Search

Your search keyword '"Pietrzak, Wioleta"' showing total 24 results
Start Over Author "Pietrzak, Wioleta"
24 results on '"Pietrzak, Wioleta"'

3. Effects of Supercritical Carbon Dioxide Extraction (SC-CO2) on the content of tiliroside in the extracts from Tilia L. flowers

Author

Pieczykolan Aleksandra, Pietrzak Wioleta, Rój Edward, and Nowak Renata

Subjects
sc-co2 extraction, tiliroside, flavonoids, linden extract, lc-esi-ms/ms, Chemistry, QD1-999
Abstract

Tiliroside is one of the main flavonoid compounds responsible for a wide spectrum of biological activity of Tilia L. Up to now, several extraction techniques have been reported for extracting this compound from Tilia L. In this work for the first time supercritical carbon dioxide extraction was used for this purpose. Experiments were performed using supercritical carbon dioxide with 5% and 10% of ethanol as solvent, aiming a recovery content of tiliroside, temperature from 45 to 80°C, pressure from 100 to 220 bar and time from 20 to 60 minutes. The statistically generated optimum extraction conditions to obtain the highest content of tiliroside were established as: pressure of 200 bar, temperature 65°C and 45-50 minutes for 5% ethanol concentration and pressure of 220 bar, temperature 65°C and 15 minutes for 10% ethanol concentration.

Published
2019
Full Text
View/download PDF

17. Eleutherococcus Species Cultivated in Europe: A New Source of Compounds with Antiacetylcholinesterase, Antihyaluronidase, Anti-DPPH, and Cytotoxic Activities

Author

Adamczyk, Kuba, primary, Olech, Marta, additional, Abramek, Jagoda, additional, Pietrzak, Wioleta, additional, Kuźniewski, Rafał, additional, Bogucka-Kocka, Anna, additional, Nowak, Renata, additional, Ptaszyńska, Aneta A., additional, Rapacka-Gackowska, Alina, additional, Skalski, Tomasz, additional, Strzemski, Maciej, additional, Sowa, Ireneusz, additional, Wójciak-Kosior, Magdalena, additional, Feldo, Marcin, additional, and Załuski, Daniel, additional

Published
2019
Full Text
View/download PDF

22. Effect of extraction method on phenolic content and antioxidant activity of mistletoe extracts from Viscum albumsubsp. abietis

Author

Pietrzak, Wioleta, Nowak, Renata, and Olech, Marta

Abstract

The total content of polyphenols and flavonoids determined in the same plant and their corresponding antioxidant activities may vary widely, depending on the extraction conditions applied. This study was conducted to optimise the extraction conditions of phenolics and flavonoids from the mistletoe plant. Various extraction methods, i.e. ultrasound-assisted extraction technology, maceration, maceration with stirring, accelerated solvent extraction (ASE), and extraction under reflux were evaluated for their percentage extraction of polyphenols (TPC) and flavonoids (TFC) from Viscum albumsubsp. abietis. In addition, the anti-radical activity of extracts was analysed using the 2,2-diphenyl-1-picrylhydrazyl method. The effects of temperature, solvent type, and concentration on the phenolic extraction efficiency and antioxidant activity were studied using chemometric and statistical methods. The results showed that the extracts of V. albumsubsp. abietiscontained large amounts of polyphenols and flavonoids (up to 57.673 mg g−1and 9.955 mg g−1of dry extract, respectively) and exhibited potent antioxidant activity, hence representing promising sources of powerful antioxidants. Due to its high extraction efficiency and considerable saving of time and solvent, ASE was more effective than the other extraction techniques. Extracts prepared with water-polar solvent mixtures displayed the highest TPC, TFC, and antioxidant activity, while organic polar solvents were the least efficient extractants.

Published
2014
Full Text
View/download PDF

23. Phenolic Acid LC/MS Profile of Chenopodium rubrumand Evaluation of Cytotoxic Activity

Author

Mynarski, Adam, Pietrzak, Wioleta, Galanty, Agnieszka, Dawiec, Emilia, Nowak, Renata, and Podolak, Irma

Abstract

The phenolic acids content of methanolic extracts before and after acidic hydrolysis of different morphological parts of Chenopodium rubrumwas determined by LC-ESI-MS/MS. Overall eleven phenolic acids were detected and quantified. The most common were p-coumaric, ferulic and salicylic acids, which were present in all analyzed extracts. Gallic, caffeic, vanillic, syringic and sinapic acids were found in bound forms. Gentisic acid was most abundant in roots (3.7 mg/100g d.w.), syringic acid in stalks (2.9 mg/100 g d.w.), ferulic acid in leaves (6.0 mg/100g d.w.), and protocatechuic acid in seeds (2.3 mg/100g d.w.). The highest concentration of examined acids was found in leaves (19.1 mg/100g d.w.) and roots (10.0 mg/100g d.w.). Cytotoxic activity of extracts was tested against human cancer cell lines HTB 140, WM 793, Du 145 and normal PNT2 cells. Only the seed extract showed activity against malignant melanoma WM 793 cell line (69.6 ± 0.7% of dead cells at 100 μg/mL).

Published
2018
Full Text
View/download PDF

24. HPTLC-densitometry determination of triterpenic acids in Origanum vulgare, Rosmarinus officinalis and Syzygium aromaticum.

Author

Nowak R, Wójciak-Kosior M, Sowa I, Sokołowska-Krzaczek A, Pietrzak W, Szczodra A, and Kocjan R

Subjects
Ursolic Acid, Chromatography, Thin Layer methods, Densitometry methods, Oleanolic Acid analysis, Origanum chemistry, Rosmarinus chemistry, Syzygium chemistry, Triterpenes analysis
Abstract

Spices play an important role in the chemoprevention and they can be a rich source of biologically active compounds such as triterpenes in the human diet. A method based on high performance thin-layer chromatography combined with densitometry for determination of ursolic and oleanolic acids in some common spices was elaborated. The prechromatographic derivatization with 1% of iodine solution was used to enable simultaneous analysis of these triterpenes. The extracts were separated on HPTLC silica gel 60 F254 plates with use of mobile phase consisting of toluene-petroleum ether-ethyl acetate-acetonitrile 5: 5: 1: 0.3 (v/v/v/v). After drying, the plates were sprayed with 10% (v/v) ethanol solution of sulfuric acid (VI) and heated to 120 degrees C for 3 min. Quantification was performed in fluorescence/reflectance mode at a wavelength of 400 nm using a computer-controlled densitometer Desaga CD 60.

Published
2013

Catalog

Books, media, physical & digital resources
See catalog results