Study of the electrochemical properties of rutin in different inert electrolytes

U ovom radu je opisano ispitivanje elektrokemijskih svojstava rutina (3`,4`,5,7-tetrahidroksiflavon-$3\beta-D$-rutinozida) u tri različita inertna elektrolita: KCl, NaCl i LiCl. Mjerenja su izvedena pomoću diferencijalne pulsne voltametrije. Iz voltamograma je vidljivo da struja i potencijal oksidacijskih strujnih vrhova rastu s porastom koncentracije rutina. Najbolji kalibracijski dijagram je dobiven u otopini s kalijevim kloridom kao inertnim elektrolitom, pa je za određivanje nepoznate koncentracije rutina u ekstraktu kore jabuke Zimnjare korišten taj kalibracijski dijagram. Određena koncentracija rutina u ispitivanom ekstraktu iznosi 18,7∙ $10^{-6}$ mol $dm^{-3}$.In this work, a study of electrochemical characterizations of rutin (3’,4’,5,7-tetrahydroxyflavone-$3\beta-D$-rutinoside) in three different inert electrolytes: KCl, NaCl and LiCl is described. Measurements were performed by differential pulse voltammetry. Voltammograms have shown that current and potential were increasing with the increase of rutin concentration. The best calibration diagram was obtained in solution with potassium chloride as inert electrolyte, so this calibration diagram was used for determination of rutin concentration in an apple peel extract of Zimnjara. Concentration of rutin in apple peel extract is 18,7∙$10^{-6}$ mol $dm^{-3}$

Ružička days : International conference 16th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Proceedings contains articles presented at Conference divided into sections: open lecture (1), chemical analysis and synthesis (3), chemical and biochemical engineering (8), food technology and biotechnology (8), medical chemistry and pharmacy (3), environmental protection (11) and meeting of young chemists (2)

Study of the electrochemical properties of rutin in different inert electrolytes

U ovom radu je opisano ispitivanje elektrokemijskih svojstava rutina (3`,4`,5,7-tetrahidroksiflavon-$3\beta-D$-rutinozida) u tri različita inertna elektrolita: KCl, NaCl i LiCl. Mjerenja su izvedena pomoću diferencijalne pulsne voltametrije. Iz voltamograma je vidljivo da struja i potencijal oksidacijskih strujnih vrhova rastu s porastom koncentracije rutina. Najbolji kalibracijski dijagram je dobiven u otopini s kalijevim kloridom kao inertnim elektrolitom, pa je za određivanje nepoznate koncentracije rutina u ekstraktu kore jabuke Zimnjare korišten taj kalibracijski dijagram. Određena koncentracija rutina u ispitivanom ekstraktu iznosi 18,7∙ $10^{-6}$ mol $dm^{-3}$.In this work, a study of electrochemical characterizations of rutin (3’,4’,5,7-tetrahydroxyflavone-$3\beta-D$-rutinoside) in three different inert electrolytes: KCl, NaCl and LiCl is described. Measurements were performed by differential pulse voltammetry. Voltammograms have shown that current and potential were increasing with the increase of rutin concentration. The best calibration diagram was obtained in solution with potassium chloride as inert electrolyte, so this calibration diagram was used for determination of rutin concentration in an apple peel extract of Zimnjara. Concentration of rutin in apple peel extract is 18,7∙$10^{-6}$ mol $dm^{-3}$

Characterization of the structural features of ripple phase of phosphocholine liposomes using FT-IR spectroscopy

Molekule 1,2-dipalmitoil-sn-glicero-3-fosfokolina (engl. 1,2-dipalmitoyl-sn-glicero-3- phosphatidylcholine, DPPC) u vodenom mediju stvaraju hidrirane dvosloje koji se, ovisno o temperaturi, nalaze u određenoj fazi. Prijelaz DPPC-a iz faze gela (Lβ') u fazu fluida (Lα), odnosno glavni fazni prijelaz opažen pri temperaturi mekšanja (Tm), prekinut je valovitom fazom (Pβ') koja se opaža pri temperaturi pretprijelaza (Tp). Budući da su Tm i Tp iznimno osjetljive na ugradnju organskih molekula u lipidni dvosloj, posebice onih koje su kadre primati i otpuštati proton, u sklopu ovog diplomskog rada istraženi su višestruki hidrirani dvosloji DPPC lipida u odsutnosti i prisutnosti male količine palmitinske kiseline (engl. palmitic acid, PA) u puferima različitih pH vrijednosti. Tm i Tp određene su analizom vibracijskih potpisa metilenskih (νsCH2) i fosfatnih (νasPO2−) skupina iz temperaturno-ovisnih FT-IR spektara. Dobiveni podaci su djelomično upotpunjeni onima dobivenima iz razlikovno-pretražne kalorimetrije (engl. differential scanning calorimetry, DSC).1,2-dipalmitoyl-sn-glycero-3-phosphocoline form hydrated bilayers in an aqueous medium which, depending on the temperature, can be found in certain phase. The transition from gel (Lβ') to fluid phase (Lα), assigned as the main phase transition with a peak at melting point temperature (Tm), is interrupted by the ripple phase (Pβ') observed at the pretransition temeprature (Tp). Since Tm and Tp are extremely sensitive to the incorporation of organic molecules into the lipid bilayer, especially those capable of receiving and releasing a proton, multiple hydrated bilayers of DPPC lipids in the absence and presence of small amounts of palmitic acid (PA) in buffers of different pH values have been investigated across this thesis. Tm and Tp have been determined by the analysis of vibrational signatures of methylene (νsCH2) and phosphate (νasPO2−) groups from temperature-dependent FT-IR spectra. These data have been partially supplemented by those obtained from differential scanning calorimetry (DSC)

Characterization of the structural features of ripple phase of phosphocholine liposomes using FT-IR spectroscopy

Molekule 1,2-dipalmitoil-sn-glicero-3-fosfokolina (engl. 1,2-dipalmitoyl-sn-glicero-3- phosphatidylcholine, DPPC) u vodenom mediju stvaraju hidrirane dvosloje koji se, ovisno o temperaturi, nalaze u određenoj fazi. Prijelaz DPPC-a iz faze gela (Lβ') u fazu fluida (Lα), odnosno glavni fazni prijelaz opažen pri temperaturi mekšanja (Tm), prekinut je valovitom fazom (Pβ') koja se opaža pri temperaturi pretprijelaza (Tp). Budući da su Tm i Tp iznimno osjetljive na ugradnju organskih molekula u lipidni dvosloj, posebice onih koje su kadre primati i otpuštati proton, u sklopu ovog diplomskog rada istraženi su višestruki hidrirani dvosloji DPPC lipida u odsutnosti i prisutnosti male količine palmitinske kiseline (engl. palmitic acid, PA) u puferima različitih pH vrijednosti. Tm i Tp određene su analizom vibracijskih potpisa metilenskih (νsCH2) i fosfatnih (νasPO2−) skupina iz temperaturno-ovisnih FT-IR spektara. Dobiveni podaci su djelomično upotpunjeni onima dobivenima iz razlikovno-pretražne kalorimetrije (engl. differential scanning calorimetry, DSC).1,2-dipalmitoyl-sn-glycero-3-phosphocoline form hydrated bilayers in an aqueous medium which, depending on the temperature, can be found in certain phase. The transition from gel (Lβ') to fluid phase (Lα), assigned as the main phase transition with a peak at melting point temperature (Tm), is interrupted by the ripple phase (Pβ') observed at the pretransition temeprature (Tp). Since Tm and Tp are extremely sensitive to the incorporation of organic molecules into the lipid bilayer, especially those capable of receiving and releasing a proton, multiple hydrated bilayers of DPPC lipids in the absence and presence of small amounts of palmitic acid (PA) in buffers of different pH values have been investigated across this thesis. Tm and Tp have been determined by the analysis of vibrational signatures of methylene (νsCH2) and phosphate (νasPO2−) groups from temperature-dependent FT-IR spectra. These data have been partially supplemented by those obtained from differential scanning calorimetry (DSC)