Rimsulfuron targets acetolactate synthase (ALS), a key enzyme in the biosynthesis of branched-chain amino acids (valine, leucine, and isoleucine) in plants. By inhibiting ALS, the compound blocks branched-chain amino acid synthesis, leading to plant death. As a sulfonylurea herbicide, it is used for postemergence weed control in maize. Its targets are plant-specific enzymes rather than mammalian biological targets. The compound is effective against glyphosate-resistant weed species.

Maize microsomes metabolized rimsulfuron (DPX-E9636) in vitro in a process that required NADPH and produced the same hydroxylated product, indicating that cytochrome P450 was involved[1].

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In vitro studies of Rimsulfuron have focused on its herbicidal activity and mechanism of action. The compound inhibits acetolactate synthase (ALS), blocking branched-chain amino acid synthesis. Its herbicidal efficacy against various weed species has been characterized. These in vitro studies provide foundational data for understanding the compound's utility in agricultural weed management.

In vivo studies of Rimsulfuron have demonstrated its efficacy as a postemergence herbicide for controlling grasses and broadleaf weeds in maize. The compound is effective against glyphosate-resistant weed species. Its environmental fate and effects on non-target organisms have been studied. Rimsulfuron is not a therapeutic agent and is intended for agricultural use only.

In vitro enzyme assays for Rimsulfuron typically involve testing its inhibitory activity against acetolactate synthase (ALS). Enzyme activity is measured by monitoring the biosynthesis of branched-chain amino acids in the presence of varying concentrations of the compound. The compound's purity and identity are confirmed using analytical chemistry methods such as high-performance liquid chromatography and mass spectrometry. All assays are performed with appropriate controls.

In vitro cell-based assays for Rimsulfuron involve culturing plant cells to evaluate its herbicidal effects. Plant cells are treated with varying concentrations of the compound and cell viability is assessed. The compound's effects on branched-chain amino acid synthesis are evaluated. All experiments are performed with appropriate controls to ensure statistical reliability.

In vivo plant experiments for Rimsulfuron are conducted to evaluate its herbicidal efficacy. Plants are treated with the compound and weed control is assessed. Parameters assessed include weed mortality, plant growth inhibition, and crop safety. The compound's efficacy against glyphosate-resistant weed species is evaluated. Control groups receiving vehicle alone are included for comparison.

Absorption, Distribution and Excretion
In rats, limsulfuron was primarily excreted in urine (64%) and feces (30%) within 72 hours following administration. Low but detectable levels of radioactivity were detected in the heart, lungs, liver, kidneys, and muscles… This study investigated the metabolism of 14C-labeled limsulfuron in male and female rats. The low-dose group received 25 mg/kg of the 14C-pyridine-labeled compound via gavage, while the high-dose group received 250 mg/kg of either 14C-pyridine or 14C-pyrimidine-labeled compounds via gavage, respectively. The repeat-dose group received the unlabeled test compound (25 mg/kg) via gavage for 14 consecutive days, followed by a repeat gavage administration of 25 mg/kg of the 14C-pyridine-labeled test compound on day 15. 93% to 96% of the administered radioactive material was excreted, with 58% to 67% appearing in the urine and 20% to 33% in the feces. Tissue distribution of the labeled residue was minimal. In each experimental group, liver accumulation was slightly higher in males than in females. Mild accumulation was also observed in the spleen of animals in the repeat-dose groups. ... Metabolism/Metabolites Metabolism of limosulfuron in plants and other animals (poultry and ruminants) appeared similar to its metabolism in rats. Metabolism involves the contraction or cleavage of sulfonylurea bridges. Although cleavage to form pyridinesulfonamide metabolites was expected, the contraction response was uncommon. The main residue found in plants was the parent compound limosulfuron. This study investigated the metabolism of 14C-labeled limosulfuron in male and female rats. The low-dose group received 25 mg/kg of the 14C-pyridine-labeled compound via gavage, while the high-dose group received 250 mg/kg of either 14C-pyridine or 14C-pyrimidine-labeled compound via gavage. The repeat-dose group received the unlabeled test compound (25 mg/kg) via gavage for 14 consecutive days, followed by a second gavage administration of 25 mg/kg of the 14C-pyridine-labeled test compound on day 15. …Metabolic profiles were determined using mixed urine and fecal samples. The highest proportion of unmetabolized parent compound was observed in the radioactivity of urine (42%–55%) and feces (5%–16%). The parent compound undergoes metabolism via the cleavage or contraction of the sulfonylurea bridge to generate 3-(ethylsulfonyl)-2-pyridinesulfonamide (IN-E9260) or N-(4,6-dimethoxy-2-pyrimidinyl)-N-((3-ethylsulfonyl)-2-pyridinyl)urea (IN-70941). IN-70941 is deamidated to generate IN-70942, which is then subjected to demethylation and hydroxylation reactions to form IN-70942.

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The pharmacokinetic properties of Rimsulfuron reflect its nature as a herbicide. It has a molecular weight of 431.45 and the molecular formula C14H17N5O7S2. The compound is a solid at room temperature. Its environmental fate and degradation have been studied for agricultural applications. Complete pharmacokinetic profiling in mammals would require further systematic studies.

Non-Human Toxicity Values
Rabbit dermal LD50 >2000 mg/kg
Rat inhalation LC50 >5.4 mg/L/4 hr
Rat oral LD50 >5000 mg/kg
Mouse oral LD50 >5000 mg/kg
Rabbit dermal LD50 >2000 mg/kg

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The toxicity profile of Rimsulfuron has been evaluated for environmental and occupational safety. As a herbicide, it may have toxic effects on non-target organisms. The compound is classified as an agricultural chemical and pesticide with mutagenic properties. Proper handling procedures including use of personal protective equipment are recommended when working with pure compound. The compound is not approved for human therapeutic use and is intended for agricultural research purposes only.

[1]. M.K.Koeppe, et al. Basis of Selectivity of the Herbicide Rimsulfuron in Maize.

Sulfuron is an N-sulfonylurea herbicide, chemically named N-carbamoyl-3-(ethylsulfonyl)pyridine-2-sulfonamide, in which the amino nitrogen atom is substituted with a 4,6-dimethoxypyrimidin-2-yl group. It is both an environmental pollutant and an exogenous substance and herbicide. Sulfuron belongs to the pyridine, N-sulfonylurea, pyrimidine, sulfone, and aromatic ether compounds. Sulfuron is a herbicide used to control annual grass and broadleaf weeds in corn, potatoes, and other crops. It is selective and systemic, absorbed through leaves and roots and transported into the plant. It is an acetolactate synthase (ALS) inhibitor. Mechanism of Action: …By inhibiting the plant enzyme acetolactate synthase, it blocks the synthesis of branched-chain amino acids.

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Rimsulfuron (CAS# 122931-48-0) is also known as DPX-E9636. It has the molecular formula C14H17N5O7S2 and a molecular weight of 431.45. The compound is a sulfonylurea herbicide used for postemergence weed control in maize. Rimsulfuron blocks branched-chain amino acid synthesis by inhibiting acetolactate synthase (ALS). It is effective against glyphosate-resistant weed species. The compound is classified as a sulfonylurea herbicide.

C14H17N5O7S2

431.44

431.056

122931-48-0

Rimsulfuron-d6

91779

Colorless crystals

1.6±0.1 g/cm3

760.1±70.0 °C at 760 mmHg

176-178 °C

413.5±35.7 °C

0.0±2.7 mmHg at 25°C

1.653

0.09

2

10

7

28

722

0

CCS(=O)(C1=C(S(=O)(NC(NC2=NC(OC)=CC(OC)=N2)=O)=O)N=CC=C1)=O

MEFOUWRMVYJCQC-UHFFFAOYSA-N

InChI=1S/C14H17N5O7S2/c1-4-27(21,22)9-6-5-7-15-12(9)28(23,24)19-14(20)18-13-16-10(25-2)8-11(17-13)26-3/h5-8H,4H2,1-3H3,(H2,16,17,18,19,20)

1-(4,6-dimethoxypyrimidin-2-yl)-3-[(3-ethylsulfonyl-2-pyridinyl)sulfonyl]urea

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO: 33.33 mg/mL (77.25 mM)

Solubility in Formulation 1: ≥ 1.25 mg/mL (2.90 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 12.5 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 1.25 mg/mL (2.90 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 12.5 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)