Pyribenzoxim 嘧啶肟草醚

嘧啶肟草醚

化学名称:
O-[2,6-双-(4,6-二甲氧基-2-嘧啶基) 氧基苯甲酰基]二苯甲酮肟

英文名称: pyribenzoxim

主要性质
熔点128-130℃，常温下为白色无味粉末状固体，能溶于水，及一些常见的有机溶剂，在极性较强的有机溶剂中溶解度较高。在中性及弱碱、弱酸性水中理化性质稳定，高温下稳定性逐渐降低。

生物活性
选择性输导型除草剂，其活性成分被植物茎叶吸收后，在体内迅速传导至幼嫩组织和根部，影响乙酰乳酸合成酶(ALS)的活性，抑制植物支链氨基酸的合成，从而使杂草枯死。该药剂被敏感植物吸收后，幼芽和根系停止生长，幼嫩组织发黄，进而整株出现趋近死亡。整个过程所需的时间较长，约10-15天受药杂草彻底死亡。主要应用于水稻移栽田、直播田的稗草、一年生莎草及阔叶杂草的防除。施药前最好将稻田中水排干，该药剂施用一周内，水稻略有发黄现象，一周后恢复，不影响产量。对哺乳动物眼睛和皮肤无刺激性，对鱼、鸟、蜂、蚕低毒。

【防治对象】广谱性除草剂，对水稻移栽田、直播田的稗草、一年生莎草及阔叶杂草有较好的防除效果。可以防除稗草、野慈姑、雨久花、谷精草、母草、狼把草、萤蔺、日本藨草、眼子菜、四叶萍、鸭舌草、节节菜、泽泻、牛毛毡、异型莎草、水莎草、千金子等。

【适用时期】
移栽田播后杂草基本出齐；抛秧田抛秧后杂草基本出齐；直播田苗后稗草3.5－4.5叶期。

【使用技术】每公顷用1%乳油3750－5250毫升（每亩250－350毫升），一年生杂草用低药量，多年生杂草用高药量。选风小、晴天、气温较高时施药，施药前排水，使杂草露出水面再喷雾。喷液量每公顷450－600升（每亩30－40升）。施药后1－2天再灌水入田，1周内水层保持5－7厘米。

【风险提示】
嘧啶肟草醚对水稻的药害：药量过高，有效成分＞60克/公顷或者重复喷施或者施药后遇低温对水稻产生药害，表现为抑制水稻生长，水稻叶发黄，对水稻产量有影响。

pyribenzoxim
Herbicide
HRAC B WSSA 2; pyrimidinyloxybenzoic

NOMENCLATURE
Common name pyribenzoxim (BSI, pa ISO)
IUPAC name benzophenone O-[2,6-bis(4,6-dimethoxypyrimidin-2-yloxy)benzoyl]oxime
Chemical Abstracts name diphenylmethanone, O-[[2,6-bis(4,6-dimethoxy-2-pyrimidinyl)oxy]benzoyl]oxime
CAS RN [168088-61-7] Development codes LGC-40863 (LG Chemical)

PHYSICAL CHEMISTRY
Mol. wt. 609.6 M.f. C32H27N5O8 Form White, odourless solid. M.p. 128-130 °C V.p. <9.9 ´ 10-1 mPa KOW logP = 3.04 Solubility In water 3.5 ppm (25 °C).

COMMERCIALISATION
History Reported by J. H. Cho et al. (Proc. 1997 Br. Crop Prot. Conf. - Weeds, 1, 39). Registered in Korea in 1997 and under development by LG Life Sciences Ltd. Patents EP 658549 A1 Manufacturers LG

APPLICATIONS
Biochemistry Branched chain amino acid synthesis (ALS or AHAS) inhibitor. Selectivity appears to derive from differential metabolism rates. Uses Post-emergence herbicide, controlling barnyardgrass (Echinochloa spp.), blackgrass (Alopecurus myosuroides) and polygonums in rice, wheat and zoysiagrass, at 30 g/ha. Formulation types EC Selected products: 'Kiljabi Gold' (LG); 'Pyanchor' (LG, Dow AgroSciences)

OTHER PRODUCTS
'Pynachor' (LG)

MAMMALIAN TOXICOLOGY
Oral Acute oral LD50 for rats and mice >5000 mg/kg. Skin and eye Acute percutaneous LD50 for rats >2000 mg/kg. Not an eye irritant, nor a skin sensitiser. Other Negative in chromosome aberration, teratogenicity and Ames tests.

ECOTOXICOLOGY
Daphnia LC50 (48 h) >100mg/l. Algae EC50 (96 h) for algae >100 mg/l. Bees LD50 (24 h) for honeybees >100 mg/l.

ENVIRONMENTAL FATE
Soil/Environment Relatively immobile and rapidly degraded in soil. In leaching tests using either sandy loam or silty clay soil, in artificial soil columns, >90% of pyribenzoxim accumulated in the 0-10 cm zone. Koc in sandy loam (pH 4.3, o.c. 1.7%) 5.19 ´ 105, in silty clay (pH 4.8, o.c. 1.6%) 5.15 ´ 105, in clay (pH 5.9, o.c. 2.5%) 8.57 ´ 104, in silt loam (pH 7.7, o.c. 0.8%) 2.47 ´ 106; Freundlich K in these soils, respectively, 8820, 8340, 2100, 20 654. DT50 in the field 7 d.