Transmembrane behaviors and quantitative structure–activity relationship of dietary flavonoids in the presence of intestinal digestive products from different carbohydrate sources based on in vitro and in silico analysis

Bioavailability plays a key role for flavonoids to exert their bioactivities. This study investigated the transmembrane transport behavior and structure–activity of dietary flavonoids. Results showed that the apparent permeability coefficients of some flavonoids could be significantly increased when digestion products from rice flour (RD) or wheat flour (WD) are present (p < 0.05), especially in the WD, potentially due to higher reducing sugar (p < 0.05). 3D-QSAR revealed that the hydrogen bond acceptor groups at positions 5 and 6 of ring A, small-volume groups at position 3′, hydrophobic groups at position 4′, and large-volume groups at position 5′ of ring B increased the transmembrane transport of flavonoids in the WD. A hydrogen bond donor group at position 4′ of ring B enhanced the transmembrane transport of flavonoid compounds in the RD. These findings contribute to our comprehensive understanding of flavonoid absorption within the context of intestinal carbohydrate digestion.