Detection of N-(1-deoxy-D-fructos-1-yl) Fumonisins B2 and B3 in Corn by High-Resolution LC-Orbitrap MS

The existence of glucose conjugates of fumonisin B-2 (FB2) and fumonisin B-3 (FB3) in corn powder was confirmed for the first time. These bound-fumonisins (FB2 and FB3 bound to glucose) were identified as N-(1-deoxy-d-fructos-1-yl) fumonisin B-2 (NDfrc-FB2) and N-(1-deoxy-d-fructos-1-yl) fumonisin B-3 (NDfrc-FB3) respectively, based on the accurate mass measurements of characteristic ions and fragmentation patterns using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitrap MS) analysis. Treatment on NDfrc-FB2 and NDfrc-FB3 with the o-phthalaldehyde (OPA) reagent also supported that d-glucose binding to FB2 and FB3 molecules occurred to their primary amine residues.