Metolachlor is an herbicide used in controlling broadleaf weed growth and is applied to agricultural areas across the United States. After application, metolachlor can degrade into oxanilic acid (OXA) and ethanesulfonic acid (ESA) metabolites, which are highly soluble in the environment. Metolachlor and its metabolites consist of two pairs of enantiomers, with the S-enantiomer being the herbicidally active isomer. Metolachlor acts by inhibiting protein synthesis. High-protein crops can be adversely affected by metolachlor applications. Certain additives included in product formulations to help protect sensitive crops like sorghum from injury. Metolachlor is usually applied to crops before plants emerge from the soil. It is used to control certain broadleaf and annual grassy weeds in field corn, soybeans, peanuts, grain sorghum, potatoes, pod crops, cotton, safflower, stone fruits, nut trees, highway right-of-ways and woody ornamentals.
Metolachlor is composed of a combination of mirror image molecules called s-isomers and r-isomers. These isomers are exact replicates of one another, only with opposite construction, as if viewed with a mirror. The isomers vary greatly in their ability to kill grasses and weeds. The s-isomer is the super-active half of the combination while the r-isomer has no biological activity. Advances in science have allowed us to isolate and produce the s-isomer alone, resulting in the development of the super-active Magnum technology, S-Metolachlor.