Цитрустың гесперидині: Химиялық құрамы мен биологиялық қасиеттері

Chemical compound

Hesperidin is a flavanone glycoside found in citrus fruits. Its aglycone is hesperetin. Its name is derived from the word "hesperidium", for fruit produced by citrus trees. Hesperidin was first isolated in 1828 by French chemist M. Lebreton from the white inner layer of citrus peels (mesocarp, albedo). Hesperidin is believed to play a role in plant defense.

Hesperidin 6 O α rhamnosyl β glucosidase, an enzyme that uses hesperidin and water to produce hesperetin and rutinose, is found in the Ascomycetes species.

As a flavanone found in the rinds of citrus fruits (such as oranges or lemons), hesperidin is under preliminary research for its possible biological properties in vivo. One review did not find evidence that hesperidin affected blood lipid levels or hypertension. Another review found that hesperidin may improve endothelial function in humans, but the overall results were inconclusive.

The biosynthesis of hesperidin stems from the phenylpropanoid pathway, in which the natural amino acid phenylalanine undergoes a deamination by phenylalanine ammonia lyase to afford (E) cinnamate. The resulting monocarboxylate undergoes an oxidation by cinnamate 4 hydroxylase to afford (E) 4 coumarate, which is transformed into (E) 4 coumaroyl CoA by 4 coumarate CoA ligase. (E) 4 coumaroyl CoA is then subjected to the type III polyketide synthase naringenin chalcone synthase, undergoing successive condensation reactions and ultimately a ring closing Claisen condensation to afford naringenin chalcone. The corresponding chalcone undergoes an isomerization by chalcone isomerase to afford (2S) naringenin, which is oxidized to (2S) eriodictyol by flavonoid 3′ hydroxylase. After O methylation by caffeoyl CoA O methyltransferase, the hesperitin product undergoes a glycosylation by flavanone 7 O glucosyltransferase to afford hesperitin 7 O β glucoside. Finally, a rhamnosyl moiety is introduced to the monoglycosylated product by 1,2 rhamnosyltransferase, forming hesperidin.