Biphenyl Columns Provide Good Separation of the Glucosides of DIMBOA and DIM(2)BOA

摘要

Hydroxamic acids are important defense compounds in cereals and have been subject to extensive research. Two important hydroxamic acids in maize are 2-beta-D-glucopyranosyloxy-4-hydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA-glc) and its 8-methoxylated derivative (DIM(2)BOA-g1c). The compounds are typically reported as resolved by mass spectrometry rather than chromatography, with DIM(2)BOA-glc quantified relative to DIMBOA-glc. Biphenyl HPLC columns, however, allow good separation of the two compounds at both the analytical and semi-preparative scale, enabling both isolation and absolute quantitation of both compounds. In combination with established sample treatment and chromatographic methods, biphenyl chromatography thus promises new possibilities for resolving benzoxazinoid glucosides.