Background/Aim. Tea and coffee are one of the most widely consumed beverages in the world due to ... more Background/Aim. Tea and coffee are one of the most widely consumed beverages in the world due to their beneficial health effects which are largely associated with their phenolic compounds composition, including chlorogenic acid. The main aim of this study was to determine 5-caffeoylquinic acid (5-CQA), as one of the major classes of chlorogenic acid, in various commercial tea and coffee samples present at the Serbian market. Methods. A high-performance liquid chromatography (HPLC) method for determination of 5-CQA in plant extracts was applied to determine the content of this active compound in commercial tea and coffee samples. Mobile phase was aqueous 1.5% acetic acid - methanol (80:20, v/v) with the flow rate of 0.8 mL/min. Run time was 15 min and column temperature 25?C. The detection was performed at 240 nm. Results. The HPLC method was modified and revalidated. The 5-CQA content varied depending on the type of tea (white, green, black tea and mate) and the processing technolog...
ABSTRACT Numerous traditional and clinically approved indications have created constant raise of ... more ABSTRACT Numerous traditional and clinically approved indications have created constant raise of demand for Hyperici herba in the world. However, the quality of the plant material depends on the plant source and abiotic factors of the habitats. The scope of the research was to find out whether other Hypericum species have similar chemical characteristics for potential medical use. Hypericum maculatum Crantz is in some Pharmacopoeias listed together with Hypericum perforatum L. as biological source of H. herba, because of similar chemical composition. Often the full taxonomic identification stating the used subspecies of H. maculatum is being avoided. Therefore, the aim of study was to chemically characterize water-alcoholic extracts of subspecies Hypericum maculatum Crantz subsp. maculatum. The samples were collected at three localities, with different habitat characteristics during three ontogenetic phases. The amounts of total phenolics and flavonoids were estimated, as well as the amounts of ferulic and chlorogenic acid, rutin, quercitrin, amentoflavone, apigenin, hypericin, and hyperforin. Chemical composition and ecological characteristics were analyzed by PCA methods. Source of sunlight and soil acidity were shown as ecological factors that potentially could be cause for chemical profiling of samples. Biological potential of extracts was estimated through antioxidant assays and inhibition of acetylcholinesterase (AChE) and α-amylase with the aim to explore potential use of plant in the treatments of diabetes and Alzheimer’s disease. All the extracts exhibited notable antioxidant potential in the used test systems as well as the ability to inhibit AChE and α-amylase. H. maculatum subsp. maculatum exhibits notable correspondence in chemical composition and biological activity with H. perforatum.
The chemical composition and antioxidant properties of the essential oil and EtOH extract of immo... more The chemical composition and antioxidant properties of the essential oil and EtOH extract of immortelle (Helichrysum italicum (Roth) G.Don subsp. italicum, Asteraceae) collected in Montenegro were evaluated. The essential oil was characterized by GC/MS analysis, and the content of total phenolics and flavonoids in the EtOH extract was determined using the FolinCiocalteu reagent. The free-radical-scavenging capacity (RSC) of both the essential oil and the EtOH extract was assessed with the 2,2-diphenyl-1-pycrylhydrazyl (DPPH) method. Moreover, the inhibition of hydroxyl radical ((.) OH) generation by the EtOH extract of immortelle was evaluated for the first time here. Neryl acetate (28.2%) and γ-curcumene (18.8%) were the main compounds in the essential oil, followed by neryl propionate (9.1%) and ar-curcumene (8.3%). The chemical composition of the oils of the examined and additional 16 selected Helichrysum italicum taxa described in literature were compared using principal compon...
ABSTRACT Seasonal variations of caffeine and antibiotic concentrations were investigated along th... more ABSTRACT Seasonal variations of caffeine and antibiotic concentrations were investigated along the selected sites of the Danube using solid phase extraction followed by HPLC (HPLC). The potential risks on the aquatic organisms were evaluated. HPLC methods for caffeine and antibiotic determination were modified and validated showing good accuracy, repeatability, selectivity and robustness. The obtained results confirmed the presence of caffeine at four sampling points, near the wastewater discharges.The mean caffeine concentrations for summer, autumn, winter and spring were 24.78, 26.83, 24.61, and 86.29 ng/L, respectively. The analysed antibiotics (sulfamethoxazole, chloramphenicol and tiamuline) were under the limit of detection in all tested samples taken from the Danube. The maximum risk indexes (MaxRIs) were calculated for caffeine at each sampling site. Four out of seven selected sampling sites showed sublethal effects on the aquatic organisms with 10 < MaxRI < 100 (class II), while the other three had no potential risk for aquatic organisms. The highest potential risk was calculated for the sampling site in the vicinity of one of the bigest wastewater discharges.
Chemical Industry and Chemical Engineering Quarterly, 2018
Given the increasing demand for potassium in Brazil, the mining and use of carnallite is becoming... more Given the increasing demand for potassium in Brazil, the mining and use of carnallite is becoming increasingly important, because the current source of potassium, sylvinite, is being depleted and there is a risk of shortages. Based on theoretical and practical data available in existing literature, this work describes the development, simulation, and economic feasibility of a process for dissolution and crystallization of potassium chloride from carnallite ore. Positive results were obtained following the application of the Hoffman diagram and determination of the corresponding equation. The proposed process provided over 85% potassium chloride crystallization, demonstrating its superior performance, compared to existing procedures.
Background/Aim. Tea and coffee are one of the most widely consumed beverages in the world due to ... more Background/Aim. Tea and coffee are one of the most widely consumed beverages in the world due to their beneficial health effects which are largely associated with their phenolic compounds composition, including chlorogenic acid. The main aim of this study was to determine 5-caffeoylquinic acid (5-CQA), as one of the major classes of chlorogenic acid, in various commercial tea and coffee samples present at the Serbian market. Methods. A high-performance liquid chromatography (HPLC) method for determination of 5-CQA in plant extracts was applied to determine the content of this active compound in commercial tea and coffee samples. Mobile phase was aqueous 1.5% acetic acid - methanol (80:20, v/v) with the flow rate of 0.8 mL/min. Run time was 15 min and column temperature 25?C. The detection was performed at 240 nm. Results. The HPLC method was modified and revalidated. The 5-CQA content varied depending on the type of tea (white, green, black tea and mate) and the processing technolog...
ABSTRACT Numerous traditional and clinically approved indications have created constant raise of ... more ABSTRACT Numerous traditional and clinically approved indications have created constant raise of demand for Hyperici herba in the world. However, the quality of the plant material depends on the plant source and abiotic factors of the habitats. The scope of the research was to find out whether other Hypericum species have similar chemical characteristics for potential medical use. Hypericum maculatum Crantz is in some Pharmacopoeias listed together with Hypericum perforatum L. as biological source of H. herba, because of similar chemical composition. Often the full taxonomic identification stating the used subspecies of H. maculatum is being avoided. Therefore, the aim of study was to chemically characterize water-alcoholic extracts of subspecies Hypericum maculatum Crantz subsp. maculatum. The samples were collected at three localities, with different habitat characteristics during three ontogenetic phases. The amounts of total phenolics and flavonoids were estimated, as well as the amounts of ferulic and chlorogenic acid, rutin, quercitrin, amentoflavone, apigenin, hypericin, and hyperforin. Chemical composition and ecological characteristics were analyzed by PCA methods. Source of sunlight and soil acidity were shown as ecological factors that potentially could be cause for chemical profiling of samples. Biological potential of extracts was estimated through antioxidant assays and inhibition of acetylcholinesterase (AChE) and α-amylase with the aim to explore potential use of plant in the treatments of diabetes and Alzheimer’s disease. All the extracts exhibited notable antioxidant potential in the used test systems as well as the ability to inhibit AChE and α-amylase. H. maculatum subsp. maculatum exhibits notable correspondence in chemical composition and biological activity with H. perforatum.
The chemical composition and antioxidant properties of the essential oil and EtOH extract of immo... more The chemical composition and antioxidant properties of the essential oil and EtOH extract of immortelle (Helichrysum italicum (Roth) G.Don subsp. italicum, Asteraceae) collected in Montenegro were evaluated. The essential oil was characterized by GC/MS analysis, and the content of total phenolics and flavonoids in the EtOH extract was determined using the FolinCiocalteu reagent. The free-radical-scavenging capacity (RSC) of both the essential oil and the EtOH extract was assessed with the 2,2-diphenyl-1-pycrylhydrazyl (DPPH) method. Moreover, the inhibition of hydroxyl radical ((.) OH) generation by the EtOH extract of immortelle was evaluated for the first time here. Neryl acetate (28.2%) and γ-curcumene (18.8%) were the main compounds in the essential oil, followed by neryl propionate (9.1%) and ar-curcumene (8.3%). The chemical composition of the oils of the examined and additional 16 selected Helichrysum italicum taxa described in literature were compared using principal compon...
ABSTRACT Seasonal variations of caffeine and antibiotic concentrations were investigated along th... more ABSTRACT Seasonal variations of caffeine and antibiotic concentrations were investigated along the selected sites of the Danube using solid phase extraction followed by HPLC (HPLC). The potential risks on the aquatic organisms were evaluated. HPLC methods for caffeine and antibiotic determination were modified and validated showing good accuracy, repeatability, selectivity and robustness. The obtained results confirmed the presence of caffeine at four sampling points, near the wastewater discharges.The mean caffeine concentrations for summer, autumn, winter and spring were 24.78, 26.83, 24.61, and 86.29 ng/L, respectively. The analysed antibiotics (sulfamethoxazole, chloramphenicol and tiamuline) were under the limit of detection in all tested samples taken from the Danube. The maximum risk indexes (MaxRIs) were calculated for caffeine at each sampling site. Four out of seven selected sampling sites showed sublethal effects on the aquatic organisms with 10 < MaxRI < 100 (class II), while the other three had no potential risk for aquatic organisms. The highest potential risk was calculated for the sampling site in the vicinity of one of the bigest wastewater discharges.
Chemical Industry and Chemical Engineering Quarterly, 2018
Given the increasing demand for potassium in Brazil, the mining and use of carnallite is becoming... more Given the increasing demand for potassium in Brazil, the mining and use of carnallite is becoming increasingly important, because the current source of potassium, sylvinite, is being depleted and there is a risk of shortages. Based on theoretical and practical data available in existing literature, this work describes the development, simulation, and economic feasibility of a process for dissolution and crystallization of potassium chloride from carnallite ore. Positive results were obtained following the application of the Hoffman diagram and determination of the corresponding equation. The proposed process provided over 85% potassium chloride crystallization, demonstrating its superior performance, compared to existing procedures.
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