REACTION OF A CYCLIC HYDROXAMIC ACID FROM GRAMINEAE WITH THIOLS

Article abstract of DOI:10.1016/0031-9422(82)85192-3

An insect inhibitor isolated from maize extracts, 2,4- dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), reacted with cysteine, mercaptoethanol, ethanethiol and dithiothreitol.Second order rate constants were 0.54, 0.73 and 1.96 l/mol min for the reaction with cysteine, mercaptoethanol and dithiothreitol, respectively.Products isolated from the reaction of DIMBOA with ethanethiol corresponded to reduction of the hydroxamic acid to amide and/or hemiacetal-hemithioacetal exchange.The reactivity of DIMBOA with sulfhydryl groups of compounds such as cysteine, may be a basis for its inhibitory action on enzymes and its toxicity. - Key Word Index - Zea mays; Gramineae; 1,4-benzoxazin-3-ones; thiols.