Metalaxyl химические свойства, назначение, производство
Описание
As an important fungicide group, acylanilides have a
longer history than triazoles. Metalaxyl (44) is one of
the most important fungicides in the group. It originates
from the class of herbicidal chloroacetanilides,
particularly metolachlor (45). Metolachlor, having a
chiral carbon center and a chiral axis, is composed
of four stereoisomers, the most herbicidally
active one of which is the (αR, 1S)-isomer (32). For
the stereoselective synthesis of this isomer, novel
iridium-ferrocenyldiphosphine catalysts for the enantioselective
hydrogenation of N-(2-ethyl-6-methylphenyl)-
N-(1 -methoxymethyl)-ethylidene-amine are reported. In
the most effective approach, the catalyst is generated
in situ from [Ir(cod)Cl]2(cod = cyclooctadiene) and the
ferrocenyldiphosphine ligand (R)-(S)-PPF-P(3,5-xyl)2 (46)
(33).When the substrate to catalyst ratio is 106, the
conversion is complete in 2 to 3 h, producing metolachlor
in optical yields over 80% (34).
Химические свойства
Pale Beige Solid
Использование
Metalaxyl is used for the control of air-borne pathogens by foliar
application and of soil-borne pathogens by soil application on a wide
range of crops. It is particularly useful against Oomycetes including
soil-borne Phytophthora diseases.
Опасность
Moderately toxic by ingestion.
Сельскохозяйственное использование
Fungicide: Metalaxyl is used as a systemic fungicide on a variety of food and non-food crops including tobacco, turf
and conifers, and ornamentals. Used in combination with
fungicides of different mode of action as a foliar spray on tropical and subtropical crops; as a seed treatment to control downy mildew; and as a soil fumigant to control soilborne pathogens.
Торговое название
AGROX® PREMIERE; ALLEGIENCE®;
APRON®; CG 117®; CGA-48988®; CHLORAXYL®;
COTGUARD®; EPERON®; DELTA-COAT; FOLIO®
GOLD; GAUCHO®; KODIAK®; METALAXIL®;
METAXANIN®; PACE®; PREVAIL®; RAXIL® (tebu-
conazole + metalaxyl); RIDOMIL® GOLD/BRAVO®;
RIDOMIL®; RIDOMIL 2E®; SUBDUE®
Фармаколо?гия
In mycelium of Phytophthora
megasperma,metalaxyl affected primarily rRNA synthesis
(polymerase I), whereas mRNA was much less sensitive;
therefore, inhibition of rRNA synthesis is considered as
the primary site of action of PAFs (23).
The PAFs exhibit strong preventive and curative
activity. They affect especially hyphal growth (inside and
outside the plant tissue) as well as haustorium and spore
formation (15). Although not fully utilized for resistance
management reasons, PAFs also exhibit strong eradicative
and antisporulant activity in the disease cycle of target
pathogens. On the other hand, PAFs do not inhibit the
early stages in the disease cycle like zoospore release,
spore germination, and penetration of the host tissue (15).
Because spores contain many ribosomes to support early
growth stages, RNA synthesis is fully operating only
after spore germination; later development stages are
therefore most sensitive to PAFs (23). As a consequence
of RNA inhibition, the precursors of RNA synthesis (i.e.,
nucleoside triphosphates) are accumulated; they activate
β-1,3-glucansynthetases, which are involved in cell wall
formation (23). Metalaxyl-treated hyphae often produce
thicker cell walls than do untreated ones.
Профиль безопасности
Moderately toxic by
ingestion. When heated to decomposition it
emits toxic fumes of NOx.
Возможный контакт
Metalaxyl is phenylamide systemic
fungicide used on a variety of food and nonfood crops
including tobacco, turf and conifers, and ornamentals. Used
in combination with fungicides of different mode of action
as a foliar spray on tropical and subtropical crops; as a seed
treatment to control downy mildew; and as a soil fumigant
to control soil-borne pathogens. Banned for use in EU.
Экологическая судьба
Soil. Little information is available on the degradation of metalaxyl in soil; however,
Sharom and Edgington (1986) reported metalaxyl acid as a possible metabolite. Repeated
applications of metalaxyl decreases its persistence. Following an initial application, the
average half-life was 28 days. After repeated applications, the half-life decreased to 14
days (Bailey and Coffey, 1985).
Carsel et al. (1986) studied the persistence of metalaxyl in various soil types. The
application rate was 2.2 kg/ha. In a fine sand, metalaxyl concentrations at soil depths of
15, 20, 45 and 60 cm were 100, 150, 100 and 75 ppb, respectively, 55 days after
Plant. In plants, metalaxyl undergoes ring oxidation, methyl ester hydrolysis, ether
cleavage, ring methyl hydroxylation and N-dealkylation (Owen and Donzel, 1986). Metalaxyl
acid was identified as a hydrolysis product in both sunflower leaves an
In pigeon peas, metalaxyl may persist up to 12 days (Indira et al., 1981; Chaube et
al., 1984).
Метаболический путь
O-Demethylation is one of the major routes of
metalaxyl degradation in the plant cell suspension
culture. Although hydroxylation of methyl groups in the
phenyl ring predominates in both lettuce and grapes,
species differences are evident in grapes, whereas
N-dealkylation and aryl hydroxylation are less
important in lettuce. Two isomeric metabolites of
methyl hydroxylation and the hydroxylated metabolite
of the phenyl ring are identified as fungus metabolites.
By UV irradiation of metalaxyl in aqueous solution, two
rearrangement products of the N-acyl group to the
4-position on the phenyl ring are identified.
Перевозки
UN3077 Environmentally hazardous substances,
solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous
material, Technical Name Required.
Несовместимости
Incompatible with alkaline materials,
strong acids, oxidizers (chlorates, nitrates, peroxides, permanganates,
perchlorates, chlorine, bromine, fluorine, etc.);
contact may cause fires or explosions. Compounds of the
carboxyl group react with all bases, both inorganic and
organic (i.e., amines) releasing substantial heat, water and a
salt that may be harmful. Incompatible with arsenic compounds
(releases hydrogen cyanide gas), diazo compounds,
dithiocarbamates, isocyanates, mercaptans, nitrides, and
sulfides (releasing heat, toxic, and possibly flammable
gases), thiosulfates and dithionites (releasing hydrogen sulfate
and oxides of sulfur).
Утилизация отходов
Small amounts may be
destroyed by alkaline hydrolysis. Admixture with alkali
can be followed by soil burial. Larger quantities can be
disposed of by incineration in admixture with acetone or
xylene and using effluent gas scrubbing. Do not reuse
empty container; proper disposal required.
Metalaxyl препаратная продукция и сырье
сырьё
препарат