A MULTI-CENTERED ELECTROPHILE FORMED FROM A UNIQUE BIOACTIVE CYCLIC HYDROXAMIC ACID, 4-HYDROXY-7-METHOXY-2H-1,4-BENZOXAZIN-3(4H)-ONE

4-Hydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (HMBOA) is a compound of considerable interest because of its pharmacological, agrochemical, and antimicrobial properties. A plausible bioactive metabolite of HMBOA is 4-acetoxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (AMBOA). Electrophilic reactions of AMBOA with phenols, anilines, thiols, heteroaromatics, amino acid derivatives and nucleic acids were investigated in relation to the chemical mechanisms of the biological effects elicited by the compound. The results suggest that HMBOA acts as an alkylating agent of proteins and nucleic acids in vivo after metabolic O-acylation.