Deglycosylation of flavonoid and isoflavonoid glycosides by human small intestine and liver β-glucosidase activity

• Published in: FEBS letters 1998-09, Vol.436 (1), p.71-75
• Main Authors: Day, Andrea J, DuPont, M.Susan, Ridley, Saxon, Rhodes, Mike, Rhodes, Michael J.C, Morgan, Michael R.A, Williamson, Gary
• Format: Article
• Language: English
• Subjects: beta-Glucosidase - antagonists & inhibitors; beta-Glucosidase - metabolism; Cell Extracts; Cell-Free System; Chamomile; Cytosol - enzymology; Flavanones; Flavonoid; Flavonoids - metabolism; Flavonol; Genistein - metabolism; Genistein 7-glucoside; Gluconates - pharmacology; Glycosides - metabolism; Glycosylation; Humans; Inositol - analogs & derivatives; Inositol - pharmacology; Intestine, Small - enzymology; Isoflavones - metabolism; Isoflavonoid (human liver); Lactones; Liver - enzymology; Oils, Volatile - metabolism; Plants, Medicinal; Quercetin - analogs & derivatives; Quercetin - metabolism; Quercetin 4′-glucoside; Rutin - metabolism; Taurocholic Acid - pharmacology; β-Glucosidase
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(98)01101-6

Flavonoid and isoflavonoid glycosides are common dietary phenolics which may be absorbed from the small intestine of humans. The ability of cell-free extracts from human small intestine and liver to deglycosylate various (iso)flavonoid glycosides was investigated. Quercetin 4′-glucoside, naringenin 7-glucoside, apigenin 7-glucoside, genistein 7-glucoside and daidzein 7-glucoside were rapidly deglycosylated by both tissue extracts, whereas quercetin 3,4′-diglucoside, quercetin 3-glucoside, kaempferol 3-glucoside, quercetin 3-rhamnoglucoside and naringenin 7-rhamnoglucoside remained unchanged. The K m for hydrolysis of quercetin 4′-glucoside and genistein 7-glucoside was ∼32±12 and ∼14±3 μM in both tissues respectively. The enzymatic activity of the cell-free extracts exhibits similar properties to the cytosolic broad-specificity β-glucosidase previously described in mammals.