No description available.

<p>Dosada&scaron;nji objavljeni literaturni podaci ukazuju da aflatoksini, usled njihovog dokazanog toksičnog, mutagenog, teratogenog i kancerogenog efekta na organizam ljudi i životinja, predstavljaju najpoznatiju i najrizičniju grupu mikotoksina. Nasuprot navedenom, dostupna naučna i stručna literatura iz Republike Srbije ukazuje na nedostatak sistematski sprovedenih monitoringa učestalosti pojave aflatoksina. Kao sirovine za ispitivanje pojave aflatoksina, u ovoj doktorskoj disertaciji, odabrani su kukuruz i mleko. Kukuruz je odabran jer predstavlja jednu od najzastupljenijih žitarica u Srbiji. Navedena činjenica dodatno povećava potrebu za istraživanjem, jer pojava aflatoksina u velikoj meri utiče i na kvalitet kukuruza, kao i smanjenje prinosa i ekonomskog profita zemlje. Cilj da se ispita mleko proistekao je iz činjenice da ono usled velike frekventnosti u ishrani, predstavlja namirnicu sa najvećim potencijalnim rizikom za unos aflatoksina u organizam ljudi.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Analiza pojave aflatoksina u kukuruzu obuhvatila je 1000 uzoraka, sakupljenih tokom perioda od četiri godine (2009-2012.). Dobijeni rezultati ukazali su da aflatoksini nisu detektovani u uzorcima kukuruza iz 2009., 2010. i 2011. godine. Međutim, od 700 analiziranih uzoraka kukuruza iz 2012., čak 553 (79%) bilo je kontaminirano aflatoksinima. Značajne razlike u pojavi aflatoksina u kukuruzu, iz različitih proizvodnih godina, mogu se objasniti izuzetno toplim i suvim vremenskim uslovima zabeleženim u 2012. godini. Su&scaron;ni vremenski uslovi bili su povoljni za razvoj plesni i sintezu aflatoksina u kukuruzu, a takođe su u velikoj meri doprineli i visokom nivou pojave aflatoksina M1 (AFM1) u mleku. Analiza 200 uzoraka različitih kategorija kravljeg mleka pokazala je da je AFM1 sa koncentracijama od 0,01 do 1,20 ug/kg detektovan u 198 (98,7%) uzoraka. Na osnovu određenih koncentracija AFM1 u uzorcima mleka, prikupljenih informacija o prosečnom unosu mleka, telesnoj težini različitih starosnih kategorija i polova 1500 ispitanika, procenjen je rizik od unosa AFM1. Dobijeni rezultati ukazali su da su sve ispitane starosne kategorije, a posebno deca, izložena visokom riziku od unosa AFM1 u organizam preko kontaminiranog mleka.<br />Usled svega navedenog, proizilazi potreba za kontinuiranim praćenjem pojave aflatoksina u kukuruzu i AFM1 u mleku, sa ciljem za&scaron;tite stanovni&scaron;tva od rizika povezanih sa njihovim dokazanim toksičnim i kancerogenim efektima. Tokom poslednjih godina, do&scaron;lo je do povećane tražnje za razvojem osetljive, tačne, jednostavne i brze metode, čijom primenom će se obezbediti pouzdano određivanje različitih aflatoksina pri niskim koncentracijama. Usled toga, ELISA metode, kao i metode tečne hromatografije sa različitim detektorima (HPLC-FLD, HPLC-UV light-FLD, LC-MS/MS) su razvijene, optimizovane i validovane. Validacija je izvr&scaron;ena prema smernicama odgovarajućih evropskih Regulativa, analizom sertifikovanih referentnih materijala i spajkovanih uzoraka. Dobijeni parametri validacije potvrdili su da se sve primenjene metode sa visokom pouzdano&scaron;ću mogu koristiti za određivanje aflatoksina u kukuruzu, odnosno AFM1 u mleku. Validovane metode su zatim primenjene za analizu aflatoksina i AFM1 u prirodno kontaminiranim uzorcima kukuruza i mleka. Analizom prirodno kontaminiranih uzoraka kukuruza uočeno je da određena koncentracija aflatoksina u velikoj meri zavisi od neravnomerne raspodele aflatoksina unutar čvrstih uzoraka. Pored toga, analiza uzoraka kukuruza iz skladi&scaron;ta, takođe je ukazala na neravnomernu raspodelu ukupnih plesni, vrste Aspergillus flavus, kao i aflatoksina. S druge strane, dobijeni koeficijenti korelacije (&gt; 0,9) između primenjenih metoda za određivanje AFM1 u mleku, ukazali su da među dobijenim rezultatima postoji snažna korelacija, koja može poticati i od relativno homogenije raspodele AFM1 unutar tečnih uzoraka.</p> / <p>Recent studies have demonstrated that аflatoxins (AFs) represent the best known and most intensively researched mycotoxins in the world, with proven toxic, mutagenic, teratogenic and carcinogenic effects on human and animal health. However, up to the author&#39;s knowledge, there are no investigations concerning the occurrence of AFs in food or feed from Republic of Serbia. For that purpose, maize and cow&acute;s milk samples were chosen as matrixes for investigation. Maize is selected because it represents one of the major crops grown in Serbia and presence of AFs leads to reduction of maize quality as well as significant economical losses. On the other hand, milk has the greatest demonstrated potential for AFs introducing into the human diet since it represents one of the main foodstuffs in human nutrition.<br />An investigation regarding occurrence of AFs in maize included 1000 samples collected during four years period (2009-2012). Obtained results indicate that AFs were not detected in maize samples collected during 2009-2011 period. However, among 700 analyzed maize samples from 2012 even 553 (79%) samples contained AFs. Significant differences in occurrence of AFs in maize could be contributed to extremely hot and dry weather conditions noted during maize growing season 2012. Described weather conditions were favorable for mould growth and AFs synthesis in maize and also could be the possible reason for high contamination frequency of aflatoxin M1 (AFM1) in milk. Analysis of 200 cow&acute;s milk samples showed that AFM1 were detected in 198 (98.7%) samples in concentrations ranged from 0.01 to 1.20 &mu;g/kg. On the basis of the obtained AFM1 concentrations in cow&rsquo;s milk samples, collected information about average milk intake and mean body weight (bw) for different age&rsquo;s categories, mean ingestion of AFM1 in ng/kg per bw per day were estimated. Obtained results showed that all age&rsquo;s categories, especially children, are exposed with high risk related to presence of AFM1 in milk.<br />Based on everything stated above, presence of AFs in maize and AFM1 in milk should be continuously controlled in order to protect the population from risks associated with its proven toxicity and carcinogenicity. During recent years, there has been an increase in demand for development of sensitive, accurate, simple and fast method which is reliable to detect AFs and AFM1 at low concentrations. For that purpose, enzyme linked immunosorbent asssay (ELISA), high performance liquid chromatography with fluorescence detector (HPLC-FLD; HPLC-UV light-FLD) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) were optimized and validated. The method validation was performed according European Union Regulative using certificated reference material as well as spiked blank maize and milk samples. The obtained validation parameters indicate that all applied methods are suitable for determination of AFs in maize as well as AFM1 in milk samples. Afterwards, validated methods were applied for analysis of natural contaminated maize and milk samples. Analysis of natural contaminated maize samples indicate that determined AFs concentration mostly depends of uneven distribution of AFs in solid samples. Furthermore, analysis of maize samples from different warehouses indicates an uneven distribution of moulds, Aspergillus flavus and AFs. On the other hand, obtained correlation coefficients (&gt;0.9) indicate that strong correlation exists between applied methods for AFM1 determination. Relatively homogeneous distribution of AFM1 in liquid samples could be the possible reason for obtained strong correlation between applied methods.</p>

<p>U okviru doktorske disertacije razvijena je brza i selektivna metoda za<br />određivanje i praćenje ostataka herbicida na bazi sulfonilurea (nikosulfuron,<br />oksasulfuron, tribenuron metil, tritosulfuron, triasulfuron, rimsulfuron i<br />prosulfuron) u zemlji&scaron;tu primenom visoko pritisne tečne hromatografije sa<br />UV detektor sa nizom fotoosetljivih dioda (HPLC-UV-DAD). Razdvajanje<br />sulfonilurea je izvedeno uz primenu Zorbax Eclipse XDB-C18 kolone. U cilju<br />definisanja odgovarajućih uslova analize, ispitan je i definisan uticaj<br />najznačajnijih eksperimentalnih faktora. Usvojeni su sledeći optimalni uslovi<br />gradijentne elucije: mobilna faza acetonitril (A) i 0,1% sirćetna kiselina (B) t<br />= 0 min, 52% A; t = 2-2,5 min, 47% A; t = 2,5-5 min, 52% A, pri konstatnom<br />protoku od 1 mL min-1 i temperaturi kolone od 250C. Na osnovu odziva<br />analitičkog signala, njegove reproduktivnosti i linearnosti, talasna dužina od<br />240 nm je usvojena kao odgovarajuća. Utvrđeno je da je uticaj matriksa bio<br />izražen te je stoga za kvantitativno određivanje sadržaja SU u uzorcima<br />zemlji&scaron;ta primenom HPLC-UV-DAD metode kori&scaron;ćena MMC kalibraciona<br />kriva. Pri analizi ekstrakata nekontaminiranog zemlji&scaron;ta ostvarena je granica<br />kvantitativnog određivanja za nikosulfuron, oksasulfuron, tribenuron metil,<br />tritosulfuron, triasulfuron, rimsulfuron i prosulfuron od 3,16 &mu;g kg-1, 3,40 &mu;g<br />kg-1, 3,76 &mu;g kg-1, 4,13 &mu;g kg-1, 3,60 &mu;g kg-1, 3,04 &mu;g kg-1 i 2,97 &mu;g kg-1,<br />redom. Za potrebe osetljivijih, selektivnijih i tačnijih određivanja SU u<br />zemlji&scaron;tu, definisana je metoda uz primenu tečne hromatografije sa<br />tandemskom masenom spektrometrijom (HPLC-MS-MS). HPLC-MS-MS je<br />kori&scaron;ćena kao referntna tehnika za proveru rezultata koji su dobijeni<br />primenom HPLC uz UV-DAD detektor. Definisan je efikasan postupak za<br />pripremu uzoraka zemlji&scaron;ta u cilju hromatografskog određivanja SU.<br />Najefikasnija ekstrakcija ostvarena je primenom sme&scaron;e dihlormetanacetonitril<br />(2:1, v/v), zaki&scaron;eljene sirćetnom kiselinom (0,8%, v/v), uz dodatak<br />uree (0,3 g/ 10g zemlji&scaron;ta). Postupak mikrotalasne estrakcije u zatvorenom<br />sistemu omogućio je najbolje uslove za ekstrakciju SU. U cilju izdvajanja SU,<br />iz matriksa ekstrakata zemlji&scaron;ta, primenjena je ekstrakcija na čvrstoj fazi (SPE) sa silika gelom kao adsorbensom. Definisana metoda za određivanje<br />ispitivanih SU, kao i razvijeni postupak pripreme uzoraka, uspe&scaron;no je<br />primenjen u analizi realnih uzoraka zemlji&scaron;ta. Veoma dobre vrednosti testa<br />povrata ostvarene pri analizi primenom HPLC-UV-DAD metode, potvrdile su<br />pre svega ispravnost postupka pripreme uzoraka, a delom i kompletne<br />metode. Tačnost razvijene metode za određivanje SU u zemlji&scaron;tu potvrđena je<br />paralelnim analizama uzoraka zemlji&scaron;ta kori&scaron;ćenjem HPLC-MS-MS.<br />Primenom Studentovog t-testa (upareni), utvrđeno je da se rezultati paralelnih<br />analiza statistički značajno ne razlikuju (P=95%). Istraživanja u okviru<br />disertacije obuhvatila su i praćenje disipacije nikosulfurona, rimsulfurona,<br />oksasulfurona i prosufurona u različitim komercijalnim dozama primene<br />tokom 50 dana u polju na tri različite dubine (0-15 cm, 15-30 cm i 30-45 cm),<br />kao i laboratorijskim uslovima na dve temperature (250C i 300C). Vreme<br />polurazgradnje (DT50) ispitivanih SU (nikosulfuron, oksasulfuron i<br />prosulfuron) definisano Mitttag-Lefler-ovom funkcijom u ogledima u<br />laboratorijskim uslovima na 250C iznosilo je 0,65 dana (50 g ha-1 a.k.), 0,64<br />dana (160 g ha-1 a.k.) i 0,66 dana (30 g ha-1 a.k.), redom, a na 300C za<br />nikosulfuron 0,20 dana (50 g ha-1 a.k.) i prosulfuron 0,49 dana (50 g ha-1 a.k.).<br />DT50 za ispitivane SU u polju, takođe definisano Mitttag-Lefler-ovom<br />funkcijom, iznosilo je 72 minuta (0,05 dana), 0,23 dana, 0,12 dana i 0,15<br />dana, za nikosulfuron, rimsulfuron, oksasulfuron i prosulfuron, redom.<br />Značajno veća disipacija koja je utvrđena istraživanjima u okviru ove<br />disertacije najverovatnije je uzrokovana uticajem abiotičkih i biotičkih<br />procesa, kao i faktora spolja&scaron;nje sredine.</p> / <p>In this thesis a fast and selective method for determination and monitoring<br />of residues sulfonylurea herbicides (SU) (nicosulfuron, oxasulfuron,<br />tribenuron methyl, tritosulfuron, triasulfuron, rimsulfuron and prosulfuron)<br />in soil, by applying high-performance liquid chromatography with UV<br />detector with diode array diodes (HPLC-UV-DAD) was developed. The<br />separation of the sulfonylurea was performed by use of a Zorbax Eclipse<br />XDB-C18 column. In order to define appropriate conditions of analysis,<br />the influence of the most significant the experimental factors was<br />investigated and defined. The following optimal conditions for gradient<br />elution: mobile phase acetonitrile (A) and 0.1% acetic acid (B) t = 0 min,<br />52% A; t = 2-2.5 min, 47% A; t = 2.5-5 min, 52% A were adopted at a<br />constant flow rate of 1 mL min-1 and column temperature of 250C. On<br />basis of the response of the analytical signal, its reproducibility and<br />linearity, the wavelength of 240 nm was adopted as an appropriate. The<br />influence of the matrix was expressed and therefore for the quantitative<br />determination of investigated SU in soil samples application of HPLCUV-<br />DAD methods was used MMC calibration curve. In the analysis of<br />extracts of nocontaminated soil limits of quantitation for nicosulfuron,<br />oxasulfuron, tribenuron methyl, tritosulfuron, triasulfuron, rimsulfuron and<br />prosulfuron was achieved 3.16 &mu;g kg-1, 3.40 &mu;g kg-1, 3.76 &mu;g kg-1, 4.13 &mu;g<br />kg-1, 3.60 &mu;g kg-1, 3.04 &mu;g kg-1 and 2.97 &mu;g kg-1, respectively. The method<br />by using liquid chromatography-tandem mass spectrometry (HPLC-MSMS)<br />was defined in order to find more sensitive, more selective and more<br />accurate way to determine concentration SU in soil. HPLC-MS-MS was<br />used as the reference technique for checking results that have been<br />obtained by HPLC with UV-DAD detector. An efficient procedure<br />preparation of soil samples for the purpose chromatographic determination<br />of SU was defined. Using a mixture of dichloromethane-acetonitrile (2: 1,<br />v / v), acidified with acetic acid (0.8%, v / v), with the addition of urea (0.3<br />g / 10 g soil) was applied as the most effective way for extraction SU.<br />Microwave extraction process in a closed system allowed the best<br />conditions for the extraction of SU. In order to extract SU from matrix<br />exctracts soil the solid phase the extraction (SPE) with silica gel as an<br />adsorbent was used. The defined method for determination of investigated SU, as well as the developed procedure of sample preparation, was<br />successfully applied in the analysis of real samples of soil. The correctness<br />of procedure of sample preparation was confirmed with very good values<br />of recovery test which was applied in the analysis by using HPLC-UVDAD.<br />The accuracy of the developed method for determination of SU was<br />confirmed by coupled analysis soil samples using HPLC-MS-MS. The<br />results of parallel analysis does not differ significantly at 95% confidence<br />level. It was obtained using Student t-test (paired). The method developed<br />in this thesis was used for monitoring the dissipation of nicosulfuron,<br />rimsulfuron, oxasulfuron prosufuron, in different commercial doses of<br />application during 50 days in field at three different depths (0-15 cm, 15-<br />30 cm and 30-45 cm) and for laboratory conditions at two temperatures<br />(25&ordm;C and 30&ordm;C). The half-life time (DT50) of investigated SU were<br />calculated by use of Mitttag-Lefler function in experiments under<br />laboratory conditions at 25&ordm;C. The values of DT50 for nicosulfuron,<br />prosufuron and oxasulfuron read: 0.65 days (50 g ha-1 a.k.), 0.64 days (160<br />g ha-1 a.k.) and 0.66 days (30 g ha-1 a.k.), respectively. In the same type of<br />experiments at 30&ordm;C we get DT50 for nicosulfuron equals 0.20 days (50 g<br />ha-1 a.k.) and for prosulfuron equals 0.49 days (50 g ha-1 a.k.). The values<br />of DT50 on experiments in field were obtain also by use of Mitttag-Lefler&#39;s<br />function, and half-life times for nicosulfuron, rimsulfuron, oxasulfuron and<br />prosufuron from the commercially recommended doses, equal 72 minutes<br />(0.05 days), 0.23 days, 0.12 days and 0.15 days, respectively. Significantly<br />greater dissipation which was determined in this thesis was probably<br />caused by the influence of abiotic and biotic processes as well as<br />environmental factors.</p>

<p>UVOD: Učestalost kardiovaskularnih bolesti je visoka i predstavlja jedan od najče&scaron;ćih uzročnika morbiditeta i mortaliteta. Među evropskim zemljama najvi&scaron;i mortalitet od kardiovaskularnih bolesti beleži se u Srbiji. Hipertenzivna bolest je hronično oboljenje i često zahteva dugotrajnu medikamentoznu terapiju antihipertenzivnim lekovima. Osobe koje boluju od arterijske hipertenzije, koja je stabilna i dobro kontrolisana antihipertenzivnim lekovima, a čija doza nije menjana poslednje četiri nedelje, mogu biti davaoci krvi. MATERIJAL I METODE: Istraživanje je sprovedeno tokom 2012. godine na teritoriji grada Novog Sada i JužnoBačkog okruga. Prikupljeno je 450 uzoraka krvi od dobrovoljnih davalaca, oba pola, starosti od 18 do 65 godina, koji boluju od hipertenzivne bolesti, a koji u cilju terapije koriste antihipertenzivne lekove. Prikupljeni uzorci plazme analizirani su metodom tečne hromatografije visokih performansi (HPLC). REZULTATI: Analizom je utvrđeno prisustvo antihipertenzivnih lekova, iznad limita kvantifikacije, u 47 uzoraka. Prisustvo metoprolola je utvrđeno u 35, a bisoprolola u 12 uzoraka. U preostalim uzorcima zabeleženo je prisustvo ispitivanih lekova u količinama koje su bile iznad limita detekcije, ali ispod limita kvantifikacije. Detektovane koncentracije metoprolola se nalaze u terapijskom rasponu i za očekivati je da bi kod primaoca bili merljivi znaci efekta leka. Kod niskih detektovanih koncentracija bisoprolola verovatnoća pojave terapijskog efekta je mala i ne može se isključiti, jer bisprolol pokazuje terapijske efekte u rasponu koncentracija od 0,01 do 0,06 mcg/mL. ZAKLJUČAK: Vremenski period privremenog prestanka uzimanja antihipertenzivnih lekova za većinu ispitivanih lekova je odgovarajući i iznosi 24 časa pre davanja krvi. Period privremenog prekidanja terapije od 24 časa pre davanja krvi za metoprolol i bisoprolol potrebno je korigovati u smislu njegovog produženja i implementacija u Vodiče za selekciju i odabir davalaca krvi.</p> / <p>INTRODUCTION: The incidence of cardiovascular diseases is high and is one of the most common causes of morbidity and mortality among European countries. The highest mortality from cardiovascular diseases is recorded in Serbia. A hypertensive disease is a chronic condition and often requires a long-term medicamentous therapy using antihypertensive medications. Persons suffering from arterial hypertension, which is stable and well controlled when using antihypertensive medications, can be blood donors, providing that the dosage has not been changed in the last four weeks of the treatment. MATERIAL AND METHODS: The study was conducted during 2012. in the city of Novi Sad area and the South Backa District. 450 blood samples were collected from volunteer donors of both sexes, aged 18. to 65., all suffering from a hypertensive disease, who used antihypertensive medications for the purpose of the therapy. The collected plasma samples were analyzed using the method of high performance liquid chromatography (HPLC). RESULTS: The analysis revealed the presence of antihypertensive drugs, that were above the limit of quantification, in 47 samples. The presence of metoprolol was determined in 35 samples, and bisoprolol was present in 12 samples. The remaining samples recorded the presence of the tested drugs in amounts that were above the detection limit, but below the limit of quantification. The detected concentrations of metoprolol are in the therapeutic range, and it is to be expected that a recipient would show measurable signs of drug effect. Regarding the low detected values of bisoprolol, the probability of a therapeutic effect is small and can not be excluded, since bisoprolol shows therapeutic effects in the concentration range of 0.01 to 0.06 mcg/mL. CONCLUSION: The period of time to temporary withdraw the dosage of antihypertensive drugs in most investigated medications proved to be appropriate and is 24 hours prior to blood donation. The period of time to temporary interrupt therapy of 24 hours before giving blood for metoprolol and bisoprolol analysis should be corrected in terms of its extension and implementation in the Blood donors selection guide.</p>

<p>Interindividualne razlike u sastavu i aktivnosti crevne mikroflore mogu uticati na metabolizam lekova kao i na njihov konačan terapijski odgovor. Simvastatin je lek iz grupe statina i karakteri&scaron;e ga izuzetno mala rastvorljivost u vodi, mala bioraspoloživost (&lt;5%) i velike interindividualne razlike u terapijskom odgovoru čiji uzroci nisu u potpunosti obja&scaron;njeni. Poslednjih godina velika pažnja se posvećuje ispitivanjima žučnih kiselina u razvoju novih farmaceutskih formulacija zbog svoje uloge u solubilizaciji i modifikaciji prodora lekova kroz biolo&scaron;ke membrane. Zbog svega navedenog, u fokusu na&scaron;eg istraživanja su bile potencijalne interakcije između simvastatina, probiotskih bakterija i žučnih kiselina o kojima se vrlo malo zna, a od izuzetne su važnosti, zbog mogućeg uticaja na farmakokinetske i farmakodinamske osobine simvastatina, pa samim tim i na konačan terapijski odgovor kod pacijenta.Cilj istraživanja je bio da se ispita prodor i metabolizam simvastatina u probiotskim bakterijama kao i uticaj različitih žučnih kiselina na transport ovog leka u bakterijske ćelije. Takođe, cilj je bio da se ispita uticaj soli žučnih kiselina na distribucioni koeficijent simvastatina, kao i interakcije žučnih kiselina sa simvastatinom na nivou transportnih proteina probiotskih bakterija kako bi se objasnila priroda očekivanih interakcija.Identifikacija i kvantifikacija uzoraka vr&scaron;ena je metodom tečne hromatografije sa masenom spektrometrijom (LC-MS/MS). Kori&scaron;ćenjem programskih paketa VolSurf+ i Molinspiration, za identifikovane metabolite su izračunati molekulski deskriptori koji opisuju fizičko-hemijske i farmakokinetske osobine molekula. Određivanje distribucionog koeficijenta vr&scaron;eno je Shake-flask metodom. Interakcije žučnih kiselina sa simvastatinom na nivou transportnih proteina probiotskih bakterija ispitane su doking studijama pomoću SwissDock programa. Prilikom dvadesetčetvoročasovne inkubacije sa probiotskim bakterijama uočen je statistički značajan pad koncentracije simvastatina u ekstracelularnom sadržaju. Ukupan sadržaj simvastatina, kao zbir ekstracelulamog i intracelularnog sadržaja, je tokom čitavog ispitivanog perioda bio statistički značajno niži u odnosu na kontrolnu grupu bez probiotika navodeći na zaključak da se deo simvastatina tokom vremena metabolisao pod dejstvom enzima ispitivanih bakterija. Detektovano je i identifikovano 8 metaboličkih produkata simvastatina. Na osnovu izračunatih vrednosti molekulskih deskriptora, očekuje se da će metabolit M-452, koji predstavlja hidroksilovani produkt simvastatinske kiseline, pokazati najbolje rezultate u pogledu fizičko-hemijskih osobina i bioraspoloživosti u biolo&scaron;kom sistemu. Žučne kiseline nisu dovele do statistički značajne modifikacije transporta simvastatina u/iz probiotskih bakterija. Ipak, u nekim vremenskim tačkama primećena je ne&scaron;to veća koncentracija leka u ekstracelulamom prostoru u grupama sa žučnim kiselinama. Ove razlike se mogu delimično objasniti rezultatima određivanja distribucionog koeficijenta koji su pokazali da ispitivane žučne kiseline dovode do statistički značajnog smanjenja distribucionog koeficijenta simvastatina usled povećanja rastvorljivosti u vodenoj fazi. Rezultatima doking studija procenjeno je da ispitivane žučne kiseline imaju veći afinitet prema čak 80% multidrug transportera ispitivanih bakterija u odnosu na simvastatin &scaron;to govori o mogućnosti ostvarivanja interakcija žučnih kiselina sa ovim lekom na nivou transportnih proteina probiotskih bakterija. Na osnovu dobijenih rezultata možemo zaključiti da probiotske bakterije imaju ogroman uticaj na sudbinu simvastatina u biolo&scaron;kom sistemu. Uzimajući u obzir činjenicu da probiotske bakterije ulaze u sastav normalne crevne flore i da svaki organizam poseduje specifičan bakterijski sastav, trebalo bi posvetiti vi&scaron;e pažnje ispitivanju njegovog uticaja na farmakokinetiku lekova. Neophodna su dalja in vivo ispitivanja kako bi se utvrdila potencijalna farmakolo&scaron;ka aktivnost identifikovanih metabolita simvastatina nastalih pod dejstvom enzimske aktivnosti probiotskih bakterija. Povećanje rastvorljivosti simvastatina pomoću žučnih kiselina otvara mogućnost za dalja istraživanja u cilju razvoja novih farmaceutskih formulacija sa pobolj&scaron;anom bioraspoloživosti i farmakokinetskim osobinama.</p> / <p>Interindividual differences in the composition and activity of the gut microflora may affect the metabolism of drugs as well as their final therapeutic response. Simvastatin is drug from the group of statins and has extremely low water solubility, low bioavailability (&lt;5%) and high interindividual differences in therapeutic response whose causes are not fully understood. In recent years, great attention has been paid to studies of bile acids in the development of new pharmaceutical formulations because of their role in the drug solubilization and modification of drug transport through biological membranes. Accordingly, interactions between simvastatin, probiotic bacteria and bile acids were the focus of our research due to great importance and potential influence on the pharmacokinetic and pharmacodynamic properties of simvastatin, and therefore the final therapeutic response in the patients. The aim of the study was to investigate the simvastatin transport and metabolism in probiotic bacteria as well as the effect of various bile acids on drug transport into the bacterial cell. Additonally, the aim was to investigate the influence of bile salts on the distribution coefficient of simvastatin, and the interactions of bile acids with simvastatin at the level of probiotic transport proteins in order to elucidate the nature of expected interactions. Identification and quantification of samples were performed with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Molecular descriptors that describe the physico-chemical and pharmacokinetic properties of identified metabolites were calculated using the software packages VolSurf+ and Molinspiration. Determination of the distribution coefficient was performed using Shake-flask method. Interaction of bile acids with simvastatin at the level of bacterial transport proteins were studied using docking studies with SwissDock program. During the twenty-four hours of incubation with probiotic bacteria, simvastatin concentrations in the extracellular contet showed a statistically significant decrease. The total amount of simvastatin, as the sum of the extracellular and intracellular amount, during the whole study period, was significantly lower in comparison with control group without probiotics, suggesting that the part of simvastatin was metabolized by the enzymatic activity of studied bacteria. Accordingly, eight metabolic products of simvastatin were detected and identified. Based on the calculated values of molecular descriptors, it is expected that the metabolite M-452, which is the hydroxylated product of simvastatin acid, will show the best results in terms of physico-chemical properties and bioavailability in biological system. Bile acids did not show a significant influence on simvastatin transport into probiotic bacteria. However, in some time points, slightly higher drug concentrations in the extracellular medium in groups with bile acids were observed. These differences can be partly explained by the results of the determination of the distribution coefficients which showed that investigated bile acids lead to a statistically significant decrease in simvastatin distribution coefficient due to increased solubility in the aqueous phase. The results of docking studies estimated that studied bile acids have stronger affinities for the 80% of bacterial multidrug transporters compared to simvastatin indicating the possibility of achieving the interactions of bile acids with simvastatin at the level of transport proteins of probiotic bacteria. Based on the obtained results it could be concluded that probiotic bacteria have great influence on the fate of simvastatin in a biological system. Taking into account the fact that probiotic bacteria are the normal part of gut microflora and that each individual has specific bacterial fingerprint, more attention should be paid on studying its influence on drug pharmakocinetics. Further in vivo studies are required in order to determine potential pharmacological activity of identified simvastatin metabolites. Increased water solubility of simvastatin with bile acids may open the possibility for further investigations with the aim of development of new pharmaceutical formulation with improved bioavailability and pharmacokinetic properties.</p>

<p>U okviru doktorske disertacije su razvijeni i optimizovani postupci pripreme uzoraka hrane (žitarica, sirovina, poluproizvoda i prehrambenih proizvoda na bazi žitarica, voća i povrća) i stočne hrane, kao i simultano određivanje tropanskih i glikoalkaloida primenom gasne i tečne hromatografije uz maseno-spektrometrijsku detekciju. Razdvajanje alkaloida primenom gasne hromatografije je izvedeno na kapilarnoj koloni (HP-5MS UI), uz detekciju sa kvadrupolnom masenom spektrometrijom SIM tehnikom, u intervalu m/z 50&ndash;550 a.m.u. Pri optimizovanim uslovima postignuto je razdvajanje homatropina, atropina i skopolamina u vremenu od 12.75 min, pri čemu<br />tropin i anisodamin nisu mogli biti detektovani. Glikoalkaloidi nisu direktno mogli biti određivani gasnom hromatografijom usled njihove visoke molekulske mase i male isparljivosti. Za simultano određivanje tropanskih alkaloida (tropin, l-hiosciamin, atropin, skopolamin, homatropin i anisodamin) i glikoalkaloida (&alpha;-solanin i &alpha;-kakonin) validirana je brza i osetljiva multirezidualna LC&ndash;MS/MS metoda. Kori&scaron;ćena je disperzivna čvrsto-fazna ekstrakcija sa 0.5% mravlje kiseline u acotonitrilu/vodi (75:25, v/v), solima magnezijum sulfat, natrijum hlorid i natrijum citrat kao i C₁₈ sorbent. Analiti su razdvojeni na Chirobiotic V koloni, sa mobilnom fazom sastavljenom od 10 mM amonijum formata u voda/acetonitril (90:10, v/v) i metanol/acetonitril (50:50, v/v), me&scaron;anim u odnosu 20:80 (v/v). Detekcija komponenti je izvedena u pozitivnom elektrosprej modu (ESI+), kori&scaron;ćenjem reakcionog vi&scaron;estrukog monitoring akvizacionog moda (MRM). Optimizovana tečno hromatografska metoda je podrazumevala brz i jednostavan proces ekstrakcije, sa prinosom od 61-111% za pojedine alkaloide, dobru linearnost u &scaron;irokom opsegu (5-80 &mu;g/kg, r²=0.998), dobru selektivnost, robusnost i preciznost (CV &lt; 5%). Granica detekcije (LOD) za sve alkaloide je bila u opsegu od 0.74 do 0.79 ng/g dok se granica kvantifikacije (LOQ) kretala od 2.17 do 2.46 ng/g u svim žitaricama, izuzev za tropin u soji i lanenom semenu (LOD = 1.55 i LOQ = 4.91 ng/g). Pri analizi uzoraka sa trži&scaron;ta alkaloidi nisu detektovani u analiziranim uzorcima hrane, kao &scaron;to su: p&scaron;enica, raž, kukuruz, bra&scaron;no od me&scaron;anih žitarica, kukuruzno bra&scaron;no, biskvit i krekeri. Stočna hrana namenjena ishrani svinja i peradi je sadržala atropin, skopolamin, &alpha;-solanin i &alpha;-kakonin u koncentracionom opsegu od 3.6 do 21.7 ng/g. Atropin i skopolamin su detektovani u koncentracionom opsegu od 2.8 do 9.8 ng/g u hrani namenjenoj ishrani krava i zečeva, dok u hrani nemenjenoj ishrani konja i divljih životinja alkaloidi nisu detektovani. U analiziranim uzorcima voća i povrća (jabuka, kru&scaron;ka, avokado, mrkva, krastvac i paprika) po prvi put u ovom radu su detektovani glikoalkaloidi, &alpha;-solanin i &alpha;-kakonin. Koncentracija oba glikoalkaloida se kretala u opsegu od 0.3 do 15 ng/g. Sadržaj glikoalkaloida u krompiru i čipsu (8708.9-18794.7 ng/g) se nalazio u okviru preporučenog ukupnog sadržaja glikoalkaloida od 200 mg/kg (sirova odvaga) (FAO/WHO, 1999). Apsorpcija i translokacija alkaloida od strane p&scaron;enice u koren, listove i stabljiku je ustanovljena upotrebom atropina ¹⁴C. Utvrđeno je da biljka nakon 15 dana apsorbuje 4.30% i 2.28% atropina ¹⁴C za niži (13676 dpm/g soil) i vi&scaron;i (37203 dpm/g soil) sadržaj standarda sa kojim je zemlji&scaron;te spajkovano, redom. Količina apsorbovanog atropina se smanjivala tokom rasta biljke. Biljka starosti 90 dana je apsorbovala 0.38% i 0.21% atropina ¹⁴C za niži i vi&scaron;i sadržaj standarda, redom. Povećanje koncentracije supstance u zemlji&scaron;tu nije uticalo na dalje povećanje apsorpcije. Do nagomilavanja supstance je do&scaron;lo u listovima (83%) dok su niže koncentracije zabilježene u korenu (8.6%), stabljici (4.2%) i semenu (4.1%). U analiziranim uzorcima vode, koja je poticala od ispiranja zemlji&scaron;ta obogaćenog atropinom ¹⁴C, nakon 30 dana supstanca je detektovana u koncentraciji od 0.5%. Tokom vremena je ustanovljeno smanjenje ispiranja ove supstance (0.01% nakon 90 dana). Analiza uzoraka zemlji&scaron;ta nakon 30 i 60 dana je pokazala značajne adsorpcione osobine atropina, tako da je količina čvrsto adsorbovanog (neekstrahovanog) atropina iznosila 60% i 70%, redom. Zaostali atropin je bio stabilan i nakon 90 dana.</p> / <p>The methods of sample preparation have been developed and optimized for food (grains, raw materials, food products based on grains and fruits and vegetables) and feed analyses for the purpose of simultaneous determination of tropane and glycoalkaloids by gas and liquid chromatography hyphenated to mass spectrometry. Separation of alkaloids by gas chromatography was achieved by using capillary column HP-5MS UI. The alkaloids have been detected by using a quadrupole mass spectrometer inSIM mode for the range of m/z 50&ndash;550 a.m.u. Under optimised conditions, good separation of homatropine, atropine and scopolamine was achieved after 12.75 min, while tropine and anisodamine couldn`t be detected. Glycoalkaloids could not be analysed directly by gas chromatography due to their high molecular weight and low volatility. For simultaneous determination of tropane alkaloids (tropine, atropine, scopolamine, homatropine, anisodamine) and glycoalkaloids (&alpha;-solanine, &alpha;-chaconine) fast and sensitive multiresidue LC&ndash;MS/MS method was validated. In sample preparation dispersive solid phase extraction (DSPE) was performed with 0.5% formic acid in acetonitrile/water (75:25, v/v) and a mixture of magnesium sulphate, sodium chloride, sodium citrate and C18 sorbent. The analytes were separated by isocratic HPLC on a Chirobiotic V column with the mobile phase that consisted of 10 mM ammonium formate in water/acetonitrile (90:10, v/v) and methanol/acetonitrile (50:50, v/v), mixed in the ratio of 20:80 (v/v).<br />Compounds were detected in positive electrospray ionization mode (ESI+), using multi reaction monitoring (MRM). Optimised liquid-chromatographic method exhibited good linearity in the range 5-80 ng/g (r²=0.998). The method has shown to be specific, selective, accurate (recoveries from 61- 111%), precise (CV &lt; 5%) and rugged. Calculated limits of detection (LOD) for all alkaloids were in the range 0.74-0.79 ng/g, while the limits of quantitation (LOQ) were in the range 2.2-4.9 ng/g in all grains, except for tropine in soybean and linseed (LOD = 1.55 and LOQ = 4.91 ng/g). The proposed method was applied in the analyses of samples obtained from local supermarkets. The alkaloids were not detected in following food samples:<br />wheat, rye, maize, mixed grain flour, corn flour, biscuits and crackers. The feeds for pigs and chicken were the most contaminated with atropine, scopolamine, &alpha;-solanine and &alpha;-chaconine with the contents of alkaloids in the range of 3.6 to 21.7 ng/g. Atropine and scopolamine were detected in cattle and rabbit feed in concentrations ranging from 2.8 to 9.8 ng/g, while in feed for horses and wild animals none of the target alkaloids were detected. Conducted research reports for the first time the presence of glycoalkaloids, &alpha;-solanine and &alpha;-chaconine in fruit and vegetable samples (apple, pear, avocado, carrot, cucumber and paprika). The concentrations of these alkaloids were in the range of 0.3 to 15 ng/g. The content of glycoalkaloids in potato and chips complied with the recommended content of total glycoalkaloids concentration of 200 mg/kg (raw weight) (FAO/WHO, 1999). Absorption and translocation of alkaloids in wheat (roots, leaves, stem) was determined by using atropine ¹⁴C. It was found that young wheat after 15 days absorbed approximately 4.30% and 2.28% of atropine ¹⁴C for low (13676 dpm/g soil) and high (37203 dpm/g soil) spiked levels in soil, respectively. Increase in the spiked concentration in the soil did not affect higher absorption of atropine ¹⁴C in wheat. The highest accumulation of atropine ¹⁴C was observed in the leaves (83%) while lower<br />concentrations were detected in the roots (8.6%), stems (4.2%) and seeds (4.1%). In collected water samples during the soil leaching, atropine ¹⁴C was detected in the concentration of 0.5%. Leaching decreased with the time (0.01% after 90 days). Analyses of soil samples after 30 and 60 days showed strong adsorption of atropine to the soil and quantity of adsorbed atropine was 60% and 70%, respectively. Adsorbed atropine in the soil was stable after 90 days.</p>

<p>Rod Hypericum obuhvata oko 500 različitih vrsta klasifikovanih u 36 sekcija. Najpoznatiji predstavnik roda je kantarion (Hypericum perforatum, Hypericaceae). Hemijska karakterizacija kantariona je bila predmet mnogobrojnih istraživanja koja su pokazala prisustvo različitih klasa jedinjenja, kao i &scaron;irok spektar biolo&scaron;kog potencijala. Međutim, ispitivanja su otkrila prisustvo istih klasa jedinjenja i u drugim predstavnicima roda Hypericum, opravdavajući hemijska istraživanja i određivanje biolo&scaron;kih aktivnosti. S obzirom da se kantarion retko plantažno uzgaja, već uglavnom sakuplja iz prirode, neretko usled nedovoljne obučenosti sakupljača lekovitog bilja dolazi do zamene propisanog biolo&scaron;kog izvora droge Hyperici herba (H. perforatum subsp. perforatum, Hypericaceae) morfolo&scaron;ki sličnim predstavnicima roda, &scaron;to posledično utiče na sadržaj aktivnih principa i biolo&scaron;ki potencijal. Zbog toga su ciljevi ove doktorske disertacije: utvrđivanje uticaja geografskog porekla i stadijuma ontogenetskog razvoja biolo&scaron;kog izvora na kvalitativni i kvantitativni hemijski sastav, biolo&scaron;ki potencijal vodeno-alkoholnog ekstrakta taksona roda Hypericum, kao i utvrđivanje kvaliteta (stepen usitnjenosti, biolo&scaron;ki izvor, hemijski sastav i biolo&scaron;ki potencijal) komercijalno dostupnih čajeva na bazi kantariona koji se nalaze u slobodnoj prodaji. Biljni materijal je obuhvatio uzorke 32 taksona roda Hypericum kao i 51 uzorak monokomponentnih čajeva na bazi kantariona prikupljenih na teritoriji centralnog dela Balkanskog poluostrva, centralne Evrope, Rusije i Turske tokom 2011-2016. godine. U većini ispitanih ekstrakta kvantifikovan je visok sadržaj ukupnih fenola i flavonoida. Rezultati određivanja sadržaja hipericina u ispitivanim ekstraktima pokazali su njegovo prisustvo kod uzoraka svih taksona prikupljenih za vreme cvetanja, pri čemu je to bila i fenofaza u kojoj je dostignut maksimalan sadržaj. Hiperforin je takođe detektovan u većini uzoraka prikupljenih za vreme cvetanja, prateći dinamiku akumulacije sličnu hipericinu. Sa druge strane apigenin i epikatehin nisu detektovani u velikom broju ispitanih ekstrakta, dok je prisustvo naringenina kvantifikovano u manje od 50% uzoraka. Amentoflavon je bio prisutan u manje od 30% ispitanih uzoraka. Visok sadržaj kvercetina i rutina je određen u svim ispitanim ekstraktima, pri čemu u slučaju kvercetina nije zabeleženo značajnije variranje tokom ontogenetskog razvoja, dok je maksimalna koncentracija rutina određena u uzorcima prikupljenim pre, ili za vreme cvetanja. U većini uzoraka detektovane su galna, hlorogenska, kafena i p-hidroksibenzojeva kiselina (naročito u periodu koji prethodi cvetanju), dok ferulna kiselina nije kvantifkovana kod vi&scaron;e od 80% ispitanih ekstrakta. Rezultati su pokazali snažnu antioksidantnu sposobnost ispitivanih ekstrakata. Uočena je snažnija inhibicija monoaminooksidaze A u odnosu na monoaminooksidazu B, kao i vi&scaron;i anti-&alpha;-glukozidazni od anti-&alpha;-amilaznog potencijala. Sposobnost inhibicije acetilholinesteraze je ocenjena kao umerena. Ispitivanje antiproliferativnog potencijala ekstrakata vrsta roda Hypericum, je pokazalo izrazit sinergistički efekat sa antineoplastičnim lekom bleomicinom (radiomimetik) kao i visoku selektivnost prema ćelijama karcinoma cerviksa i melanoma, za razliku od umerenog antiproliferativnog potencijala i niske selektivnosti samih ekstrakata prema malignim ćelijama. Zabeležen je značajan broj neusitnjenih (in toto) komercijalno dostupnih uzoraka čajeva na bazi kantariona, dok su kao biolo&scaron;ki izvor ispitanih uzoraka čajeva identifikovane različite podvrste H. perforatum. Sličnost hemijskog profila i biolo&scaron;kog potencijala velikog broja ispitanih taksona sa H. perforatum ukazuju na mogućnost njihove eksploatacije. Međutim, zavisnost navedenih parametara od geografskog porekla biljnog materijala ističe značajan uticaj abiotičkih ekolo&scaron;kih faktora na kvalitet droge. Hemijski sastav i morfolo&scaron;ko ispitivanje uzoraka monokomponentnih čajeva na bazi kantariona ukazuju na neophodnost kontrole njihovog kvaliteta.</p> / <p>The genus Hypericum includes more than 500 different species classified in 36 sections. The most known representative of genus is St. John&#39;s wort (Hypericum perforatum, Hypericaceae). Chemical characterization of St. John&#39;s wort was the subject of many conducted researches which demonstrated the presence of different classes of compounds, as well as a wide spectrum of biological potential. However, the studies have also shown the presence of the same compounds in other representative of the genus Hypericum, justifying the evaluation of their chemical composition and biological potential. Considering the fact that St. John&#39;s wort is rarely being cultivated, rather collected from nature, unqualified collectors may substitute the official biological source of Hyperici herba (H. perforatum subsp. perforatum, Hypericaceae) for morphologically similar representatives of the genus, consequently affecting the quantities of active principles and biological potential of the drug. The aims of this PhD thesis were to evaluate the influence of geographical origin and stage of ontogenetic development of biological source on qualitative and quantitative chemical composition and biological potential of water - alcoholic extract of different Hypericum taxa, as well as to determine the quality (grinding degree, biological source, chemical composition and biological potential) of commercially available St. John&rsquo;s wort teas on the market. The plant material included samples of 32 taxa of genus Hypericum, as well as 51 commercially available sample of monocomponent teas based on St. John&#39;s wort collected at territory of central part of Balkan Peninsula, central Europe, Russia and Turkey, during period 2011 - 2016. High amounts of total phenolics and flavonoids were quantified in the most of the examined extracts. Quantification of hypericin showed its presence in all of the samples collected during flowering period, while that was also the ontogenetic stage of its maximum accumulation. Hyperforin was also quantified in most of the samples collected during flowering period, following the hypericin trend of accumulation. On the other hand, apigenin and epicatechin were not detected in large number of the examined extracts, while naringenin was detected in less than 50% of samples. Amentoflavone was present in less than 30% of the examined samples. High amounts of quercetin and rutin were determined in all of the examined samples. No significant changes in the amounts of quercetin during ontogenetic development were noticed, while the highest amounts of rutin were determined in samples collected before, or during flowering. Gallic, chlorogenic, caffeic and p-hydroxybenzoic acid were detected in most of the examined samples (especially in period before opening of the flowers), while ferulic acid was not quantified in more than 80% of samples. The results have demonstrated strong antioxidant potential of the examined extracts. Stronger potential of the examined extracts to inhibit monoamine oxidase A than monoamine oxidase B, as well as stronger anti-&alpha;-glucosidase than anti-&alpha;-amylase potential were recorded. The obtained anticholinesterase activity of the examined extracts was moderate. The examination of antiproliferative potential of different Hypericum species extracts has shown additive effects in combination with bleomycin (radiomimetic), as well as high selectivity toward cervix and melanoma cancer cells. On the other hand, moderate antiproliferative potential and low selectivity during treatment of cancer cells only with the examined extracts was recorded. Significant share of in toto commercially available tea samples based on St. John&#39;s wort was noticed, while different subspecies of H. perforatum were identified as biological sources of the examined teas. Chemical profile and biological potential resemblance between a large number of investigated taxa and H. perforatum point to possibilities of their exploitation. However, the dependence of listed parameters from geographical origin of plant material emphasizes the importance of abiotic ecological factors for the quality of herbal drug. Chemical composition and morphological examination of monocomponent teas based on St. John&rsquo;s wort stress the importance of their quality control.</p>

<p>Ispitana&nbsp; je&nbsp; mogućnost ekstrakcije fumonizina iz kukuruza&nbsp;sa vodom i fosfatnim puferom, umesto sa sme&scaron;om&nbsp;acetonitril&ndash;metanol&ndash;voda.&nbsp; Ekstrakcione metode&nbsp;neorganskim&nbsp; rastvaraĉima&nbsp; su&nbsp; uspe&scaron;no&nbsp; primenjene za&nbsp;odreĊivanje&nbsp; fumonizina&nbsp; B₁, B_2&nbsp;i&nbsp; B_3&nbsp;metodom&nbsp; tečne&nbsp;hromatografije sa fluorescentnom detekcijom, kao i&nbsp;ukupnih fumonizina pomoću&nbsp; imunohemijske metode.&nbsp;Analiziran&nbsp; je&nbsp; veći broj&nbsp; uzoraka na&nbsp; prisustvo i sadržaj&nbsp;fumonizina.&nbsp; Ispitani su uzorci&nbsp; kukuruza (235), sakupljeni&nbsp;tokom vi&scaron;egodi&scaron;njeg perioda (2005.&nbsp; i 2009&minus;2013.&nbsp; godine)&nbsp; i&nbsp;p&scaron;enice (83) roda 2010. i 2012. godine, sa područja&nbsp; severne&nbsp;Srbije.&nbsp; Ispitana je kontaminiranost kukuruza sa područja&nbsp;<br />severne Srbije fumonizinima, drugim mikotoksinima i&nbsp;plesnima, kao i mogući uticaj klimatskih faktora na stepen&nbsp;kontaminacije.&nbsp; Rezultati kontaminiranosti useva&nbsp;fumonizinima&nbsp; za svaku godinu&nbsp; pojedinačno&nbsp; su povezivani&nbsp;sa vremenskim prilikama koje su&nbsp; pratile istu. Različita&nbsp;hrana na bazi žitarica je analizirana ELISA metodama.&nbsp;Razvijena je ELISA i metoda&nbsp; tečne hromatografije sa&nbsp;fluorescentnom detekcijom&nbsp; za određivanje fumonizina u tri&nbsp;vrste lekovitog bilja sa područja Srbije.&nbsp; Ispitana je&nbsp;mogućnost&nbsp; primene infracrvene spektroskopije sa&nbsp;Furijeovim transformom&nbsp; za &nbsp;odredivanje&nbsp; fumonizina.&nbsp;Razvijen je&nbsp; ekspertni sistem za re&scaron;avanje problema izbora&nbsp;<br />optimalnog postupka određivanja fumonizina u kukuruzu.</p> / <p>Possibility of fumonisin extraction from maize using water and phosphate buffer instead of acetonitrile-methanol-water mixture was examined. The methods of extraction without organic solvents have successfully been applied for the determination of fumonisins&nbsp; B1, B2 and&nbsp; B3 using&nbsp; liquid chromatography-fluorescence detection&nbsp; method,&nbsp; as well as total fumonisins using enzyme-linked immunosorbent&nbsp; assay&nbsp; (ELISA).&nbsp; Large number of samples was analyzed for the presence and content of fumonisins. Maize samples (total 235) collected throughout several-year period (2005 and 2009-2013) and wheat samples (total 83) from 2010 and 2012 harvest originating from the territory of northern Serbia were analyzed. Contamination of maize originating from the territory of northern Serbia with&nbsp;fumonisins and other mycotoxins and moulds was examined, as well as the potential impact of climatic factors on contamination level.&nbsp; The results on the fumonisin-contamination of cereals obtained for each individual year are related with the climatic&nbsp; conditions characteristic for the relevant year. A variety of cereal-based food was analyzed using ELISA methods. Improved&nbsp; liquid chromatography-fluorescence&nbsp; detection method and ELISA for the determination of fumonisins in three &nbsp;medicinal plant&nbsp; species from the territory of Serbia were developed.&nbsp; Possible application of&nbsp; Fourier transform&nbsp; infrared spectroscopy&nbsp; (FTIR) for quantification of fumonisin was investigated.&nbsp; An expert system&nbsp; to solve the problem of selecting an optimal&nbsp;method for&nbsp; determination of fumonisins in&nbsp; maize has been developed.</p>

<p>Sprovedena studija po prvi put izve&scaron;tava o prisustvu patulina, sekundarnog metabolita određenih vrsta plesni, u proizvodima od jabuka, kao i proceni rizika usled unosa patulina od strane odojčadi, dece, adolescenata i odrasle populacije u Republici Srbiji. Ukupno 356 uzoraka sokova i ka&scaron;ica za odojčad i malu decu (48 i 66, redom), sokova za decu (mala pakovanja sa cevčicom, 100) i sokova u porodičnom pakovanju (142), sakupljeno je sa trži&scaron;ta tokom tri godine i analizirano primenom tečne hromatografije sa ultraljubičastom detekcijom, metodom koja je predhodno validirana. Prisustvo patulina je detektovano u 44% i 17% uzoraka sokova i ka&scaron;ica za odojčad i malu decu, redom, u količinama nižim od zakonskog ograničenja od 10 &mu;g/kg (maksimalno 8,3 i 7,7 &mu;g/kg, redom). Udeo kontaminiranih uzoraka među sokovima za decu iznosio je 43%, sa najvi&scaron;om koncentracijom patulina od 30,2 &mu;g/kg ispod maksimalno dozvoljenog nivoa od 50 &mu;g/kg. Patulin je detektovan u 51% sokova u porodičnom pakovanju, sa 0,7% uzoraka iznad zakonske granice od 50 &mu;g/kg (prosečna koncentracija 4,3 &mu;g/kg). Sokovi od jabuka su pokazali značajno vi&scaron;i udeo kontaminiranih uzoraka (74% u odnosu na 28%), kao i vi&scaron;i prosečni sadržaj patulina (6,4 u odnosu na 2,1 &mu;g/kg) u poređenju sa sokovima od me&scaron;anog voća. Procena rizika usled unosa patulina od strane odojčadi, dece, adolescenata i odrasle populacije u Republici Srbiji, sprovedena primenom determinističkog i probabilističkog pristupa, uključujući rezultate biodostupnosti patulina, pokazala je da je odnos između procenjenog dnevnog unosa i toksikolo&scaron;ke referentne doze za patulin od 0,4 &mu;g/kg telesne mase, koji se označava kao &ldquo;hazard quotient&rdquo;, znatno ispod 1, &scaron;to ukazuje na tolerantan nivo izloženosti i nepostojanje razloga za zabrinutost za zdravlje populacije. Dodatno, analiza ostataka pesticida i toksičnih metala potvrdila je bezbednost proizvoda od jabuka na trži&scaron;tu. Međutim, identifikacija vi&scaron;estrukih ostataka pesticida je razlog za aktivan pristup i pažljivo planiranje i sprovođenje monitoringa bezbednosti hrane, posebno hrane za odojčad i malu decu, kao najosetljivije populacione grupe.</p> / <p>This study reports for the first time the occurrence of patulin, a secondary metabolite of certain fungi, in apple-based food, as well as risk assessment related to patulin intake by infants, children, adolescents and adults in Serbia. In total, 356 samples of infant fruit juices (48), infant pur&eacute;e (66), juices for children (small package with straw, 100), and juices in family package (142) were collected from the market over three years (2013&ndash;15) and analysed using validated method based on liquid chromatography with ultraviolet detection. Patulin was found in 44% of infant juices and 17% of infant pur&eacute;e, with all values below the legal limit of 10 &mu;g/kg (maximum 8.3 and 7.7 &mu;g/kg, respectively). The proportion of contaminated samples among fruit juices for children was 43%, with the highest patulin concentration at 30.2 &mu;g/kg, not exceeding the maximum allowed level of 50 &mu;g/kg. Patulin was found in 51% of juices in family package, with 0.7% of the samples in excess of the legal limit of 50 &mu;g/kg (mean 4.3 &mu;g/kg). Apple juices showed significantly higher percentage of contaminated samples (74% versus 28%), as well as higher mean patulin content (6.4 versus 2.1 &mu;g/kg) when compared with the multifruit ones. Risk assessment of patulin intake by Serbian infants, children, adolescents and adults, conducted by deterministic and probabilistic approaches and including the bioaccessibility results, revealed a ratio between exposure and toxicological reference dose for patulin of 0,4 &mu;g/kg body weigth, called hazard quotients, well below 1, indicating a tolerable exposure level and no health concern. Furthermore, analysis of pesticide residues and toxic metals confirmed safety of apple products on the market. However, identification of multiple pesticide residues is a reason for an active attitude and carefully planned and conducted monitoring of food safety, expecialy in the case of food for infants and young children, as they are the most susceptible population group.</p>

<p>Doktorsku disertaciju čine tri celine kojima je zajednički element ispitivanje fenola, u pogledu njihovog sadržaja i dostupnosti u dijetetskim suplementima na bazi grožđa i japanskog troskota, ispitivanja uticaja suplementacije kod eksperimentalnih životinja, odnosno mogućnosti ekstrakcije fenolnih jedinjenja iz komine grožđa. Osnovni ciljevi prvog dela bili su ispitivanje bezbednosti i kvaliteta 14 suplemenata na bazi grožđa i japanskog troskota u pogledu ujednačenosti mase, sadržaja i brzine rastvorljivosti. U drugom delu je radi provere terapijske delotvornosti suplementa koji sadrži čist resveratrol ispitan njegov uticaj na glikemiju i lipidni status eksperimentalnih životinja. Treći deo je obuhvatio analizu pet različitih komina grožđa i razvoj metode ekstrakcije fenola iz odabrane komine kako bi se dobili ekstrakti sa &scaron;to je moguće većim prinosom, koristeći rastvarače koji su bezbedni po ljudsko zdravlje. Rezultati su pokazali da dva od četrnaest suplemenata nisu ispunila zahteve farmakopeje za lekove u pogledu ujednačenosti mase i sadržaja aktivne komponente, dok ni jedan suplement nije ispunio zahteve u pogledu brzine rastvorljivosti aktivne supstance, zbog čega se postavlja pitanje delotvornosti ispitanih suplemenata. Ni kod jednog suplementa nisu kvantifikovani ostaci pesticida ni toksični metali, čime je potvrđena njihova bezbednost. Farmakodinamska ispitivanja na pacovima pokazala su antioksidantna, anti-dijabetska i hipolipidemijska svojstva dijetetskog suplementa na bazi resveratrola, čime je potvrđena njegova delotvornost. Za potvrdu delotvornosti suplementa na ljudima neophodno je sprovesti dobro dizajnirano kliničko ispitivanje na dovoljnom broju ispitanika. Analiza pet različitih komina grožđa pokazala je da ovaj nusprodukt proizvodnje vina sadrži različite fenole, od kojih je samo katehin bio prisutan u značajnoj količini. Kvalitativan i kvantitativan sastav komine značajno varira zavisno od sorte i berbe grožđa, kao i od primenjenog tehnolo&scaron;kog procesa proizvodnje vina. Imajući u vidu sveobuhvatne kriterijume u pogledu efikasnosti ekstrakcije, zaključeno je da su 55% etanol, odnos uzorak / rastvarač 1:40, pH 4,5, T 55&deg;C i vreme od 30 min optimalni eksperimentalni uslovi za ekstrakciju fenola iz komine grožđa. U zavisnosti od osnovnog cilja procesa ekstrakcije ovi parametri se mogu lako modifikovati. Vi&scaron;estruke su mogućnosti za iskori&scaron;ćenje komine grožđa, a jedan od njih bi mogla biti i da se koristi kao sirovina za izradu dijetetskih suplemenata.</p> / <p>The dissertation consists of three parts with a common element &ndash; testing phenols in terms of content and availability in grape and Polygonum cuspidatum-based dietary supplements, testing the supplement&rsquo;s impact on experimental animals and the possibility to extract phenolic compounds from grape pomace. The primary objectives of the first part were testing safety and quality of fourteen grape and Polygonum cuspidatum-based supplements in terms of uniformity of mass, content and dissolution profile. In the second part, to test the therapeutic efficacy of a supplement containing pure resveratrol, its effect on the glycemia and lipid profile of experimental animals was examined. The third part covers the analysis of five different grape pomaces and the development of a phenol extraction method from the selected grape pomace to obtain extracts with the highest possible yield, using solvents that are safe for human health. The results showed that two out of fourteen supplements have not met the Pharmacopoeia requirements in terms of uniformity of mass and active substance content, while no supplement has met requirements in terms of dissolution test of the active substance, which raises the question of the effectiveness of the tested supplements. No pesticide or heavy metal residues were quantified in any of the supplements which confirms their safety. Pharmacodynamic testing on rats has shown antioxidant, antidiabetic and hypolipidemic properties of the resveratrol-based dietary supplement which confirms its efficacy. In order to confirm the supplement efficacy on people, it is necessary to conduct a well-designed clinical trial on a sufficient number of human participants. The analysis of five different grape pomaces revealed that this byproduct of vine production contains different phenols, and only catechin was present in significant amounts. The qualitative and quantitative composition of grape pomace varies significantly depending on grape variety and harvesting as well as on the technological process that was applied in vine production. Considering the comprehensive criteria in terms of extraction efficacy, it was concluded that optimal experimental conditions for the extraction of phenol from grape pomace include 55% ethanol, sample/solvent ratio 1:40, pH 4.5, T 55&deg;C for 30 minutes. Depending on the primary objective in the extraction process, these parameters can be easily modified. There are multiple possibilities for utilizing grape pomace and one of them could be as raw material in production of dietary supplements.</p>