Dietary flavonoid and isoflavone glycosides are hydrolysed by the lactase site of lactase phlorizin hydrolase

FEBS Lett. 2000 Feb 25;468(2-3):166-70. doi: 10.1016/s0014-5793(00)01211-4.

Abstract

Lactase phlorizin hydrolase (LPH; EC 3.2.1.62) is a membrane-bound, family 1 beta-glycosidase found on the brush border of the mammalian small intestine. LPH, purified from sheep small intestine, was capable of hydrolysing a range of flavonol and isoflavone glycosides. The catalytic efficiency (k(cat)/K(m)) for the hydrolysis of quercetin-4'-glucoside, quercetin-3-glucoside, genistein-7-glucoside and daidzein-7-glucoside was 170, 137, 77 and 14 (mM(-1) s(-1)) respectively. The majority of the activity occurred at the lactase and not phlorizin hydrolase site. The ability of LPH to deglycosylate dietary (iso)flavonoid glycosides suggests a possible role for this enzyme in the metabolism of these biologically active compounds.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Flavonoids / metabolism*
  • Flavonols
  • Glycosides / metabolism
  • Intestinal Absorption
  • Intestinal Mucosa / enzymology*
  • Intestine, Small / enzymology
  • Isoflavones / metabolism*
  • Kinetics
  • Lactase
  • Lactase-Phlorizin Hydrolase / chemistry
  • Lactase-Phlorizin Hydrolase / isolation & purification
  • Lactase-Phlorizin Hydrolase / metabolism*
  • Lactose / metabolism
  • Mammals
  • Microvilli / enzymology
  • Phlorhizin / metabolism
  • Quercetin / analogs & derivatives
  • Quercetin / metabolism
  • Sheep
  • Substrate Specificity
  • beta-Galactosidase / chemistry
  • beta-Galactosidase / metabolism*

Substances

  • Flavonoids
  • Flavonols
  • Glycosides
  • Isoflavones
  • isoquercitrin
  • Quercetin
  • Phlorhizin
  • Lactase
  • beta-Galactosidase
  • Lactase-Phlorizin Hydrolase
  • Lactose
  • spiraeoside