From
Toxline at Toxnet
Congenital
Anomalies 1995 Mar;35(1):123-32
Species
difference in developmental toxicity of an N-phenylimide
herbicide between rats and rabbits and sensitive period
of the toxicity to rat embryos.
Kawamura
S, Kato T, Matsuo M, Sasaki M, Katsuda Y, Hoberman AM,
Yasuda M
Environmental
Health Science Laboratory, Sumitomo
Chemical Co., Ltd., Osaka, Japan.
An N-phenylimide herbicide, S-53482, exhibited developmental
toxicity in rats in the absence of maternal toxicity
at a dose of 30 mg/kg. The developmental toxicities
noted were embryolethality, teratogenicity
(mainly ventricular septal defect (VSD) and wavy ribs)
and growth retardation. In contrast to rats,
the herbicide showed no developmental toxicity in rabbits
even at a maternal toxic dose of 3,000 mg/kg. There
was a remarkable species difference between rats and
rabbits. A single dose of S-53482 was administered
to pregnant rats on one of gestation days 11 through
15 (detection of plug = day 0). Day
12 of gestation was the most sensitive day for embryonic
death, VSD, and decreased fetal body weight.
It is likely that there is a common mechanism for the
three types of developmental toxicity and that S-53482
does not produce VSD by its direct damage to embryonic
heart tissue.
|
Toxicology
and Applied Pharmacology, Vol. 141, No. 2, pages 520-525,
17 references, 1996
Species
Difference in Protoporphyrin IX Accumulation Produced
by an N-Phenylimide Herbicide in Embryos between Rats
and Rabbits
Kawamura S, Kato T, Matsuo M,
Katsuda Y, Yasuda M
Species differences in protoporphyrin-IX accumulation
produced by an N-phenylimide herbicide were studied
in rat and rabbit embryos. Rats and rabbits exhibit
differences in developmental toxicity following treatment
with the herbicide S-53482 (103361-09-7).
S-53482 causes embryolethality,
teratogenicity, and growth retardation in rats,
while no developmental toxicity is seen in rabbits.
The herbicidal activity of S-53482 is due to the photodynamic
action of accumulated protoporphyrin-IX as a result
of inhibition of protoporphyrinogen-oxidase, one of
the key enzymes in prophyrin biosynthesis common to
plants and animals as part of chlorophyll and heme synthesis.
To determine if there is a link between developmental
toxicity and enzyme inhibition, protoporphyrin-IX accumulations
were investigated using embyros from Crj:CD-rats and
JW-rabbits. Pregnant females were dosed with S-53482
at 1,000mg/kg on day 12 of gestation. Protoporphyrin-IX
concentration was increased in rat embryos by two orders
of magnitude when compared to that of untreated embryos.
On the other hand, no increase in proporphyrin
accumulation was seen in rabbit embryos. The authors
conclude that the species differences in proporphyrin
accumulation correspond very well to differences in
developmental toxicity exhibited by S-53482.
|
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9035345&dopt=Abstract
Teratology.
1996 Nov;54(5):237-44.
Histological
changes in rat embryonic blood cells as a possible mechanism
for ventricular septal defects produced by an N-phenylimide
herbicide.
Kawamura
S, Yoshioka T, Kato T, Matsuo M, Yasuda M.
Environmental
Health Science Laboratory, Sumitomo
Chemical Co., Ltd., Osaka, Japan.
An
N-phenylimide herbicide, S-53482,
inhibits protoporphyrinogen oxidase, an enzyme common
to chlorophyll and heme biosynthesis, and produces
embryolethality, teratogenicity [mainly ventricular
septal defects (VSD) and wavy ribs], and growth retardation
in rats. In order to elucidate the mechanism
of the developmental toxicity, in particular VSD, effects
of the herbicide on rat embryonic blood cells were investigated
histologically at the light and electron microscopic
levels at 6, 12, 24, 36, and 48 h after oral administration
of the chemical to pregnant rats on day 12 of gestation,
the most sensitive day for toxicity. Electron and light
microscopy demonstrated mitochondrial lesions, including
abnormal iron deposits that were probably due to inhibition
of heme biosynthesis, in erythroblasts derived from
the yolk sac. Subsequently, degeneration of these erythroblasts
occurred followed by erythrophagocytosis. Histologically
hearts from exposed embryos had a thin ventricular wall,
which may reflect a compensatory reaction to a loss
of embryonic blood cells. Thus, the
herbicide may induce VSD due to hematological dysfunction
caused by the inhibition of heme biosynthesis rather
than by direct injurious effects on the heart.
PMID:
9035345 [PubMed - indexed for MEDLINE]
|
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15382510
Pest Manag Sci. 2004 Sep;60(9):939-43.
Hydrolysis and photolysis of flumioxazin
in aqueous buffer solutions.
Kwon JW, Armbrust KL, Grey TL.
Mississippi State Chemical Laboratory, Mississippi State University,
PO Box CR, Mississippi State, MS 39762-5622, USA.
To determine the degradation rates and degradation products
of the herbicide flumioxazin in aqueous buffer solutions (pH
5, 7 and 9), its hydrolysis and photolysis were investigated
at 30 degrees C in the dark, and in a growth chamber fitted
with fluorescent lamps simulating the UV output of sunlight.
The rate of hydrolysis of flumioxazin was accelerated by increasing
pH. The t(1/2) values at pH 5, 7 and 9 were 16.4, 9.1 and 0.25
h, respectively. Two degradation products were detected and
their structural assignments were made on the basis of LC-MS
data. Degradation product I was detected in all buffer solutions
while degradation product II was detected in acidic buffer only.
Both degradation products appeared to be stable to further hydrolysis.
After correcting for the effects of hydrolysis, the photolytic
degradation rate also increased as a function of pH and was
approximately 10 times higher at pH 7 than that at pH 5, showing
t(1/2) values of 4.9 and 41.5 h, respectively. Degradation products
formed by photolysis were the same as those formed by hydrolysis.
Flumioxazin was degraded more extensively at high pH and should
degrade in surface water.
PMID: 15382510 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15234090
Environ
Pollut. 2004 Sep;131(2):233-41.
Comparison
of different physiological parameter responses in Lemna minor
and Scenedesmus obliquus exposed to herbicide flumioxazin.
Geoffroy
L, Frankart C, Eullaffroy P.
Laboratoire
d'Eco-Toxicologie, Unite de recherche Vignes et Vins de Champagne,
UPRES-EA 2069, Universite de Reims Champagne-Ardenne BP 1039,
F51687 Reims 2, France.
The sensitivity
of different physiological parameters in Scenedesmus obliquus
and Lemna minor exposed to herbicide (flumioxazin) was investigated
to indicate the most convenient and sensitive parameter. To
assess toxicity of flumioxazin, we used a panel of biomarkers:
pigment contents, chlorophyll fluorescence parameters and antioxidative
enzyme activities. Algae and duckweed were exposed to 48-h IC50
for growth rate. In L. minor, the sensitivity of the parameters
was as follows: QN > Oxygen emmision > phiS(PSII) >
QP > phi(PSII) > CAT, GR > Pigment> APO > Growth.
For S. obliquus, this ranking was as follows: CAT > Oxygen
emission > QP > APO > GR > Pigment > phiS(PSII)
> Growth > phi(PSII) > QN (from the greatest to the
least sensitive). The results demonstrated that the observed
toxicity is related not only to interspecific variations but
also to the selected parameter.
PMID: 15234090
[PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15084087
J AOAC Int.
2004 Jan-Feb;87(1):56-9.
Gas chromatographic/mass
spectrometric determination of flumioxazin extracted from soil
and water.
Ferrell
JA, Vencill WK.
University
of Georgia, Department of Crop and Soil Sciences, Athens, GA
30602, USA.
A method
was developed for determining flumioxazin in soil and water.
Recovery efficiencies for solid-phase extraction (SPE) of flumioxazin
from deionized, well, and surface water were between 72 and
77%. SPE was superior to liquid-liquid extraction, using water-hexane
and water-chloroform emulsions, which resulted in retrieval
efficiencies of 25 and 22%, respectively. However, liquid-liquid
extraction with ethyl acetate improved recovery of total flumioxazin
to >64%. Extraction from soil samples by direct solvent/soil
extraction methods recovered between 18 and 76% of applied flumioxazin,
depending on the solvent combination used. However, the use
of accelerated solvent extraction techniques resulted in a 106
+/- 8% recovery of flumioxazin from soil. In analysis by capillary
gas chromatography with mass selective detection, flumioxazin
had a calculated limit of detection of 9 ng/mL with a retention
time of 16.66 min.
PMID: 15084087
[PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14705902
J Agric
Food Chem. 2003 Jul 30;51(16):4719-21.
Flumioxazin
soil persistence and mineralization in laboratory experiments.
Ferrell
JA, Vencill WK.
Department
of Crop and Soil Sciences, University of Georgia, Athens, Georgia
30602.
Flumioxazin
is an herbicide registered for use in soybean and peanut. However,
few published papers concerning the soil persistence of flumioxazin
are available. Therefore, laboratory studies were initiated
to determine the half-life (t(1/2)) of flumioxazin in Greenville
sandy clay loam and Tifton loamy sand soils when incubated at
15 and 25 degrees C. Results indicated that temperature had
little effect on flumioxazin persistence. The t(1/2) for the
Greenville soil was 17.9 and 16.0 days while the Tifton soil
was 13.6 and 12.9 days, at 15 and 25 degrees C, respectively.
These data correspond to the greater clay content of the Greenville
soil (32%) as compared to the Tifton soil (2%). Therefore, the
Greenville soil had greater soil adsorption and less flumioxazin
was generally available to be degraded by soil microorganisms.
In soils that were heat treated to reduce microbe populations,
99% of initial flumioxazin was accounted for after 16 days.
Mineralization of flumioxazin, measured as (14)CO(2) evolution,
was also greater in the Tifton soil (2.2% after 64 days) than
in the Greenville soil (2.0% after 64 days). From these data,
it was concluded that microbes were the most influential factor
concerning the degradation of flumioxazin.
PMID: 14705902
[PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12919779&dopt=Abstract
Chemosphere.
2003 Oct;53(3):199-206.
Stress reactions
in Vitis vinifera L. following soil application of the herbicide
flumioxazin.
Saladin
G, Magne C, Clement C.
Laboratoire
de Biologie et Physiologie Vegetales, URVVC UPRES EA 2069, Universite
de Reims Champagne Ardenne, UFR Sciences, Moulin de la Housse,
BP 1039, F-51687 Cedex 2, Reims, France
In order
to evaluate the stress effects of flumioxazin (fmx) on grapevine,
a non-target plant (Vitis vinifera L.), physiological parameters
such as carbohydrate content, water status or nitrogenous metabolites
were investigated on fruiting cuttings and plants grown in vineyard.
In the leaves of cuttings, the soil-applied herbicide induced
stress manifestations including a decrease of the dry weight
percentage and the soluble carbohydrate content during the first
week after treatment. Thereafter, a decrease of the osmotic
potential was observed, as well as a decrease of total protein
content and a parallel accumulation of free amino acids, including
proline. Altogether, these results suggest that soil-applied
fmx induced a stress in grapevines, leading to leaf proteolysis.
However, this stress was partially recovered 3 weeks after herbicide
application, suggesting that the cuttings were capable to adapt
to the fmx exposure. In the vineyard,
the flumioxazin effects were still significant 5 months after
the treatment, particularly in the CH cv. They included
a decrease of the leaf dry weight percentage and soluble carbohydrate
content, as well as an increase of the osmotic potential. The
decrease of leaf soluble carbohydrates may have dramatic consequences
for the berry growth and the reserve constitution. Moreover,
treated plants were characterized by a decrease of the free
amino acid content and an accumulation of ammonium, while the
protein level did not significantly increase, suggesting a degradation
of amino acids. The alteration of carbon
and nitrogen status after herbicide treatment may affect the
grapevine vigour in a long term.
PMID: 12919779
[PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12822940&dopt=Abstract
J Agric
Food Chem. 2003 Jul 2;51(14):4017-22.
Effects
of Flumioxazin Herbicide on Carbon Nutrition of Vitis vinifera
L.
Saladin
G, Magne C, Clement C.
Laboratoire
de Biologie et Physiologie Vegetales, URVVC UPRES EA 2069, Universite
de Reims Champagne-Ardenne, UFR Sciences, Moulin de la Housse,
BP 1039, 51687 Reims Cedex 2, France.
To evaluate
the impact of the herbicide flumioxazin (fmx) on nontarget
grapevines, its effects were assessed on fruiting cuttings
and field-grown plants. The stress caused by the herbicide differed
according to the grapevine model. In cuttings, leaf gas exchange
and photosynthetic pigment levels as well as hexose contents
decreased, whereas sucrose and starch accumulated, suggesting
an inhibition of photosynthesis and an increase of carbohydrate
reserves as a response to the fmx-induced stress. Paradoxically,
in the field-grown grapevine leaves, fmx caused a stimulation
of photosynthesis, an accumulation of photosynthetic pigments
and monosaccharides, in parallel with a mobilization of sucrose
and starch. These results suggest that fmx reaches grapevine
leaves via root uptake and has prolonged effects. In cuttings,
fmx generated a toxic effect related to its target, whereas
in field-grown plants, fmx had rather positive physiological
effects and acts as a signal further stimulating photosynthesis
and related parameters.
PMID:
12822940 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12789529&dopt=Abstract
Plant Cell
Rep. 2003 Apr;21(8):821-7. Epub
2003 Mar 06.
Impact of flumioxazin
herbicide on growth and carbohydrate physiology in Vitis vinifera
L.
Saladin
G, Magne C, Clement C.
Laboratoire
de Biologie et Physiologie Vegetales, URVVC UPRES EA 2069, Universite
de Reims Champagne-Ardenne, UFR Sciences, Moulin de la Housse,
BP 1039, 51687, Reims Cedex 2, France.
The impact
of flumioxazin herbicide on in vitro-grown
grapevine ( Vitis vinifera L. cv. Chardonnay) was investigated.
The herbicide treatments (1, 10 or 100 micro M flumioxazin in
MM medium) had a negative impact on photosynthesis, as revealed
by a reduction in foliar chlorophyll and carotenoid contents,
gas exchanges and alteration in plastid structure and, consequently,
resulted in a strong inhibition of plantlet growth. Surprisingly,
soluble sugars and starch accumulated in all organs, suggesting
a stimulation of sugar uptake from the medium. Moreover, photosynthetic
activity and starch content partially recovered within 3 weeks
of treatment at the weakest herbicide concentration. These results
provide new insights into the physiological responses of non-target
crops to flumioxazin, showing that flumioxazin is active in
photosynthetic tissues of the non-target grapevine via root
uptake, which is contrary to what is mentioned in the literature,
and that the in vitro-grown plantlet is a good model for investigating
the physiological effects of pesticides on crop species.
PMID: 12789529
[PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12819925&dopt=Abstract
Plant Cell
Rep. 2003 Jun 18 [Epub ahead of
print].
Stress effects
of flumioxazin herbicide on grapevine ( Vitis vinifera L.) grown
in vitro.
Saladin
G, Clement C, Magne C.
UPRES EA
2069 URVVC, Laboratoire de Biologie et Physiologie Vegetales,
UFR Sciences, Universite de Reims Champagne-Ardenne, Moulin
de la Housse, BP 1039, 51687, Reims Cedex 2, France.
Among
the herbicides used in vineyards, the pre-emergence soil-applied
flumioxazin (FMX) is a recently synthesized molecule that inhibits
chlorophyll biosynthesis in weed species. The aim of this work
was to characterize the effects of FMX on non-target grapevine
( Vitis vinifera L. cv. Chardonnay) plantlets grown in vitro.
FMX treatment (from 1 to 100 &mgr; M) represented a stress,
as revealed by measurement of several parameters. Stem and leaves
underwent dehydration and a decrease in both water- and osmotic-potential.
Treated plantlets exhibited concomitant accumulation of soluble
carbohydrates in all tissues and of free proline in stems and
leaves. Moreover, FMX caused lipid peroxidation and electrolyte
leakage in leaf tissues. These results
indicate that the herbicide FMX is toxic for grapevine grown
in vitro. In addition to inhibiting protoporphyrinogen IX oxidase,
it causes water stress and membrane alteration in tissues and,
as a consequence, generates the accumulation of carbohydrates
and free proline.
PMID: 12819925
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12485590&dopt=Abstract
Ecotoxicol
Environ Saf. 2002 Nov;53(3):439-45.
Photosynthetic
responses of Lemna minor exposed to xenobiotics, copper, and
their combinations.
Frankart
C, Eullaffroy P, Vernet G.
Laboratory
of Eco-Toxicology, Europol'Agro, Faculty of Sciences, University
of Reims Champagne-Ardenne, Reims, France. cecile.frankart@univ-reims.fr
The effects
on the photosynthetic process of copper and pesticides, used
in vineyards, and their combinations, were investigated by measuring
different chlorophyll fluorescence parameters in Lemna minor.
Cu and flumioxazin had a severe impact
on duckweed since a decrease in their photosynthetic capacity
was detected after 24h of exposure to 200 and 1 microg.L(-1),
respectively. However, fungicides used to control Botrytis
cinerea (procymidone, pyrimethanil, and fludioxonil) seem to
have no marked effects on duckweed even at very high concentrations
(50 mg.L(-1)). Analysis of the combinations between copper (200
microg.L(-1)) and pesticides revealed different patterns of
response: a synergistic effect was observed when Cu(2+) was
added to flumioxazin (1 microg.L(-1)). In contrast, an antagonism
was detected when duckweed was exposed to a mixture of Cu(2+)
and fludioxonil or procymidone. However, these interactions
always tended toward additivity when pesticide concentrations
increased. Additivity was also observed for the Cu(2+)-pyrimethanil
mixture at each fungicide concentration.
PMID: 12485590
[PubMed - indexed for MEDLINE]
Full
free report available at
http://www.genesdev.org/cgi/content/full/15/1/90
Genes Dev.
2001 Jan 1;15(1):90-103.
A plastidic ABC
protein involved in intercompartmental communication of light
signaling.
Moller
SG, Kunkel T, Chua NH.
Laboratory
of Plant Molecular Biology, Rockefeller University, 1230 York
Avenue, New York, New York 10021-6399, USA.
Plants perceive
light via specialized photoreceptors of which the phytochromes
(phyA-E), absorbing far-red (FR) and red light (R) are best
understood. Several nuclear and cytoplasmic proteins have been
characterized whose deficiencies lead to changes in light-dependent
morphological responses and gene expression. However, no plastid
protein has yet been identified to play a role in phytochrome
signal transduction. We have isolated a new Arabidopsis mutant,
laf (long after FR) 6, with reduced responsiveness preferentially
toward continuous FR light. The disrupted gene in laf6 encodes
a novel plant ATP-binding-cassette (atABC1) protein of 557 amino
acids with high homology to ABC-like proteins from lower eukaryotes.
In contrast to lower eukaryotic ABCs, however, atABC1 contains
an N-terminal transit peptide, which targets it to chloroplasts.
atABC1 deficiency in laf6 results in an accumulation of the
chlorophyll precursor protoporphyrin IX and in attenuation of
FR-regulated gene expression. The long hypocotyl phenotype of
laf6 and the accumulation of protoporphyrin IX in the mutant
can be recapitulated by treating wild-type (WT) seedlings with
flumioxazin, a protoporphyrinogen IX oxidase (PPO) inhibitor.
Moreover, protoporphyrin IX accumulation in flumioxazin-treated
WT seedlings can be reduced by overexpression of atABC1. Consistent
with the notion that ABC proteins are involved in transport,
these observations suggest that functional atABC1 is required
for the transport and correct distribution of protoporphyrin
IX, which may act as a light-specific signaling factor involved
in coordinating intercompartmental communication between plastids
and the nucleus.
PMID: 11156608
[PubMed - indexed for MEDLINE]
http://www.fluorideaction.org/pesticides/flumioxazin.epafacts.apr01.pdf
Environmental
Protection Agency, Washington, DC. Office of Prevention, Pesticides
and Toxic Substances -
2001
Pesticide
Fact Sheet: Flumioxazin.
This document contains up-to-date chemical information, including
a summary of the Agency's regulatory position and rationale,
on a specific pesticide or group of pesticides. A Fact Sheet
is issued after one of the following actions has occurred. Issuance
or reissuance of a registration standard; Issuance of each special
review document; Registration of a significantly changed use
pattern; Registration of a new chemical or; An immediate need
for information to resolve controversial issues relating to
a specific chemical or use pattern.
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10794647&dopt=Abstract
J Agric
Food Chem. 1999 Jun;47(6):2429-38.
Metabolism
of 7-fluoro-6-(3,4,5,6-tetrahydrophthalimido)-4- (2-propynyl)-2H-1,4-benzoxazin-3(4H)-one
(S-53482, flumioxazin)
in the rat: II. Identification of reduced metabolites.
Tomigahara
Y, Onogi M, Kaneko H, Nakatsuka I, Yamane S.
Environmental
Health Science Laboratory, Sumitomo Chemical
Co., Ltd., Kasugade-Naka, Konohana-Ku, Osaka, Japan.
On single
oral administration of (14)C-S-53482 [7-fluoro-6-(3,4,5, 6-tetrahydrophthalimido)-4-(2-propynyl)-2H-1,4-benzoxazin-3(
4H)-one, Flumioxazin] labeled at the 1- and 2-positions of tetrahydrophthaloyl
group to rats at 1 (low dose) or 100 (high dose) mg/kg, the
radiocarbon was almost completely eliminated within 7 days after
administration in both groups with generally very low residual
(14)C tissue levels. The predominant excretion route was via
the feces. The major fecal and urinary metabolites involved
reduction or sulfonic acid addition reactions at the 1,2-double
bond of the 3,4,5,6-tetrahydrophthalimide moiety and hydroxylation
of the cyclohexene or cyclohexane ring. One urinary and four
fecal metabolites were identified using chromatographic techniques
and spectroanalyses (NMR and MS). Three of five identified metabolites
were unique forms, reduced at the 1,2-double bond of the 3,4,5,
6-tetrahydrophthalimide moiety. On the basis of the metabolites
identified in this study, the metabolic pathways of S-53482
in rats are proposed. To specify tissues forming reduced metabolites,
an in vitro study was conducted. Reduction
was found to take place in red blood cells.
PMID: 10794647
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10563890&dopt=Abstract
J Agric
Food Chem. 1999 Jan;47(1):305-12.
Metabolism of
7-fluoro-6-(3,4,5,6-tetrahydrophthalimido)-4- (2-propynyl)-2H-1,4-benzoxazin-3(4H)-one
(S-53482) in rat. 1. Identification
of a sulfonic acid type conjugate.
Tomigahara
Y, Matsui M, Matsunaga H, Isobe N, Kaneko H, Nakatsuka I, Yoshitake
A, Yamane S.
Environmental
Health Science Laboratory, Sumitomo Chemical
Company, Ltd., 1-98, 3-Chome, Kasugade-Naka, Konohana-Ku,
Osaka 554, Japan.
To examine
the metabolic fate of 7-fluoro-6-(3,4,5, 6-tetrahydrophthalimido)-4-(2-propynyl)-2H-1,4-benzoxazin-3(
4H)-one (S-53482), rats were given a single oral dose of [phenyl-(14)C]-S-53482
at 1 (low) or 100 (high) mg/kg. The radiocarbon was almost completely
eliminated within 7 days after administration in both groups.
(14)C recoveries (expressed as percentages relative to the dosed
(14)C) in feces and urine were 56-72 and 31-43%, respectively,
for the low dose and 78-85 and 13-23%, respectively, for the
high dose. S-53482 and seven metabolites were identified in
urine and feces. Six of them were purified by several chromatographic
techniques and identified by spectroanalyses (NMR and MS). Alcohol
derivatives and an acetoanilide derivative were isolated from
urine. Three sulfonic acid conjugates having a sulfonic acid
group incorporated into the double bond of the 3,4,5,6-tetrahydrophthalimide
moiety were isolated from feces. On the basis of the metabolites
identified in this study, the metabolic pathways of S-53482
in rats are proposed.
PMID:
10563890 [PubMed - indexed for MEDLINE]
Teratology,
Vol. 54, No. 5, pages 237-244, 22 references, 1996
Histological
Changes in Rat Embryonic Blood Cells as a Possible Mechanism
for Ventricular Septal Defects Produced by an N-Phenylimide
Herbicide
Kawamura
S, Yoshioka T, Kato T, Matsuo M, Yasuda M
[Note: S-53482 is Flumioxazin]
The effects
of the N-phenylimide herbicide S-53482 (103361097) on rat embryonic
blood cells were examined histologically at the light and electron
microscopic levels. Pregnant Crj:CD-rats were administered S-53482
at 1,000mg/kg by oral intubation on day 12 of gestation. Rats
were sacrificed at 6, 12, 24, 36, or 48 hours after treatment,
and embryos were examined. Mitochondrial lesions were noted
on electron and light microscopic examination, including abnormal
iron deposits likely the result of inhibition of heme
biosynthesis in erythroblasts derived from the yolk sac. Degeneration
of these erythroblasts occurred followed by erythrophagocytosis.
The findings showed that S-53482 did not induce ventricular
septal defects (VSD) due to direct injurious effects on embryonic
heart tissue. The authors suggest that S-53482 did inhibit protoporphyrinogen-oxidase
in rat embryos which suppressed normal heme biosynthesis and
produced erythroblastic regeneration. This in turn resulted
in embryonic anemia. Anemic hypoxia was compensated for by enlargement
of the heart. VSD was then produced by mechanical distortion
of the heart or abnormal cardiac hemodynamics.
From Toxline at Toxnet
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY; 57 (1).
1997. 36-43.
Protoporphyrinogen oxidase of mouse
and maize: Target site selectivity and thiol effects on peroxidizing
herbicide action.
BIRCHFIELD NB, CASIDA JE
Environ. Chem. Toxicol. Lab., Dep. Environ. Sci. Policy Manage.,
Univ. Calif., Berkeley, CA 94720-3112, USA.
BIOSIS COPYRIGHT: BIOL ABS. The action of light-dependent peroxidizing
herbicides involves inhibition of protoporphyrinogen oxidase
(protox) at a high-affinity specific binding site readily assayed
with our new N-aryltetrahydrophthalimide radioligand ((3H)THP),
the desmethyl analog of flumipropyn. Protox of mouse liver mitochondria
and maize etioplasts is similar in sensitivity to most of the
14 herbicides and analogs examined as inhibitors of (3H)THP
binding, indicating that target site specificity is not a major
factor in selective toxicity between mammals and plants. In
assays using mouse protox, the 14 compounds fall into two groups
upon correlating their ability to inhibit (3H)THP binding (without
added thiol) and enzymatic activity (with added glutathione
(GSH) or dithiothreitol (DTT) as an antioxidant for the substrate).
The inhibitory potency of the THPs in protox activity assays
is reduced by DTT relative to their potency in (3H)THP binding
assays without added thiol. This "thiol effect"
CAS Registry Numbers: (CAS Nos. in blue
are fluorinated pesticides)
126100-25-2 - unknown
103361-09-7
- Flumioxazin
87547-04-4 - Flumiclorac
84478-42-2 - 1H-Isoindole-1,3(2H)-dione,
2-(4-chloro-2-fluoro-5-(2-propynyloxy)phenyl)-4,5,6,7-tetrahydro-
50594-67-7 - Acifluorfen-methyl
50594-66-6 - Acifluorfen
42874-03-3 - Oxyfluorofen
40575-34-6 - 1-Pyrrolidinecarboxylic acid, 2,4-dichlorophenyl
ester
39986-11-3 - 1H-Isoindole-1,3(2H)-dione, 2-(4-((4-chlorophenyl)methoxy)phenyl)-4,5,6,7-tetrahydro-
39985-63-2 - 1H-Isoindole-1,3(2H)-dione, 2-(4-chlorophenyl)-4,5,6,7-tetrahydro-
19666-30-9 - Oxadiazon
1836-75-5 - Nitrofen
From Toxline at Toxnet
PEANUT SCIENCE;
23 (1). 1996. 30-36
Flumioxazin for
weed control in Texas peanuts (Arachis hypogaea L.).
GRICHAR
WJ, COLBURN AE
Res. Sci.,
Tex. Agric. Exp. Stn., Yoakum, TX 77995, USA.
Abstract:
BIOSIS COPYRIGHT: BIOL ABS. Field experiments were conducted
in 1991 and 1993 to evaluate flumioxazin alone and in various
herbicide programs for weed control in peanut. Flumioxazin
alone provided inconsistent control of annual grasses,
while the addition of pendimethalin or trifluralin improved
control considerably. Pitted morningglory (Ipomoea lacunosa
L.) and ivy leaf morning glory (Ipomoea hederacea (L.) Jacq.)
control was >75% when flumioxazin was used alone. Flumioxazin
caused early season peanut stunting with some recovery within
4 to 6 wk. Postemergence applications of imazethapyr
or lactofen increased peanut stunting.
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