Conversion of the aldrin/dieldrin metabolite dihydrochlordene dicarboxylic acid-14C in rats

Upon intravenous application of dihydrochlordene dicarboxylic acid-¹⁴C to rats, the radioactivity is quickly excreted, and 44% of the excreted radioactivity consists of metabolites. Nine metabolites have been isolated from feces and urine extracts. Three metabolites could be identified by means of authentic samples by thin layer chromatography, gas chromatography, and mass spectrometry: two isomers of dechlorodihydrochlordene-dicarboxylic acid (metabolites I and II, total 22.5%) and dihydrochlordene-dicarboxylic acid-dimethyl-ester (metabolite III, 11.3%).     

Microsomal oxidase activities in relation to age and chlorcyclizine induction in American cockroach,Periplaneta americana,fat body,midgut and hindgut

Female adult American cockroaches, Periplaneta americana L., showed definite age-dependent changes in levels of activity of the microsomal mixed-function oxidases. Cytochrome P-450 levels, EPN-detoxication, and p-nitroanisole O-demethylation activities were very low in young adult insects but increased steadily reaching a natural peak at about 100 days in fat body and at about 90 days in midgut and hindgut. The activities then declined rapidly reaching levels of young insects at about 130 to 140 days of age. NADPH-neotetrazolium-reductase activity was high in young insects, declined later in adult life, and returned to a peak at about 100 days.Injections of chlorcyclizine, a known microsomal enzyme inducer, significantly increased levels of cytochrome P-450, EPN-detoxication, p-nitroanisole O-demethylation, and NADPH-NT-reductase activities in young cockroaches. The drug injections were effective, however, only before the natural activity peak was reached. Beyond this point the injections had no inductive effect indicating that the microsomal oxidases in this insect are uninducible when normal enzyme levels are falling.NADPH-NT-reductase activity in male cockroaches, while being somewhat higher than in females, showed a similar age-dependent curve with the peak occurring at about 120 days.Age-dependent carbaryl resistance in male and female insects tended to follow levels of the microsomal oxidase activities. Fifty to 60-day-old insects, however, tended to be more resistant to the insecticide than microsomal enzyme levels would indicate.RNA levels of normal female insects showed age-dependent curves similar to those of the microsomal enzyme activities, being low in young adults and reaching a peak at about 100 days. Chlorcyclizine injections had little or no effect on total microsomal RNA levels.     

Behavior of 14C oryzalin in soil and plants

Radiochemical studies of field soil treated with ¹⁴C oryzalin (3,5-dinitro-N⁴,N⁴-dipropylsulfanilamide) indicated that the compound was readily degradable. One year after soil treatment with oryzalin, 45% of the original radioactivity had dissipated, 25% was extractable, and 30% was “soil bound”. The extractable fraction contained oryzalin and several degradation products, some of which were isolated and identified. No single degradation product accounted for more than 3% of the applied oryzalin. The “soil-bound” radioactivity was extractable with hot alkali. No significant radioactive residues were detectable in either seed or forage of soybean and wheat plants. No specific metabolites of oryzalin were identified in soybean plants. Trace amounts of radioactivity found in plant tissue appeared to be associated with the various plant constituents.     

Studies on effects of certain quinones: III. Photosynthetic 14CO2 incorporation by Rhodospirillum rubrum

Substituted naphthoquinones, 2,3,-dichloro-1,4-naphthoquinone, and 2-methyl-1,4-naphthoquinone produced marked changes in the pattern of ¹⁴C-distribution during ¹⁴CO₂-fixation by photosynthetic bacterium Rhodospirillum rubrum. The most obvious change in the labeling pattern during photoautotrophic ¹⁴CO₂-fixation was a several-fold increase in 3-phosphoglyceric acid accompanied with a decrease in the amount of glutamate. In photoheterotrophic cells, quinones caused an appreciable increase in ¹⁴C-glycolic acid and concomitant decrease, although not proportional, in the amount of ¹⁴C-sugar phosphate. The level of ¹⁴C-incorporated in poly-β-hydroxybutyrate and ether-extractable lipids was considerably decreased in photoautotrophic and photoheterotrophic cells treated with quinones. The ability of quinones to interfere with the synthesis of NADH and ATP, and their ability to interact with sulfhydryl enzymes and coenzymes appears to be responsible for the changes observed.     

Characterization of acetylcholinesterases of acaricide-resistant and susceptible strains of the cattle tick Boophilus microplus (Can.): I. Extraction of the critical component and comparison with enzyme from other sources

The critical acetylcholinesterase component, that is responsible for the resistance mechanism of decreased sensitivity to the inhibitor in the cattle tick Boophilus microplus (Can.), has been isolated from the organophosphorus-susceptible Yeerongpilly and resistant Biarra and Ridgelands strains. With the substrate acetylthiocholine this enzyme component gave a pH activity profile similar for all strains. Optimal substrate concentration for Ridgelands was 1.73.10^?2M compared to 2.70.10^?4M for the other strains. Computed Km values were 1.98.10^?5M, 3.65.10^?5M, and 6.43.10^?6M for Yeerongpilly, Biarra, and Ridgelands strains, respectively, while the corresponding V_max figures were 336, 135, and 21 μmoles acetylthiocholine hydrolyzed per gram of larvae per hour. These results are discussed in relation to the resistance mechanism and compared with similar parameters derived for this enzyme from bovine erythrocytes, the sheep blowfly Lucilia cuprina, and the sheep nematode Trichostrongylus colubtiformis.     

Effect of 2,4,5-T and picloram on the regeneration of blackberry (Rubus procerus P.J. Muell) from root segments

The formation of roots and shoots on root segments of Rubus procerus P.J. Muell was prevented by soaking the segments for 24 h in a 10^?4M solution of 2,4,5-T or a 10^?5M solution of picloram. Shoot numbers were significantly increased after treatment with 10^?9M and 10^?10M 2,4,5-T, but picloram did not cause a significant increase in shoot numbers. Measurement of the concentration of 2,4,5-T in the extracambial tissue showed that roots treated with 10^?4M 2,4,5-T contained 5× 10^?8 mmole 2,4,5-T per mg dry weight, and by extrapolation, roots treated with 10^?9M 2,4,5-T contained 2× 10^?10 mmole/mg dry weight. Action du 2,4,5-T et du piclorame sur la régénération de la ronce (Rubus procerus P.J. Muell) è partir de fragments de racines La formation de racines et de tiges è partir de fragments de racines dc Ruhus procerus P.J. Muell a été supprimée par trempage des fragmenls pendant 24 heures dans une solution a 10^?4M et de 2.4,5-T, ou dans une solution 10^?5M de piclorame. Le nombre de pousses s'est accru significativement après traitement avec le 2,4,5.-T è 10^?9M et 10^?10M, mais le piclorame n'a pas provoqué d'accroissemcnt significatif du nombre de pousses. La mesure de la concentration de 2,4,5-T dans le tissu extra-cambial a montré que les racines trailées avec du 2,4,5-T è 10^?4M contenaient 5×10^?8 mmole de 2.4,5-T par mg de poids sec et par extrapolation, quc les racines traitées avec du 2,4,5-T k 10^?9M devaient contenir 2 × 10^?12 mmole/mg de poids sec. Die Wirkiing von 2,4,5-T und Picloram auf den Wuchs der Wurzehegmenten von Bromheeren (Rubus procerus P.J. Muell). Die Bildung von Wurzeln und Sprossen aus Wurzelsegmen-ten von Ruhu.i procerus P.J. Muell wurde durch 24-stündiges Einlegen der Wurzelstücke in 10^?4M 2,4,5-T bzw 10^?5M Picloram verhindert. Die Anzahl neugebiideter Sprosse wurde nach Einlegen in 10^?9M und 10^?10M 2,4,5-T, nicht jedoch durch Picloram, signifikant erhöht. Im extracambialen Gewebe von Wurzeln, die mit 10^?4M 2,4,5-T behand-elt worden waren, wurden 5×10^?8mMol 2,4,5-T je mg Trockengewiclu bestimmt. Durch Extrapolation wurde ermittclt. dass mit 10^?9M 2,4,5-T behandelte Wurzeln 2× 10^?12mMol/mg Trockengewicht cnthielten.     

Alfalfa metabolism of propham

Root-treated alfalfa absorbs, translocates, and metabolizes [phenyl-¹⁴C]isopropyl carbanilate ([¹⁴C]propham). After 7 days of root treatment, the distribution of radiolabel was 73% for shoots and 27% for roots. Shoots and roots were extracted and separated into the polar, nonpolar, and solid residual components using a mixture of chloroform, methanol and water. The insoluble residues accounted for approximately 40% of the ¹⁴C found in shoots and roots. The nonpolar fraction (6.1% of the radiolabel in shoots and roots) was not characterized, but was shown to be some component other than parent propham. Propham was not found in either shoots or roots. The polar metabolites were partly purified on Amberlite XAD-2. Cellulase-liberated aglycones were derivatized and separated by high-performance liquid and gas-liquid chromatography. The infrared, nuclear magnetic resonance, and mass spectral data showed that the polar metabolites of alfalfa shoots and roots were glycoside conjugates of isopropyl 2-hydroxycarbanilate (2-hydroxypropham) and isopropyl 4-hydroxycarbanilate (4-hydroxypropham). Conjugated 4-hydroxypropham accounted for 45.9% of the ¹⁴C in the shoots and 3.4% of the ¹⁴C in the roots. Conjugated 2-hydroxypropham accounted for 3.4% of the ¹⁴C in the shoots and 1.4% of the ¹⁴C in the roots.     

Mercapturic acid formation in the metabolism of propachlor,CDAA, and fluorodifen in the rat

When [¹⁴C]F₃-fluorodifen (2,4′-dinitro-4-trifluoromethyl diphenylether), carbonyl-[¹⁴C]CDAA (N,N-diallyl-2-chloroacetamide), and carbonyl-¹⁴C-propachlor (2-chloro-N-isopropylacetanilide) were fed to rats, 57 to 86% of the ¹⁴C was excreted via the urine within 48 hr. Although very little radioactivity was excreted in the feces of CDAA-treated rats, 15–22% of the ¹⁴C was excreted in the feces of propachlor- of fluorodifentreated rats and an average of 8% of the ¹⁴C remained in these rats 48 hr after treatment. Oxidation of the ¹⁴C label to [¹⁴C]O₂ was not a major process in the metabolism of these herbicides. The only major radioactive metabolite present in the 24-h urine of fluorodifen-treated rats, 2-nitro-4-trifluoromethylphenyl mercapturic acid, accounted for 41% of the administered dose of ¹⁴C. In the metabolism of CDAA, the corresponding mercapturic acid accounted for 76% of the dose; it was the only major metabolite present in the 24-h urine. In contrast, three major metabolites were detected in the 24-h urine of propachlortreated rats, and the mercapturic acid accounted for only 20% of the dose. The mercapturic acid of each herbicide was identified by mass spectrometry.     

Antifungal mode of action of triforine

Rapidly growing mycelia of Aspergillus fumigatus treated with 10 μg/ml triforine (N,N′-bis-(1-formamido-2,2,2-trichloroethyl)-piperazine) showed little or no inhibition in dry weight increase prior to 2 h. By 2.5–3 h, triforine inhibited dry weight increase by 85%. The effects of triforine on protein, DNA, and RNA syntheses corresponded to the effect on dry weight increase both in time of onset and magnitude. Neither glucose nor acetate oxidation were inhibited by triforine.Ergosterol synthesis was almost completely inhibited by triforine even in the first hour after treatment. Inhibition of ergosterol synthesis was accompanied by an accumulation of the ergosterol precursors 24-methylenedihydrolanosterol, obtusifoliol, and 14α-methyl-Δ^{8, 24 (28)}-ergostadienol. Mycelia treated with 5 μg/ml of triarimol (α-(2,4-dichlorophenyl)-α-phenyl-5-pyrimidinemethanol) also accumulated the same sterols as well as a fourth sterol believed to be Δ^{5, 7}-ergostadienol.Identification of 4,4-dimethyl-Δ^{8, 24 (28)}-ergostadienol in untreated mycelia indicates that the C-14 methyl group is the first methyl group removed in the biosynthesis of ergosterol by A. fumigatus. The lack of detectable quantities of 4,4-dimethyl-Δ^{8, 24 (28)}-ergostadienol in triforine or triarimol-treated mycelia and the accumulation of C-14 methylated sterols in treated mycelia suggests that both fungicides inhibit sterol C-14 demethylation. The accumulation of Δ^{5, 7}-ergostadienol in triarimol-treated mycelia further implies that triarimol also inhibits the introduction of the sterol C-22(23) double bond.Two strains of Cladosporium cucumerinum tolerant to triforine and triarimol were also tolerant to the fungicide S-1358 (N-3-pyridyl-S-n-butyl-S′-p-t-butylbenzyl imidodithiocarbonate).     

Etude des phénomènes de sorption entre deux triazines herbicides et des acides humiques

A study of sorption phenomena between two triazine herbicides and humic acids Terbutryne is very readily adsorbed by humic acids while atrazine is only slightly adsorbed and this only in an acid environment. The influence of pH on adsorption and the competitive effect of the cations Ca²⁺, Al³⁺ and Fe³⁺ shows that the proton form of the molecules of the two herbicides can be adsorbed by an ion exchange-type mechanism; the neutral form of terbutryne molecules could be adsorbed by other mechanisms. Desorption of terbutryne is accompanied by a more marked hysteresis phenomenon in the case of neutral molecules, and, in an acid environment, calcium shows a weak capacity for displacement in relation lo the adsorbed herbicide.