CYP2B6 metabolized both alachlor and butachlor to CDEPA, acetochlor to CMEPA, and metolachlor to an unknown metabolite.
Because conjugation of alachlor with GSH occurs slowly in humans, alachlor may be available as a substrate for human P450s leading to the formation of CDEPA.
In the current study, incubations of the parent herbicides with liver microsomes resulted in major differences between rats and humans in the formation of CDEPA or CMEPA.
Likewise in human liver microsomes, the rate of metabolism of butachlor to CDEPA was significantly less than the rate observed with rat liver microsomes.
Also, the slow rate of metabolism of butachlor to CDEPA suggests that the length of the alkoxy group needs to be less than six atoms.