED50 of SEF19 for the suppression of uterine hypertrophy was 0.8 mumol/kg. These results suggest that SEF19 may serve as a potent and selective agent for the treatment of estrogen-dependent breast cancer.

Androstenedione↗
PubMed2005

Sustained and complete hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) degradation in zero-valent iron simulated barriers under different microbial conditions.

Flow-through columns packed with "aged" zero-valent iron (ZVI) between layers of soil and sand were constructed to mimic a one-dimensional permeable reactive iron barrier (PRB). The columns were continuously fed RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine, ca. 18 mg l(-1)) for over one year. Two columns were bioaugmented with dissimilatory iron reducing bacteria (DIRB) Shewanella algae BrY or Geobacter metallireducens GS-15 to investigate their potential to enhance the reactivity of aged iron by reductive dissolution of passivating iron oxides or via production of biogenic reactive minerals. A third column was not bioaugmented to evaluate colonization by indigenous soil microorganisms. [14C]-RDX was completely removed in all columns at the start of the iron layer, and concentration profiles showed rapid and sustainable RDX removal over one year; however, a phylogenetic profile conducted after one year using DGGE analysis of recovered DNA did not detect S. algae BrY or G. metallireducens in their respective columns. Bacterial DNA was recovered from within the ZVI. Several unidentified 14C-labeled byproducts were present in the effluent of all columns. Dissolved 14C removal and the detection of dissolved inorganic 14C in these columns (but not in the sterile control) suggest microbial-mediated mineralization of RDX and sorption/precipitation of degradation products. Enhanced RDX mineralization in bioaugmented columns was temporary relative to the indigenously colonized column. However, shorter acclimation periods associated with bioaugmented PRBs may be desirable for rapid RDX mineralization, thereby preventing breakthrough of potentially undesirable byproducts. Overall, these results show that high RDX removal efficiency by ZVI-PRBs is achievable and sustainable and that the efficacy and start-up of ZVI-PRBs might be enhanced by bioaugmentation.

Biodegradation, Environmental↗
PubMedDate not supplied

Molecular modeling of triazine type MDR modulators using CoMFA and CoMSIA approaches.

In the present study a series of 30 triazine derivatives was investigated by 3D QSAR methods with respect to their MDR reversing activity in vitro. Two approaches were applied and compared: comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). Molecular models with good predictive power were derived using steric, electrostatic and hydrophobic fields of the compounds. The results indicated the dominant role of the electrostatic and hydrophobic fields for MDR reversing activity of the investigated modulators. The obtained statistical parameters (Qcv2, Qpr2) showed that the CoMFA and CoMSIA models have similar predictivity. The CoMSIA models were slightly better than the CoMFA ones and obtained with lower number of principal components. The models were graphically interpreted using CoMFA and CoMSIA contour plots. The structural regions responsible for the differences in anti-MDR activity were analyzed in respect to their electrostatic and hydrophobic nature. An easier interpretation of the CoMSIA contour plots was noticed.

Drug Resistance, Multiple↗
PubMedDate not supplied

Genotoxicity assessment of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX).

Hexahydro-1,3,5-trinitro-1,3,5-triazine, a polynitramine compound, commonly known as RDX, has been used as an explosive in military munitions formulations since World War II. There is considerable data available regarding the toxicity and carcinogenicity of RDX. It has been classified as a possible carcinogen (U.S. Environmental Protection Agency, Integrated Risk Information System, 2005, www.epa.gov/IRIS/subst/0313.htm). In order to better understand its gentoxic potential, the authors conducted the in vitro mouse lymphoma forward mutation and the in vivo mouse bone marrow micronucleus assays. Pure RDX (99.99%) at concentrations ranging from 3.93 to 500 microg/ml showed no cytotoxicity and no mutagenicity in forward mutations at the thymidine kinase (TK) locus in L5178Y mouse lymphoma cells, with and without metabolic activation. This finding was also confirmed by repeat assays under identical conditions. In addition, RDX did not induce micronuclei in mouse bone marrow cells when tested to the maximum tolerated dose of 250 mg/kg in male mice. These results show that RDX was not mutagenic in these in vitro and in vivo mammalian systems.

Animals↗
PubMedDate not supplied

Reevaluation of a twenty-four-month chronic toxicity/carcinogenicity study of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in the B6C3F1 hybrid mouse.

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) has been widely used as an explosive in U.S. army munitions formulations since World War II. Two-year carcinogenicity studies revealed RDX to be noncarcinogenic in two strains of rats, but a 2-year carcinogenicity study in B6C3F1 mice revealed an increased incidence of hepatocellular neoplasms in females. Based on results of the study in B6C3F1 mice, RDX has been classified as a possible carcinogen. The authors reevaluated the archived histological sections from the B6C3F1 mouse study, using current histopathologic diagnostic criteria and interpretations. The earlier evaluation showed a statistically significant increase in the incidence of hepatocellular adenoma/carcinoma in female mice from the three highest dose groups (7, 35, and 175/100 mg/kg/day). The revaluation yielded a slightly lower incidence at each of the dose levels in female mice. The reduced number of hepatocellular neoplasms was largely due to reclassification of hepatocellular adenomas as foci of cytoplasmic alteration, in compliance with current diagnostic criteria. The reevaluation was reviewed by a pathology working group (PWG), which arrived at a consensus classification of each lesion. Based on the consensus diagnoses of the PWG, only one female group (35 mg/kg/day) showed a significant increase when compared to controls. The incidence of hepatocellular neoplasms for all groups, including the 35 mg/kg/day group, was within the reported incidence range for spontaneous hepatocellular neoplasms in female B6C3F1 mice. The increased incidence of hepatocellular neoplasms in female mice given RDX at 35 mg/kg/day was interpreted as equivocal evidence of a carcinogenic effect.

Adenoma↗
PubMed2004

Antibacterial and antifugal mono- and di-substituted symmetrical and unsymmetrical triazine-derived Schiff-bases and their transition metal complexes.

A new series of antibacterial and antifungal triazine-derived mono- and di-substituted (symmetrical and unsymmetrical) Schiff-bases and their cobalt(II), copper(II), nickel(II) and zinc(II) metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments and IR and electronic spectral measurements. IR spectra indicated the ligands to act as tridentate towards divalent metal ions via a trazine-N, the azomethine-N and, indole-NH and deprotonated-O of salicylaldehyde. The magnetic moments and electronic spectral data suggest octahedral geometry for the Co(II), Ni(II) and Zn(II)complexes and square-pyramid for Cu(II) complexes. NMR spectral data of the ligands and their diamagnetic zinc(II) complexes well-define their proposed structures/geometries. Elemental analyses data of the ligands and metal complexes agree with their proposed structures/geometries. The synthesized ligands, along with their metal complexes were screened for their antibacterial activity against Escherichia coli, Bacillus subtillis, Shigella flexneri, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi and for antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata. The results of these studies show the metal complexes to be more antibacterial/ antifungal against two or more species as compared to the uncomplexed Schiff-base ligands.

Anti-Bacterial Agents↗
PubMed1982

Short-term oral toxicity of a 2,4,6-trinitrotoluene and hexahydro-1,3,5-trinitro-1,3,5-triazine mixture in mice, rats, and dogs.

The oral toxicity of a mixture of 2,4,6-trinitrotoluene and hexahydro-1,3,5-trinitro-1,3,5-triazine (1:0.62, w/w) compounds typically found in munitions plant effluents, was evaluated in mammalian species. Single-dose oral LD50s of the mixture were 574 and 594 mg/kg in male and female rats and 947 and 1130 mg/kg in male and female mice, respectively. Long dispersion periods during preparation or ultraviolet irradiation of the mixture lowered the LD50s. In repeated-exposure studies, dogs were given 0.50, 5.0 or 50 mg/kg X d by capsule for up to 90 d. Rats and mice were fed the mixture in the diet at 0.005, 0.05, or 0.5% for 90 d; mice were also fed at 0.25%. Mortality resulted at the highest dose level in each species. All three species showed depression of body weight or body weight gain, depressed food intake, moderate to severe anemia, and alterations in the spleen (hemosiderosis), liver (hepatomegaly), and testes (atrophy) at the highest dose levels. Cholesterol was elevated in rats and dogs after 90 d. Several species differences were also noted. Uric acid values were elevated in rats but not in dogs, serum glutamic-pyruvic transaminase (SGPT) activity was low in dogs but unchanged in rats, and rats developed hypoplasia of the uterus but dogs did not. Signs of anemia were present at the intermediate dose levels. The lowest dose level in all three species was designated at a "no observable effects" level, based on the absence of clearly treatment-related effects. In a 4-wk study, the irradiated mixture fed to rats at 0.003, 0.03, or 0.3% in the diet was less toxic than the unirradiated mixture.

Anemia↗
PubMed1993

Groundwater pesticides: interactive effects of low concentrations of carbamates aldicarb and methomyl and the triazine metribuzin on thyroxine and somatotropin levels in white rats.

Using full-factorial design experiments for three variables at two levels each and center replicates, we examined the effects of common agricultural carbamate insecticides, aldicarb and methomyl, and a triazine herbicide, metribuzin, on hormone levels in Sprague-Dawley rats. Fifty-four female rats were sampled at 2 and 6 wk during a 6-wk exposure to individual chemicals or to combinations of them. Some main effects and interaction effects were significant. For example, rats treated with the herbicide (metribuzin) were hyperthyroid. The interactions of all three chemicals also significantly increased thyroxine levels. One year later, we repeated these experiments for 16 wk using 54 male rats; the results were very similar. Metribuzin alone significantly increased thyroxine throughout the second study (at 7, 13, and 16 wk). Somatotropin levels were significantly altered after 13 wk of exposure. The same concentrations and mixtures of these three pesticides have now been shown to be implicated in learning impairment and other neurological functions, immune parameter changes, and endocrine changes. These findings support the concept of the interconnectedness of the nervous, endocrine, and immune systems and raise the likelihood of impacts on all three systems if one is shown to be affected. Development, growth, and reproduction all depend on the proper function of these three systems. These results strongly suggest the need to reassess currently allowed "safe" levels of chemicals based on adult dosages that are accepted in ground-water and in our food supplies.

Aldicarb↗
PubMed2004

Biodegradation of 1,3,5-trinitro-1,3,5-triazine (RDX).

Two bacteria were isolated from 1,3,5-trinitro-1,3,5-triazine (RDX) contaminated soil at Picatinny Arsenal, New Jersey. These organisms were subsequently identified as Rhiziobium rhizogenes BL and Burkholderia sp.BL by the Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSMZ, German Collection of Microorganisms and Cell Cultures). In addition a fungus, identified as Cladosporium cladosporioides by DSMZ, was found to be growing on water wet RDX. All of these organisms were found to degrade RDX. The two bacteria were found to represent new species that have not been reported before. It was found that these organisms along with an added carbon source could degrade RDX to simple gaseous products. Data are presented that elucidate the mechanisms of RDX biodegradation for these organisms.

Biodegradation, Environmental↗
PubMed2003

Selective synthesis and reactions of 6-substituted-2-beta-galactosyl-1,2,4-triazines of potential anticancer activity.

Selective synthesis and reactions of different 6-substituted-2-beta-D-galactosyl-3-thioxo-2,3-dihydro-1,2,4-triazin-5(4H)-ones using the developed amino or aryl protecting group strategy were investigated. Primary human anticancer screening of twelve selected compounds (in vitro) resulted in an active compound against both MCF7 (Breast) and SF-268(CNS) cell lines.

Antineoplastic Agents↗
PubMed2004

Synthesis of some novel 6-benzyl(or substituted benzyl)-2-beta-D-glucopyranosyl-1,2,4-triazolo[4,3-b][1,2,4]triazines as potential antimicrobial chemotherapeutics.

Glucosidation of the new 8-amino-6-benzyl(or substituted benzyl)-2,8-dihydro-1,2,4-triazolo[4,3-b][1,2,4]triazin-7(3H)-ones (3a-d) with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide 4 gave the corresponding N-glucosides 5a-d. Chemical transformations leading to new functionalities have also been achieved to give compounds 7-12. Antimicrobial activity of compounds 5a-c against Aspergillus fumigatus, Penicillium italicum, Syncephalastrum racemosum, Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli is described.

Anti-Bacterial Agents↗