TY  - JOUR
AU  - Božić, Bojana
AU  - Korać, Jelena
AU  - Stanković, Dalibor M.
AU  - Stanić, Marina
AU  - Romanović, Mima Č.
AU  - Bogdanović-Pristov, Jelena
AU  - Spasić, Snežana D.
AU  - Popović-Bijelić, Ana D.
AU  - Spasojević, Ivan
AU  - Bajčetić, Milica
PY  - 2018
UR  - https://linkinghub.elsevier.com/retrieve/pii/S0891584918311213
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7896
AB  - An increase in the copper pool in body fluids has been related to a number of pathological conditions, including infections. Copper ions may affect antibiotics via the formation of coordination bonds and/or redox reactions. Herein, we analyzed the interactions of Cu2+ with eight β-lactam antibiotics using UV–Vis spectrophotometry, EPR spectroscopy, and electrochemical methods. Penicillin G did not show any detectable interactions with Cu2+. Ampicillin, amoxicillin and cephalexin formed stable colored complexes with octahedral coordination environment of Cu2+ with tetragonal distortion, and primary amine group as the site of coordinate bond formation. These β-lactams increased the solubility of Cu2+ in the phosphate buffer. Ceftazidime and Cu2+ formed a complex with a similar geometry and gave rise to an organic radical. Ceftriaxone-Cu2+ complex appears to exhibit different geometry. All complexes showed 1:1 stoichiometry. Cefaclor reduced Cu2+ to Cu1+ that further reacted with molecular oxygen to produce hydrogen peroxide. Finally, meropenem underwent degradation in the presence of copper. The analysis of activity against Escherichia coli and Staphylococcus aureus showed that the effects of meropenem, amoxicillin, ampicillin, and ceftriaxone were significantly hindered in the presence of copper ions. The interactions with copper ions should be taken into account regarding the problem of antibiotic resistance and in the selection of the most efficient antimicrobial therapy for patients with altered copper homeostasis. © 2018 Elsevier Inc.
T2  - Free Radical Biology and Medicine
T1  - Coordination and redox interactions of β-lactam antibiotics with Cu2+ in physiological settings and the impact on antibacterial activity
VL  - 129
SP  - 279
EP  - 285
DO  - 10.1016/j.freeradbiomed.2018.09.038
ER  - 

@article{
author = "Božić, Bojana and Korać, Jelena and Stanković, Dalibor M. and Stanić, Marina and Romanović, Mima Č. and Bogdanović-Pristov, Jelena and Spasić, Snežana D. and Popović-Bijelić, Ana D. and Spasojević, Ivan and Bajčetić, Milica",
year = "2018",
abstract = "An increase in the copper pool in body fluids has been related to a number of pathological conditions, including infections. Copper ions may affect antibiotics via the formation of coordination bonds and/or redox reactions. Herein, we analyzed the interactions of Cu2+ with eight β-lactam antibiotics using UV–Vis spectrophotometry, EPR spectroscopy, and electrochemical methods. Penicillin G did not show any detectable interactions with Cu2+. Ampicillin, amoxicillin and cephalexin formed stable colored complexes with octahedral coordination environment of Cu2+ with tetragonal distortion, and primary amine group as the site of coordinate bond formation. These β-lactams increased the solubility of Cu2+ in the phosphate buffer. Ceftazidime and Cu2+ formed a complex with a similar geometry and gave rise to an organic radical. Ceftriaxone-Cu2+ complex appears to exhibit different geometry. All complexes showed 1:1 stoichiometry. Cefaclor reduced Cu2+ to Cu1+ that further reacted with molecular oxygen to produce hydrogen peroxide. Finally, meropenem underwent degradation in the presence of copper. The analysis of activity against Escherichia coli and Staphylococcus aureus showed that the effects of meropenem, amoxicillin, ampicillin, and ceftriaxone were significantly hindered in the presence of copper ions. The interactions with copper ions should be taken into account regarding the problem of antibiotic resistance and in the selection of the most efficient antimicrobial therapy for patients with altered copper homeostasis. © 2018 Elsevier Inc.",
journal = "Free Radical Biology and Medicine",
title = "Coordination and redox interactions of β-lactam antibiotics with Cu2+ in physiological settings and the impact on antibacterial activity",
volume = "129",
pages = "279-285",
doi = "10.1016/j.freeradbiomed.2018.09.038"
}

Božić, B., Korać, J., Stanković, D. M., Stanić, M., Romanović, M. Č., Bogdanović-Pristov, J., Spasić, S. D., Popović-Bijelić, A. D., Spasojević, I.,& Bajčetić, M.. (2018). Coordination and redox interactions of β-lactam antibiotics with Cu2+ in physiological settings and the impact on antibacterial activity. in Free Radical Biology and Medicine, 129, 279-285.
https://doi.org/10.1016/j.freeradbiomed.2018.09.038

Božić B, Korać J, Stanković DM, Stanić M, Romanović MČ, Bogdanović-Pristov J, Spasić SD, Popović-Bijelić AD, Spasojević I, Bajčetić M. Coordination and redox interactions of β-lactam antibiotics with Cu2+ in physiological settings and the impact on antibacterial activity. in Free Radical Biology and Medicine. 2018;129:279-285.
doi:10.1016/j.freeradbiomed.2018.09.038 .

Božić, Bojana, Korać, Jelena, Stanković, Dalibor M., Stanić, Marina, Romanović, Mima Č., Bogdanović-Pristov, Jelena, Spasić, Snežana D., Popović-Bijelić, Ana D., Spasojević, Ivan, Bajčetić, Milica, "Coordination and redox interactions of β-lactam antibiotics with Cu2+ in physiological settings and the impact on antibacterial activity" in Free Radical Biology and Medicine, 129 (2018):279-285,
https://doi.org/10.1016/j.freeradbiomed.2018.09.038 . .

TY  - JOUR
AU  - Božić, Bojana
AU  - Korać, Jelena
AU  - Stanković, Dalibor M.
AU  - Stanić, Marina
AU  - Popović-Bijelić, Ana D.
AU  - Bogdanović-Pristov, Jelena
AU  - Spasojević, Ivan
AU  - Bajčetić, Milica
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1878
AB  - Toxic effects of unconjugated bilirubin (BR) in neonatal hyperbilirubinemia have been related to redox and/or coordinate interactions with Cu2+. However, the development and mechanisms of such interactions at physiological pH have not been resolved. This study shows that BR reduces Cu2+ to Cu1+ in 1:1 stoichiometry. Apparently, BR undergoes degradation, i.e. BR and Cu2+ do not form stable complexes. The binding of Cu2+ to inorganic phosphates, liposomal phosphate groups, or to chelating drug penicillamine, impedes redox interactions with BR. Cu1+ undergoes spontaneous oxidation by O-2 resulting in hydrogen peroxide accumulation and hydroxyl radical production. In relation to this, copper and BR induced synergistic oxidative/damaging effects on erythrocytes membrane, which were alleviated by penicillamine. The production of reactive oxygen species by BR and copper represents a plausible cause of BR toxic effects and cell damage in hyperbilirubinemia. Further examination of therapeutic potentials of copper chelators in the treatment of severe neonatal hyperbilirubinemia is needed.
T2  - Chemico-Biological Interactions
T1  - Mechanisms of redox interactions of bilirubin with copper and the effects of penicillamine
VL  - 278
SP  - 129
EP  - 134
DO  - 10.1016/j.cbi.2017.10.022
ER  - 

@article{
author = "Božić, Bojana and Korać, Jelena and Stanković, Dalibor M. and Stanić, Marina and Popović-Bijelić, Ana D. and Bogdanović-Pristov, Jelena and Spasojević, Ivan and Bajčetić, Milica",
year = "2017",
abstract = "Toxic effects of unconjugated bilirubin (BR) in neonatal hyperbilirubinemia have been related to redox and/or coordinate interactions with Cu2+. However, the development and mechanisms of such interactions at physiological pH have not been resolved. This study shows that BR reduces Cu2+ to Cu1+ in 1:1 stoichiometry. Apparently, BR undergoes degradation, i.e. BR and Cu2+ do not form stable complexes. The binding of Cu2+ to inorganic phosphates, liposomal phosphate groups, or to chelating drug penicillamine, impedes redox interactions with BR. Cu1+ undergoes spontaneous oxidation by O-2 resulting in hydrogen peroxide accumulation and hydroxyl radical production. In relation to this, copper and BR induced synergistic oxidative/damaging effects on erythrocytes membrane, which were alleviated by penicillamine. The production of reactive oxygen species by BR and copper represents a plausible cause of BR toxic effects and cell damage in hyperbilirubinemia. Further examination of therapeutic potentials of copper chelators in the treatment of severe neonatal hyperbilirubinemia is needed.",
journal = "Chemico-Biological Interactions",
title = "Mechanisms of redox interactions of bilirubin with copper and the effects of penicillamine",
volume = "278",
pages = "129-134",
doi = "10.1016/j.cbi.2017.10.022"
}

Božić, B., Korać, J., Stanković, D. M., Stanić, M., Popović-Bijelić, A. D., Bogdanović-Pristov, J., Spasojević, I.,& Bajčetić, M.. (2017). Mechanisms of redox interactions of bilirubin with copper and the effects of penicillamine. in Chemico-Biological Interactions, 278, 129-134.
https://doi.org/10.1016/j.cbi.2017.10.022

Božić B, Korać J, Stanković DM, Stanić M, Popović-Bijelić AD, Bogdanović-Pristov J, Spasojević I, Bajčetić M. Mechanisms of redox interactions of bilirubin with copper and the effects of penicillamine. in Chemico-Biological Interactions. 2017;278:129-134.
doi:10.1016/j.cbi.2017.10.022 .

Božić, Bojana, Korać, Jelena, Stanković, Dalibor M., Stanić, Marina, Popović-Bijelić, Ana D., Bogdanović-Pristov, Jelena, Spasojević, Ivan, Bajčetić, Milica, "Mechanisms of redox interactions of bilirubin with copper and the effects of penicillamine" in Chemico-Biological Interactions, 278 (2017):129-134,
https://doi.org/10.1016/j.cbi.2017.10.022 . .