Tembotrione
[CAS# 335104-84-2]

Identification

• Classification: Analytical chemistry >> Standard >> Pesticides, veterinary drugs and fertilizers
• Name: Tembotrione
• Synonyms: 2-[2-Chloro-4-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl]-1,3-cyclohexanedione; BAY 747
• Molecular Formula: C₁₇H₁₆ClF₃O₆S
• Molecular Weight: 440.82
• CAS Registry Number: 335104-84-2
• EC Number: 608-879-8
• SMILES: CS(=O)(=O)C1=C(C(=C(C=C1)C(=O)C2C(=O)CCCC2=O)Cl)COCC(F)(F)F

Properties

• Solubility: Practically insoluble (0.075 g/L) (25 °C), Calc.^*
• Density: 1.458±0.06 g/cm³ (20 °C 760 Torr), Calc.^*
• Boiling point: 612.9±55.0 °C 760 mmHg (Calc.)^*
• Flash point: 324.4±31.5 °C (Calc.)^*
• Index of refraction: 1.519 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07;GHS08;GHS09 Warning
• Risk Statements: H317-H361d:-H373:-H400:-H410:
• Safety Statements: P203-P260-P261-P272-P273-P280-P302+P352-P318-P319-P321-P333+P317-P362+P364-P391-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Skin sensitization	Skin Sens.	1	H317
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Reproductive toxicity	Repr.	2	H361d
Reproductive toxicity	Repr.	2	H361
Skin sensitization	Skin Sens.	1B	H317
Reproductive toxicity	Repr.	2	H361d

• Transport Information: UN 3077 9 / PGIII

Discovery and Applications

Tembotrione is a selective herbicide belonging to the triketone chemical class, developed for post-emergent control of broadleaf and some grass weeds in maize (corn) cultivation. Its molecular formula is C₁₆H₁₃ClF₃NO₅S, and its structure includes a triketone moiety, a trifluoromethyl group, a chlorobenzene ring, and a sulfonyl linkage. These structural features contribute to its high herbicidal activity and selectivity.

Tembotrione functions by inhibiting the enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD), which plays a central role in the biosynthesis of plastoquinone and tocopherols in plants. These compounds are essential cofactors in the production of carotenoids, which protect chlorophyll from photooxidation. When HPPD is inhibited, carotenoid synthesis is disrupted, leading to chlorophyll degradation, bleaching of leaf tissue, and ultimately plant death. The symptoms in susceptible weeds typically appear as white or yellow leaves followed by necrosis.

Tembotrione was introduced as part of a new generation of herbicides aimed at improving weed control while offering better crop safety and environmental performance. It is absorbed through both foliage and roots, and is rapidly translocated within the plant, ensuring systemic action. Tembotrione is typically applied in post-emergent stages of weed growth, offering flexibility in weed management timing.

In maize, tembotrione is well tolerated due to the inclusion of safeners in commercial formulations. These safeners enhance the crop's ability to metabolize and detoxify the herbicide, reducing phytotoxicity while allowing effective weed suppression. Common formulations often combine tembotrione with other active ingredients or adjuvants to improve weed control spectrum and manage herbicide resistance.

Tembotrione is effective against a wide range of broadleaf weeds, including species resistant to older herbicides like atrazine and ALS inhibitors. Its unique mode of action makes it a valuable tool in integrated weed management programs, especially in areas where resistance to other herbicide classes has become a challenge.

Environmental studies show that tembotrione has moderate soil persistence and low leaching potential. It degrades primarily through microbial activity and photolysis. In mammals, it has low acute toxicity, and its use is considered safe when applied according to approved guidelines. However, as with all herbicides, proper handling, protective equipment, and adherence to label instructions are necessary to ensure environmental and operator safety.

In summary, tembotrione is a modern, selective triketone herbicide used primarily in maize to control a broad spectrum of post-emergence weeds. Its action as an HPPD inhibitor and its compatibility with safeners make it an effective and reliable component of contemporary herbicide programs.

References

2023. Metabolism of Tembotrione, a Triketone Herbicide, confers Differential Sensitivity in Winter Wheat (Triticum aestivum). Journal of Agricultural and Food Chemistry, 72(12).
DOI: 10.1021/acs.jafc.3c08852

2024. Sorption and mobility assessment of tembotrione in soils of upper, trans and middle Gangetic plain zones of India. Biomedical Chromatography, 38(9).
DOI: 10.1002/bmc.5939

2024. Management of Diverse Weed Flora in Widely Spaced Sugarcane Plant Crop in Tropical India Through Sequential and Tank Mix Application of Herbicides. Sugar Tech, 26(5).
DOI: 10.1007/s12355-024-01515-9