イマザピック標準品 化学特性,用途語,生産方法
外観
白色〜うすい褐色, 結晶性粉末〜粉末
使用
Imazapic is registered throughout the world for use
in peanuts, rangeland, sugarcane, and imidazolinoneresistant
canola (12). A nonionic surfactant or oil adjuvant
is required for maximum activity.
薬理学
Imazapic kills plants by inhibiting acetolactate synthase
(ALS) (I50 = 1 μM), which is the first common enzyme in
the biosynthesis of the branched chain amino acids, valine,
leucine, and isoleucine. Imazapic is rapidly absorbed
through the leaves of plants. Once it enters the plant,
imazapic translocates to the growing points and growth
ceases within 1 day after herbicide application followed by
chlorosis and then necrosis of the growing points. Total
plant death will occur within 2 to 3 weeks after treatment.
環境運命予測
Imazapic is weakly to moderately adsorbed on sandy loam
and silt loam soils. The Freundlich adsorption coefficient
ranges from 0.17 to 2.99, (12). Because imazapic is a weak
acid and exists in different ionic states, soil pH has an effect
on soil binding properties. The anionic form predominates
at soil pH as low as 5.5, and this form binds weakly to soil. The neutral or molecular form is important at
soil pH from 4 to 6.5. This form binds to soil organic
matter and clay. The cationic form is important at pH
less than 4. Because the soil is a heterogeneous mixture of acid and base chemical groups, there may be sites within
a particular soil that are 2 to 3 pH units higher or lower
than the average pH. The cationic form will bind tightly to
the lower pH components. Because of these interactions,
small decreases in pH below 6 will result in large increases
in binding. The half-life of imazapic in the soil is 106 d.
Imazapic remains in the top 30 cm of the soil with low
leaching potential. The degradation route of imazapic in
the soil has not been determined.
代謝
Plant Metabolism. The selectivity of imazapic is due to
differential rates and routes of metabolism in tolerant
crops versus susceptible weeds(10). Imazapic
has excellent selectivity in peanuts, but is not selective in
soybeans. The difference in the tolerance of these two
legumes is due to the different routes of metabolism
of imazapic in the two crops. The primary metabolite
in soybeans is an imidazopyrrolo-pyridine derivative,
whereas in peanuts, the primary metabolite is the
glucose conjugate of hydroxy-imazapic. Although the
imidazopyrrolo-pyridine derivative formed in soybean is
immobile and is not an inhibitor of acetolactate synthase,
the rate of degradation of imazapic in soybeans is not rapid
enough for selectivity (10). In imidazolinone-resistant
crops, the primary mechanism of selectivity is due to
an altered acetolactate synthase that is not inhibited by
the imazapic (11).
Animal Metabolism (12). Metabolism studies in the rat
showed that imazapic is rapidly excreted in the urine.
There was no accumulation of imazapic or any of its
derivatives in the liver, kidney, muscle, fat, or blood.
イマザピック標準品 上流と下流の製品情報
原材料
準備製品