SOIL TRANSFORMATION OF WHEAT AND CORN METABOLITES MBOA AND DIM2BOA INTO AMINOPHENOXAZINONES

The defensive cyclic hydroxamates 7-methoxy-2,4-dihydroxy-1,4(2H)-benz oxazin-3-one (DIMBOA) and 8-dimethoxy-2,4-dihydroxy-1,4(2H)-benzoxazin -3-one (DIM2BOA) of wheat and com are transformed in nonsterile soil, via 6-methoxy-2(3H)-benzoxazolone (MBOA) and 6,7-di-methoxy-2(3H)-benz oxazolone (M2BOA) respectively, into 2-amino-7-meth-oxy-3H-phenoxazin- 3-one and 2-amino-4,6,7-trimethoxy-3H-phenoxazin-3-one. The soil trans formation is similar of that undergone by the rye metabolite 2(3H)-ben zoxazolone (BOA) into 2-amino-3H-phenoxazin-3-one. The transformations to phenoxazinones are not observed in sterile soil. The 2-amino-3H-ph enoxazin-3-one inhibits barnyard grass radicle elongation, but the met hoxylated aminophenoxazinones are not significantly inhibitory.