Metabolizam flavonoida i fenolnih kiselina

Professional paper - Professional paper

• Author: Daria Čović
• Author: Mirza Bojić
• Author: Marica Medić-Šarić
• Author's institution: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of medicinal chemistry)
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract (english)

Polyphenols are among the most ubiquitous groups of molecules distributed in food
of plant origin. There is a variety of biological effects exerted by polyphenols in vitro and
in vivo including antioxidant, antimutagen and anti-inflammacory effects. To evaluate a
potential beneficial effects of polyphenols in human health, it is necessary to understand
absorption, distribuition and metabolism of these compounds.
The main structural parametars that effect intestinal absorption of polyphenols are
molecular weight, glycosilation and esterification. Most polyphenols with exception of
catechins and proantocyanidins are rarely found in free form in food. Flavonoids occur
mainly glycosilated and phenolic acids esterified to small organic acids or arabinoxylans
from plant cell walls. They are partly hydrolised to their aglycones in small intestine and
extensively by enzymes of bacterial origin in colon.
Their pharmacological effects are highly dependent on the number and position of
the hydroxyl groups in the molecule. These groups are mainly conjugated to form O-glucuronides,
sulphate esters and O-metyl ethers. Thus conjugation of polyphenols effects
their biological and toxical properties and consequently the health itself. Polyphenols are
almost entirely conjugated and unmodified forms are generally either absent or present
in low concentrations. Oxidation is less represented methabolic pathway, but can also
have significant influence on biological properties. Given metabolic reactions occur
mainly in liver and small intestine.
Conjugates effluxed back from enterocytes to intestinal lumen or excreted from liver
through the bile, reach the colon where they are hydrolised by microbial enzymes into
aglycones and reabsorped, resulting in enterohepatic cycling. Colon microflora also
metabolise non absorbed polyphenols in a wide array oflow molecular weight compounds.
These metabolites are responsabile for some of the health effects of polyphenols, parti-·
culary of those poorly absorbed through the small intestine.

• Keywords (croatian): polifenoli; flavonoidi; fenolne kiseline
• Language: croatian
• Publication type: Professional paper - Professional paper
• Publication status: Published
• Peer review: Peer review - domestic
• Publication version: Published version
• Journal title: Farmaceutski glasnik
• Numbering: vol. 65, no. 12, pp. 693-704
• p-ISSN: 0014-8202
• URN:NBN: urn:nbn:hr:163:775841
• Publication: 2009
• Type of resource: Text
• Access conditions: Open access
• Created on: 2020-09-30 14:06:31