<p><strong>Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR).</strong></p><p>U radu je spektrofotometrijski ispitivana brzina oksidacije L-askorbinske kiseline. Tok reakcije je praćen snimanjem UV apsorpcionih spektara termostatiranih rastvora L-askorbinske kiseline u puferima različitih vrednosti rN: acetatnom (4-6). fosfatnom (5-8). fosfatno-citratnom (6-8), boratnom (8-11). glicinskom (9-11) i univerzalnom (4-11) !zveden je jednostavan oblik kinetičke jednačine reakcije vi&scaron;eg i razlomljenog reda. Dobijena jednačina je univerzalna, jer obuhvata jednačine nultog, prvog, drugog, trećeg i razlomljenog reda izračunate su vrednosti reda reakcije i one variraju sa promenom vrednosti rN unutar jednog puferskog sistema. Veza između vrednosti konstanti brzine oksidacije L-askorbinske kiseline i vrednosti rN ispitivanih pufera je linearna do vrednosti rN=10.00. Vrednosti koeficijenta pravca prave su različite za ispitivane pufere. Vrsta anjona prisutna u puferu kao i prisusutvo jona metala u kori&scaron;ćenim hemikalijama utiču na vrednosti konstante brzine oksidacije L-askorbinske kiseline i one su različite u raznim puferima istih vrednosti rN. Vrednosti konstante brzine oskidacije L-askorbinske kiseline su največe u univerzalnom puferu pri svim vrednostima rN. Prisutna sme&scaron;a anjona manje utiče na oksidaciju L-askorbinske kiseline nego pojedinačni anjoni, verovatno zbog među- sobnih interakcija.</p> / <p><strong>Abstract was processed by technology for Optical character recognition (OCR).</strong></p><p>The paper deats with the spectrophotometric study of L-ascorbic acid oxidation rate. The course of reaction has been observed by recording the UV absorption spectra of thermostated solution of L-ascorbic acid in buffers with different рН values: acetate (4-6), phosphate (5-8), phosphate-citrate (6-8), borate (8-11), glycine (9-11) and universal (4-11). A simple form of kinetic eguation of higher and fractional order reaction has been observed. The obtained eguation is universal as it comprises the eguations of zero, first, second, third and fractional order. The reaction order values have been calculated and they vary with change of рН values within each buffer system. The relation between the values of L-ascorbic acid oxidation rate constants and рН value of the studied buffers is linear up to рН value = 10.00. The straight line stopes are different for investigated buffers. The anion type present in a buffer as wett as the presence of metal ions in applied chemicals affect the values of L-ascorbic acid oxidation rate constant and they are different in different buffers with the same рН values. The values of L-ascorbic acid oxidation rate constant are the highest in the universal buffer at all рН values. The present anion mixture affects the L-ascorbtc acid oxidation to a tesser degree than single anions, presumabty due to mutuat interactions.</p>

<p>&nbsp;&nbsp; Cilj ove doktorske disertacije predstavljao je ispitivanje fitohemijskog sastava i biolo&scaron;ke aktivnosti vodenih i metanolnih ekstrakata svežih i suvih plodova, kao&nbsp; i pekmeza&nbsp; pripremljenog&nbsp; po tradicionalnoj recepturi od plodova&nbsp; četiri (od kojih se jedna javlja u dve forme)&nbsp; samonike&nbsp; vrsta&nbsp; roda&nbsp; <em>Sorbus</em>&nbsp; L.:&nbsp; S.<em> aucuparia</em>, S.<em> domestica</em>, S. <em>torminalis</em>&nbsp; f.&nbsp; t<em>orminalis</em>, S. <em>torminalis</em>&nbsp; f. <em>semitorminalis</em>&nbsp; i&nbsp; S. intermedia Ispitivanje fitohemijskog sastava obuhvatalo je LC-MS/MS analizu&nbsp; 44 odabrana fenolna jedinjenja&nbsp; i&nbsp; hinske kiseline (organska&nbsp; kiselina). Takođe, spektrofotometrijski je&nbsp; određen&nbsp; sadržaj&nbsp; ukupnih fenolnih i flavonoidnih jedinjenja, kao i&nbsp; sadržaj askorbinske kiseline. Evaluacija biolo&scaron;ke aktivnosti obuhvatala je&nbsp; <em>in vitro&nbsp; </em>ispitivanja antioksidantne aktivnosti, kao i ispitivanje uticaja ekstrakata odabranih vrsta&nbsp; roda&nbsp;<em> Sorbus</em>&nbsp; na aktivnost enzima acetilholinesteraze, antimikrobni, kao i antiproliferativni potencijal.</p><p>&nbsp;&nbsp; Sumiranjem dobijenih rezultata može se zaključiti da sveži i suvi plodovi ispitivanih vrsta&nbsp; <em>Sorbus</em>,&nbsp; kao i&nbsp; pekmezi&nbsp; predstavljaju&nbsp; umeren izvor&nbsp; fenolnih jedinjenja.&nbsp; Kao najzastupljenije fenolne kiseline izdvojile su se protokatehinska i&nbsp; ferulna, a među flavonoidima amentoflavon i kvercetin-3<em>-O-</em>glukozid.&nbsp; Pored toga, hinska kiselina je zabeležena u značajnoj količini u svim analiziranim ekstraktima.</p><p>&nbsp;&nbsp;&nbsp; Ekstrakti ispitivanih vrsta pokazali su&nbsp; umeren&nbsp; antioksidantni potencijal koji se ogleda u njihovoj sposobnosti neutralizacije nekoliko radikalskih vrsta, redukcionom potencijalu i sposobnosti inhibicije lipidne peroksidacije.&nbsp; Ispitivanjem uticaja ekstrakata odabranih vrsta&nbsp;<em> Sorbus</em>&nbsp; naaktivnost&nbsp; enzima&nbsp; acetilholinesteraze&nbsp; dokazana&nbsp; je&nbsp; jedino&nbsp; umerena aktivnost&nbsp; ekstrakata vrste&nbsp; <em>S. aucuparia</em>.&nbsp; Takođe, ispitivani ekstrakti&nbsp; vrsta roda&nbsp; <em>Sorbus</em>&nbsp; ispoljili su umerenu&nbsp; antimikrobnu&nbsp; aktivnost u pogledu inhibicije&nbsp; rasta Gram pozitivne bakterije,&nbsp; <em>Staphylococcus aureus</em>, i Gram negativne bakterije,&nbsp;<em> Escherichia coli</em>.&nbsp; Vodeni i metanolni ekstrakti svežih i suvih plodova vrste&nbsp; <em>S. aucuparia</em>&nbsp; pokazali su umeren i inhibitorni potencijal prema rastu tumorskih (HeLa, MCF7, HT-29), ali i netumorskih ćelijskih linija (MRC-5).&nbsp; Rezultati dobijeni u ovoj doktorskoj distertaciji&nbsp; ukazuju na značajan&nbsp; biopotencijal plodova i pekmeza&nbsp; ispitivanih vrsta&nbsp;<em> Sorbus</em>&nbsp; i ukazuju na njihovu primenu u prehrambenoj industriji u vidu funkcionalne hrane.</p> / <p>The aim of presented&nbsp; PhD&nbsp; thesis was investigation of phytochemical composition and biological activity of water and methanol extracts of fresh and air-dried&nbsp; fruits, as&nbsp;&nbsp; well&nbsp; as&nbsp; jam,&nbsp; made according to traditional recipe,&nbsp; of fruits&nbsp; of four&nbsp; (one of them occurs in two forms)&nbsp; wild growing&nbsp; <em>Sorbus</em>&nbsp; L. species:&nbsp; <em>S. aucuparia, S. domestica, S. torminalis&nbsp; f. torminalis, S. torminalis f. semitorminalis</em> and <em>S. intermedia</em>. Examination of phytochemical composition included LC-MS/MS analysis of 44 selected phenolic compounds&nbsp; and&nbsp; quinic acid (organic acid).&nbsp; Also, total phenolic and flavonoid contents, as well as&nbsp; ascorbic acid&nbsp; content,&nbsp; were determined spectrophotometrically. Biological activity evaluation of extracts of<em>&nbsp; Sorbus</em>&nbsp; species included&nbsp;<em> in vitro&nbsp;</em> investigation of antioxidant, anti-acetylcholinesterase, antimicrobial&nbsp; and cytotoxic activity.</p><p>&nbsp;&nbsp; According to obtained results, fresh and air-dried&nbsp; fruits, as well as jam&nbsp; present&nbsp; moderate&nbsp; source of phenolic compounds. Amongs examined phenolic acids protocatechuic&nbsp; and ferulic acids were the most abundant, and amongs investigated flavonoids amentoflavone and quercetin-3-<em>O</em>-glucoside wete present in noticeable amount.&nbsp; Furthermore, high concentration of quinic acid was present in all examined extracts.</p><p>&nbsp;&nbsp; Extracts of all examined species showed&nbsp; moderate&nbsp;&nbsp; antioxidant activity in terms of radical scavenging ability, reduction potential and inhibition of lipid peroxidation.&nbsp; Also, investigation of&nbsp; anti-acetylcholinesterase activity revealed moderate activity only of extracts of <em>S. aucuparia</em>. Furthermore, examinated extracts of<em> Sorbus</em> species showedmoderate antimicrobial activity against Gram&ndash;positive bacteria, <em>Staphylococcus aureus</em>, and Gram-negative bacteria,&nbsp;<em> Escherichia coli</em>.&nbsp; In addition, water&nbsp; and methanol&nbsp; extracts of fresh and air-dried&nbsp; fruits of&nbsp;<em> S.aucuparia</em>&nbsp; showed&nbsp; inhibitory activity toward&nbsp; tumor (HeLa, MCF7, HT-29), and also non-tumor (MRC-5) cell lines. Presented results indicate significant&nbsp; biopotential of examined&nbsp; fruits of&nbsp; <em>Sorbus&nbsp;</em> species&nbsp; and&nbsp; support their use in food industry as functional food.</p>