http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12809295
J Environ Qual. 2003 May-Jun;32(3):949-56.
Soil sorption of acidic pesticides: modeling
pH effects.
Spadotto CA, Hornsby AG.
Embrapa Environment. C.P. 69, 13820-000 Jaguariuna, SP, Brazil.
spadotto@cnpma.embrapa.br
A model of acidic pesticide sorption in soils was developed
from theoretical modeling and experimental data, which initially
considered a combination of a strongly acidic pesticide and
a variable-charge soil with high clay content. Contribution
of 2,4-D [(2,4-dichlorophenoxy) acetic acid] anionic-form sorption
was small when compared with molecular sorption. Dissociation
of 2,4-D was not sufficient to explain the variation in Kd as
a function of pH. Accessibility of soil organic functional groups
able to interact with the pesticide (conformational changes)
as a function of organic matter dissociation was proposed to
explain the observed differences in sorption. Experimental 2,4-D
sorption data and K(oc) values from literature for flumetsulam
[N-(2,6-difluorophenyl)-5-methyl [1,2,4] triazolo [1,5-a] pyrimidine-2-sulfonamide]
and sulfentrazone [N-[2,4-dichloro-5-[4-(difluromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]
phenyl] methanesulfonamide] in several soils fit the model.
PMID: 12809295 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10432190&dopt=Abstract
Cell Mol
Biol (Noisy-le-grand) 1999
Jun;45(4):433-44
Protoporphyrin
IX fluorescence kinetics in C6 glioblastoma cells after delta-aminolevulinic
acid incubation: effect of a protoporphyrinogen oxidase inhibitor.
Carre
J, Eleouet S, Rousset N, Vonarx V, Heyman D, Lajat Y, Patrice
T
Departement
Laser, Hopital Laennec, Nantes, France.
PpIX synthesis
after incubation with delta-aminolevulinic acid (ALA) is highly
variable from one cell to another within a single cell population
and in human glioblastomas in vivo. To improve PpIX synthesis,
we attempted to modify the PpIX synthesis pathway in a C6 glioma
cell model. To perform this experiment we used confocal microspectrofluorometry
to analyse the effects of a highly purified form of sulfentrazone
(FP846) on the kinetics of PpIX synthesis after ALA administration
to living C6 cells. Our results show that PpIX fluorescence
was maximal (seven-fold higher than basal values) 3 to 4 hrs.
after the beginning of incubation with ALA. FP846 depressed
this increase in fluorescence nearly to basal levels not only
in C6 cells but also in HT29 and HepG2 cells. Fluorescence spectra
shape were not affected by FP846, except for intensity. ALA/PpIX-induced
photocytoxicity was perfectly correlated with fluorescence intensity
recorded in cell cytoplasm. ALA alone (100 microg/ml) did not
induce a significant decrease in cell survival, but irradiation
of 25 J/cm2 leading to an overall cell death of 60%. FP846 added
together with ALA suppressed ALA/PpIX-induced phototoxicity.
The fact that the FP846-induced decrease in PpIX synthesis was
not the same in animal and plant cells suggests that the porphyrin
metabolic pathway differs due to the relative amounts of substrate
or the effect of inhibitor and that another chemical would be
needed alone or in combination with FP846 to improve PpIX synthesis.
PMID: 10432190, UI: 99359137
From Toxline at Toxnet
WEED SCIENCE; 46 (2). 1998. 271-277.
Evaluation of soybean injury from sulfentrazone
and inheritance of tolerance.
SWANTEK JM, SNELLER CH, OLIVER LR
Dep. Agron., Univ. Arkansas, Fayetteville, AR 72704, USA.
BIOSIS COPYRIGHT: BIOL ABS. Experiments were conducted in the
field and greenhouse to evaluate the effects of cultivar and
sulfentrazone rate on soybean injury and yield from soil-applied
sulfentrazone and to determine soybean inheritance of sulfentrazone
tolerance. Excessive rainfall and cool
growing conditions in 1996 enhanced sulfentrazone injury and
caused yield reduction in the susceptible cultivars 'KS4895'
and 'Hutcheson at 0.56 kg ai ha-1 and KS4895 at 0.42 kg ha-1.
Yields of tolerant cultivars 'Deltapine 3478' and 'Manokin'
were not reduced. Sulfentrazone at 0.42
kg ha-1 reduced soybean stand 17 and 35% for tolerant and susceptible
cultivars, respectively. Field and greenhouse inheritance
studies were conducted on plant families developed from two
crosses: Manokin (tolerant) by 'Asgrow A4715' (susceptible)
and 'Northrup King S59-60' (tolerant) by KS4895 (susceptible).
The sulfentrazone tolerance of Manokin and Northrup King S59-60
appeared to be controlled by a single gene, with tolerance
From Toxline at Toxnet
Source:
214TH AMERICAN CHEMICAL SOCIETY NATIONAL MEETING, LAS VEGAS,
NEVADA, USA, SEPTEMBER 7-11, 1997.
ABSTRACTS OF PAPERS AMERICAN CHEMICAL SOCIETY; 214 (1-2). 1997.
AGRO 114.
THE
TRUE STORY SULFENTRAZONE METABOLITES IN VARIOUS CROPS
CHEN AW
BIOSIS COPYRIGHT: BIOL ABS. RRM MEETING ABSTRACT PLANT SULFENTRAZONE
HERBICIDE METABOLISM UPTAKE 3-HYDROXYMETHYL SULFENTRAZONE METABOLITE
SULFENTRAZONE-3-CARBOXYLIC ACID DECARBOXYLATION 3-DESMETHYL
SULFENTRAZONE PESTICIDES BIOCHEMISTRY AND BIOPHYSICS AGRONOMY
From Toxline at Toxnet
Source: 213TH NATIONAL MEETING OF THE AMERICAN CHEMICAL SOCIETY,
SAN FRANCISCO, CALIFORNIA, USA, APRIL 13-17, 1997. ABSTRACTS
OF PAPERS AMERICAN CHEMICAL SOCIETY; 213 (1-3). 1997.
AGRO 96.
FORMATION AND DECLINE OF MAJOR SULFENTRAZONE
PHOTOPRODUCTS IN BUFFERED AQUEOUS SOLUTION BY SIMULATED SUNLIGHT
WILLUT JM, MCLAUGHLIN TM, SHOMO RE, FANG
XP, GRAVELLE WD, VARANYAK LA
BIOSIS COPYRIGHT: BIOL ABS. RRM MEETING ABSTRACT PESTICIDES
SULFENTRAZONE FILTERED XENON LAMP BUFFERED AQUEOUS SOLUTION
PHOTOLYSIS SIMULATED SUNLIGHT EQUIPMENT
From Toxline at Toxnet
WEED SCIENCE; 45 (5). 1997. 733-738.
Sulfentrazone adsorption and mobility
as affected by soil and pH.
GREY TL, WALKER RH, WEHTJE GR, HANCOCK
HG
1733 N. Longgrove Rd., Cecilia, KY 42724, USA.
BIOSIS COPYRIGHT: BIOL ABS. Laboratory experiments were conducted
to evaluate soil adsorption and mobility of sulfentrazone. Sulfentrazone
is a new phenyl triazolinone herbicide intended for use in soybean.
Adsorption was evaluated through a soil solution technique,
and mobility was evaluated with soil thin-layer chromatography.
Experimental variables included soil, sulfentrazone concentration
(adsorption study only), and pH. Adsorption was influenced by
all experimental variables; however, pH had the greatest effect.
Adsorption generally decreased in response co increasing pH.
However, the greatest decrease occurred above the pKa of sulfentrazone
(i.e., 6.56). Mobility generally reflected adsorption.
Pesticide Biochemistry and Physiology; Volume 53, Issue 3 , November
1995, Pages 172-179
Microbioassays to Determine the Activity
of Membrane Disrupter Herbicides
Molin W. T. and Khan R. A.
Univ Arizona, Dept Plant Sci, Tucson, AZ 85721, USA
Two methods to determine the activity of membrane disrupter
herbicides on leakage from cucumber (Cucumis sativa L., "Medalist")
cotyledon discs are described. In these bioassays, leakage could
be measured from a single disc (4 mm diameter) in 300 l of incubation
solution. The 96-well microtiter plates were convenient assay
containers because a large number of replications and herbicide
concentrations could be rested side-by-side without an excessive
space requirement. In the first assay, nitrite leakage was measured
from discs incubated in nitrate solution. Nitrite was sequestered
in cells as long as the membranes remained intact. A loss in
membrane integrity, caused by membrane
disrupter herbicides (acifluorfen, oxyfluorfen, paraquat,
oxadiazon, sulfentrazone), resulted
in the leakage of nitrite into the incubation solutions. Membrane
disruption was also measured directly with N-methyl benzothionoline
hydrazone hydrochloride which forms a stable chromatophore with
saturated and unsaturated aldehydes, ketones, keto acids, and
many other related compounds. Leakage of ammonia and malonyl
dialdehyde were also measured. These assays may have advantages
in industrial or academic laboratories where comparison of the
activities of herbicides under several experimental conditions
is necessary.
From Toxline at Toxnet
Journal of Agricultural and Food Chemistry, Vol. 39, No. 8,
pages 1509-1514, 6 references, 1991
Metabolism and Distribution of the Experimental
Triazolone Herbicide F6285 (1-(2,4-dichloro-5-(N-(methylsulfonyl)amino)phenyl)-1,
4-dihydro-3-methyl-4-(difluoromethyl)-5H-triazol-5-one) in the
Rat, Goat, and Hen
Leung LY, Lyga JW, Robinson RA
A series of investigations was conducted in Sprague-Dawley-rats,
lactating dairy goats, and white-leghorn-laying-hens to gain
an understanding of the comparative metabolism of F6285 (122836355)
in animals. Oral doses of carbon-14 radiolabeled F6285 were
administered to rats at 10mg/kg; to lactating dairy goats at
2mg/kg, 300 parts per million (ppm) in feed daily for 5 days;
and to hens at 3mg/kg, 45ppm in diet daily for 7 days. These
doses were quantitatively excreted in the urine, feces or hen
excreta. In all the species examined, unchanged F6285 and two
nonconjugated metabolites were noted. These
metabolites were isolated and characterized by mass spectrophotometry
or nuclear magnetic resonance as the 3-hydroxymethyl
derivative of F6285 and the corresponding 3-carboxylic acid.
The latter decomposed at high temperatures or acid pH to give
the corresponding 3-demethyl compound. In the rat, a minor metabolite,
tentatively characterized as the 2,3-dihydro-3-hydroxymethyl
derivative of F6285 was also detected. A minimal residence
was observed in edible animal tissue, milk and eggs.
