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PubMed1977

Mutagenicity of the triazine herbicides atrazine, cyanazine, and simazine in Drosophila melanogaster.

Assays for dominant lethal mutations, sex-linked recessive lethal mutations, and chromosomal breakage, nondisjunction and loss were performed on Drosophila melanogaster males treated by injection or by larval feeding of the herbicides atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine), cyanazine [2-chloro-4-(1-cyano-1-methylethylamino)-6-ethylamino-1,3,5-triazine], or simazine [2-chloro-4,6-bis-(ethylamino)-1,3,5-triazine]. The three herbicides significantly increased the rate of apparent dominant lethals, but this reduction in egg hatch was probably due to physiologic toxicity to sperm. Atrazine significantly increased X-linked recessive lethals and X or Y loss after treatment by larval feeding. Injection of simazine elevated X-linked lethals, whereas treatment by larval feeding did not. None of these herbicides significantly increased partial loss of the Y chromosome nor sex chromosome nondisjunction. Much larger experiments are needed to determine with confidence the mutagenic potential of these herbicides.

Animals↗
PubMed1994

Possible antiestrogenic properties of chloro-s-triazines in rat uterus.

Several published reports have indicated that certain chloro-s-triazine herbicides may alter endocrine function in rats, possibly by androgen receptor binding. In direct tests of estrogenic bioactivity, oral doses of up to 300 mg/kg/d of atrazine, simazine, or the common metabolite diaminochlorotriazine (DACT) did not significantly increase uterine weight of ovariectomized Sprague-Dawley female rats. The highest dose, which was approximately 10% of the LD50 for these compounds, did cause body weight loss. When administered concomitantly with sc injections of estradiol (2 micrograms/kg), 300 mg/kg of orally administered chlorotriazines significantly reduced uterine weight in comparison to animals given estrogen alone. Neither atrazine, simazine, nor DACT, at oral doses up to 300 mg/kg/d, stimulated incorporation of [3H]thymidine into uterine DNA of immature Sprague-Dawley female rats. However, oral treatment at doses of 50 mg/kg and higher significantly reduced thymidine incorporation into uterine DNA extracted from immature rats given a single injection of 0.15 microgram estradiol. Oral doses of 300 mg/kg of atrazine, simazine, or DACT significantly reduced expression of progesterone receptor binding in cytosol fractions prepared from uteri of ovariectomized rats injected sc with 1 microgram estradiol; 50 mg/kg triazine was not effective in this case. Uterine progesterone receptor levels were not stimulated in rats given oral doses up to 300 mg/kg of these triazines without estradiol injections. These results suggest that atrazine, simazine, and DACT possess no intrinsic estrogenic activity but that they are capable of weak inhibition of estrogen-stimulated responses in the rat uterus. This inhibition may play a role in the previously observed disruptive actions of chlorotriazines on reproductive endocrine function of female rats.

Administration, Oral↗
PubMed1975

Promotion of Sorghum Callus Growth by the s-Triazine Herbicides.

Growth-promoting action of simazine and other s-triazine herbicides was detected by the use of sorghum (Sorghum bicolor [L]. Moench) callus tissue and the chlorophyll retention test. Soil application of simazine [2-chloro-4, 6-bis(ethylamino)-s-triazine] at sublethal levels nearly doubled the growth-promoting action of sorghum root exudates. Treated plants yielded up to 26% more total protein than untreated plants. This indicated that the level of callus growth-promoting action in the root exudate of the plant has a positive effect on its final total protein yield and confirms a positive effect of simazine on total protein content in certain instances. The results may provide a new understanding of the mode of action of s-triazines applied at sublethal levels in increasing protein content and certain enzymic activities of treated plants. It is speculated that the growth-promoting action of these herbicides is hormonal in nature and most likely kinetin-like.

Journal Article↗
PubMed1981

Lipid composition of chloroplast membranes from weed biotypes differentially sensitive to triazine herbicides.

Chloroplasts were isolated from triazine-sensitive and triazine-resistant biotypes of common groundsel (Senecio vulgaris L.), common lambsquarter (Chenopodium album L.), and redroot pigweed (Amaranthus retroflexus L.). Chloroplast lipids were extracted and analyzed for differences among sensitive and resistant biotypes. The distribution of lipid between major lipid classes differed in chloroplasts from resistant and susceptible biotypes. Chloroplasts from resistant biotypes contained higher proportions of monogalactosyl diglyceride and phosphatidyl ethanolamine and lower proportions of digalactosyl diglyceride and phosphatidyl choline than did chloroplasts from susceptible biotypes. Monogalactosyl diglyceride and phosphatidyl ethanolamine were also quantitatively higher in membranes of resistant versus susceptible biotypes. The major lipid classes of resistant chloroplast membranes contained lipids comparatively richer in unsaturated fatty acids with the exceptions of digalactosyl diglyceride from all three biotypes and phosphatidyl ethanolamine from common groundsel. Results correlated changes in triazine sensitivity with qualitative and quantitative differences in the lipid composition of chloroplast membranes.

Journal Article↗
PubMed1986

Characterization of Triazine-Resistant and -Susceptible Isolines of Canola (Brassica napus L.).

Morphometric, electrophoretic, and immunological procedures were used to probe the structural and physiological differences between triazine-resistant (R) and susceptible (S) isolines of canola (Brassica napus L.). The R biotype exhibited increased grana stacking and decreased amounts of starch compared to the S biotype. Likewise, characters associated with an increase in grana stacking (lower chlorophyll a/b ratio, increased chlorophyll a/b light-harvesting complex, and relatively lower amounts of the P700 chlorophyll a protein and chloroplast coupling factor) were all observed in the R isoline of canola. Proteins which occur with approximately equal frequency in grana and stroma lamellae (plastocyanin, cutochrome f) or present only in the stroma (ribulose 1,5-bisphosphate carboxylase/oxygenase) were not quantitatively different in the two biotypes. Gross anatomical parameters (volume of epidermis, palisade mesophyll, spongy mesophyll, and air space) were similar in the two isolines. Thus, the triazine-resistance mutation does not confer a shade-type anatomy despite the chloroplast changes that are characteristic of shade biotypes or shade adaptions. These data indicate that the differences in chloroplast structure noted previously in comparisons of nonisonuclear R and S weed biotypes reflect differences in the triazineresistance factor rather than characters unrelated to triazine resistance.

Journal Article↗
PubMed1988

Comparison of Triazine-Resistant and -Susceptible Biotypes of Senecio vulgaris and Their F(1) Hybrids.

The relationship of triazine resistance to decreased plant productivity was investigated in Senecio vulgaris L. F(1) reciprocal hybrids were developed from pure-breeding susceptible (S) and resistant (R) lines. The four biotypes (S, S x R, R, R x S) were compared in terms of atrazine response, electron transport, carbon fixation, and biomass production. Atrazine response, carbon fixation rate, and PSII and whole-chain electron transport rates of hybrids were nearly identical to those of their respective maternal parents. Significant differences occurred between the two susceptible (S, S x R) and two resistant (R, R x S) biotypes in atrazine response (I(50)), carbon fixation rate, and PSII and whole-chain electron transport rates; PSI rates were identical in all four biotypes. Coupled and uncoupled, whole-chain electron transport rates of thylakoids of the two susceptible biotypes were approximately 50% greater than those of the two resistant biotypes at photon flux densities greater than 215 micromoles per square meter per second. Carbon exchange rates of the two susceptible biotypes were 23% greater than those of the two resistant biotypes. Hybrid biotypes (S x R, R x S) were not identical to their maternal parents in biomass production. The S, S x R, and R x S plants all achieved greater biomass than R plants. These results suggest that while the resistance mutation influences thylakoid performance, reduced productivity of triazine-resistant plants cannot be ascribed solely to decreases in electron transport or carbon assimilation rates brought about by the altered binding protein. Since the F(1) hybrids differed from their maternal parents only in nuclear genes, it appears that the detrimental effects of the triazine resistance mutation on plant growth may be attenuated by interactions of the plastid and nuclear genomes.

Journal Article↗
PubMed1990

Similar Photosynthetic Performance in Low Light-Grown Isonuclear Triazine-Resistant and -Susceptible Brassica napus L.

Triazine-resistant plants grown under moderate to high photon flux density (PFD) conditions exhibit decreased photon yield, decreased light-saturated O(2) evolution and slower growth than triazine-susceptible plants. In this study we tested the hypothesis that the comparable growth previously observed in resistant and susceptible Brassica napus L. lines grown under low PFD was accompanied by comparable photon yield and light-saturated O(2) evolution. We measured photon yield, O(2) flash yield, fluorescence decay kinetics, fluorescence transient kinetics, and quenching components, F(v)/F(m) and light saturated O(2) evolution in leaf disks of low PFD-grown triazine-resistant and susceptible B. napus isogenic lines. Results indicated that slow electron transfer from the primary to secondary quinone electron acceptors of photosystem II was still present in the resistant line but photon yield and light-saturated O(2) evolution were similar in the two B. napus lines. We conclude that the alteration in the D1 protein that confers resistance does not necessarily cause decreased photosynthetic performance. Decreased photon yield in resistant plants grown at high PFD is not a direct consequence of the alteration in D1, but represents secondary damage.

Journal Article↗
PubMed2004

Different packing in three polymorphs of 2,4,6-trimethoxy-1,3,5-triazine.

2,4,6-trimethoxy-1,3,5-triazine was found to exhibit three different polymorphs. The alpha-polymorph undergoes reversible phase transformation to the beta-polymorph at 340 K with an enthalpy of 3.9 kJ mol(-1). The heat of fusion of the beta-polymorph at 404 K is 18.1 kJ mol(-1). The low-temperature phase (alpha-polymorph) crystallizes in the orthorhombic space group Pnma. The high-temperature phase (beta-polymorph) can be obtained from the melt and crystallizes in the monoclinic space group P2(1). The gamma-polymorph is obtained by crystallization from a 1:1 mixture of methanol and methylenechloride from hydrolyzed 2,4-dimethoxy-6-oxybenzophenone-1,3,5-triazine. The gamma-polymorph melts at 409 K with an enthalpy of 11.4 kJ mol(-1). The gamma-polymorph crystallizes in the trigonal space group R3c. The molecules occupy a crystallographic threefold axis. Molecules of 2,4,6-trimethoxy-1,3,5-triazine are planar in all three polymorphs. The major difference between the three polymorphs is the mode of packing of the molecules in the crystal.

Journal Article↗
PubMedDate not supplied

Coupled effects of treated effluent irrigation and wetting-drying cycles on transport of triazines through unsaturated soil columns.

The physical and chemical parameters controlling the movement of atrazine (6-chloro-N2-ethyl-N4-isopropyl-l,3,5-triazine-2,4-diamine; 98.8%) and prometryn [N,N'-bis(1-methylethyl)-6-(methylthio)-l,3,5triazine-2,4-diamine; 99.5%] were investigated in columns infiltrated with treated effluent under unsaturated transient conditions and subjected to drying events at 22 or 60 degrees C followed by rewetting. Three soils varying in soil pH and texture and three solutions were used. The infiltrating solutions consisted of either a CaCl2 matrix (CC), a swine waste-derived lagoon effluent (SW), or a simulated buffer solution (SB) representative of the element composition and pH of the SW but with no dissolved organic matter. Several parameters were monitored including leachate triazine concentrations, pH, dissolved organic carbon (DOC), inorganic carbon, and flow rates. Compared with CC, application of SW and SB increased column leachate pH, enhanced dissolution of organic carbon and particle dispersion, and decreased average flow rates, which allowed for increased desorption time. The coupled effect of these processes enhanced movement of triazines in some cases, with SW generally having the greatest effect. The individual effect of increased pH was more pronounced for prometryn (pKa=4.05) versus atrazine (pKa=1.66), and most dramatic for the soil with the lowest initial pH. High-temperature drying, which simulated intensive evaporation, further enhanced the dissolution of soil organic matter and the reduction in leachate flow rates with SW and SB applications; however, the net effect under the experimental conditions employed varied with soil type. Relative to low-temperature drying, high-temperature drying in the silty clay loam-packed columns reduced pesticide migration.

Atrazine↗
PubMed2006

[Determination of triazines in surface water using solid phase extraction-high performance liquid chromatography].

A method was developed to monitor triazines in surface water using the combination of solid phase extraction (SPE) and high performance liquid chromatography. Four different SPE cartridges were tested for extracting six triazines, including atrazine (A), simazine (S), prometryn (P), desethylatrazine (DEA), 2-hydroxyatrazine (OHA) and desisopropylatrazine (DIA), and finally ENVI-18 was selected as optimal. The method for solid phase extraction was further systematically studied for details. Optimal results of orthogonal design were determined as follows: pH 6, 5 mL methanol as eluting solvent, and no methanol added into water sample before extraction. The detection limits of six triazines were 0.14 microg/L for P, 0.12 microg/L for A, 0.08 microg/L for S, 0.08 microg/L for DEA, 0.10 microg/L for OHA and 0.18 microg/L for DIA. This method was applied for environmental aquatic samples, and the results showed that the concentration of prometryn in a lake was detected as (9.33 +/- 0.27) microg/L, as well as the concentrations of atrazine and prometryn in a river were detected as (5.28 +/- 0.43) microg/L and (7.12 +/- 0.54) microg/L respectively.

English Abstract↗
PubMed1988

Synthesis of some 1,2,4-triazine derivatives with potential biological activity.

6-Substituted benzyl-3-thioxo-1,2,4-triazin-5-ones 5a-e and the 4-amino derivatives 12c, e were prepared and converted into their corresponding 3-methylthio derivatives 6a-e and 13c, e, respectively of compounds 6a-e with primary and secondary amines gave the corresponding 3-amino-1,2,4-triazin-5-ones 7a-i and 8a, b. Cyclocondensation of compounds 6a-e and 13c, e with anthranilic acid was proved to give the corresponding triazino [3,2-b] quinazolindiones 9a-e and the 1-amino derivatives 11a, b.

Chemical Phenomena↗
PubMed1976

Conversion of biguanides into substituted s-triazines assayable by GC or mass fragmentography.

Substituted s-triazines were prepared by the treatment of biguanides with various organic acid anhydrides. This reaction permits the ready conversion of the hypoglycemic drugs phenformin, buformin, and metformin and of other analogous biguanides into compounds suitable for GC and mass fragmentographic determination with a high degree of sensitivity. Mass spectral data and Kováts retention indexes are presented for all s-triazines prepared for this study.

Biguanides↗
PubMed1978

Synthesis of as-triazines as potential antiviral agents.

Four acenaphtho[1,2-e]-as-triazines and 11 5,6-diaryl-as-triazines, all substituted with an aliphatic or aromatic amino function in the 3-position, were synthesized. Two acenaphthotriazines were active against vesicular stomatitis virus in tissue culture.

Animals↗
PubMed1982

In vivo pharmacokinetics of triazinate in L-1210 and W-256 cells.

A pharmacokinetic model for triazinate uptake in L-1210 cells in mice and W-256 cells in rats was developed to describe the observed concentration profiles with time in these cells following a 36 mg/m2 ip injection. The L-1210 cell permeability to triazinate was found to the approximately or 15 times smaller compared with W-256 cells. Similarly, the partition coefficient for L-1210 cells was calculated to be approximately or 175 times smaller than for W-256 cells. Cell membrane permeability appears to be the key parameter determining the drug transport at a short time after injection.

Animals↗
PubMed1999

Biodegradation of s-triazine compounds by a stable mixed bacterial community.

The potential for biodegradation of s-triazine pesticides was investigated in laboratory batch and sequence batch experiments using a stable mixed bacterial community enriched on atrazine. The experiments were performed aerobically in a mineral salt solution complemented with a mixture of s-triazines as sole carbon and energy sources. Comparisons were made between the efficiency of the inoculum for atrazine degradation in mineral salt solution and in wastewater. In batch cultivation, atrazine, simazine, hydroxyatrazine, and terbutylazine were degraded to concentrations below 0.1 mg/liter after 6 days; evidence of the mineralization was the detection of 14CO2 from [U-ring-14C] atrazine and the production of nitrate and chloride ions. The low degradation rate observed for cyanuric acid and desethylatrazine suggests that degradation proceeded via N-dealkylation and dechlorination. Nevertheless, degradation of ametryne and cyromazine presume the involvement of other degradation pathways. Evidence was given that presence of other additional carbon sources is not an obstacle to atrazine biodegradation, since better results were obtained using wastewater.

Alcaligenes↗
PubMed1994

Effects of variable selection on CoMFA coefficient contour maps in a set of triazines inhibiting DHFR.

An example of a CoMFA study is described with the aim to discuss one of the major problems of this 3D QSAR method: lack of variable selection. It is shown that the use of nonrelevant energy parameters might produce CoMFA contour maps which poorly reflect the actual nature of the binding site and are in part statistical artefacts. The data set employed in our analysis comprises triazine inhibitors of dihydrofolate reductase (DHFR), isolated from chicken liver, which have already been the object of a QSAR study by other authors. Since three-dimensional structures of triazine-DHFR complexes are known, it was possible not only to reduce ambiguities in the superimposition of the ligands, but also to compare the resulting CoMFA contour maps with the enzyme active site.

Amino Acid Sequence↗