TY  - JOUR
AU  - Lazović, Mila
AU  - Ivković, Đurđa
AU  - Jankov, Milica
AU  - Dimkić, Ivica
AU  - Janakiev, Tamara
AU  - Trifković, Jelena
AU  - Milojković-Opsenica, Dušanka
AU  - Ristivojević, Petar
PY  - 2024
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6444
AB  - Due to the promising applications of propolis as a natural food preservative, functional ingredient or supplement, on one side, and the inherent toxicity and high volatility of organic solvents used for extraction of phenolics from propolis, a range of natural eutectic solvents (NESs) was evaluated for the extraction of phenolic compounds from poplar type propolis to create “green-labelled” food products. The phenolic profile of novel green propolis extracts was evaluated using high-performance thin-layer chromatography, while 16 phenolic compounds were quantified by ultra-high-performance liquid chromatography hyphenated with mass spectrometry. Pinocembrin and chrysin were the most dominant phenolics with an average concentration of 3111 and 3039 mg/kg in lactic acid-based NES, respectively. Biological activity, such as antioxidative and antimicrobial activities, were determined using spectrophotometric and well diffusion methods. Considering all spectrophotometric assays lactic acid-based presented as the best extraction medium for phenolic extraction, with TPC, TFC and RSA values 150.0 mg GAE/g, 190.0 mg RUE/g, and 132.8 mg TE/g on average, respectively. From 38 studied NESs, choline-chloride:tartaric acid (1:1 n/n), glycerol:lactic acid (1:1 n/n) and glycine: lactic acid (1:3 n/n) were the most promising extraction medium for obtaining the propolis extracts enriched with bioactive compounds. Additionally, proposed green solvents were proved to be the designer solvents and showed potential to be tuned to target specific phenolic compounds. Improved, or at least maintained, biological activity of NES propolis extracts support its application in agriculture industry.
PB  - Elsevier
T2  - Food Bioscience
T1  - Enhancement of propolis food preservation and functional ingredient characteristics by natural eutectic solvents extraction of phytochemicals
VL  - 57
SP  - 103467
DO  - 10.1016/j.fbio.2023.103467
ER  - 

@article{
author = "Lazović, Mila and Ivković, Đurđa and Jankov, Milica and Dimkić, Ivica and Janakiev, Tamara and Trifković, Jelena and Milojković-Opsenica, Dušanka and Ristivojević, Petar",
year = "2024",
abstract = "Due to the promising applications of propolis as a natural food preservative, functional ingredient or supplement, on one side, and the inherent toxicity and high volatility of organic solvents used for extraction of phenolics from propolis, a range of natural eutectic solvents (NESs) was evaluated for the extraction of phenolic compounds from poplar type propolis to create “green-labelled” food products. The phenolic profile of novel green propolis extracts was evaluated using high-performance thin-layer chromatography, while 16 phenolic compounds were quantified by ultra-high-performance liquid chromatography hyphenated with mass spectrometry. Pinocembrin and chrysin were the most dominant phenolics with an average concentration of 3111 and 3039 mg/kg in lactic acid-based NES, respectively. Biological activity, such as antioxidative and antimicrobial activities, were determined using spectrophotometric and well diffusion methods. Considering all spectrophotometric assays lactic acid-based presented as the best extraction medium for phenolic extraction, with TPC, TFC and RSA values 150.0 mg GAE/g, 190.0 mg RUE/g, and 132.8 mg TE/g on average, respectively. From 38 studied NESs, choline-chloride:tartaric acid (1:1 n/n), glycerol:lactic acid (1:1 n/n) and glycine: lactic acid (1:3 n/n) were the most promising extraction medium for obtaining the propolis extracts enriched with bioactive compounds. Additionally, proposed green solvents were proved to be the designer solvents and showed potential to be tuned to target specific phenolic compounds. Improved, or at least maintained, biological activity of NES propolis extracts support its application in agriculture industry.",
publisher = "Elsevier",
journal = "Food Bioscience",
title = "Enhancement of propolis food preservation and functional ingredient characteristics by natural eutectic solvents extraction of phytochemicals",
volume = "57",
pages = "103467",
doi = "10.1016/j.fbio.2023.103467"
}

Lazović, M., Ivković, Đ., Jankov, M., Dimkić, I., Janakiev, T., Trifković, J., Milojković-Opsenica, D.,& Ristivojević, P.. (2024). Enhancement of propolis food preservation and functional ingredient characteristics by natural eutectic solvents extraction of phytochemicals. in Food Bioscience
Elsevier., 57, 103467.
https://doi.org/10.1016/j.fbio.2023.103467

Lazović M, Ivković Đ, Jankov M, Dimkić I, Janakiev T, Trifković J, Milojković-Opsenica D, Ristivojević P. Enhancement of propolis food preservation and functional ingredient characteristics by natural eutectic solvents extraction of phytochemicals. in Food Bioscience. 2024;57:103467.
doi:10.1016/j.fbio.2023.103467 .

Lazović, Mila, Ivković, Đurđa, Jankov, Milica, Dimkić, Ivica, Janakiev, Tamara, Trifković, Jelena, Milojković-Opsenica, Dušanka, Ristivojević, Petar, "Enhancement of propolis food preservation and functional ingredient characteristics by natural eutectic solvents extraction of phytochemicals" in Food Bioscience, 57 (2024):103467,
https://doi.org/10.1016/j.fbio.2023.103467 . .

TY  - JOUR
AU  - Jankov, Milica
AU  - Ristivojević, Petar
AU  - Cvijetić, Ilija
AU  - Milojković-Opsenica, Dušanka
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6232
AB  - High-Performance Thin-Layer Chromatography (HPTLC)-radical scavenging capacity (RSC) assays are stan- dard techniques for the separation and identification of antioxidants from complex mixtures. HPTLC coupled with DPPH · visualization of chromatograms allows for the detection of individual antioxidants. However, other HPTLC-RSC assays that recognize compounds exhibiting different mechanisms of radical- scavenging activity are rarely reported. In this study, we developed an integrated approach that combines five HPTLC-RSC assays, principal component analysis (PCA) and quantum chemical calculations to assess the antioxidant capacity of Sempervivum tectorum L. leaf extracts. Two HPTLC assays - potassium hexa- cyanoferrate(III) total reducing power assay (TRP) and total antioxidant capacity by phosphomolybdenum method (TAC) - were developed for the first time. The method supports a more in-depth study of the RSC of natural products, as it compares the radical scavenging fingerprints of S. tectorum leaf extracts and recognizes differences in their individual bioactive constituents. Kaempferol, kaempferol 3- O -glucoside, quercetin 3- O -glucoside, caffeic acid, and gallic acid were identified as the compounds that discriminate HPTLC-RSC assays according to their mechanism of action and capture the similarities between 20 S. tec- torum samples. Additionally, DFT calculations on M06–2X/6–31 + G (d,p) level were applied to map ther- modynamic feasibility of hydrogen atom transfer (HAT) and single electron transfer (SET) mechanisms of the identified compounds. Based on experimental and theoretical results, a combination of HPTLC-ABTS and HPTLC-TAC assays were proposed as the optimal method for mapping the antioxidants from S. tec- torum . This study represents a step forward in identifying and quantifying individual antioxidants from complex food and natural product matrices in a more rational manner.
PB  - Elsevier
T2  - Journal of Chromatography A
T1  - Assessing radical scavenging capacity of Sempervivum tectorum L. leaf extracts: An integrated high-performance thin-layer chromatography/ in silico /chemometrics approach
VL  - 1703
SP  - 464082
DO  - 10.1016/j.chroma.2023.464082
ER  - 

@article{
author = "Jankov, Milica and Ristivojević, Petar and Cvijetić, Ilija and Milojković-Opsenica, Dušanka",
year = "2023",
abstract = "High-Performance Thin-Layer Chromatography (HPTLC)-radical scavenging capacity (RSC) assays are stan- dard techniques for the separation and identification of antioxidants from complex mixtures. HPTLC coupled with DPPH · visualization of chromatograms allows for the detection of individual antioxidants. However, other HPTLC-RSC assays that recognize compounds exhibiting different mechanisms of radical- scavenging activity are rarely reported. In this study, we developed an integrated approach that combines five HPTLC-RSC assays, principal component analysis (PCA) and quantum chemical calculations to assess the antioxidant capacity of Sempervivum tectorum L. leaf extracts. Two HPTLC assays - potassium hexa- cyanoferrate(III) total reducing power assay (TRP) and total antioxidant capacity by phosphomolybdenum method (TAC) - were developed for the first time. The method supports a more in-depth study of the RSC of natural products, as it compares the radical scavenging fingerprints of S. tectorum leaf extracts and recognizes differences in their individual bioactive constituents. Kaempferol, kaempferol 3- O -glucoside, quercetin 3- O -glucoside, caffeic acid, and gallic acid were identified as the compounds that discriminate HPTLC-RSC assays according to their mechanism of action and capture the similarities between 20 S. tec- torum samples. Additionally, DFT calculations on M06–2X/6–31 + G (d,p) level were applied to map ther- modynamic feasibility of hydrogen atom transfer (HAT) and single electron transfer (SET) mechanisms of the identified compounds. Based on experimental and theoretical results, a combination of HPTLC-ABTS and HPTLC-TAC assays were proposed as the optimal method for mapping the antioxidants from S. tec- torum . This study represents a step forward in identifying and quantifying individual antioxidants from complex food and natural product matrices in a more rational manner.",
publisher = "Elsevier",
journal = "Journal of Chromatography A",
title = "Assessing radical scavenging capacity of Sempervivum tectorum L. leaf extracts: An integrated high-performance thin-layer chromatography/ in silico /chemometrics approach",
volume = "1703",
pages = "464082",
doi = "10.1016/j.chroma.2023.464082"
}

Jankov, M., Ristivojević, P., Cvijetić, I.,& Milojković-Opsenica, D.. (2023). Assessing radical scavenging capacity of Sempervivum tectorum L. leaf extracts: An integrated high-performance thin-layer chromatography/ in silico /chemometrics approach. in Journal of Chromatography A
Elsevier., 1703, 464082.
https://doi.org/10.1016/j.chroma.2023.464082

Jankov M, Ristivojević P, Cvijetić I, Milojković-Opsenica D. Assessing radical scavenging capacity of Sempervivum tectorum L. leaf extracts: An integrated high-performance thin-layer chromatography/ in silico /chemometrics approach. in Journal of Chromatography A. 2023;1703:464082.
doi:10.1016/j.chroma.2023.464082 .

Jankov, Milica, Ristivojević, Petar, Cvijetić, Ilija, Milojković-Opsenica, Dušanka, "Assessing radical scavenging capacity of Sempervivum tectorum L. leaf extracts: An integrated high-performance thin-layer chromatography/ in silico /chemometrics approach" in Journal of Chromatography A, 1703 (2023):464082,
https://doi.org/10.1016/j.chroma.2023.464082 . .

TY  - CONF
AU  - Jankov, Milica
AU  - Milojković-Opsenica, Dušanka
AU  - Ristivojević, Petar
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6209
AB  - Sempervivum tectorum L. is a perennial plant with succulent leaves arranged in a rosette. Despite its wide use in traditional medicine for the treatment of various changes on the skin, nervousness, anxiety, menstrual ailments, etc., it still does not have a biography in the European Pharmacopoeia¹. The antibacterial effect of juice squeezed from the leaves and tea made from dried leaves was tested against bacteria that cause inflammation of the ear and bladder². Direct bioautography on HPTLC plates for the investigation of antibacterial activity of the houseleek leaves extracts was done for the first time. Four HPTLC bioassays were developed for gram-positive bacteria (B. subtilis, M. lysodeikticus, MRSA, and S. aureus), and two for gramnegative bacteria (E. coli and K. pneumoniae). Antibacterial activity of grampositive bacteria comes from active compounds at RF 0.57 and 0.92. HPTLC bioassays show higher sensitivity for gram-negative bacteria, as numerous active bands were observed at RF 0.03, 0.38, 0.42, 0.56, 0.57, 0.86 and 0.92. By applying chemometrics and principal components analysis, the HPTLC bioassays of grampositive bacteria were separated into two groups on the scores plot graphic along PC1 axis. The bioassays for B. subtilis and M. lysodeikticus form a less uniform group in the upper left quadrant, while the bioassays for MRSA and S. aureus form a homogeneous group in the lower right quadrant. Presence or absence of the active bands at RF 0.57 and 0.92 affect these separations. The bioassays for the two gramnegative bacteria are separated along both axes on the scores plot graphic from each other but also from the other bioassays for the gram-positive bacteria. This separation is influenced by the presence of numerous active bands. For further investigation it is necessary to identify compounds responsible for the antibacterial activity of the houseleek leaves extracts.
C3  - 9th Conference of Young Chemists of Serbia, Book of Abstracts, 4th November 2023, University of Novi Sad - Faculty of Science
T1  - Assessment of antibacterial activity of Sempervivum tectorum L. leaves extracts using HPTLC bioassays and chemometrics
UR  - https://hdl.handle.net/21.15107/rcub_cherry_6209
ER  - 

@conference{
author = "Jankov, Milica and Milojković-Opsenica, Dušanka and Ristivojević, Petar",
year = "2023",
abstract = "Sempervivum tectorum L. is a perennial plant with succulent leaves arranged in a rosette. Despite its wide use in traditional medicine for the treatment of various changes on the skin, nervousness, anxiety, menstrual ailments, etc., it still does not have a biography in the European Pharmacopoeia¹. The antibacterial effect of juice squeezed from the leaves and tea made from dried leaves was tested against bacteria that cause inflammation of the ear and bladder². Direct bioautography on HPTLC plates for the investigation of antibacterial activity of the houseleek leaves extracts was done for the first time. Four HPTLC bioassays were developed for gram-positive bacteria (B. subtilis, M. lysodeikticus, MRSA, and S. aureus), and two for gramnegative bacteria (E. coli and K. pneumoniae). Antibacterial activity of grampositive bacteria comes from active compounds at RF 0.57 and 0.92. HPTLC bioassays show higher sensitivity for gram-negative bacteria, as numerous active bands were observed at RF 0.03, 0.38, 0.42, 0.56, 0.57, 0.86 and 0.92. By applying chemometrics and principal components analysis, the HPTLC bioassays of grampositive bacteria were separated into two groups on the scores plot graphic along PC1 axis. The bioassays for B. subtilis and M. lysodeikticus form a less uniform group in the upper left quadrant, while the bioassays for MRSA and S. aureus form a homogeneous group in the lower right quadrant. Presence or absence of the active bands at RF 0.57 and 0.92 affect these separations. The bioassays for the two gramnegative bacteria are separated along both axes on the scores plot graphic from each other but also from the other bioassays for the gram-positive bacteria. This separation is influenced by the presence of numerous active bands. For further investigation it is necessary to identify compounds responsible for the antibacterial activity of the houseleek leaves extracts.",
journal = "9th Conference of Young Chemists of Serbia, Book of Abstracts, 4th November 2023, University of Novi Sad - Faculty of Science",
title = "Assessment of antibacterial activity of Sempervivum tectorum L. leaves extracts using HPTLC bioassays and chemometrics",
url = "https://hdl.handle.net/21.15107/rcub_cherry_6209"
}

Jankov, M., Milojković-Opsenica, D.,& Ristivojević, P.. (2023). Assessment of antibacterial activity of Sempervivum tectorum L. leaves extracts using HPTLC bioassays and chemometrics. in 9th Conference of Young Chemists of Serbia, Book of Abstracts, 4th November 2023, University of Novi Sad - Faculty of Science.
https://hdl.handle.net/21.15107/rcub_cherry_6209

Jankov M, Milojković-Opsenica D, Ristivojević P. Assessment of antibacterial activity of Sempervivum tectorum L. leaves extracts using HPTLC bioassays and chemometrics. in 9th Conference of Young Chemists of Serbia, Book of Abstracts, 4th November 2023, University of Novi Sad - Faculty of Science. 2023;.
https://hdl.handle.net/21.15107/rcub_cherry_6209 .

Jankov, Milica, Milojković-Opsenica, Dušanka, Ristivojević, Petar, "Assessment of antibacterial activity of Sempervivum tectorum L. leaves extracts using HPTLC bioassays and chemometrics" in 9th Conference of Young Chemists of Serbia, Book of Abstracts, 4th November 2023, University of Novi Sad - Faculty of Science (2023),
https://hdl.handle.net/21.15107/rcub_cherry_6209 .

TY  - JOUR
AU  - Lazović, Mila
AU  - Cvijetić, Ilija
AU  - Jankov, Milica
AU  - Milojković-Opsenica, Dušanka
AU  - Trifković, Jelena
AU  - Ristivojević, Petar
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6230
AB  - Natural Eutectic Solvents (NES) are a promising class of environmentally friendly liquids that offer an alternative to conventional organic solvents. To investigate their potential for extracting phenolic compounds from plant materials, we employed the COSMO-RS (COnductor like Screening MOdel for Real Solvents) computational method. Nineteen NES solvents were prepared to determine the most selective and effective solvent for extracting phenolic compounds from Teucrium chamaedrys using both theoretical and experimental evaluation. Screening of extraction efficiency was performed by quantification of individual compounds using ultra-high-performance liquid chromatography with a diode array detector and a triple-quadrupole mass spectrometer (UHPLC-DAD-MS/MS), as well as spectrophotometric assays (total phenolic content, total flavonoid content, and radical scavenging activity). In this paper, we propose a new approach to model NES properties using COSMO-RS. While the majority of previous studies have modeled these solvents as individual or pseudo-component complexes between hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA), we have developed a ternary HBD:HBA:water supramolecular complex model to represent NES solution structures more accurately. This model provides insights into the intermolecular interactions driving the extraction process and predicts extraction efficiencies that agree with experimental data. Two eutectic mixtures (choline chloride:succinic acid in molar ratio 1:1 and 20% of water (w/w) and choline chloride: glycerol in molar ratio 1:1 and 20% of water (w/w)) showed strong affinity towards phenolic compounds. Overall, our findings suggest that the ternary complex model is a more appropriate approach for modeling NES properties.
PB  - Elsevier
T2  - Journal of Molecular Liquids
T1  - COSMO-RS in prescreening of Natural Eutectic Solvents for phenolic extraction from Teucrium chamaedrys
VL  - 387
SP  - 122649
DO  - 10.1016/j.molliq.2023.122649
ER  - 

@article{
author = "Lazović, Mila and Cvijetić, Ilija and Jankov, Milica and Milojković-Opsenica, Dušanka and Trifković, Jelena and Ristivojević, Petar",
year = "2023",
abstract = "Natural Eutectic Solvents (NES) are a promising class of environmentally friendly liquids that offer an alternative to conventional organic solvents. To investigate their potential for extracting phenolic compounds from plant materials, we employed the COSMO-RS (COnductor like Screening MOdel for Real Solvents) computational method. Nineteen NES solvents were prepared to determine the most selective and effective solvent for extracting phenolic compounds from Teucrium chamaedrys using both theoretical and experimental evaluation. Screening of extraction efficiency was performed by quantification of individual compounds using ultra-high-performance liquid chromatography with a diode array detector and a triple-quadrupole mass spectrometer (UHPLC-DAD-MS/MS), as well as spectrophotometric assays (total phenolic content, total flavonoid content, and radical scavenging activity). In this paper, we propose a new approach to model NES properties using COSMO-RS. While the majority of previous studies have modeled these solvents as individual or pseudo-component complexes between hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA), we have developed a ternary HBD:HBA:water supramolecular complex model to represent NES solution structures more accurately. This model provides insights into the intermolecular interactions driving the extraction process and predicts extraction efficiencies that agree with experimental data. Two eutectic mixtures (choline chloride:succinic acid in molar ratio 1:1 and 20% of water (w/w) and choline chloride: glycerol in molar ratio 1:1 and 20% of water (w/w)) showed strong affinity towards phenolic compounds. Overall, our findings suggest that the ternary complex model is a more appropriate approach for modeling NES properties.",
publisher = "Elsevier",
journal = "Journal of Molecular Liquids",
title = "COSMO-RS in prescreening of Natural Eutectic Solvents for phenolic extraction from Teucrium chamaedrys",
volume = "387",
pages = "122649",
doi = "10.1016/j.molliq.2023.122649"
}

Lazović, M., Cvijetić, I., Jankov, M., Milojković-Opsenica, D., Trifković, J.,& Ristivojević, P.. (2023). COSMO-RS in prescreening of Natural Eutectic Solvents for phenolic extraction from Teucrium chamaedrys. in Journal of Molecular Liquids
Elsevier., 387, 122649.
https://doi.org/10.1016/j.molliq.2023.122649

Lazović M, Cvijetić I, Jankov M, Milojković-Opsenica D, Trifković J, Ristivojević P. COSMO-RS in prescreening of Natural Eutectic Solvents for phenolic extraction from Teucrium chamaedrys. in Journal of Molecular Liquids. 2023;387:122649.
doi:10.1016/j.molliq.2023.122649 .

Lazović, Mila, Cvijetić, Ilija, Jankov, Milica, Milojković-Opsenica, Dušanka, Trifković, Jelena, Ristivojević, Petar, "COSMO-RS in prescreening of Natural Eutectic Solvents for phenolic extraction from Teucrium chamaedrys" in Journal of Molecular Liquids, 387 (2023):122649,
https://doi.org/10.1016/j.molliq.2023.122649 . .

TY  - JOUR
AU  - Lazović, Mila
AU  - Cvijetić, Ilija
AU  - Jankov, Milica
AU  - Milojković-Opsenica, Dušanka
AU  - Trifković, Jelena
AU  - Ristivojević, Petar
PY  - 2022
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/5637
AB  - To replace common organic solvents that present inherent toxicity and have high volatility and to improve the extraction efficiency, a range of natural deep eutectic solvents (NADESs) were evaluated for the extraction of phenolic compounds from Agrimonia eupatoria. Screening of NADES efficiency was carried out based on the total phenolic and flavonoid content and radical-scavenging activity, determined by spectrophotometry, as well as phenolic compounds quantified, obtained using ultra-high-performance liquid chromatography with a diode array detector and a triple-quadrupole mass spectrometer. Increased extraction efficiency when compared with organic solvent was achieved using NADES mixtures choline chloride (ChCl):urea 1:2 and choline chloride:glycerol 1:1. Flavonol glycosides were the most abundant compounds in all extracts. The COSMO-RS model provided insights into the most important intermolecular interactions that drive the extraction process. Moreover, it could explain the extraction efficiency of flavonol glycosides using ChCl:glycerol NADES. The current article offers experimental evidence and mechanistic insights for the selection of optimal NADES to extract bioactive components from Agrimonia eupatoria. © 2022 by the authors.
PB  - MDPI
T2  - Plants
T1  - Efficiency of Natural Deep Eutectic Solvents to Extract Phenolic Compounds from Agrimonia eupatoria: Experimental Study and In Silico Modelling
VL  - 11
SP  - 2346
DO  - 10.3390/plants11182346
ER  - 

@article{
author = "Lazović, Mila and Cvijetić, Ilija and Jankov, Milica and Milojković-Opsenica, Dušanka and Trifković, Jelena and Ristivojević, Petar",
year = "2022",
abstract = "To replace common organic solvents that present inherent toxicity and have high volatility and to improve the extraction efficiency, a range of natural deep eutectic solvents (NADESs) were evaluated for the extraction of phenolic compounds from Agrimonia eupatoria. Screening of NADES efficiency was carried out based on the total phenolic and flavonoid content and radical-scavenging activity, determined by spectrophotometry, as well as phenolic compounds quantified, obtained using ultra-high-performance liquid chromatography with a diode array detector and a triple-quadrupole mass spectrometer. Increased extraction efficiency when compared with organic solvent was achieved using NADES mixtures choline chloride (ChCl):urea 1:2 and choline chloride:glycerol 1:1. Flavonol glycosides were the most abundant compounds in all extracts. The COSMO-RS model provided insights into the most important intermolecular interactions that drive the extraction process. Moreover, it could explain the extraction efficiency of flavonol glycosides using ChCl:glycerol NADES. The current article offers experimental evidence and mechanistic insights for the selection of optimal NADES to extract bioactive components from Agrimonia eupatoria. © 2022 by the authors.",
publisher = "MDPI",
journal = "Plants",
title = "Efficiency of Natural Deep Eutectic Solvents to Extract Phenolic Compounds from Agrimonia eupatoria: Experimental Study and In Silico Modelling",
volume = "11",
pages = "2346",
doi = "10.3390/plants11182346"
}

Lazović, M., Cvijetić, I., Jankov, M., Milojković-Opsenica, D., Trifković, J.,& Ristivojević, P.. (2022). Efficiency of Natural Deep Eutectic Solvents to Extract Phenolic Compounds from Agrimonia eupatoria: Experimental Study and In Silico Modelling. in Plants
MDPI., 11, 2346.
https://doi.org/10.3390/plants11182346

Lazović M, Cvijetić I, Jankov M, Milojković-Opsenica D, Trifković J, Ristivojević P. Efficiency of Natural Deep Eutectic Solvents to Extract Phenolic Compounds from Agrimonia eupatoria: Experimental Study and In Silico Modelling. in Plants. 2022;11:2346.
doi:10.3390/plants11182346 .

Lazović, Mila, Cvijetić, Ilija, Jankov, Milica, Milojković-Opsenica, Dušanka, Trifković, Jelena, Ristivojević, Petar, "Efficiency of Natural Deep Eutectic Solvents to Extract Phenolic Compounds from Agrimonia eupatoria: Experimental Study and In Silico Modelling" in Plants, 11 (2022):2346,
https://doi.org/10.3390/plants11182346 . .

TY  - DATA
AU  - Lazović, Mila
AU  - Cvijetić, Ilija
AU  - Jankov, Milica
AU  - Milojković-Opsenica, Dušanka
AU  - Trifković, Jelena
AU  - Ristivojević, Petar
PY  - 2022
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/5659
AB  - To replace common organic solvents that present inherent toxicity and have high volatility and to improve the extraction efficiency, a range of natural deep eutectic solvents (NADESs) were evaluated for the extraction of phenolic compounds from Agrimonia eupatoria. Screening of NADES efficiency was carried out based on the total phenolic and flavonoid content and radical-scavenging activity, determined by spectrophotometry, as well as phenolic compounds quantified, obtained using ultra-high-performance liquid chromatography with a diode array detector and a triple-quadrupole mass spectrometer. Increased extraction efficiency when compared with organic solvent was achieved using NADES mixtures choline chloride (ChCl):urea 1:2 and choline chloride:glycerol 1:1. Flavonol glycosides were the most abundant compounds in all extracts. The COSMO-RS model provided insights into the most important intermolecular interactions that drive the extraction process. Moreover, it could explain the extraction efficiency of flavonol glycosides using ChCl:glycerol NADES. The current article offers experimental evidence and mechanistic insights for the selection of optimal NADES to extract bioactive components from Agrimonia eupatoria. © 2022 by the authors.
PB  - MDPI
T2  - Plants
T1  - Supplementary material for: Lazović, M., Cvijetić, I., Jankov, M., Milojković-Opsenica, D., Trifković, J.,& Ristivojević, P.. (2022). Efficiency of Natural Deep Eutectic Solvents to Extract Phenolic Compounds from Agrimonia eupatoria: Experimental Study and In Silico Modelling. in Plants MDPI., 11, 2346. https://doi.org/10.3390/plants11182346
VL  - 11
SP  - 2346
UR  - https://hdl.handle.net/21.15107/rcub_cherry_5659
ER  - 

@misc{
author = "Lazović, Mila and Cvijetić, Ilija and Jankov, Milica and Milojković-Opsenica, Dušanka and Trifković, Jelena and Ristivojević, Petar",
year = "2022",
abstract = "To replace common organic solvents that present inherent toxicity and have high volatility and to improve the extraction efficiency, a range of natural deep eutectic solvents (NADESs) were evaluated for the extraction of phenolic compounds from Agrimonia eupatoria. Screening of NADES efficiency was carried out based on the total phenolic and flavonoid content and radical-scavenging activity, determined by spectrophotometry, as well as phenolic compounds quantified, obtained using ultra-high-performance liquid chromatography with a diode array detector and a triple-quadrupole mass spectrometer. Increased extraction efficiency when compared with organic solvent was achieved using NADES mixtures choline chloride (ChCl):urea 1:2 and choline chloride:glycerol 1:1. Flavonol glycosides were the most abundant compounds in all extracts. The COSMO-RS model provided insights into the most important intermolecular interactions that drive the extraction process. Moreover, it could explain the extraction efficiency of flavonol glycosides using ChCl:glycerol NADES. The current article offers experimental evidence and mechanistic insights for the selection of optimal NADES to extract bioactive components from Agrimonia eupatoria. © 2022 by the authors.",
publisher = "MDPI",
journal = "Plants",
title = "Supplementary material for: Lazović, M., Cvijetić, I., Jankov, M., Milojković-Opsenica, D., Trifković, J.,& Ristivojević, P.. (2022). Efficiency of Natural Deep Eutectic Solvents to Extract Phenolic Compounds from Agrimonia eupatoria: Experimental Study and In Silico Modelling. in Plants MDPI., 11, 2346. https://doi.org/10.3390/plants11182346",
volume = "11",
pages = "2346",
url = "https://hdl.handle.net/21.15107/rcub_cherry_5659"
}

Lazović, M., Cvijetić, I., Jankov, M., Milojković-Opsenica, D., Trifković, J.,& Ristivojević, P.. (2022). Supplementary material for: Lazović, M., Cvijetić, I., Jankov, M., Milojković-Opsenica, D., Trifković, J.,& Ristivojević, P.. (2022). Efficiency of Natural Deep Eutectic Solvents to Extract Phenolic Compounds from Agrimonia eupatoria: Experimental Study and In Silico Modelling. in Plants MDPI., 11, 2346. https://doi.org/10.3390/plants11182346. in Plants
MDPI., 11, 2346.
https://hdl.handle.net/21.15107/rcub_cherry_5659

Lazović M, Cvijetić I, Jankov M, Milojković-Opsenica D, Trifković J, Ristivojević P. Supplementary material for: Lazović, M., Cvijetić, I., Jankov, M., Milojković-Opsenica, D., Trifković, J.,& Ristivojević, P.. (2022). Efficiency of Natural Deep Eutectic Solvents to Extract Phenolic Compounds from Agrimonia eupatoria: Experimental Study and In Silico Modelling. in Plants MDPI., 11, 2346. https://doi.org/10.3390/plants11182346. in Plants. 2022;11:2346.
https://hdl.handle.net/21.15107/rcub_cherry_5659 .

Lazović, Mila, Cvijetić, Ilija, Jankov, Milica, Milojković-Opsenica, Dušanka, Trifković, Jelena, Ristivojević, Petar, "Supplementary material for: Lazović, M., Cvijetić, I., Jankov, M., Milojković-Opsenica, D., Trifković, J.,& Ristivojević, P.. (2022). Efficiency of Natural Deep Eutectic Solvents to Extract Phenolic Compounds from Agrimonia eupatoria: Experimental Study and In Silico Modelling. in Plants MDPI., 11, 2346. https://doi.org/10.3390/plants11182346" in Plants, 11 (2022):2346,
https://hdl.handle.net/21.15107/rcub_cherry_5659 .

TY  - CONF
AU  - Jankov, Milica
AU  - Ristivojević, Petar
AU  - Milojković-Opsenica, Dušanka
PY  - 2022
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6210
AB  - The houseleek (Sempervivum tectorum L.) has a wide application in traditional medicine for skin changes treatment, ear, throat and bladder infections, stomach ulcers. Recently, several studies confirmed antioxidative, antimicrobial and antiinflammatory effects of houseleek [1,2]. Several spectroscopic techniques have been proposed to measure the free radical scavenging capacity (RSC), regardless of the individual compounds which contribute to the total free RSC. On the other hand, high-performance thin-layer chromatography (HPTLC) hyphenated with biochemical detection allows identification of single compounds responsible for radical scavenging activity (RSA). The main aim of current study is to identify single radical scavengers using four HPTLC-based assays such as 2,2-Diphenyl-1picrylhydrazyl assay (DPPH), 2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay (ABTS), potassium hexacyanoferrate(III) total reducing power assay (TRP) and total antioxidant capacity by phosphomolybdenum assay (TAC) in combination with principal component analysis (PCA). The best of our knowledge, HPTLC-TRP and HPTLC-TAC were developed for the first time. PCA was used for the classification of samples with similar RSA and the identification of radical scavengers responsible for classification. HPTLC-DPPH, HPTLC-ABTS and HPTLC-TRP chromatograms showed similar bioactive profiles. Further, HPTLCTAC fingerprint differs from the others with observed numerous new zones with hRF at 73, 83, 89, and 98 values. Based on PCA, HPTLC-ABTS and HPTLC-TRP assays showed similar grouping of samples. Phenolic compounds such as gallic acid (hRF = 48), kaempferol (hRF = 69) and unknown compound at hRF = 18 are recognized as markers responsible for the separation between samples.
C3  - 8th Conference of Young Chemists of Serbia, Belgrade, Serbia, 29th October, 2022. In: Book of Abstracts
T1  - Four radical scavenging activity-HPTLC assays in combination with chemometrics for the assessment of antioxidant activity of Sempervivum tectorum L. leaf extracts
UR  - https://hdl.handle.net/21.15107/rcub_cherry_6210
ER  - 

@conference{
author = "Jankov, Milica and Ristivojević, Petar and Milojković-Opsenica, Dušanka",
year = "2022",
abstract = "The houseleek (Sempervivum tectorum L.) has a wide application in traditional medicine for skin changes treatment, ear, throat and bladder infections, stomach ulcers. Recently, several studies confirmed antioxidative, antimicrobial and antiinflammatory effects of houseleek [1,2]. Several spectroscopic techniques have been proposed to measure the free radical scavenging capacity (RSC), regardless of the individual compounds which contribute to the total free RSC. On the other hand, high-performance thin-layer chromatography (HPTLC) hyphenated with biochemical detection allows identification of single compounds responsible for radical scavenging activity (RSA). The main aim of current study is to identify single radical scavengers using four HPTLC-based assays such as 2,2-Diphenyl-1picrylhydrazyl assay (DPPH), 2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay (ABTS), potassium hexacyanoferrate(III) total reducing power assay (TRP) and total antioxidant capacity by phosphomolybdenum assay (TAC) in combination with principal component analysis (PCA). The best of our knowledge, HPTLC-TRP and HPTLC-TAC were developed for the first time. PCA was used for the classification of samples with similar RSA and the identification of radical scavengers responsible for classification. HPTLC-DPPH, HPTLC-ABTS and HPTLC-TRP chromatograms showed similar bioactive profiles. Further, HPTLCTAC fingerprint differs from the others with observed numerous new zones with hRF at 73, 83, 89, and 98 values. Based on PCA, HPTLC-ABTS and HPTLC-TRP assays showed similar grouping of samples. Phenolic compounds such as gallic acid (hRF = 48), kaempferol (hRF = 69) and unknown compound at hRF = 18 are recognized as markers responsible for the separation between samples.",
journal = "8th Conference of Young Chemists of Serbia, Belgrade, Serbia, 29th October, 2022. In: Book of Abstracts",
title = "Four radical scavenging activity-HPTLC assays in combination with chemometrics for the assessment of antioxidant activity of Sempervivum tectorum L. leaf extracts",
url = "https://hdl.handle.net/21.15107/rcub_cherry_6210"
}

Jankov, M., Ristivojević, P.,& Milojković-Opsenica, D.. (2022). Four radical scavenging activity-HPTLC assays in combination with chemometrics for the assessment of antioxidant activity of Sempervivum tectorum L. leaf extracts. in 8th Conference of Young Chemists of Serbia, Belgrade, Serbia, 29th October, 2022. In: Book of Abstracts.
https://hdl.handle.net/21.15107/rcub_cherry_6210

Jankov M, Ristivojević P, Milojković-Opsenica D. Four radical scavenging activity-HPTLC assays in combination with chemometrics for the assessment of antioxidant activity of Sempervivum tectorum L. leaf extracts. in 8th Conference of Young Chemists of Serbia, Belgrade, Serbia, 29th October, 2022. In: Book of Abstracts. 2022;.
https://hdl.handle.net/21.15107/rcub_cherry_6210 .

Jankov, Milica, Ristivojević, Petar, Milojković-Opsenica, Dušanka, "Four radical scavenging activity-HPTLC assays in combination with chemometrics for the assessment of antioxidant activity of Sempervivum tectorum L. leaf extracts" in 8th Conference of Young Chemists of Serbia, Belgrade, Serbia, 29th October, 2022. In: Book of Abstracts (2022),
https://hdl.handle.net/21.15107/rcub_cherry_6210 .

TY  - CONF
AU  - Ivković, Đurđa
AU  - Krstić-Ristivojević, Maja
AU  - Jankov, Milica
AU  - Milojković-Opsenica, Dušanka
AU  - Trifković, Jelena
AU  - Andrić, Filip
AU  - Ristivojević, Petar
PY  - 2022
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6214
AB  - Excess of free radicals in skin causes oxidative stress, which results to skin aging and
appearance of age spots. The enzyme tyrosinase is responsible for mentioned process.
Slowing down of this unwanted process is one of the challenges of modern science. Thus,
the aim of this study is to examine the potential of selected plant extracts to reduce
oxidation stress and the appearance of hyperpigmentation. The extracts were characterized
by the use of high-performance thin-layer chromatography and high-performance liquid
chromatography coupled with mass spectrometry. The antioxidant activity of the extracts
and potential for the inhibition of tyrosinase enzyme were determined. Nineteen phenolic
compounds were quantificated in the tested extracts. The obtained results demonstrate that
the extracts of Morus alba (92%), Rubus (86%) and Agrimona eupatoria (84%) are the
most effective inhibitors. The Teucrium chamaedrys and Agrimona eupatoria showed high
values of antioxidant activity. The listed samples are commercial.
C3  - 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings
T1  - Skin anti-ageing potential of 18 medicinal herbs collected from Serbia
IS  - 44
UR  - https://hdl.handle.net/21.15107/rcub_cherry_6214
ER  - 

@conference{
author = "Ivković, Đurđa and Krstić-Ristivojević, Maja and Jankov, Milica and Milojković-Opsenica, Dušanka and Trifković, Jelena and Andrić, Filip and Ristivojević, Petar",
year = "2022",
abstract = "Excess of free radicals in skin causes oxidative stress, which results to skin aging and
appearance of age spots. The enzyme tyrosinase is responsible for mentioned process.
Slowing down of this unwanted process is one of the challenges of modern science. Thus,
the aim of this study is to examine the potential of selected plant extracts to reduce
oxidation stress and the appearance of hyperpigmentation. The extracts were characterized
by the use of high-performance thin-layer chromatography and high-performance liquid
chromatography coupled with mass spectrometry. The antioxidant activity of the extracts
and potential for the inhibition of tyrosinase enzyme were determined. Nineteen phenolic
compounds were quantificated in the tested extracts. The obtained results demonstrate that
the extracts of Morus alba (92%), Rubus (86%) and Agrimona eupatoria (84%) are the
most effective inhibitors. The Teucrium chamaedrys and Agrimona eupatoria showed high
values of antioxidant activity. The listed samples are commercial.",
journal = "58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings",
title = "Skin anti-ageing potential of 18 medicinal herbs collected from Serbia",
number = "44",
url = "https://hdl.handle.net/21.15107/rcub_cherry_6214"
}

Ivković, Đ., Krstić-Ristivojević, M., Jankov, M., Milojković-Opsenica, D., Trifković, J., Andrić, F.,& Ristivojević, P.. (2022). Skin anti-ageing potential of 18 medicinal herbs collected from Serbia. in 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings(44).
https://hdl.handle.net/21.15107/rcub_cherry_6214

Ivković Đ, Krstić-Ristivojević M, Jankov M, Milojković-Opsenica D, Trifković J, Andrić F, Ristivojević P. Skin anti-ageing potential of 18 medicinal herbs collected from Serbia. in 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings. 2022;(44).
https://hdl.handle.net/21.15107/rcub_cherry_6214 .

Ivković, Đurđa, Krstić-Ristivojević, Maja, Jankov, Milica, Milojković-Opsenica, Dušanka, Trifković, Jelena, Andrić, Filip, Ristivojević, Petar, "Skin anti-ageing potential of 18 medicinal herbs collected from Serbia" in 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings, no. 44 (2022),
https://hdl.handle.net/21.15107/rcub_cherry_6214 .

TY  - CONF
AU  - Imamoto, Minami
AU  - Jankov, Milica
AU  - Ristivojević, Petar
AU  - Trifković, Jelena
AU  - Milojković-Opsenica, Dušanka
AU  - Andrić, Filip
PY  - 2022
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6211
C3  - 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings
T1  - HPTLC-guided optimization of ultrasound assisted extraction of polyphenols from green tea leaves (Camellia sinensis) using image analysis and multicriteria optimization
UR  - https://hdl.handle.net/21.15107/rcub_cherry_6211
ER  - 

@conference{
author = "Imamoto, Minami and Jankov, Milica and Ristivojević, Petar and Trifković, Jelena and Milojković-Opsenica, Dušanka and Andrić, Filip",
year = "2022",
journal = "58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings",
title = "HPTLC-guided optimization of ultrasound assisted extraction of polyphenols from green tea leaves (Camellia sinensis) using image analysis and multicriteria optimization",
url = "https://hdl.handle.net/21.15107/rcub_cherry_6211"
}

Imamoto, M., Jankov, M., Ristivojević, P., Trifković, J., Milojković-Opsenica, D.,& Andrić, F.. (2022). HPTLC-guided optimization of ultrasound assisted extraction of polyphenols from green tea leaves (Camellia sinensis) using image analysis and multicriteria optimization. in 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings.
https://hdl.handle.net/21.15107/rcub_cherry_6211

Imamoto M, Jankov M, Ristivojević P, Trifković J, Milojković-Opsenica D, Andrić F. HPTLC-guided optimization of ultrasound assisted extraction of polyphenols from green tea leaves (Camellia sinensis) using image analysis and multicriteria optimization. in 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings. 2022;.
https://hdl.handle.net/21.15107/rcub_cherry_6211 .

Imamoto, Minami, Jankov, Milica, Ristivojević, Petar, Trifković, Jelena, Milojković-Opsenica, Dušanka, Andrić, Filip, "HPTLC-guided optimization of ultrasound assisted extraction of polyphenols from green tea leaves (Camellia sinensis) using image analysis and multicriteria optimization" in 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings (2022),
https://hdl.handle.net/21.15107/rcub_cherry_6211 .

TY  - CONF
AU  - Jankov, Milica
AU  - Ristivojević, Petar
AU  - Trifković, Jelena
AU  - Cvijetić, Ilija
AU  - Milojković-Opsenica, Dušanka
PY  - 2022
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6212
AB  - Houseleek leaves (Sempervivum tectorum L.) has a wide application in folk medicine for treating skin changes. Twenty different extracts of houseleek leaves were characterized by spectrophotometry and high-performance thin-layer chromatography (HPTLC). The antioxidant capacity of the extracts was determined using four spectrophotometric assays, while the content of total phenols was determined by the Folin-Ciocalteu's method. The principal component analysis (PCA) was applied to the results obtained by spectrophotometric assays in order to group the samples according to the intensity of antioxidant activity. The samples were divided into two clusters, except for three separated samples. A similar phenolic profile of S. tectorum leaves extracts obtained by HPTLC was observed. Kaempferol and kaempferol 3-O-glucoside, gallic and caffeic acids as well as the quercetin 3-O-glucoside have been identified in houseleek leaves extracts.
C3  - 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings
T1  - Spectrophotometric determination of total phenolic content and antioxidant capacity of houseleek leaf extracts (Sempervivum tectorum L.) and phenolic profile
UR  - https://hdl.handle.net/21.15107/rcub_cherry_6212
ER  - 

@conference{
author = "Jankov, Milica and Ristivojević, Petar and Trifković, Jelena and Cvijetić, Ilija and Milojković-Opsenica, Dušanka",
year = "2022",
abstract = "Houseleek leaves (Sempervivum tectorum L.) has a wide application in folk medicine for treating skin changes. Twenty different extracts of houseleek leaves were characterized by spectrophotometry and high-performance thin-layer chromatography (HPTLC). The antioxidant capacity of the extracts was determined using four spectrophotometric assays, while the content of total phenols was determined by the Folin-Ciocalteu's method. The principal component analysis (PCA) was applied to the results obtained by spectrophotometric assays in order to group the samples according to the intensity of antioxidant activity. The samples were divided into two clusters, except for three separated samples. A similar phenolic profile of S. tectorum leaves extracts obtained by HPTLC was observed. Kaempferol and kaempferol 3-O-glucoside, gallic and caffeic acids as well as the quercetin 3-O-glucoside have been identified in houseleek leaves extracts.",
journal = "58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings",
title = "Spectrophotometric determination of total phenolic content and antioxidant capacity of houseleek leaf extracts (Sempervivum tectorum L.) and phenolic profile",
url = "https://hdl.handle.net/21.15107/rcub_cherry_6212"
}

Jankov, M., Ristivojević, P., Trifković, J., Cvijetić, I.,& Milojković-Opsenica, D.. (2022). Spectrophotometric determination of total phenolic content and antioxidant capacity of houseleek leaf extracts (Sempervivum tectorum L.) and phenolic profile. in 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings.
https://hdl.handle.net/21.15107/rcub_cherry_6212

Jankov M, Ristivojević P, Trifković J, Cvijetić I, Milojković-Opsenica D. Spectrophotometric determination of total phenolic content and antioxidant capacity of houseleek leaf extracts (Sempervivum tectorum L.) and phenolic profile. in 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings. 2022;.
https://hdl.handle.net/21.15107/rcub_cherry_6212 .

Jankov, Milica, Ristivojević, Petar, Trifković, Jelena, Cvijetić, Ilija, Milojković-Opsenica, Dušanka, "Spectrophotometric determination of total phenolic content and antioxidant capacity of houseleek leaf extracts (Sempervivum tectorum L.) and phenolic profile" in 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 9th-10th June, 2022. In: Book of Abstracts and Proceedings (2022),
https://hdl.handle.net/21.15107/rcub_cherry_6212 .

TY  - CONF
AU  - Ivković, Đurđa
AU  - Lazović, Mila
AU  - Jankov, Milica
AU  - Ristivojević, Petar
PY  - 2022
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6223
AB  - Propolis is a resinous substance collected by honeybees (Apis mellifera L.) from
different plant parts such as branches, plant buds, leaves, and exudates partially digested
by β-glycosidase from bees’ saliva, and after that mixed with beeswax. It is commonly
used in folk medicine to prevent and treat colds, ulcers, rheumatism, diabetes, and dental
caries. Commercially available products most often comprise ethanolic extracts of
propolis. However, high alcohol content and strong residual flavour make such products
unsuitable for patients intolerant to alcohol, especially children. Due to mentioned
drawbacks, propylene glycolic, aqueous, fructose, or olive oil propolis extracts are
commonly found on the market as safer alternatives. These solvents are more appealing
options but the extraction efficiency is up to 10 times lower compared to ethanol. Thus,
there are high demands for the development of effective and ethanol-free extractions1,2
.
The overall aim of the study is to determine total phenolic, flavonoid content and radical
scavenging activity of high-quality and natural-based propolis extract enriched with
bioactives using new generation of solvents as Natural Deep Eutectic Solvents
(NADES)1
. Thirty-eight different green NADES have been used for the extraction of
phenols from poplar types of propolis. The NADES were prepared by mixing different
molar ratios of polycarboxylic acids, amino acids, glycerol, urea, potassium acetate,
choline chloride and ethylene glycol. The highest values of TPC, TFC, and DPPH were
obtained using following NADES systems: lactic acid/glycerol=1/1; lactic
acid/glycine=3/1; glycerol/proline=1/1; choline chloride/succinic acid=2/1 and choline
chloride/ethylene glycol=1/4.

References
1. V. Bankova, B. Trusheva & Milena Popova, J. Apic. Res. 2021, 60, 734.
2. L. Kubiliene, V. Laugaliene, A. Pavilonis, A. Maruska, D. Majiene, K. Barcauskaite,
BMC Complement. Altern. Med. 2015, 15, 1.

Acknowledgment
This work was supported by the Ministry of Education, Science and Technological
Development of the Republic of Serbia, Contract numbers: 451-03-68/2022-14/200168
and 451-03-68/2022-14/200288.
C3  - 8th Conference of Young Chemists of Serbia, Belgrade, Serbia, 29th October, 2022. In: Book of Abstracts
T1  - Total phenolic, flavonoid contents and radical scavenging activities of NADES- based propolis extracts
IS  - 35
UR  - https://hdl.handle.net/21.15107/rcub_cherry_6223
ER  - 

@conference{
author = "Ivković, Đurđa and Lazović, Mila and Jankov, Milica and Ristivojević, Petar",
year = "2022",
abstract = "Propolis is a resinous substance collected by honeybees (Apis mellifera L.) from
different plant parts such as branches, plant buds, leaves, and exudates partially digested
by β-glycosidase from bees’ saliva, and after that mixed with beeswax. It is commonly
used in folk medicine to prevent and treat colds, ulcers, rheumatism, diabetes, and dental
caries. Commercially available products most often comprise ethanolic extracts of
propolis. However, high alcohol content and strong residual flavour make such products
unsuitable for patients intolerant to alcohol, especially children. Due to mentioned
drawbacks, propylene glycolic, aqueous, fructose, or olive oil propolis extracts are
commonly found on the market as safer alternatives. These solvents are more appealing
options but the extraction efficiency is up to 10 times lower compared to ethanol. Thus,
there are high demands for the development of effective and ethanol-free extractions1,2
.
The overall aim of the study is to determine total phenolic, flavonoid content and radical
scavenging activity of high-quality and natural-based propolis extract enriched with
bioactives using new generation of solvents as Natural Deep Eutectic Solvents
(NADES)1
. Thirty-eight different green NADES have been used for the extraction of
phenols from poplar types of propolis. The NADES were prepared by mixing different
molar ratios of polycarboxylic acids, amino acids, glycerol, urea, potassium acetate,
choline chloride and ethylene glycol. The highest values of TPC, TFC, and DPPH were
obtained using following NADES systems: lactic acid/glycerol=1/1; lactic
acid/glycine=3/1; glycerol/proline=1/1; choline chloride/succinic acid=2/1 and choline
chloride/ethylene glycol=1/4.

References
1. V. Bankova, B. Trusheva & Milena Popova, J. Apic. Res. 2021, 60, 734.
2. L. Kubiliene, V. Laugaliene, A. Pavilonis, A. Maruska, D. Majiene, K. Barcauskaite,
BMC Complement. Altern. Med. 2015, 15, 1.

Acknowledgment
This work was supported by the Ministry of Education, Science and Technological
Development of the Republic of Serbia, Contract numbers: 451-03-68/2022-14/200168
and 451-03-68/2022-14/200288.",
journal = "8th Conference of Young Chemists of Serbia, Belgrade, Serbia, 29th October, 2022. In: Book of Abstracts",
title = "Total phenolic, flavonoid contents and radical scavenging activities of NADES- based propolis extracts",
number = "35",
url = "https://hdl.handle.net/21.15107/rcub_cherry_6223"
}

Ivković, Đ., Lazović, M., Jankov, M.,& Ristivojević, P.. (2022). Total phenolic, flavonoid contents and radical scavenging activities of NADES- based propolis extracts. in 8th Conference of Young Chemists of Serbia, Belgrade, Serbia, 29th October, 2022. In: Book of Abstracts(35).
https://hdl.handle.net/21.15107/rcub_cherry_6223

Ivković Đ, Lazović M, Jankov M, Ristivojević P. Total phenolic, flavonoid contents and radical scavenging activities of NADES- based propolis extracts. in 8th Conference of Young Chemists of Serbia, Belgrade, Serbia, 29th October, 2022. In: Book of Abstracts. 2022;(35).
https://hdl.handle.net/21.15107/rcub_cherry_6223 .

Ivković, Đurđa, Lazović, Mila, Jankov, Milica, Ristivojević, Petar, "Total phenolic, flavonoid contents and radical scavenging activities of NADES- based propolis extracts" in 8th Conference of Young Chemists of Serbia, Belgrade, Serbia, 29th October, 2022. In: Book of Abstracts, no. 35 (2022),
https://hdl.handle.net/21.15107/rcub_cherry_6223 .

TY  - CONF
AU  - Jankov, Milica
AU  - Cvijetić, Ilija
AU  - Milojković-Opsenica, Dušanka
PY  - 2022
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6213
AB  - Previously, we identified kaempferol, quercetin and their 3-O-glycosides as potent antioxidants in methanolic extract of houseleek (Sempervivum tectorum) leaves using the High-Performance Thin-Layer Chromatography (HPTLC) and DPPH· (2,2-diphenyl-1-picrylhydrazyl) derivatization. Herein, we report bond dissociation enthalpies (BDEs) and ionization potentials (IPs) of these compounds calculated using Density Functional Theory (DFT) with M06-2X functional and 6-31+G(d,p) basis set in the gas phase and SMD models of water (physiological medium) and pentyl ethanoate (simulated lipid environment). BDEs and IPs map the thermodynamic feasibility of hydrogen atom transfer (HAT) and single electron transfer followed by proton transfer (SET-PT), two common mechanisms how small molecules quench reactive free radicals. 
The HAT is a favorable antioxidant mechanism for all studied compounds in both solvents. The lowest BDE of 76.64 kcal/mol was found for 3’–OH group of quercetin, which is comparable with BDE for resveratrol. Glycosylation in the 3’-position of flavone ring blocks this antioxidant hotspot, increases the IP by 3-7 kcal/mol in all media, and negligibly influences the activity of –OH groups on A and B rings. This result corroborates previous results on the antioxidant activity of S. tectorum leaf juice obtained by EPR spectroscopy [1].
C3  - 1-EuSPMF Book of Abstracts
T1  - DFT study of the antioxidant activity of polyhydroxyflavones identified in houseleek leaf extracts
UR  - https://hdl.handle.net/21.15107/rcub_cherry_6213
ER  - 

@conference{
author = "Jankov, Milica and Cvijetić, Ilija and Milojković-Opsenica, Dušanka",
year = "2022",
abstract = "Previously, we identified kaempferol, quercetin and their 3-O-glycosides as potent antioxidants in methanolic extract of houseleek (Sempervivum tectorum) leaves using the High-Performance Thin-Layer Chromatography (HPTLC) and DPPH· (2,2-diphenyl-1-picrylhydrazyl) derivatization. Herein, we report bond dissociation enthalpies (BDEs) and ionization potentials (IPs) of these compounds calculated using Density Functional Theory (DFT) with M06-2X functional and 6-31+G(d,p) basis set in the gas phase and SMD models of water (physiological medium) and pentyl ethanoate (simulated lipid environment). BDEs and IPs map the thermodynamic feasibility of hydrogen atom transfer (HAT) and single electron transfer followed by proton transfer (SET-PT), two common mechanisms how small molecules quench reactive free radicals. 
The HAT is a favorable antioxidant mechanism for all studied compounds in both solvents. The lowest BDE of 76.64 kcal/mol was found for 3’–OH group of quercetin, which is comparable with BDE for resveratrol. Glycosylation in the 3’-position of flavone ring blocks this antioxidant hotspot, increases the IP by 3-7 kcal/mol in all media, and negligibly influences the activity of –OH groups on A and B rings. This result corroborates previous results on the antioxidant activity of S. tectorum leaf juice obtained by EPR spectroscopy [1].",
journal = "1-EuSPMF Book of Abstracts",
title = "DFT study of the antioxidant activity of polyhydroxyflavones identified in houseleek leaf extracts",
url = "https://hdl.handle.net/21.15107/rcub_cherry_6213"
}

Jankov, M., Cvijetić, I.,& Milojković-Opsenica, D.. (2022). DFT study of the antioxidant activity of polyhydroxyflavones identified in houseleek leaf extracts. in 1-EuSPMF Book of Abstracts.
https://hdl.handle.net/21.15107/rcub_cherry_6213

Jankov M, Cvijetić I, Milojković-Opsenica D. DFT study of the antioxidant activity of polyhydroxyflavones identified in houseleek leaf extracts. in 1-EuSPMF Book of Abstracts. 2022;.
https://hdl.handle.net/21.15107/rcub_cherry_6213 .

Jankov, Milica, Cvijetić, Ilija, Milojković-Opsenica, Dušanka, "DFT study of the antioxidant activity of polyhydroxyflavones identified in houseleek leaf extracts" in 1-EuSPMF Book of Abstracts (2022),
https://hdl.handle.net/21.15107/rcub_cherry_6213 .