2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one 2 -D-glucosyltransferase

2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one 2-D-glucosyltransferase (, uridine diphosphoglucose-2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one 2-glucosyltransferase, BX8, BX9, benzoxazinoid glucosyltransferase, DIMBOA glucosyltransferase) is an enzyme with systematic name UDP-alpha-D-glucose:2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one 2-beta-D-glucosyltransferase. It catalyses two chemical reactions which allow plants such as maize to store toxic metabolites, DIBOA and DIMBOA as non-toxic glucosides.

For example, the enzyme interconverts DIMBOA and the (2R) stereoisomer of its glucoside, using UDP-glucose to transfer the added sugar unit. In a similar way, the glucoside of DIBOA (a compound lacking the methoxy group of DIMBOA) is an alternative substrate:

The hydroxamic acids, DIMBOA and DIBOA are used to defend the plants in which they occur from pathogens.

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