Metribuzin short-term

Metribuzin is a member of the substituted as-triazinone group of herbicides. Activity is due to interference with photosystem II electron transport in plant chloroplasts (Dodge, 1983). The metabolism of metribuzin in plants has been the subject of many short-term and long-term studies dating back to the early 1970s. 

The short-term metabolism of metribuzin may involve two major nonconjugative pathways, two major conjugative pathways, and/or production of nonextractable residues. 

Figure 7.18 The short-term metabolism of metribuzin in soybean.

Other studies (Robinson et al, 1970 Gronberg et al, 1971 Morgan, 1972, 1973 Church and Flint, 1973 Stanley and Flint, 1974) also examined the water-soluble fraction from 14C-metribuzin-treated plants. Size-exclusion chromatography (SEC) of the water-soluble fractions indicated molecular weights for the radioactive residues from 300 to 800 atomic mass units (AMU). Stanley and Flint (1974) showed that many of the SEC fractions from metribuzin-treated alfalfa had a peptidic component. This was in accord with the short-term studies of Falb and Smith (1987), who used SEC to show many high molecular weight water-soluble metabolites of both peptidic and glucosidic nature. 

---