Determination of chemical composition antioxidative and antimicrobial properties of poplar type propolis collected from different regions of Serbia.

Abstract

Cilj ove doktorske disertacije je hemijska i funkcionalna karakterizacija propolisa topola tipa koji potiče iz različitih regiona Srbije primenom analitičkih i tehnika za određivanje antimikrobne aktivnosti u kombinaciji sa multivarijantnim hemometrijskim metodama. Fenolni profili srpskog propolisa je određen visokoefikasnom tankoslojnom hromatografijom (High Performance Thin-Layer Chromatography, HPTLC) da bi se uočile sličnosti, odnosno razlike između uzoraka različitog botaničkog i geografskog porekla. Ispitivani su fenolni profili propolisa iz regiona (Hrvatska, Slovenija) i nemačkog kao tipičnog zapadnoevropskog propolisa topola tipa u cilju poređenja sa srpskim. Na osnovu dobijenih rezultata srpski propolis je klasifikovan prema botaničkom poreklu na dva tipa. Analiza glavnih komponenata je primenjena u cilju određivanja fenola karakterističnih za srpski propolis i potvrde prisustva dva tipa propolisa. Primenom visokoefikasne tečne hromatografije u kombinaciji sa linearnim trapom i Orbitrapom MS/MS (Ultra Performance Liquid Chromatography (UPLC)-Lineartrap Orbitrap MS/MS) visoke rezolucije određen je sadržaj flavonoida karakterističnih za propolis topola tipa. Takođe, različite klase fenolnih jedinjenja su identifikovane u srpskom propolisu i određeni fenolni markeri za oba tipa propolisa. Analiza glavnih komponenata je primenjena na rezultate dobijene visokoefikasnom tečnom hromatografijom u kombinaciji sa linearnim trapom i Orbitrapom MS/MS da bi se klasifikovali uzorci srpskog propolisa i odredili fenolni markeri za oba tipa propolisa. Pored toga, analiza glavnih komponenata je primenjena na masene signale (dobijene direktnom analizom u realnom vremenu, DART) u cilju poređenja nemačkog propolisa sa srpskim. Fenolni profil ekstrakata smola pupoljaka topole kao potencijalnog botaničkog izvora je određen u cilju poređenja sa ekstraktima propolisa...The main goal of this PhD thesis was chemical and functional characterization of poplar type of propolis using different analytical and techniques for determination of antimicrobial activity in combination with multivariate chemomometric methods. Phenolic profile of Serbian propolis was determined using HPTLC (High Performance Thin-Layer Chromatography) technique in order to determine similarities and differences bewteen samples according to their geografical and botanical origin. From the obtained results, samples of Serbian propolis can be separated in two types according to their botanical origin. Further, phenolic profile of Slovenian, Croatian and German propolis, as typical representative of Western European type of propolis, were investigated in order to get comparation with Serbian propolis. Principal component analysis was applied in order to determine caractersitic phenol marker compounds in Serbian propolis. Powerful ultra high-performance liquid chromatography coupled with mass spectrometry (UPLC-Orbitrap MS/MS technique) was apllied for determination of phenolic profile of Serbian propolis, and quantification of caracteristic phenol marker compounds in Serbian propolis. Also, different classes of phenolic compounds were identified in Serbian propolis and detremined caracteristic phytochemical markers of both types of propolis. Principal component analysis was applied on quantified phenols in order to verify two types of propolis, and determine phenol marker compounds. Principal component analysis was applied on samples of German propolis and mass signals obtained from direct analysis in real time technique, were used as variables. UV/VIS spectra and cyclic voltammetry also conformed existence of two types of Serbian propolis. Results obtained from cyclic voltammetry show differences between phenol content and antioxidative capacity among these botanically different types of propolis. Multivariate analysis was applied on UV/VIS spectra of propolis, and those results confirmed presence of two types of propolis. Phenolic profille of polpar buds, as one of potential botanical source of propolis, were determined in order to compared them with propolis extracts..