Bioactive Benzoxazinoids in Rye Bread Are Absorbed and Metabolized in Pigs

Recently, bioactive benzoxazinoids were discovered in cereal grains and bakery products. In this study, we studied the uptake, distribution, and metabolism of these secondary metabolites using a pig model. Twelve benzoxazinoid compounds and their 4 transformation products were quantified in the pigs' diets and biofluids using high-performance liquid chromatography coupled to electrospray ionization triple quadrupole mass spectrometry. The 2-β-D-glucopyranosyloxy-4-hydroxy-1,4-benzoxazin-3-one (DIBOA-glc) was the most dominant benzoxazinoid (232 nmol/g DM) seconded by the double-hexose derivative of DIBOA (provisionally characterized here as DIBOA-glc-hex) in the rye-based diet. DIBOA-glc (derived from the diet and intestinal deglycosylation of DIBOA-glc-hex) was apparently reduced to 2-β-D-glucopyranosyloxy-1,4-benzoxazin-3-one (HBOA-glc), the most dominant benzoxazinoid in the blood (829 nmol/L). The benzoxazinoid compounds were excreted in the urine, with HBOA-glc (18 μmol/L) as a major metabolite. In this study, we determined for the first time the bioavailability of dietary benzoxazinoids that have high digestibility, distribution, and metabolism in mammals. These findings could be a milestone for the exploitation of healthful and pharmacological properties of benzoxazinoids.