Phlorizin is a glucoside of phloretin, a dihydrochalcone. A white solid, samples often appear yellowing to impurities. It is of sweet taste and contains four molecules of water in the crystal. It is poorly soluble in diethyl ether and cold water, but soluble in ethanol and hot water. Upon prolonged exposure to aqueous solutions phlorizin hydrolysis to phloretin and glucose.
Occurrence
Phlorizin is found primarily in unripe
Malus (
apple)
root bark of
apple,
and trace amounts have been found in strawberry.
In
Malus, it is most abundant in vegetative tissues (such as leaves and bark) and seeds. Closely related species, such as
pear (
Pyrus communis),
cherry, and other
fruit trees in the
Rosaceae do not contain phlorizin.
Phlorizin is a phytochemical that belongs to the class of
. In natural sources, it may occur with other polyphenols such as
quercetin,
catechin,
epicatechin,
, and
rutin.
Pharmacology
Phlorizin is an inhibitor of SGLT1 and SGLT2 because it competes with
Glucose for binding to the carrier; this action reduces
renal glucose transport, lowering the amount of glucose in the blood.
Phlorizin was studied as a potential pharmaceutical treatment for type 2 diabetes, but has since been superseded by more selective and more promising synthetic analogs, such as
empagliflozin,
canagliflozin and
dapagliflozin.
Phlorizin is not an effective drug because when orally consumed, it is nearly entirely converted into phloretin by hydrolytic enzymes in the small intestine.
