Mehanizmi bioloških efekata jedinjena dobijenih alkalnom hidrolizom jabučnog pektina
Mechanisms of biological effects of compounds obtained by alkaline hydrolysis of apple pectin
Докторанд
Martinov, Jelena B.Ментор
Krstić, MiodragЧланови комисије
Spasić, MihajloMilosavljević, Tomica
Simić, Tatjana
Damjanov, Dragomir
Метаподаци
Приказ свих података о дисертацијиСажетак
Jabuka (Malus domestica Borkh) je od davnina poznata po svojim pozitivnim
nutritivnim i lekovitim svojstvima pa je njen hemijski sastav intenzivno proučavan. Za
pektin iz jabuka, kao i iz drugih izvora npr. citrusnog voća, je poznato da pozitivno
utiče na gastrointestinalni trakt, dominantno putem uticaja na gastrointestinalnu
mikrobiotu. Pretpostavka je da se taj uticaj uglavnom ostvaruje preko njegove
polimerne strukture i slabe rastvorljivosti.
Mi smo derivatizovali pektin primenom alkalne hidrolize u prisustvu vodonik
peroksida. Dobijeni proizvod okarakterisali smo FTIR spektroskopijom i pokazali da u
odnosu na polazni materijal ima simetrične i asimetrične vibracije istezanja
karboksilatnih grupa. Ovo indukuje mogućnost da dobijeni derivat ima specifične
reakcije sa hidroksilnim radikalima koji nastaju u Fentonovoj reakciji in vitro, a uslovi
za postojanje Fentonove reakcije in vivo postoje u gastrointestinalnom traktu u prisustvu
Fe i vitamina C.
Ispitivanja EPR spektroskopijom p...okazala su da derivat jabučnog pektina u
sistemu Fentonove reakcije podstiče stvaranje ugljen-dioksid radikalskog anjona (•CO2
-
radikala) umesto hidroksidnog radikala. Za ovaj radikal su prethodna ispitivanja
pokazala da ima duži poluživot od hidroksidnog radikala i da specifično reaguje sa
određenim proteinima. To ukazuje na mogućnost da derivat pektina koji smo mi dobili
u gastrointestinalnom traktu ima dodatno pozitivne efekte putem direktnog uticaja na
mikrobiotu.
Stoga smo ispitali antimikrobnu aktivnost pektina i njegovih derivata i pokazali,
da derivati pektina dobijeni alkalnom hidrolizom jabučnog pektina (APDO) sprečavaju
rast Saccharomyces cerevisiae i Candide albicans, dok nemaju uticaj na rast
Escherichia coli i Staphylococcus aureus...
Apple (Malus domestica Borkh) has long been known for its positive nutritive
and medical properties, so its chemical composition has been intensively studied. For
apple pectin, as well as from other sources e.g. citrus fruit, is known that have positive
effect on gastrointestinal tract, predominantly through the influence to gastrointestinal
microbiota. The assumption is that this effect is mainly achieved through its polymeric
structure and poor solubility.
We have derivatized pectin using alkaline hydrolysis in the presence of
hydrogen peroxide. The obtained product was characterized by FTIR spectroscopy and
showed symmetric and asymmetric stretching vibrations of the carboxylate groups in
comparing with the starting material. This induces the possibility that the resulting
derivative has specific reactions with the hydroxyl radicals formed in the Fenton
reaction in vitro, and the conditions for the existence of a Fenton reaction in vivo exist
in the gastrointestinal tract in the pre...sence of Fe and vitamin C.
EPR spectroscopy studies have shown that the apple pectin derivative in the
Fenton reaction system induces the formation of carbon dioxide radicals anion (•CO2
-
radicals) instead of hydroxyl radicals. Preliminary studies for this radical have shown
that it has a longer half-life than hydroxyl radicals and specifically reacts with certain
proteins. This indicates the possibility that the pectin derivative that we get has
additional positive effects in the gastrointestinal tract through the direct impact on the
microbiota.
Therefore, we examined antimicrobial effect of pectin and its derivatives and
showed that the pectin derivatives obtained by alkaline hydrolysis of apple pectin
(APDO) inhibited the growth of Saccharomyces cerevisiae and Candide albicans and
had no influence on the growth of Escherichia coli and Staphylococcus aureus.
We also analyzed the effects of pectin derivatives (apple and citrus) and
oligosaccharides derived from polygalacturonic acid (APDO, CPDO and PGDO) on the
growth of one Gram-negative representative strain of Escherichia coli ATCC 25922 and
one Gram-positive representative strain of Staphylococcus aureus in the presence of
substances that imitate conditions in a gastrointestinal tract that favors the Fenton
reaction...
Факултет:
Универзитет у Београду, Медицински факултетДатум одбране:
16-07-2018Пројекти:
- Морфолошко-експериментална и молекуларно-биолошка испитивања билиопанкреасног система релевантна за ендоскопску дијагностику и терапију хроничног панкреатитиса (RS-MESTD-MPN2006-2010-145011)