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PubMed2003

Comparison of the ecotoxicological impact of the triazines Irgarol 1051 and atrazine on microalgal cultures and natural microalgal communities in Lake Geneva.

The antifouling herbicide Irgarol 1051 has been detected in recent years in numerous estuaries, marinas, harbors and coastal areas, and in some harbors on Lake Geneva, but so far only a few studies have investigated the ecotoxicological effects of this compound on microalgae. The purpose of this study was to assess the ecotoxicological impact of Irgarol 1051 on the algal communities of Lake Geneva, and to compare its phytotoxicity to that of the common triazine herbicide, atrazine. We investigated the response of phytoplanktonic and periphytonic algal communities and single-species isolates collected from the lake, to the PS II inhibitor Irgarol 1051 (growth, proxy of photosynthetic activity and community structure). A short-term bioassay was developed based on in vivo fluorescence, together with nanocosm experiments with natural algal communities, and single-species tests on algal strains isolated from the lake. The toxicity of Irgarol 1051 towards periphyton and phytoplankton was shown to be higher than that of atrazine. Indications of the tolerance induced by this triazine in the algal communities of Lake Geneva, suggests that even at the levels of contamination reported in some parts of the lake, Irgarol 1051 is already exerting selection pressure. Information about sensitivities, selection and tolerance from laboratory experiments are used to explain the observations in natural microalgal communities from the lake.

Atrazine↗
PubMedDate not supplied

Occurrence of triazines in surface and drinking water of Liaoning Province in Eastern China.

The Liaoning Province in Eastern China has a prosperous economy and traditional agricultural background. Steadily increasing water demand implies the direct use of surface water for drinking water support and foodstuff production. Due to the extensive use, high persistence, water solubility and relatively weak adsorptivity, the chloro s-triazines contaminate the aquatic environment and are therefore regularly and most frequently detected in ground and surface water. Water sample enrichment procedures were performed by solid-phase extraction (SPE) using different materials. During a 1-year monitoring program on the Liao-He River, water sample enrichment was performed using C(18)-SPE cartridges. These SPE cartridges showed low recoveries for the atrazine metabolites, although high triazine values were detected. Based on these results, a pilot sampling on drinking water in the Liao-He region was performed. This time, in addition to the C(18)-SPE cartridges, a new polymer SPE sorbent made from a balance ratio of two monomers, the lipophilic divinylbenzene and the hydrophilic N-vinylpyrrolidone, was used. Both materials were characterized by establishing breakthrough curves for the investigated analytes and up to large volumes.

China↗
PubMed2002

Physiological response of freshwater microalga (Chlorella vulgaris) to triazine and phenylurea herbicides.

The effects of two herbicides used wide-spread, isoproturon (phenylurea) and terbutryn (triazine), on growth, dry weight, elemental composition, photosynthetic pigments and protein content, and cell volume assayed by flow cytometry in the freshwater microalgae Chlorella vulgaris were studied. Different parameters for algal activity show widely different sensitivities to these aquatic pollutants. After 96 h of herbicide exposure, terbutryn was the strongest inhibitor of growth, giving an EC50 value for growth twice lower than that for isoproturon cultures (EC50 terbutryn=0.097 microM; EC50 isoproturon=0.199 microM). However, lower concentrations of the triazine herbicide provoked an increase in the cellular density and growth rate of this microalga, not observed in the phenylurea-treated cultures. Cellular volume and dry weight of C. vulgaris cells were increased strongly in the presence of isoproturon and terbutryn. Other cellular parameters, such as pigment and protein content, were stimulated with both herbicides at higher concentrations.

Adaptation, Physiological↗
PubMed2000

Synthesis, structural characterization and antitumor activity of novel 2,4-diamino-1,3,5-triazine derivatives.

The syntheses, structural elucidation based on NMR spectroscopy and X-ray analysis of 8 as well as antitumor activities of novel 2,4-diamino-1,3,5-triazine derivatives 5 and 7-22 are described. Screenings performed at NCI showed that most derivatives possessed a moderate to strong growth inhibition activity on various tumor panel cell lines between 0.148 and 56.2 microM concentrations. 2-Amino-6-bromomethyl-4-(3,5,5-trimethyl-2-pyrazoline)-1,3,5-triazine 11 showed the most potent antitumor activity with the mean midpoint values of log(10) GI50, log(10) TGI50 and log(10) LC50 of all tests equal to -5.26, -4.81 and -4.37, respectively and therefore, it can be considered as a lead structure for further development of anticancer agents.

Antineoplastic Agents↗
PubMed2002

Synthesis and pharmacological activity of new carbonyl derivatives of 1-aryl-2-iminoimidazolidine: part 2. Synthesis and pharmacological activity of 1,6-diaryl-5,7(1H)dioxo-2,3-dihydroimidazo[1,2-a][1,3,5]triazines.

Synthesis and pharmacological activity of 1,6-diaryl-5,7(1H)dioxo-2,3-dihydroimidazo-[1,2-a][1,3,5]triazines (C) are presented. The title compounds were obtained from 1-arylimidazolinurea derivatives in cyclization reaction with difunctional carbonyl reagents--phosgene (method I) or carbonyldiimidazole (CDI) (method II). Their molecular structures were confirmed by the X-ray analysis of 1-phenyl-6-(4-chlorophenyl)-5,7(1H)-dioxo-2,3-dihydroimidazo[1,2-a][1,3,5]triazine (C2) crystals. Compounds C exhibited significant depressive action on the central nervous system (CNS) of the laboratory animals, correlated with very low acute toxicity (LD(50) > 2000 mg kg(-1) i.p.), and showed antinociceptive activity in behavioural models. Reversion of this effect by small dose of naloxone (5 mg kg(-1)) can suggest opioid-like mechanism of antinociception produced by these and other carbonyl derivatives of 1-aryl-2-iminoimidazolidine. Additionally, an effect on the serotonin neurotransmission pathway was also observed. The receptor mechanism of activity for investigated compounds was confirmed only for the opioid mu receptor in binding affinity assay test. Same tests performed for the serotonin 5-HT(2) and benzodiazepine BZD receptors showed no affinity for tested compounds. The opioid-like and serotonergic activities are similar to these described earlier for chain carbonyl 1-aryl-2-iminoimidazolidine derivatives containing urea moiety, mainly due to similar chemical structure, although compounds C are not able to adopt any of the higher energy conformations of urea derivatives. Rigid location of aromatic ring (Ar') at N6, acting as a spacer blocking any direct access to the carbonyl groups (e.g. through the hydrogen bonding), could be responsible for lack of affinity toward 5-HT(2) expressed in the binding assay test.

5-Hydroxytryptophan↗
PubMed1999

Combinatorial mixture synthesis and biological evaluation of dihydrophenyl triazine antifolates.

The traditional 'one-pot' three component synthesis was adapted successfully for combinatorial mixtures synthesis of dihydrophenyl triazines, which are nonclassical, dihydrofolate reductase (DHFR) inhibitors. Each library was designed to comprise eight reaction mixture pots and in every pot there were three dihydrophenyl triazines. A total of three libraries were synthesized and the final number of compounds harvested was 64. The products precipitated out of the reaction mixture and could be collected easily and cleansed by washing. Solid supports and further purification processes were not required. The reactions were monitored by TLC and a HPLC method was developed to determine the number of products in each pot. All 24 pots were screened for inhibitory activity against the rat liver DHFR. Two pots showed good inhibitory activity and the products in them were individually synthesized, characterized and biologically tested again. One lead compound was identified amongst all the compounds synthesized, and would be further optimized.

Animals↗
PubMed2002

Affinity partitioning of glucose-6-phosphate dehydrogenase and hexokinase in aqueous two-phase systems with free triazine dye ligands.

The partitioning of glucose-6-phosphate dehydrogenase (G6PDH) (E.C. 1.1.1.49) and hexokinase (E.C. 2.7.1.1) in polyethylene glycol (PEG)-hydroxypropyl starch (PES) and PEG-phosphate aqueous two-phase systems was investigated with free triazine dyes, Cibacron Blue F3GA and Procion Red HE3B, as their affinity ligands. It was found that the free reactive triazine dyes, not bound to phase-forming polymers, preferentially partitioned in the top-PEG phase in the PEG-salt and PEG-PES systems. The effect of various parameters such as type and concentration of affinity ligands, pH of the system, molecular mass of PEG and phase composition on partitioning of the enzymes was estimated. Phosphate is a key factor affecting the enzyme partitioning in the PEG-PES system. Cibacron F3GA changed the partition coefficient of G6PDH from 0.73 to 1.59.

Chromatography, Affinity↗
PubMed2002

Hollow fiber-protected liquid-phase microextraction of triazine herbicides.

A new microextraction technique termed hollow fiber-protected liquid-phase microextraction (LPME) was developed. Triazines were employed as model compounds to assess the extraction procedure and were determined by gas chromatography/mass spectrometry. Toluene functioned as both the extraction solvent and the impregnation solvent. Some important extraction parameters, such as effect of salt, agitation, pH, and exposure time were optimized. The new method provided good average enrichment factors of > 150 for eight analytes, good repeatability (RSDs <3.50%, n = 7), and good linearity (r2 > or = 0.9995) for spiked deionized water samples. The limits of detection (LODs) were in the range of 0.007-0.063 microg/L (S/N = 3) under selected ion monitoring mode. In addition to enrichment, hollow fiber-protected LPME also served as a technique for sample cleanup because of the selectivity of the membrane, which prevented large molecules and extraneous materials, such as humic acids in solution, from being extracted. The utilization of this procedure in the extraction of a slurry sample (mixture of soil and water) also gave good precision (RSDs <5.00%, n = 3) and LODs (0.04-0.18 microg/L, S/N = 3). Finally, the comparison of the new method with the static solvent drop LPME and solid-phase microextraction was performed. The results demonstrated that hollow fiber-protected LPME was a fast, accurate, and stable sample pretreatment method that gave very good enrichment factors for the extraction of triazine herbicides from aqueous or slurry samples.

Gas Chromatography-Mass Spectrometry↗
PubMed2002

Label-free parallel screening of combinatorial triazine libraries using reflectometric interference spectroscopy.

The parallel reflectometric interference spectroscopy is presented as a label-free optical detection method. A new setup was adapted to accommodate sample carriers in a 96-well microplate. It allows for the first time simultaneous plate imaging by a CCD camera for the parallel detection of specific biomolecular interaction in the microplate wells at heterogeneous phase using direct optical monitoring. The detection of binding events with time resolution enables a highly parallel functional biomolecular interaction analysis (BIA). The combination of this new screening setup with combinatorial solid-phase synthesis is performed in the wells of glass-bottom microplates to accomplish the synthesis and the screening platform within one device. As a model system for a solid-phase substance library, synthesis of a triazine library and the subsequent BIA with four different antibodies were carried out. The presented setup enables a time resolution of 18 s with a total screening time of less than 35 min including baseline adjustment, BIA, and regeneration of the screening device for 96 samples in parallel. The binding studies reveal a fast classification of the different monoclonal and polyclonal antibodies and enable the detection of triazines with high binding affinity. The presented prototype is the first parallelized optical label-free detection system for biomolecular interaction analysis that is suitable for a high-throughput screening based on the 96-well microplate format.

Antibodies↗
PubMed2004

Membrane-assisted solvent extraction of triazines, organochlorine, and organophosphorus compounds in complex samples combined with large-volume injection-gas chromatography/mass spectrometric detection.

The performance of the fully automated membrane-assisted solvent extraction was investigated for 47 environmental contaminants (among them 30 organochlorine compounds, 9 organophosphorus compounds, and 7 triazines). The extraction took place in a 20-mL headspace vial filled with the aqueous sample and containing a polypropylene membrane bag with 1 mL of cyclohexane as extractant. This device was handled by a multipurpose sampler, which enabled the sample to be mixed at a defined temperature with subsequent large-volume injection of the organic extract taken out of the membrane bag. After optimization of extraction parameters, the method was validated for the three compound classes, triazines and organochlorine and organophosphorus compounds, using spiked distilled water. Then, the extraction yield of these analytes from several complex samples such as a natural and a synthetic wastewater, a bacterial culture, and orange juice was determined and compared to a conventional liquid-liquid extraction. Furthermore, the possibility of reducing matrix interference by adding salt, methanol, or detergent during membrane-assisted solvent extraction was investigated.

Gas Chromatography-Mass Spectrometry↗
PubMed2005

Specific triazine resistance in bacterial reaction centers induced by a single mutation in the QA protein pocket.

We report here the first example of a reaction center mutant from Rhodobacter sphaeroides, where a single mutation (M266His --> Leu) taking place in the primary quinone protein pocket confers selective resistance to triazine-type inhibitors (terbutryn, ametryn, and atrazine), which bind in the secondary quinone protein pocket, at about 13 A from the mutation site. The M266His --> Leu mutation involves one of the iron atom ligands. Interestingly, neither the secondary quinone nor the highly specific inhibitor stigmatellin binding affinities are affected by the mutation. It is noticeable that in the M266His --> Ala mutant a nativelike behavior in observed. We suggest that the long side chain of Leu in position M266 may lack space to accommodate in the Q(A) pocket therefore transferring its hindrance to the Q(B) pocket. This may occur via the structural feature formed by the Q(A)-M219His-Fe-L190His-inhibitor (or Q(B)) connection, pushing L189Leu and/or L229Ile in closer contact to the triazine molecules, therefore decreasing their bindings. This opens the possibility to finely tune, in reaction center proteins, the affinity for herbicides by designing mutations distant from their binding sites.

Atrazine↗
PubMedDate not supplied

Prediction of Henry's law constants of triazine derived herbicides from quantum chemical continuum solvation models.

The Henry's law constants (H) for triazine derived herbicides are calculated using quantum chemical solvation models, SM2, SM3, PCM-DFT, and CPCM-DFT, and their performances are discussed. The results show considerable differences in performance among the different levels of theory. The values of H calculated by the semiempirical methods agree much better with the experimental values than those obtained at the DFT level. The differences are discussed in terms of the different contributions, electrostatic and no-electrostatic, to Gibbs free energy of solvation. In addition, the Henry's law constants of some triazine derived herbicides whose values have not been reported earlier are predicted as well.

Analysis of Variance↗
PubMed2005

Sol-gel immunosorbents doped with polyclonal antibodies for the selective extraction of malathion and triazines from aqueous samples.

Sol-gel immunosorbents (IS) prepared by encapsulation of polyclonal antibodies in silica were packed in cartridges and evaluated for selective immunoaffinity extraction (IAE) of malathion and triazines from aqueous samples. Encapsulated atrazine antibodies highly cross-reacted with simazine and propazine but did not recognize prometon and prometryn. No cross-reactivity of malathion antibodies was observed with the closely related metabolites oxomalathion and isomalathion. Mean IS binding capacities per milligram of entrapped antibody were 0.33 nmol of malathion and 0.47 nmol of atrazine (approximately 100 ng each). This capacity remained constant for at least 10 weeks, and the cartridge reusability was excellent (>60 IAE runs); also, high preconcentration factors were feasible because the breakthrough of analytes from IS cartridges did not occur up to the 250 mL sample volumes, provided that the capacity was not surpassed. Simple and rapid methods for determination of malathion or three triazines in surface water were developed using off-line IAE and HPLC-UV. The application to 50 mL dam water samples spiked at approximately 1 ng/mL of pesticides resulted in recoveries of approximately 90% and RSD < 5% (n=7). LODs for this sample volume (direct injection of IS eluates) were in the range of 0.15-0.50 ng/mL. Lower LODs (0.03-0.1 ng/mL) were achieved by online analysis of whole eluates previously loaded in RP precolumns.

Antibodies↗
PubMed2006

Crystallographic evidence of nitrate-pi interactions involving the electron-deficient 1,3,5-triazine ring.

The reaction of Zn(NO3)2.6H2O or Cu(NO3)2.3H2O with the star-shaped ligand 2,4,6-tris(di-2-picolylamino)[1,3,5]triazine (dipicatriz) in acetonitrile results in the formation of the mono- or trinuclear coordination compounds [Zn(dipicatriz)(NO3)2] (1), [Zn3(dipicatriz)(NO3)6](CH3CN)3 (2), and [Cu3(dipicatriz)(NO3)2(H2O)6](NO3)4 (3), depending on the metal-to-ligand ratios used during the crystallization process. Their crystal structures exhibit unique supramolecular interactions. Compounds 1 and 2 show anion-pi interactions between coordinated nitrate ions and the s-triazine ring. Compound 3 exhibits remarkable interactions between two noncoordinated nitrate anions and the two faces of the electron-deficient heteroaromatic ring, corroborating earlier theoretical investigations in this area. New theoretical investigations have been carried out on nitrate-pi interactions, taking into account the particular position of the anion toward the aromatic ring observed in the crystal structures.

Acetonitriles↗
PubMed1989

Pyrido[3,4-e]-1,2,4-triazines and related heterocycles as potential antifungal agents.

The preparation and biological activities of a series of pyrido[3,4-e]-1,2,4-triazines, 1,2,4-triazino[5,6-c]quinolines, and related fused triazines are described. Methyl, amino, and acylamino substituents were placed in the pyridyl ring of the former system. Other structural modifications included various alkyl, cycloalkyl, substituted phenyl, and heterocyclic groups in the 3-position of these ring systems. In agar dilution assays, actives in this series inhibited strains of Candida, Aspergillus, Mucor, and Trychophyton species at MIC's of less than or equal to 16 micrograms/mL.

Antifungal Agents↗
PubMed1977

Antifolate studies. Activities of 40 potential antimalarial compounds against sensitive and chlorguanide triazine resistant strains of folate-requiring bacteria and Escherichia coli.

As part of the search for new antimalarial drugs, a screening program was developed using sensitive and chlorguanide triazine (CGT, cycloguanil) resistant strains of the folate-requiring bacteria, Streptococcus faecium durans, Lactobacillus casei, and Pediococcus cerevisiae. The activities of 40 compounds have been studied against these strains and Escherichia coli. Observations have been made on the points of 50% growth inhibition, the fold increase of resistance shown to each compound by the resistant strains as compared with the parent sensitive strains, and the reversal of growth inhibition by folic acid with S. faecium and L. casei by folinic acid with P. cerevisiae and by p-aminobenzoic acid with E. coli. Comparisons have been made of the activities of the test compounds with those of the standard antimalarial antifoltes, CGT and pyrimethamine (PM), and the antibacterial results have been compared with the activities of the compounds against Plasmodium berghei infections in the mouse and against human malaria infections where data are available. Of the 17 compounds reversed by folates, five had patterns of activity similar to CGT and PM in that they were most active against S. faecium and nine compounds exhibited a different pattern, being highly active against all four test bacteria. This suggests that these latter compounds either have different pharmacokinetic properties or have additional modes of action. The three CGT-resistant organisms responded to antifolates in different ways. S. faecium (R) and P. cerevisiae (R) strains were cross resistant to 4,6-diaminotriazines, 2,4-diaminopyrimidines, 2,4-diaminoquinazolines, and active 2,4-diaminopteridines. L. casei (R) was cross resistant to the triazines but was collaterally sensitive to all the other antifolates. Most of the compounds not reversed by folates were much less inhibitory for the test organisms; they were most active against L. casei. In general, their growth inhibitory concentrations varied less for the four test organisms and the responses of the sensitive and CGTR strains were similar. However, there was some cross resistance to five compounds and some collateral sensitivity to five others. Comparison of the bacteriological data with the activities of the compounds against Plasmodium berghei in the mouse showed little correlation between the two test systems; each appears to provide independent and useful information.

Animals↗
PubMed1976

Synthesis and antimicrobial activity of some novel heterocycles. Azolo-as-triazines.

A general method for the preparation of substituted azolo-as-triazines is reported. The various alpha-aminoazoles (3-aminopyrazole, 3-amino-s-triazole, 5-amino-v-triazole, 2-aminoimidazole, 4(5)-aminoimidazole, and their substituted derivatives) were diazotized and coupled with active methylene reagents (beta-diketones, beta-keto esters, beta-keto acids, ethyl cyanoacetate and malononitrile) to afford intermediates which were then cyclized in methanol, acetic acid, or benzene. The cyclized products were the corresponding pyrazolo[2,3-c]- (2), s-triazolo[2,3-c]- (3), imidazo[3,4-c]- (4), v-triazolo[1,2-c]- (5), and imidazo[3,4-c]-as-triazines (6) with substituents such as amino, alkyl (or hydrogen), ester, ketone, or nitrile, depending on the methylene reagent used. Of the 28 compounds synthesized (representative of the five heterocycles) six, with various substituents, exhibited specific in vitro antimicrobial activity. Compounds 2b and 2d inhibited the gram-negative bacterium Pseudomonas, 3a, and 5a inhibited the gram-positive Staphylococcus, 2h inhibited the dermatophyte Trichophyton, and 2c inhibited the yeast Candida in the MIC (minimum inhibitory concentration) range of 0.40-0.16 mumol/ml.

Anti-Bacterial Agents↗