Degradation of the sulfonylurea herbicide LGC-42153 in flooded soil.
LGC-42153, 2-fluoro-1-[3-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)pyridin-2-yl] propyl methoxyacetate, is a new sulfonylurea herbicide for use in rice. Its breakdown and metabolism was studied in soil under flooded conditions using two radioactive tracer compounds labelled at either the propyl group or the pyrimidine ring. The half-life of LGC-42153 was approximately 3.0 days. The mass balance over 120 days ranged from 94.0 to 104.2% of applied radiocarbon, and no significant amount of volatiles or [14C]carbon dioxide were observed. Solvent non-extractable radiocarbon reached about 11-14% of applied radiocarbon at 120 days after treatment. The major metabolic reaction was the cleavage of the carboxyl ester bond to give 1-(4,6-dimethoxypyrimidin-2-yl)-3-[2-(1-hydroxy-2-fluoropropyl)pyridine-3-sulfonyl]urea, which underwent hydrolysis of the sulfonylurea bridge giving 2-(1-hydroxy-2-fluoro)propyl-3-pyridinesulfonamide and 4,6-dimethoxy-2-aminopyrimidine.
Kim
Jin
J
School of Agricultural Biotechnology, Seoul National University, 103 Seodundong, Suwon 441-744, Korea.
Liu
Kwang-Hyeon
KH
Kang
Seung-Hun
SH
Koo
Suk-Jin
SJ
Kim
Jeong-Han
JH
D002250:Carbon Radioisotopes; D004190:Disasters; D006540:Herbicides / Q000378:metabolism*; D015394:Molecular Structure; D011743:Pyrimidines / Q000737:chemistry / Q000378:metabolism*; D012987:Soil / Q000032:analysis*; D013449:Sulfonamides / Q000737:chemistry / Q000378:metabolism*; D013453:Sulfonylurea Compounds / Q000378:metabolism*
D002250:Carbon Radioisotopes; D006540:Herbicides; C471785:N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-2-(1-methoxyacetoxy-2-fluoropropyl)-3-pyridinesulfonamide; D011743:Pyrimidines; D012987:Soil; D013449:Sulfonamides; D013453:Sulfonylurea Compounds