TY  - JOUR
AU  - Kaličanin, Nevena
AU  - Kovačević, Gordana
AU  - Spasojević, Milica
AU  - Prodanović, Olivera
AU  - Jovanović-Šanta, Suzana
AU  - Škorić, Dušan
AU  - Opsenica, Dejan
AU  - Prodanović, Radivoje
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5370
AB  - The aim of this research was to improve the operational stability and enable the reusability of ω-transaminase for synthesis of new enantiopure chiral amines of steroids. Dihydrotestosterone was used to optimize the synthetic procedure of corresponding amino-steroid on a larger scale. The obtained product 3α-amino-5α-androstan-17β-ol was isolated and characterized. The enzyme was immobilized on a methacrylate-based carrier, giving the specific activity of 1.84 U/g of dry polymer. Higher residual activity of the immobilized enzyme in comparison to the soluble form (100 % versus 35%) after 24 h incubation in 35 % dimethylformamide (DMF) was obtained. The soluble enzyme retained 19 % of the initial activity after 2 h incubation in 35 % DMF at 70 °C, while the activity of the immobilized enzyme decreased only to 75 %. Immobilized retained 85 % of initial activity after ten consecutive cycles of 3α-amino-5α-androstan-17β-ol synthesis. We have tested the specificity of the ArRMut11 variant, further increased its stability by immobilization, and used it in several cycles for the synthesis of 3α-amino-5α-androstan-17β-ol. We showed that the enzyme previously evolved for higher stability as the immobilized variant showed more increased stability and high reusability that can more effectively be applied for the biosynthesis of amino steroids.
PB  - Elsevier
T2  - Process Biochemistry
T1  - Immobilization of ArRMut11 omega-transaminase for increased operational stability and reusability in the synthesis of 3α-amino-5α-androstan-17β-ol
VL  - 121
SP  - 674
EP  - 680
DO  - 10.1016/j.procbio.2022.08.016
ER  - 

@article{
author = "Kaličanin, Nevena and Kovačević, Gordana and Spasojević, Milica and Prodanović, Olivera and Jovanović-Šanta, Suzana and Škorić, Dušan and Opsenica, Dejan and Prodanović, Radivoje",
year = "2022",
abstract = "The aim of this research was to improve the operational stability and enable the reusability of ω-transaminase for synthesis of new enantiopure chiral amines of steroids. Dihydrotestosterone was used to optimize the synthetic procedure of corresponding amino-steroid on a larger scale. The obtained product 3α-amino-5α-androstan-17β-ol was isolated and characterized. The enzyme was immobilized on a methacrylate-based carrier, giving the specific activity of 1.84 U/g of dry polymer. Higher residual activity of the immobilized enzyme in comparison to the soluble form (100 % versus 35%) after 24 h incubation in 35 % dimethylformamide (DMF) was obtained. The soluble enzyme retained 19 % of the initial activity after 2 h incubation in 35 % DMF at 70 °C, while the activity of the immobilized enzyme decreased only to 75 %. Immobilized retained 85 % of initial activity after ten consecutive cycles of 3α-amino-5α-androstan-17β-ol synthesis. We have tested the specificity of the ArRMut11 variant, further increased its stability by immobilization, and used it in several cycles for the synthesis of 3α-amino-5α-androstan-17β-ol. We showed that the enzyme previously evolved for higher stability as the immobilized variant showed more increased stability and high reusability that can more effectively be applied for the biosynthesis of amino steroids.",
publisher = "Elsevier",
journal = "Process Biochemistry",
title = "Immobilization of ArRMut11 omega-transaminase for increased operational stability and reusability in the synthesis of 3α-amino-5α-androstan-17β-ol",
volume = "121",
pages = "674-680",
doi = "10.1016/j.procbio.2022.08.016"
}

Kaličanin, N., Kovačević, G., Spasojević, M., Prodanović, O., Jovanović-Šanta, S., Škorić, D., Opsenica, D.,& Prodanović, R.. (2022). Immobilization of ArRMut11 omega-transaminase for increased operational stability and reusability in the synthesis of 3α-amino-5α-androstan-17β-ol. in Process Biochemistry
Elsevier., 121, 674-680.
https://doi.org/10.1016/j.procbio.2022.08.016

Kaličanin N, Kovačević G, Spasojević M, Prodanović O, Jovanović-Šanta S, Škorić D, Opsenica D, Prodanović R. Immobilization of ArRMut11 omega-transaminase for increased operational stability and reusability in the synthesis of 3α-amino-5α-androstan-17β-ol. in Process Biochemistry. 2022;121:674-680.
doi:10.1016/j.procbio.2022.08.016 .

Kaličanin, Nevena, Kovačević, Gordana, Spasojević, Milica, Prodanović, Olivera, Jovanović-Šanta, Suzana, Škorić, Dušan, Opsenica, Dejan, Prodanović, Radivoje, "Immobilization of ArRMut11 omega-transaminase for increased operational stability and reusability in the synthesis of 3α-amino-5α-androstan-17β-ol" in Process Biochemistry, 121 (2022):674-680,
https://doi.org/10.1016/j.procbio.2022.08.016 . .

TY  - JOUR
AU  - Mrđan, Gorana S.
AU  - Vastag, Gyöngyi Gy.
AU  - Škorić, Dušan
AU  - Radanović, Mirjana M.
AU  - Verbić, Tatjana
AU  - Milčić, Miloš
AU  - Stojiljković, Ivana N.
AU  - Marković, Olivera
AU  - Matijević, Borko
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4055
AB  - Derivatives of thiocarbohydrazone studied so far have shown great biological activity such as antioxidant, antimicrobial, and
anticancer.Most of these compounds are bis-substituted derivatives,while monothiocarbohydrazones are much less investigated.
Еighteen monothiocarbohydrazones were synthesized and subjected to physicochemical characterization in order to facilitate the
examination of their potential biological activity and application in future studies. The structure of synthesized derivatives was
confirmed with NMR and FT–IR spectroscopy, and with elemental analysis. For one of the compounds, single-crystal X-ray
diffraction analysis was performed. Specific and non-specific molecular interactions were interpreted by LSER principles, using
Catalan’s model. For additional information about the dominance and influence of the interactions presented, correlations with
Hansen’s solubility parameters were calculated. Influence of the type and position of the substituent on absorption maxima was
determined with LFER (linear free-energy relationship) principles, using Hammett’s equation. Acidity constants of the synthesized
compounds were theoretically calculated and experimentally determined. Moreover, the excitation of a molecule by a
photon of UV–Vis light was interpreted by time-dependent density functional theory (TD–DFT) calculations of UV absorption
bands, and intramolecular charge transfer (ICT) was quantified by calculations of the charge transfer distances (DCT).
PB  - Springer
T2  - Structural Chemistry
T1  - Synthesis, physicochemical characterization, and TD–DFT calculations of monothiocarbohydrazone derivatives
DO  - 10.1007/s11224-020-01700-y
ER  - 

@article{
author = "Mrđan, Gorana S. and Vastag, Gyöngyi Gy. and Škorić, Dušan and Radanović, Mirjana M. and Verbić, Tatjana and Milčić, Miloš and Stojiljković, Ivana N. and Marković, Olivera and Matijević, Borko",
year = "2021",
abstract = "Derivatives of thiocarbohydrazone studied so far have shown great biological activity such as antioxidant, antimicrobial, and
anticancer.Most of these compounds are bis-substituted derivatives,while monothiocarbohydrazones are much less investigated.
Еighteen monothiocarbohydrazones were synthesized and subjected to physicochemical characterization in order to facilitate the
examination of their potential biological activity and application in future studies. The structure of synthesized derivatives was
confirmed with NMR and FT–IR spectroscopy, and with elemental analysis. For one of the compounds, single-crystal X-ray
diffraction analysis was performed. Specific and non-specific molecular interactions were interpreted by LSER principles, using
Catalan’s model. For additional information about the dominance and influence of the interactions presented, correlations with
Hansen’s solubility parameters were calculated. Influence of the type and position of the substituent on absorption maxima was
determined with LFER (linear free-energy relationship) principles, using Hammett’s equation. Acidity constants of the synthesized
compounds were theoretically calculated and experimentally determined. Moreover, the excitation of a molecule by a
photon of UV–Vis light was interpreted by time-dependent density functional theory (TD–DFT) calculations of UV absorption
bands, and intramolecular charge transfer (ICT) was quantified by calculations of the charge transfer distances (DCT).",
publisher = "Springer",
journal = "Structural Chemistry",
title = "Synthesis, physicochemical characterization, and TD–DFT calculations of monothiocarbohydrazone derivatives",
doi = "10.1007/s11224-020-01700-y"
}

Mrđan, G. S., Vastag, G. Gy., Škorić, D., Radanović, M. M., Verbić, T., Milčić, M., Stojiljković, I. N., Marković, O.,& Matijević, B.. (2021). Synthesis, physicochemical characterization, and TD–DFT calculations of monothiocarbohydrazone derivatives. in Structural Chemistry
Springer..
https://doi.org/10.1007/s11224-020-01700-y

Mrđan GS, Vastag GG, Škorić D, Radanović MM, Verbić T, Milčić M, Stojiljković IN, Marković O, Matijević B. Synthesis, physicochemical characterization, and TD–DFT calculations of monothiocarbohydrazone derivatives. in Structural Chemistry. 2021;.
doi:10.1007/s11224-020-01700-y .

Mrđan, Gorana S., Vastag, Gyöngyi Gy., Škorić, Dušan, Radanović, Mirjana M., Verbić, Tatjana, Milčić, Miloš, Stojiljković, Ivana N., Marković, Olivera, Matijević, Borko, "Synthesis, physicochemical characterization, and TD–DFT calculations of monothiocarbohydrazone derivatives" in Structural Chemistry (2021),
https://doi.org/10.1007/s11224-020-01700-y . .

TY  - JOUR
AU  - Vajdle, Olga
AU  - Guzsvány, Valéria
AU  - Škorić, Dušan
AU  - Csanadi, Janos
AU  - Petkovic, Milos
AU  - Avramov Ivić, Milka
AU  - Kónya, Zoltán
AU  - Petrović, Slobodan D.
AU  - Bobrowski, Andrzej
PY  - 2017
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2187
AB  - The renewable silver-amalgam film electrode (Hg(Ag)FE) was applied for voltammetric characterization and determination of semi-synthetic macrolide antibiotics azithromycin (AZI), clarithromycin (CLA) and roxithromycin (ROX) in the Britton-Robinson buffer as supporting electrolyte ranging the pH from 4.0 to 11.9. All three macrolides showed reduction signals in fairly negative potential range. During direct cathodic square wave voltammetric (SWV) investigations conducted over the potential range from -0.75 V to -2.00V vs SCE, either one or two reduction peaks were obtained in the potential range from -1.5 to -1.9 V. The shapes and intensities of the signals depend on the applied pH values in wider pH ranges. For analytical purposes concerning the development of direct cathodic SWV and adsorptive stripping SWV (SW-AdSV) methods the neutral and slightly alkaline media were suitable as pH 7.2, pH 7.4 and pH 7.0 for AZI, CIA and ROX, respectively. Based on the cyclic voltammograms recorded at these pH values, adsorption-controlled electrode kinetics process can be proposed for all three macrolides. Furthermore, the water suppressed H-1 NMR measurements in the pH range between 6.0 and 10.5 indicated that the macrolide molecules at the optimal analytical conditions are predominantly in protonated form via their tertiary amino groups which supported in all three cases their adsorption on the appropriately polarized Hg(Ag)FE electrode. The optimized direct cathodic SWV methods showed good linearity in concentration ranges 4.81-23.3 mu gmL(-1), 1.96-28.6 mu gmL(-1) and 1.48-25.9 mu gmL(-1) for AZI, CIA and ROX, respectively. The development of the SW-AdSV methods resulted in the linear responses at lower concentration ranges as 1.0-2.46 mu gmL(-1), 0.05-0.99 mu gmL(-1) and 0.10-0.99 mu gmL(-1), for AZI, CIA and ROX, respectively. The relative standard deviation for all developed methods was not higher than 1.0% except the SWV method for AZI with 4.7%. In the case of all three investigated macrolide antibiotics the protonated form of the tertiary amino group(s) at appropriate accumulation potential and time favored the adsorption of the ionic form of the target molecules offering the opportunity for the development of SW-AdSV methods for their trace level analysis on Hg(Ag)FE. Optimized SW-AdSV method was applied for determination of ROX in pharmaceutical preparation Runac.
PB  - Oxford : Pergamon-Elsevier Science Ltd
T2  - Electrochimica Acta
T1  - Voltammetric behavior and determination of the macrolide antibiotics azithromycin, clarithromycin and roxithromycin at a renewable silver - amalgam film electrode
VL  - 229
SP  - 334
EP  - 344
DO  - 10.1016/j.electacta.2017.01.146
ER  - 

@article{
author = "Vajdle, Olga and Guzsvány, Valéria and Škorić, Dušan and Csanadi, Janos and Petkovic, Milos and Avramov Ivić, Milka and Kónya, Zoltán and Petrović, Slobodan D. and Bobrowski, Andrzej",
year = "2017",
abstract = "The renewable silver-amalgam film electrode (Hg(Ag)FE) was applied for voltammetric characterization and determination of semi-synthetic macrolide antibiotics azithromycin (AZI), clarithromycin (CLA) and roxithromycin (ROX) in the Britton-Robinson buffer as supporting electrolyte ranging the pH from 4.0 to 11.9. All three macrolides showed reduction signals in fairly negative potential range. During direct cathodic square wave voltammetric (SWV) investigations conducted over the potential range from -0.75 V to -2.00V vs SCE, either one or two reduction peaks were obtained in the potential range from -1.5 to -1.9 V. The shapes and intensities of the signals depend on the applied pH values in wider pH ranges. For analytical purposes concerning the development of direct cathodic SWV and adsorptive stripping SWV (SW-AdSV) methods the neutral and slightly alkaline media were suitable as pH 7.2, pH 7.4 and pH 7.0 for AZI, CIA and ROX, respectively. Based on the cyclic voltammograms recorded at these pH values, adsorption-controlled electrode kinetics process can be proposed for all three macrolides. Furthermore, the water suppressed H-1 NMR measurements in the pH range between 6.0 and 10.5 indicated that the macrolide molecules at the optimal analytical conditions are predominantly in protonated form via their tertiary amino groups which supported in all three cases their adsorption on the appropriately polarized Hg(Ag)FE electrode. The optimized direct cathodic SWV methods showed good linearity in concentration ranges 4.81-23.3 mu gmL(-1), 1.96-28.6 mu gmL(-1) and 1.48-25.9 mu gmL(-1) for AZI, CIA and ROX, respectively. The development of the SW-AdSV methods resulted in the linear responses at lower concentration ranges as 1.0-2.46 mu gmL(-1), 0.05-0.99 mu gmL(-1) and 0.10-0.99 mu gmL(-1), for AZI, CIA and ROX, respectively. The relative standard deviation for all developed methods was not higher than 1.0% except the SWV method for AZI with 4.7%. In the case of all three investigated macrolide antibiotics the protonated form of the tertiary amino group(s) at appropriate accumulation potential and time favored the adsorption of the ionic form of the target molecules offering the opportunity for the development of SW-AdSV methods for their trace level analysis on Hg(Ag)FE. Optimized SW-AdSV method was applied for determination of ROX in pharmaceutical preparation Runac.",
publisher = "Oxford : Pergamon-Elsevier Science Ltd",
journal = "Electrochimica Acta",
title = "Voltammetric behavior and determination of the macrolide antibiotics azithromycin, clarithromycin and roxithromycin at a renewable silver - amalgam film electrode",
volume = "229",
pages = "334-344",
doi = "10.1016/j.electacta.2017.01.146"
}

Vajdle, O., Guzsvány, V., Škorić, D., Csanadi, J., Petkovic, M., Avramov Ivić, M., Kónya, Z., Petrović, S. D.,& Bobrowski, A.. (2017). Voltammetric behavior and determination of the macrolide antibiotics azithromycin, clarithromycin and roxithromycin at a renewable silver - amalgam film electrode. in Electrochimica Acta
Oxford : Pergamon-Elsevier Science Ltd., 229, 334-344.
https://doi.org/10.1016/j.electacta.2017.01.146

Vajdle O, Guzsvány V, Škorić D, Csanadi J, Petkovic M, Avramov Ivić M, Kónya Z, Petrović SD, Bobrowski A. Voltammetric behavior and determination of the macrolide antibiotics azithromycin, clarithromycin and roxithromycin at a renewable silver - amalgam film electrode. in Electrochimica Acta. 2017;229:334-344.
doi:10.1016/j.electacta.2017.01.146 .

Vajdle, Olga, Guzsvány, Valéria, Škorić, Dušan, Csanadi, Janos, Petkovic, Milos, Avramov Ivić, Milka, Kónya, Zoltán, Petrović, Slobodan D., Bobrowski, Andrzej, "Voltammetric behavior and determination of the macrolide antibiotics azithromycin, clarithromycin and roxithromycin at a renewable silver - amalgam film electrode" in Electrochimica Acta, 229 (2017):334-344,
https://doi.org/10.1016/j.electacta.2017.01.146 . .

TY  - JOUR
AU  - Vajdle, Olga
AU  - Guzsvány, Valéria
AU  - Škorić, Dušan
AU  - Anojčić, Jasmina
AU  - Jovanov, Pavle
AU  - Avramov Ivić, Milka
AU  - Csanadi, Janos
AU  - Kónya, Zoltán
AU  - Petrović, Slobodan D.
AU  - Bobrowski, Andrzej
PY  - 2016
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4319
AB  - Erythromycin, a macrolide antibiotic, has similar antimicrobial spectrum to penicillin and it is widely used, especially in the treatment of patients who are allergic to penicillin. In this work, the application of a renewable silver-amalgam film electrode (Hg(Ag)FE) for the characterization and determination of erythromycin ethylsuccinate (EES), a widely used esterified form of this antibiotic, by means of cyclic voltammetry (CV) and square wave voltammetry (SWV) is presented. In the aqueous Britton-Robinson buffer (pH 5.0-9.0) that served as the supporting electrolyte, one reduction peak of EES was observed in the investigated potential range between -0.75 V and -1.80 V vs SCE, with peak potential maxima ranging from -1.59 V to -1.70 V, which strongly depended on the applied pH, as did the peak shape. For the analytical purposes the pH of 7.0 was selected, since in this electrolyte the EES peak was well-shaped and separated from the background current of the supporting electrolyte in both cases; in the direct cathodic SWV and in the case of square wave adsorptive stripping voltammetry (SW-AdSV). It was established, by the E-p-pH correlation, that protons strongly influenced the electrochemical reduction of EES. The CVs recorded between 0.025-0.50 V s (1) at pH 7.0 confirmed that the electrode reaction is adsorption-controlled. Based on the series of H-1 NMR measurements it is proved that the tertiary amino group of EES is mainly in its protonated form at pH 7.0 which may lead, at appropriate accumulation potential and time, to the favored adsorption of the target ionic form of the analyte improving on such way the sensitivity of the SW-AdSV method. The optimized procedures resulted in stable SWV responses with good linear correlation in the EES concentration range from 4.53 to 29.8 mu g mL (1) (LOD = 1.36 mu g mL (1)), and from 0.69 mu g mL (1) to 2.44 mu g mL (1) (LOD 0.21 mu g mL (1)) in the case of optimized SW-AdSV. The relative standard deviation is below 1.5%. The reliability of the elaborated procedures and thus the accuracy of the obtained results were validated by comparing them with those obtained by means of HPLC-DAD measurements. The direct cathodic SWV method was successfully applied for the determination of EES in the pharmaceutical preparation Eritromicin (R), while SW-AdSV was applied in the case of the spiked urine sample. In both cases, the standard addition method was used.
PB  - Oxford : Pergamon-Elsevier Science Ltd
T2  - Electrochimica Acta
T1  - Voltammetric behavior of erythromycin ethylsuccinate at a renewable silver-amalgam film electrode and its determination in urine and in a pharmaceutical preparation
VL  - 191
SP  - 44
EP  - 54
DO  - 10.1016/j.electacta.2015.12.207
ER  - 

@article{
author = "Vajdle, Olga and Guzsvány, Valéria and Škorić, Dušan and Anojčić, Jasmina and Jovanov, Pavle and Avramov Ivić, Milka and Csanadi, Janos and Kónya, Zoltán and Petrović, Slobodan D. and Bobrowski, Andrzej",
year = "2016",
abstract = "Erythromycin, a macrolide antibiotic, has similar antimicrobial spectrum to penicillin and it is widely used, especially in the treatment of patients who are allergic to penicillin. In this work, the application of a renewable silver-amalgam film electrode (Hg(Ag)FE) for the characterization and determination of erythromycin ethylsuccinate (EES), a widely used esterified form of this antibiotic, by means of cyclic voltammetry (CV) and square wave voltammetry (SWV) is presented. In the aqueous Britton-Robinson buffer (pH 5.0-9.0) that served as the supporting electrolyte, one reduction peak of EES was observed in the investigated potential range between -0.75 V and -1.80 V vs SCE, with peak potential maxima ranging from -1.59 V to -1.70 V, which strongly depended on the applied pH, as did the peak shape. For the analytical purposes the pH of 7.0 was selected, since in this electrolyte the EES peak was well-shaped and separated from the background current of the supporting electrolyte in both cases; in the direct cathodic SWV and in the case of square wave adsorptive stripping voltammetry (SW-AdSV). It was established, by the E-p-pH correlation, that protons strongly influenced the electrochemical reduction of EES. The CVs recorded between 0.025-0.50 V s (1) at pH 7.0 confirmed that the electrode reaction is adsorption-controlled. Based on the series of H-1 NMR measurements it is proved that the tertiary amino group of EES is mainly in its protonated form at pH 7.0 which may lead, at appropriate accumulation potential and time, to the favored adsorption of the target ionic form of the analyte improving on such way the sensitivity of the SW-AdSV method. The optimized procedures resulted in stable SWV responses with good linear correlation in the EES concentration range from 4.53 to 29.8 mu g mL (1) (LOD = 1.36 mu g mL (1)), and from 0.69 mu g mL (1) to 2.44 mu g mL (1) (LOD 0.21 mu g mL (1)) in the case of optimized SW-AdSV. The relative standard deviation is below 1.5%. The reliability of the elaborated procedures and thus the accuracy of the obtained results were validated by comparing them with those obtained by means of HPLC-DAD measurements. The direct cathodic SWV method was successfully applied for the determination of EES in the pharmaceutical preparation Eritromicin (R), while SW-AdSV was applied in the case of the spiked urine sample. In both cases, the standard addition method was used.",
publisher = "Oxford : Pergamon-Elsevier Science Ltd",
journal = "Electrochimica Acta",
title = "Voltammetric behavior of erythromycin ethylsuccinate at a renewable silver-amalgam film electrode and its determination in urine and in a pharmaceutical preparation",
volume = "191",
pages = "44-54",
doi = "10.1016/j.electacta.2015.12.207"
}

Vajdle, O., Guzsvány, V., Škorić, D., Anojčić, J., Jovanov, P., Avramov Ivić, M., Csanadi, J., Kónya, Z., Petrović, S. D.,& Bobrowski, A.. (2016). Voltammetric behavior of erythromycin ethylsuccinate at a renewable silver-amalgam film electrode and its determination in urine and in a pharmaceutical preparation. in Electrochimica Acta
Oxford : Pergamon-Elsevier Science Ltd., 191, 44-54.
https://doi.org/10.1016/j.electacta.2015.12.207

Vajdle O, Guzsvány V, Škorić D, Anojčić J, Jovanov P, Avramov Ivić M, Csanadi J, Kónya Z, Petrović SD, Bobrowski A. Voltammetric behavior of erythromycin ethylsuccinate at a renewable silver-amalgam film electrode and its determination in urine and in a pharmaceutical preparation. in Electrochimica Acta. 2016;191:44-54.
doi:10.1016/j.electacta.2015.12.207 .

Vajdle, Olga, Guzsvány, Valéria, Škorić, Dušan, Anojčić, Jasmina, Jovanov, Pavle, Avramov Ivić, Milka, Csanadi, Janos, Kónya, Zoltán, Petrović, Slobodan D., Bobrowski, Andrzej, "Voltammetric behavior of erythromycin ethylsuccinate at a renewable silver-amalgam film electrode and its determination in urine and in a pharmaceutical preparation" in Electrochimica Acta, 191 (2016):44-54,
https://doi.org/10.1016/j.electacta.2015.12.207 . .

TY  - JOUR
AU  - Vajdle, Olga
AU  - Guzsvány, Valéria
AU  - Škorić, Dušan
AU  - Anojčić, Jasmina
AU  - Jovanov, Pavle
AU  - Avramov Ivić, Milka
AU  - Csanadi, Janos
AU  - Kónya, Zoltán
AU  - Petrović, Slobodan D.
AU  - Bobrowski, Andrzej
PY  - 2016
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1964
AB  - Erythromycin, a macrolide antibiotic, has similar antimicrobial spectrum to penicillin and it is widely used, especially in the treatment of patients who are allergic to penicillin. In this work, the application of a renewable silver-amalgam film electrode (Hg(Ag)FE) for the characterization and determination of erythromycin ethylsuccinate (EES), a widely used esterified form of this antibiotic, by means of cyclic voltammetry (CV) and square wave voltammetry (SWV) is presented. In the aqueous Britton-Robinson buffer (pH 5.0-9.0) that served as the supporting electrolyte, one reduction peak of EES was observed in the investigated potential range between -0.75 V and -1.80 V vs SCE, with peak potential maxima ranging from -1.59 V to -1.70 V, which strongly depended on the applied pH, as did the peak shape. For the analytical purposes the pH of 7.0 was selected, since in this electrolyte the EES peak was well-shaped and separated from the background current of the supporting electrolyte in both cases; in the direct cathodic SWV and in the case of square wave adsorptive stripping voltammetry (SW-AdSV). It was established, by the E-p-pH correlation, that protons strongly influenced the electrochemical reduction of EES. The CVs recorded between 0.025-0.50 V s (1) at pH 7.0 confirmed that the electrode reaction is adsorption-controlled. Based on the series of H-1 NMR measurements it is proved that the tertiary amino group of EES is mainly in its protonated form at pH 7.0 which may lead, at appropriate accumulation potential and time, to the favored adsorption of the target ionic form of the analyte improving on such way the sensitivity of the SW-AdSV method. The optimized procedures resulted in stable SWV responses with good linear correlation in the EES concentration range from 4.53 to 29.8 mu g mL (1) (LOD = 1.36 mu g mL (1)), and from 0.69 mu g mL (1) to 2.44 mu g mL (1) (LOD 0.21 mu g mL (1)) in the case of optimized SW-AdSV. The relative standard deviation is below 1.5%. The reliability of the elaborated procedures and thus the accuracy of the obtained results were validated by comparing them with those obtained by means of HPLC-DAD measurements. The direct cathodic SWV method was successfully applied for the determination of EES in the pharmaceutical preparation Eritromicin (R), while SW-AdSV was applied in the case of the spiked urine sample. In both cases, the standard addition method was used.
PB  - Oxford : Pergamon-Elsevier Science Ltd
T2  - Electrochimica Acta
T1  - Voltammetric behavior of erythromycin ethylsuccinate at a renewable silver-amalgam film electrode and its determination in urine and in a pharmaceutical preparation
VL  - 191
SP  - 44
EP  - 54
DO  - 10.1016/j.electacta.2015.12.207
ER  - 

@article{
author = "Vajdle, Olga and Guzsvány, Valéria and Škorić, Dušan and Anojčić, Jasmina and Jovanov, Pavle and Avramov Ivić, Milka and Csanadi, Janos and Kónya, Zoltán and Petrović, Slobodan D. and Bobrowski, Andrzej",
year = "2016",
abstract = "Erythromycin, a macrolide antibiotic, has similar antimicrobial spectrum to penicillin and it is widely used, especially in the treatment of patients who are allergic to penicillin. In this work, the application of a renewable silver-amalgam film electrode (Hg(Ag)FE) for the characterization and determination of erythromycin ethylsuccinate (EES), a widely used esterified form of this antibiotic, by means of cyclic voltammetry (CV) and square wave voltammetry (SWV) is presented. In the aqueous Britton-Robinson buffer (pH 5.0-9.0) that served as the supporting electrolyte, one reduction peak of EES was observed in the investigated potential range between -0.75 V and -1.80 V vs SCE, with peak potential maxima ranging from -1.59 V to -1.70 V, which strongly depended on the applied pH, as did the peak shape. For the analytical purposes the pH of 7.0 was selected, since in this electrolyte the EES peak was well-shaped and separated from the background current of the supporting electrolyte in both cases; in the direct cathodic SWV and in the case of square wave adsorptive stripping voltammetry (SW-AdSV). It was established, by the E-p-pH correlation, that protons strongly influenced the electrochemical reduction of EES. The CVs recorded between 0.025-0.50 V s (1) at pH 7.0 confirmed that the electrode reaction is adsorption-controlled. Based on the series of H-1 NMR measurements it is proved that the tertiary amino group of EES is mainly in its protonated form at pH 7.0 which may lead, at appropriate accumulation potential and time, to the favored adsorption of the target ionic form of the analyte improving on such way the sensitivity of the SW-AdSV method. The optimized procedures resulted in stable SWV responses with good linear correlation in the EES concentration range from 4.53 to 29.8 mu g mL (1) (LOD = 1.36 mu g mL (1)), and from 0.69 mu g mL (1) to 2.44 mu g mL (1) (LOD 0.21 mu g mL (1)) in the case of optimized SW-AdSV. The relative standard deviation is below 1.5%. The reliability of the elaborated procedures and thus the accuracy of the obtained results were validated by comparing them with those obtained by means of HPLC-DAD measurements. The direct cathodic SWV method was successfully applied for the determination of EES in the pharmaceutical preparation Eritromicin (R), while SW-AdSV was applied in the case of the spiked urine sample. In both cases, the standard addition method was used.",
publisher = "Oxford : Pergamon-Elsevier Science Ltd",
journal = "Electrochimica Acta",
title = "Voltammetric behavior of erythromycin ethylsuccinate at a renewable silver-amalgam film electrode and its determination in urine and in a pharmaceutical preparation",
volume = "191",
pages = "44-54",
doi = "10.1016/j.electacta.2015.12.207"
}

Vajdle, O., Guzsvány, V., Škorić, D., Anojčić, J., Jovanov, P., Avramov Ivić, M., Csanadi, J., Kónya, Z., Petrović, S. D.,& Bobrowski, A.. (2016). Voltammetric behavior of erythromycin ethylsuccinate at a renewable silver-amalgam film electrode and its determination in urine and in a pharmaceutical preparation. in Electrochimica Acta
Oxford : Pergamon-Elsevier Science Ltd., 191, 44-54.
https://doi.org/10.1016/j.electacta.2015.12.207

Vajdle O, Guzsvány V, Škorić D, Anojčić J, Jovanov P, Avramov Ivić M, Csanadi J, Kónya Z, Petrović SD, Bobrowski A. Voltammetric behavior of erythromycin ethylsuccinate at a renewable silver-amalgam film electrode and its determination in urine and in a pharmaceutical preparation. in Electrochimica Acta. 2016;191:44-54.
doi:10.1016/j.electacta.2015.12.207 .

Vajdle, Olga, Guzsvány, Valéria, Škorić, Dušan, Anojčić, Jasmina, Jovanov, Pavle, Avramov Ivić, Milka, Csanadi, Janos, Kónya, Zoltán, Petrović, Slobodan D., Bobrowski, Andrzej, "Voltammetric behavior of erythromycin ethylsuccinate at a renewable silver-amalgam film electrode and its determination in urine and in a pharmaceutical preparation" in Electrochimica Acta, 191 (2016):44-54,
https://doi.org/10.1016/j.electacta.2015.12.207 . .