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Mechanochemical and in-solution synthesis of caffeine complexes with α-, β-, and γ-cyclodextrins was optimized. It was found that short-duration, low-energy cogrinding, and evaporation (instead of freeze-drying) are effective methods for the formation and isolation of these complexes. The products obtained, their pure components, and their mixtures were examined by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), FT-IR and Raman spectroscopy. Moreover, molecular modeling provided an improved understanding of the association process between the guest and host molecules in these complexes. The complexes were found to exhibit high toxicity in zebrafish (Danio rerio) embryos, in contrast to pure caffeine and cyclodextrins at the same molar concentrations. HPLC measurements of the caffeine levels in zebrafish embryos showed that the observed cytotoxicity is not caused by an increased caffeine concentration in the body of the organism, as the concentrations are similar regardless of the administered caffeine form. Therefore, the observed high toxicity could be the result of the synergistic effect of caffeine and cyclodextrins.
Sebastian Szmeja; Tomasz Gubica; Andrzej Ostrowski; Aldona Zalewska; Łukasz Szeleszczuk; Katarzyna Zawada; Monika Zielińska-Pisklak; Krzysztof Skowronek; Małgorzata Wiweger. Caffeine-Cyclodextrin Complexes as Solids: Synthesis, Biological and Physicochemical Characterization. International Journal of Molecular Sciences 2021, 22, 4191 .
AMA StyleSebastian Szmeja, Tomasz Gubica, Andrzej Ostrowski, Aldona Zalewska, Łukasz Szeleszczuk, Katarzyna Zawada, Monika Zielińska-Pisklak, Krzysztof Skowronek, Małgorzata Wiweger. Caffeine-Cyclodextrin Complexes as Solids: Synthesis, Biological and Physicochemical Characterization. International Journal of Molecular Sciences. 2021; 22 (8):4191.
Chicago/Turabian StyleSebastian Szmeja; Tomasz Gubica; Andrzej Ostrowski; Aldona Zalewska; Łukasz Szeleszczuk; Katarzyna Zawada; Monika Zielińska-Pisklak; Krzysztof Skowronek; Małgorzata Wiweger. 2021. "Caffeine-Cyclodextrin Complexes as Solids: Synthesis, Biological and Physicochemical Characterization." International Journal of Molecular Sciences 22, no. 8: 4191.
High-pressure homogenization (HPH) is one of the food-processing methods being tested for use in food preservation as an alternative to pasteurization. The effects of the HPH process on food can vary depending on the process parameters used and product characteristics. The study aimed to investigate the effect of pressure, the number of passes, and the inlet temperature of HPH processing on the quality of cloudy blackcurrant juice as an example of food rich in bioactive compounds. For this purpose, the HPH treatment (pressure of 50, 150, and 220 MPa; one, three, and five passes; inlet temperature at 4 and 20 °C) and the pasteurization of the juice were performed. Titratable acidity, pH, turbidity, anthocyanin, vitamin C, and total phenolics content, as well as colour, and antioxidant activity were measured. Heat treatment significantly decreased the quality of the juice. For processing of the juice, the best were the combinations of the following: one pass, the inlet temperature of 4 °C, any of the used pressures (50, 150, and 220 MPa); and one pass, the inlet temperature of 20 °C, and the pressure of 150 MPa. Vitamin C and anthocyanin degradation have been reported during the HPH. The multiple passes of the juice through the machine were only beneficial in increasing the antioxidant capacity but negatively affected the colour stability.
Bartosz Kruszewski; Katarzyna Zawada; Piotr Karpiński. Impact of High-Pressure Homogenization Parameters on Physicochemical Characteristics, Bioactive Compounds Content, and Antioxidant Capacity of Blackcurrant Juice. Molecules 2021, 26, 1802 .
AMA StyleBartosz Kruszewski, Katarzyna Zawada, Piotr Karpiński. Impact of High-Pressure Homogenization Parameters on Physicochemical Characteristics, Bioactive Compounds Content, and Antioxidant Capacity of Blackcurrant Juice. Molecules. 2021; 26 (6):1802.
Chicago/Turabian StyleBartosz Kruszewski; Katarzyna Zawada; Piotr Karpiński. 2021. "Impact of High-Pressure Homogenization Parameters on Physicochemical Characteristics, Bioactive Compounds Content, and Antioxidant Capacity of Blackcurrant Juice." Molecules 26, no. 6: 1802.
The development of functional beverages often requires a compromise between the palatability and high content of bio-active compounds. The purpose of this study was to elaborate on the fruit-herbal beverages with defined pro-health functions and evaluate their consumer acceptance. The beverages contained 80% of juices obtained from the fruits of aronia, rugosa rose, acerola, sea buckthorn, and cranberry. Each beverage was supplemented with different plant extracts which enhanced the designed functions of the beverage. The beverages were sweetened with sugar or with steviol glycosides, and were preserved by thermal pasteurization. The main groups of bio-active compounds and antioxidant capacity using ABTS, DPPH, and ORAC methods were analysed before and after pasteurization. The sensory acceptance was tested by 60 adult consumers who assessed the desirability of taste, odour, colour, and overall quality. Each beverage contained substantial amounts of polyphenols, including anthocyanins; rosehip-acerola and sea buckthorn beverages were also sources of vitamin C and carotenoids. All these components were stable under thermal treatment. Rosehip-acerola beverages had the highest antioxidant capacity, which was measured using all three methods exhibited. The highest level of consumer acceptance and willingness to purchase went to aronia beverages, while the sea buckthorn gained the lowest. There was no significant difference between the acceptance of beverages sweetened with sugar and stevia. Women and the 25- to 34-year-old consumer group rated the overall acceptability of the beverages slightly higher, although this was not reflected in their inclination to buy them. Attitude toward proper body mass and health had no influence on overall acceptance and willingness to complete the purchases. The main motivation for purchasing the functional beverages was their sensory acceptance, even if the consumers were informed of their potential health benefits.
Sylwia Skąpska; Krystian Marszałek; Łukasz Woźniak; Justyna Szczepańska; Joanna Danielczuk; Katarzyna Zawada. The Development and Consumer Acceptance of Functional Fruit-Herbal Beverages. Foods 2020, 9, 1819 .
AMA StyleSylwia Skąpska, Krystian Marszałek, Łukasz Woźniak, Justyna Szczepańska, Joanna Danielczuk, Katarzyna Zawada. The Development and Consumer Acceptance of Functional Fruit-Herbal Beverages. Foods. 2020; 9 (12):1819.
Chicago/Turabian StyleSylwia Skąpska; Krystian Marszałek; Łukasz Woźniak; Justyna Szczepańska; Joanna Danielczuk; Katarzyna Zawada. 2020. "The Development and Consumer Acceptance of Functional Fruit-Herbal Beverages." Foods 9, no. 12: 1819.
Aronia fruits contain many valuable components that are beneficial to human health. However, fruits are characterized by significant variations in chemical composition dependent on the growing conditions and harvesting period. Therefore, there is a need to formulate the extracts with a precisely defined content of health-promoting substances. Aronia dry extracts (ADE) were prepared from frozen pomace applying water extraction, followed by purification and spray-drying. Subsequently, the content of anthocyanins, phenolic acids, and polyphenols was determined. The high-quality chokeberry pomace enabled obtaining extracts with anthocyanin content much higher than the typical market standards. Moreover, it was found that the antioxidant capacity of aronia extracts exceeded those found in other fruit preparations. Antioxidant and free-radical scavenging properties were evaluated using a 2,2′-diphenyl-1-picrylhydrazyl using Electron Paramagnetic Resonance (EPR) spectroscopy (DPPH-EPR) test and Oxygen Radical Absorbance Capacity (ORAC) assay. The inhibition of lipid peroxidation and the level of inflammatory markers have been also investigated using lipopolysaccharide (LPS)-stimulated RAW 264 cells. It was revealed that ADE standardized to 25% of anthocyanins depresses the level of markers of inflammation and lipid peroxidation (Interleukin 1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), and malondialdehyde (MDA)) in in vitro conditions. Additionally, it was confirmed that ADE at all analyzed concentrations did not show any cytotoxic effect as demonstrated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.
Mariusz Banach; Magdalena Wiloch; Katarzyna Zawada; Wojciech Cyplik; Wojciech Kujawski. Evaluation of Antioxidant and Anti-Inflammatory Activity of Anthocyanin-Rich Water-Soluble Aronia Dry Extracts. Molecules 2020, 25, 4055 .
AMA StyleMariusz Banach, Magdalena Wiloch, Katarzyna Zawada, Wojciech Cyplik, Wojciech Kujawski. Evaluation of Antioxidant and Anti-Inflammatory Activity of Anthocyanin-Rich Water-Soluble Aronia Dry Extracts. Molecules. 2020; 25 (18):4055.
Chicago/Turabian StyleMariusz Banach; Magdalena Wiloch; Katarzyna Zawada; Wojciech Cyplik; Wojciech Kujawski. 2020. "Evaluation of Antioxidant and Anti-Inflammatory Activity of Anthocyanin-Rich Water-Soluble Aronia Dry Extracts." Molecules 25, no. 18: 4055.
Katarzyna Rybicka-Jasińska; Katarzyna Orłowska; Maksymilian Karczewski; Katarzyna Zawada; Rota Gryko. Front Cover: Why Cyclopropanation is not Involved in Photoinduced α-Alkylation of Ketones with Diazo Compounds (Eur. J. Org. Chem. 47/2018). European Journal of Organic Chemistry 2018, 2018, 6598 -6598.
AMA StyleKatarzyna Rybicka-Jasińska, Katarzyna Orłowska, Maksymilian Karczewski, Katarzyna Zawada, Rota Gryko. Front Cover: Why Cyclopropanation is not Involved in Photoinduced α-Alkylation of Ketones with Diazo Compounds (Eur. J. Org. Chem. 47/2018). European Journal of Organic Chemistry. 2018; 2018 (47):6598-6598.
Chicago/Turabian StyleKatarzyna Rybicka-Jasińska; Katarzyna Orłowska; Maksymilian Karczewski; Katarzyna Zawada; Rota Gryko. 2018. "Front Cover: Why Cyclopropanation is not Involved in Photoinduced α-Alkylation of Ketones with Diazo Compounds (Eur. J. Org. Chem. 47/2018)." European Journal of Organic Chemistry 2018, no. 47: 6598-6598.
Diazo compounds are widely used reagents in organic synthesis. Direct photolysis leads to singlet carbenes while in the presence of a photosensitizer carbenes in the triplet state are generated. However, their reactivity under light irradiation remains poorly understood. Herein, we report photocatalytic, direct alkylation of enamines, generated from ketones, with diazo esters in the presence of free base porphyrins acting as photoredox catalysts. Based on the experimental and theoretical studies, we propose a plausible mechanism involving generation of an enamine radical cation that subsequently reacts with diazo compounds thus excluding the controversial cyclopropanation‐ring opening pathway.
Katarzyna Rybicka-Jasińska; Katarzyna Orłowska; Maksymilian Karczewski; Katarzyna Zawada; Dorota Gryko. Why Cyclopropanation is not Involved in Photoinduced α-Alkylation of Ketones with Diazo Compounds. European Journal of Organic Chemistry 2018, 2018, 6634 -6642.
AMA StyleKatarzyna Rybicka-Jasińska, Katarzyna Orłowska, Maksymilian Karczewski, Katarzyna Zawada, Dorota Gryko. Why Cyclopropanation is not Involved in Photoinduced α-Alkylation of Ketones with Diazo Compounds. European Journal of Organic Chemistry. 2018; 2018 (47):6634-6642.
Chicago/Turabian StyleKatarzyna Rybicka-Jasińska; Katarzyna Orłowska; Maksymilian Karczewski; Katarzyna Zawada; Dorota Gryko. 2018. "Why Cyclopropanation is not Involved in Photoinduced α-Alkylation of Ketones with Diazo Compounds." European Journal of Organic Chemistry 2018, no. 47: 6634-6642.
Sylwia Skąpska; Krystian Marszałek; Łukasz Woźniak; Katarzyna Zawada; Iwona Wawer. Aronia dietary drinks fortified with selected herbal extracts preserved by thermal pasteurization and high pressure carbon dioxide. LWT - Food Science and Technology 2017, 85, 423 -426.
AMA StyleSylwia Skąpska, Krystian Marszałek, Łukasz Woźniak, Katarzyna Zawada, Iwona Wawer. Aronia dietary drinks fortified with selected herbal extracts preserved by thermal pasteurization and high pressure carbon dioxide. LWT - Food Science and Technology. 2017; 85 ():423-426.
Chicago/Turabian StyleSylwia Skąpska; Krystian Marszałek; Łukasz Woźniak; Katarzyna Zawada; Iwona Wawer. 2017. "Aronia dietary drinks fortified with selected herbal extracts preserved by thermal pasteurization and high pressure carbon dioxide." LWT - Food Science and Technology 85, no. : 423-426.
The aim of this study was to evaluate the effect of repeated exposure (5 times for 15min) of 1800MHz radio-frequency radiation (RFR) on N-methyl-d-aspartate receptor subunit NR1 (NMDA-NR1) expression in the brains of rats in a persistent inflammatory state. We also measured the effect of RFR combined with tramadol (TRAM) to determine the potential antioxidant capacity of this agent.
Paweł Bodera; Katerina Makarova; Katarzyna Zawada; Bożena Antkowiak; Małgorzata Paluch; Elżbieta Sobiczewska; Bahriye Sirav; Andrzej K. Siwicki; Wanda Stankiewicz. The effect of 1800 MHz radio-frequency radiation on NMDA receptor subunit NR1 expression and peroxidation in the rat brain in healthy and inflammatory states. Biomedicine & Pharmacotherapy 2017, 92, 802 -809.
AMA StylePaweł Bodera, Katerina Makarova, Katarzyna Zawada, Bożena Antkowiak, Małgorzata Paluch, Elżbieta Sobiczewska, Bahriye Sirav, Andrzej K. Siwicki, Wanda Stankiewicz. The effect of 1800 MHz radio-frequency radiation on NMDA receptor subunit NR1 expression and peroxidation in the rat brain in healthy and inflammatory states. Biomedicine & Pharmacotherapy. 2017; 92 ():802-809.
Chicago/Turabian StylePaweł Bodera; Katerina Makarova; Katarzyna Zawada; Bożena Antkowiak; Małgorzata Paluch; Elżbieta Sobiczewska; Bahriye Sirav; Andrzej K. Siwicki; Wanda Stankiewicz. 2017. "The effect of 1800 MHz radio-frequency radiation on NMDA receptor subunit NR1 expression and peroxidation in the rat brain in healthy and inflammatory states." Biomedicine & Pharmacotherapy 92, no. : 802-809.
K. Makarova; K. Zawada; D. Wagner; J. Skowyra. Optimization of Antioxidant Properties of Creams with Berry Extracts by Artificial Neural Networks. Acta Physica Polonica A 2017, 132, 44 -51.
AMA StyleK. Makarova, K. Zawada, D. Wagner, J. Skowyra. Optimization of Antioxidant Properties of Creams with Berry Extracts by Artificial Neural Networks. Acta Physica Polonica A. 2017; 132 (1):44-51.
Chicago/Turabian StyleK. Makarova; K. Zawada; D. Wagner; J. Skowyra. 2017. "Optimization of Antioxidant Properties of Creams with Berry Extracts by Artificial Neural Networks." Acta Physica Polonica A 132, no. 1: 44-51.
K. Zawada; K. Makarova; D. Kowalska; I. Wawer. The Optimization of Antioxidant Properties of Herbal Bathing Salts. Acta Physica Polonica A 2017, 132, 56 -61.
AMA StyleK. Zawada, K. Makarova, D. Kowalska, I. Wawer. The Optimization of Antioxidant Properties of Herbal Bathing Salts. Acta Physica Polonica A. 2017; 132 (1):56-61.
Chicago/Turabian StyleK. Zawada; K. Makarova; D. Kowalska; I. Wawer. 2017. "The Optimization of Antioxidant Properties of Herbal Bathing Salts." Acta Physica Polonica A 132, no. 1: 56-61.
Metalloporphyrins are not only vital in biological systems but also valuable catalysts in organic synthesis. On the other hand catalytic properties of free base porphyrins are less explored. They are mostly known as efficient photosensitizers for the generation of singlet oxygen via photoinduced energy transfer processes but under light irradiation they can also participate in electron transfer processes. Indeed, we have found that free-base tetraphenylporphyrin (H2TPP) is an efficient photoredox catalyst for the reaction of aldehydes with diazo compounds leading to -alkylated derivatives. The performance of a porphyrin-catalyst can be optimized by tailoring various substituents at the periphery of the macrocycle at both the β- and meso-positions. This allows for the fine tuning of their optical and electrochemical properties, hence their catalytic activity.
Katarzyna Rybicka-Jasińska; Wenqian Shan; Katarzyna Zawada; Karl M. Kadish; Dorota Gryko. Porphyrins as Photoredox Catalysts: Experimental and Theoretical Studies. Journal of the American Chemical Society 2016, 138, 15451 -15458.
AMA StyleKatarzyna Rybicka-Jasińska, Wenqian Shan, Katarzyna Zawada, Karl M. Kadish, Dorota Gryko. Porphyrins as Photoredox Catalysts: Experimental and Theoretical Studies. Journal of the American Chemical Society. 2016; 138 (47):15451-15458.
Chicago/Turabian StyleKatarzyna Rybicka-Jasińska; Wenqian Shan; Katarzyna Zawada; Karl M. Kadish; Dorota Gryko. 2016. "Porphyrins as Photoredox Catalysts: Experimental and Theoretical Studies." Journal of the American Chemical Society 138, no. 47: 15451-15458.
Bisphenol A (BPA) acts as an endocrine-disrupting compound even at a low concentration. Degradation of BPA could lead to the formation of toxic products. In this study, we compare the toxicity of BPA and seven intermediate products of its degradation. The accuracy of three molecular docking programs (Surflex, Autodock, and Autodock Vina) in predicting the binding affinities of selected compounds to human (ERα, ERβ, and ERRγ) and zebrafish (ERα, ERRγA, and ERRγB) estrogen and estrogen-related receptors was evaluated. The docking experiments showed that 4-isopropylphenol could have similar toxicity to that of BPA due to its high affinity to ERRγ and ERRγB and high octanol–water partitioning coefficient. The least toxic compounds were hydroquinone and phenol. Those compounds as well as BPA were screened in the zebrafish (Danio rerio) embryo test. 4-isopropylphenol had the strongest toxic effect on zebrafish embryos and caused 100% lethality shortly after exposure. BPA caused the delay in development, multiple deformations, and low heartbeats (30 bps), whereas hydroquinone had no impact on the development of the zebrafish embryo. Thus, the results of zebrafish screening are in good agreement with our docking experiment. The molecular docking could be used to screen the toxicity of other xenoestrogens and their products of degradation.
Katerina Makarova; Pawel Siudem; Katarzyna Zawada; Justyna Kurkowiak. Screening of Toxic Effects of Bisphenol A and Products of Its Degradation: Zebrafish (Danio rerio) Embryo Test and Molecular Docking. Zebrafish 2016, 13, 466 -474.
AMA StyleKaterina Makarova, Pawel Siudem, Katarzyna Zawada, Justyna Kurkowiak. Screening of Toxic Effects of Bisphenol A and Products of Its Degradation: Zebrafish (Danio rerio) Embryo Test and Molecular Docking. Zebrafish. 2016; 13 (5):466-474.
Chicago/Turabian StyleKaterina Makarova; Pawel Siudem; Katarzyna Zawada; Justyna Kurkowiak. 2016. "Screening of Toxic Effects of Bisphenol A and Products of Its Degradation: Zebrafish (Danio rerio) Embryo Test and Molecular Docking." Zebrafish 13, no. 5: 466-474.
Oxidative DNA damage leads to abnormalities in endogenous cellular processes and constitutes a direct link between free radicals, antioxidants and squamous cell carcinoma (SCC). Oxygen radical absorbance capacity (ORAC) method is used to measure antioxidant capacity versus oxygen free radicals. There is no report on the application of ORAC to evaluate salivary antioxidant capacity in patients with head and neck SCC. This study investigated the relation between total antioxidant capacity of saliva, measured with ORAC method, and the incidence, location, size and histopathological grading of SCC.Salivary antioxidant capacity was assessed in 30 male and female patients with histopathologically confirmed oral and laryngeal SCC. Histopathological grading of SCC was based on WHO classification.Mean ORAC in patients with SCC was higher than the mean value in the control group. Statistically significant difference was observed in the study group versus the control group. No significant differences were observed for ORAC values in relation to histopathological grading, tumour size and spread to lymph nodes.The obtained results can advocate local compensatory mechanism in saliva in response to increased oxidative stress associated with primary tumour. ORAC can become an additional factor in head and neck SCC prognosis, but further investigation is required.
Piotr Wesołowski; Katarzyna Zawada; Andrzej Wojtowicz; Izabela Strużycka; Tomasz Kamiński. Assessment of salivary total antioxidant capacity in patients with primary untreated head and neck squamous cell carcinoma with ORAC. Journal of Oral Pathology & Medicine 2016, 45, 753 -757.
AMA StylePiotr Wesołowski, Katarzyna Zawada, Andrzej Wojtowicz, Izabela Strużycka, Tomasz Kamiński. Assessment of salivary total antioxidant capacity in patients with primary untreated head and neck squamous cell carcinoma with ORAC. Journal of Oral Pathology & Medicine. 2016; 45 (10):753-757.
Chicago/Turabian StylePiotr Wesołowski; Katarzyna Zawada; Andrzej Wojtowicz; Izabela Strużycka; Tomasz Kamiński. 2016. "Assessment of salivary total antioxidant capacity in patients with primary untreated head and neck squamous cell carcinoma with ORAC." Journal of Oral Pathology & Medicine 45, no. 10: 753-757.
Marek Wasek; Joanna Giebultowicz; Małgorzata Sochacka; Katarzyna Zawada; Wiktoria Modzelewska; Leszek M Krześniak; Piotr Wroczyński. THE MEASUREMENT OF ANTIOXIDANT CAPACITY AND POLYPHENOL CONTENT IN SELECTED FOOD SUPPLEMENTS. Acta Poloniae Pharmaceutica - Drug Research 2015, 72, 1 .
AMA StyleMarek Wasek, Joanna Giebultowicz, Małgorzata Sochacka, Katarzyna Zawada, Wiktoria Modzelewska, Leszek M Krześniak, Piotr Wroczyński. THE MEASUREMENT OF ANTIOXIDANT CAPACITY AND POLYPHENOL CONTENT IN SELECTED FOOD SUPPLEMENTS. Acta Poloniae Pharmaceutica - Drug Research. 2015; 72 (5):1.
Chicago/Turabian StyleMarek Wasek; Joanna Giebultowicz; Małgorzata Sochacka; Katarzyna Zawada; Wiktoria Modzelewska; Leszek M Krześniak; Piotr Wroczyński. 2015. "THE MEASUREMENT OF ANTIOXIDANT CAPACITY AND POLYPHENOL CONTENT IN SELECTED FOOD SUPPLEMENTS." Acta Poloniae Pharmaceutica - Drug Research 72, no. 5: 1.
Cookies are a group of convenient food products that are popular among consumers. They may contain high amounts of fats, which can be prone to oxidation. To retard the oxidative deterioration, synthetic and natural antioxidants may be added. Herb and spice extracts can be sources of natural biologically active substances with antioxidant activity. In this work, electron paramagnetic resonance spectroscopy was used to monitor the lipid oxidation in cookies with rosemary and thyme extracts subjected to the storage in elevated temperature. It was shown that thyme extract can be used as a natural antioxidant source for the preparation of bakery products, while the rosemary extract should be used with care in fat-rich products exposed to high temperatures.
Katarzyna Zawada; Mariola Kozłowska; Anna Żbikowska. Oxidative stability of the lipid fraction in cookies – the EPR study. Nukleonika 2015, 60, 469 -473.
AMA StyleKatarzyna Zawada, Mariola Kozłowska, Anna Żbikowska. Oxidative stability of the lipid fraction in cookies – the EPR study. Nukleonika. 2015; 60 (3):469-473.
Chicago/Turabian StyleKatarzyna Zawada; Mariola Kozłowska; Anna Żbikowska. 2015. "Oxidative stability of the lipid fraction in cookies – the EPR study." Nukleonika 60, no. 3: 469-473.
In the present work, we report the results of a spin trapping ESR study of four essential oils widely used for skin care products such as creams and bath salts. The studied essential oils are Rosmarini aetheroleum (rosemary), Menthae piperitae aetheroleum (mint), Lavandulae aetheroleum (lavender), and Thymi aetheroleum (thyme). Fenton reaction in the presence of ethanol was used to generate free radicals. The N-tert-butyl-α-phenylnitrone (PBN) was used as a spin trap. In the Fenton reaction, the rosemary oil had the lowest effect on radical adduct formation as compared to the reference Fenton system. Since essential oils are known to be lipid soluble, we also conducted studies of essential oils in Fenton reaction in the presence of lipids. Two model lipids were used, namely 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). The obtained results suggested that in the presence of DOPC lipids, the •OH and PBN/•CHCH3(OH) radicals are formed in both phases, that is, water and lipids, and all the studied essential oils affected the Fenton reaction in a similar way. Whereas, in the DPPC system, the additional type of PBN/X (aN = 16.1 G, aH = 2.9 G) radical adduct was generated. DFT calculations of hyperfine splittings were performed at B3LYP/6-311+G(d,p)/EPR-II level of theory for the set of c-centered PBN adducts in order to identify PBN/X radical.
Katerina Makarova; Kinga Drązikowska; Beata Suska; Katarzyna Zawada; Iwona Wawer. Spin trapping studies of essential oils in lipid systems. Nukleonika 2015, 60, 461 -468.
AMA StyleKaterina Makarova, Kinga Drązikowska, Beata Suska, Katarzyna Zawada, Iwona Wawer. Spin trapping studies of essential oils in lipid systems. Nukleonika. 2015; 60 (3):461-468.
Chicago/Turabian StyleKaterina Makarova; Kinga Drązikowska; Beata Suska; Katarzyna Zawada; Iwona Wawer. 2015. "Spin trapping studies of essential oils in lipid systems." Nukleonika 60, no. 3: 461-468.
We report the synthesis of well-defined silver nanoparticles with high antibacterial activity. Nitroxides on their surface may be oxidized under the influence of ROS to oxoammonium ions which are capable of interacting with bacterial membrane.
Magdalena Gozdziewska; Grzegorz Cichowicz; Katarzyna Markowska; Katarzyna Zawada; Elżbieta Megiel. Nitroxide-coated silver nanoparticles: synthesis, surface physicochemistry and antibacterial activity. RSC Advances 2015, 5, 58403 -58415.
AMA StyleMagdalena Gozdziewska, Grzegorz Cichowicz, Katarzyna Markowska, Katarzyna Zawada, Elżbieta Megiel. Nitroxide-coated silver nanoparticles: synthesis, surface physicochemistry and antibacterial activity. RSC Advances. 2015; 5 (72):58403-58415.
Chicago/Turabian StyleMagdalena Gozdziewska; Grzegorz Cichowicz; Katarzyna Markowska; Katarzyna Zawada; Elżbieta Megiel. 2015. "Nitroxide-coated silver nanoparticles: synthesis, surface physicochemistry and antibacterial activity." RSC Advances 5, no. 72: 58403-58415.
Vegetable oils are important constituents of a healthy diet. Still, unsaturated fatty acids present in vegetable oils are susceptible to oxidation, which leads to undesirable changes in sensory, chemical and nutritional properties of oils. To prevent this problem, antioxidants are applied with herbs and spices being one of the most important sources of natural antioxidants. Electron paramagnetic resonance spectroscopy (EPR) can be used to detect free radicals, which are the short-lived intermediates of lipid oxidation, and to monitor changes in oxidation susceptibility. In this study, the ESR spin trapping technique was used as a potential method for the evaluation of the resistance to free radical formation in rapeseed and sunflower oils enriched with herb extracts. The antioxidant effect of herb extracts on vegetable oils was also investigated by measuring their ability to scavenge DPPH free radical using EPR spectroscopy. The herb extracts generally improved the radical scavenging properties of sunflower and rapeseed oils but their influence on the onset of rapid lipid oxidation as measured by spin-trapping EPR depended on the type of oil and on the extract concentration.
Mariola Kozłowska; Katarzyna Zawada. Evaluation of oxidative stability of vegetable oils enriched with herb extracts by EPR spectroscopy. Chemical Papers 2015, 69, 1 .
AMA StyleMariola Kozłowska, Katarzyna Zawada. Evaluation of oxidative stability of vegetable oils enriched with herb extracts by EPR spectroscopy. Chemical Papers. 2015; 69 (7):1.
Chicago/Turabian StyleMariola Kozłowska; Katarzyna Zawada. 2015. "Evaluation of oxidative stability of vegetable oils enriched with herb extracts by EPR spectroscopy." Chemical Papers 69, no. 7: 1.
We propose a novel route for preparation of core–shell nanostructures based on the macroradicals coupling with nitroxides attached to the nanoparticle surface.
Katarzyna Zawada; Waldemar Tomaszewski; Elżbieta Megiel. A smart synthesis of gold/polystyrene core–shell nanohybrids using TEMPO coated nanoparticles. RSC Advances 2014, 4, 23876 -23885.
AMA StyleKatarzyna Zawada, Waldemar Tomaszewski, Elżbieta Megiel. A smart synthesis of gold/polystyrene core–shell nanohybrids using TEMPO coated nanoparticles. RSC Advances. 2014; 4 (45):23876-23885.
Chicago/Turabian StyleKatarzyna Zawada; Waldemar Tomaszewski; Elżbieta Megiel. 2014. "A smart synthesis of gold/polystyrene core–shell nanohybrids using TEMPO coated nanoparticles." RSC Advances 4, no. 45: 23876-23885.
Marta K Jamróz; Katarzyna Paradowska; Katarzyna Zawada; Katerina Makarova; Sławomir Kaźmierski; Iwona Wawer. 1 H and 13 C NMR-based sugar profiling with chemometric analysis and antioxidant activity of herbhoneys and honeys. Journal of the Science of Food and Agriculture 2013, 94, 246 -255.
AMA StyleMarta K Jamróz, Katarzyna Paradowska, Katarzyna Zawada, Katerina Makarova, Sławomir Kaźmierski, Iwona Wawer. 1 H and 13 C NMR-based sugar profiling with chemometric analysis and antioxidant activity of herbhoneys and honeys. Journal of the Science of Food and Agriculture. 2013; 94 (2):246-255.
Chicago/Turabian StyleMarta K Jamróz; Katarzyna Paradowska; Katarzyna Zawada; Katerina Makarova; Sławomir Kaźmierski; Iwona Wawer. 2013. "1 H and 13 C NMR-based sugar profiling with chemometric analysis and antioxidant activity of herbhoneys and honeys." Journal of the Science of Food and Agriculture 94, no. 2: 246-255.