Mode of action

The mode of action of butachlor is by inhibiting the elongase responsible for the elongation of very long-chain fatty acids and the geranylgeranyl pyrophosphate cyclization enzymes[4]. It also affects the various other metabolic processes and redox homeostasis adversely, in addition to lipid biosynthesis[5].

Warning and risk

Butachlor can cause severe toxicity. Acute toxicity Butachlor causes slight erythema and edema in rabbits when exposed to 24 h continuously[6]. It can also cause primary ocular irritation in 2 of 6 white rabbits tested. It can also cause dermal sensation, moderate-to-severe erythema with edema in guinea pig, where the dermal hypersensitivity was checked in a modified Buehler assay. Human and Animal toxicity Butachlor can cause DNA strand breaks and chromosomal aberrations in mammalian cells exhibited[7]. Butachlor can also trigger necrosis in human PBMN cells due to their oxidative role in intracellular reactive oxygen species[ROS] production, and the consequent mitochondrial dysfunction, oxidative DNA damage and chromosomal breakage[8]. Butachlor has mutagenic effects in primary rat tracheal epithelial cells and in Chinese hamster ovarian cells[9]. It is also known cause stomach tumors in rats[10].

Hazard

Moderately toxic.

Trade name

BUTANEX?; BUTANOX?; CP 53619?; HILTACHLOR?; LAMBAST?; MACHETE?; MACHETTE?; PILLARSET?; RASAYANCHLOR?; WEEDOUT?; VENDAVAL?

Metabolic pathway

In vitro incubation of butachlor with rat liver fractions forms a considerable amount of glutathione conjugate, while the conjugating activity is not efficient for the kidney S9 fraction. Further biotransformation of the glutathione conjugate to mercapturate is not observed in the liver S9 fraction. Butachlor is initially conjugated with glutathione in the liver and is apparently transported to the kidneys where it is transformed to mercapturic acid.

Overview

Machette [also known as butachlor] belongs to the chloroacetanilide group herbicides. Butachlor, together with other chloroacetanilide-class herbicides including acetochlor, alachlor, metachlor, and propachlor, are the most consumed chemicals all over the world in agriculture. Butachlor [N-[butoxymethyl]-2-chloro-2’,6’-diethyl acetanilide] is a widely recommended herbicide for application in rice cultivation. It is a systemic selective pre-emergent herbicide applied on rice, tea, wheat, beans and other crops viz. corn, soybean[1]. Butachlor is most commonly used to control a wide range of annual grass and broad leaf weeds[2] as well as submerged macrophytes in freshwater fishponds. Butachlor was developed by Monsanto Co. [USA] in 1968 and commonly used as a post-emergence herbicide in Asia and Africa[3]. It can be manufactured by the reaction of chloroacetyl chloride with the azomethine of 2,6-diethylaniline and formaldehyde, followed by treatment with n-butanol. Butachlor was introduced to Japan in 1973 for weed control in transplanted rice paddies.

Applications

Butachlor is a chloroacetanilide herbicide, which is used extensively all over the world as pre-emergence control of unwanted weeds. It is used for controlling a wide range of annual grass and broad leaf weeds[2] as well as submerged macrophytes in freshwater fishponds.

Agricultural Uses

Herbicide: Used for pre-emergence control of annual grasses, sedges and broadleaf weeds in rice crops. Used primarily in Asia, South America, Europe and Africa. Not registered for use in the U.S. Not approved for use in EU countries.