Search results

1

The composition of pigments in relation to seasonal blooms of phytoplankton in the Gulf of Gdansk

100%

Lotocka M., Falkowski L.

Oceanological Studies

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1994

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issue 67/10

65-72

EN

Carotenoid pigments have been identified anf qualified in samples collected during phytoplankton blooms in teh Gulf of Gdansk.The qualitative and quantitative determination of pigments have been performed by HPLC technique.The results were compared with those obtained by conventional, spectrophotometric methods applied to the same smples.

2

Simultaneous determination of retinol, retinyl palmitate and β-carotene in rat serum treated with 7,12-dimethylbenz[a]anthracene and Hypericum Perforatum L. by high-performance liquid chromatography with diode-array detection

80%

Levent A., Ekin S., Oto G.

Open Chemistry

|

2010

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vol. 8

|

issue 1

108-115

EN

A new and simple high-performance liquid chromatography method was developed and validated for the simultaneous determination of retinol, retinyl palmitate and β-carotene in rat serum treated with Hypericum Perforatum L. and 7,12-dimethylbenz[a]anthracene. Furthermore, vitamin C was determined spectrophotometrically. High-performance liquid chromatography analysis was performed utilizing an Inertsil ODS3 reversed phase column with methanol-acetonitrile-tetrahydrofuran (65:30:5, v/v/v) as mobile phase, at a flow rate of 1.5 mL min−1 and 40°C. Diode-array detection was conducted at 325 and 450 nm for retinol and retinyl palmitate, and β-carotene, respectively with a running time of 26 min. The high-performance liquid chromatography assay and extraction procedure proposed are simple, rapid, sensitive and accurate. This method was then applied to determine the amounts of retinol, retinyl palmitate and β-carotene in rat serum. Results of this study demonstrated that at 60th day in the 7,12-dimethylbenz[a]anthracene-treated group there was a significant decrease (pa] anthracene + Hypericum Perforatum L. treated group compared to the control group.. [...]

3

Phenolic profile, chemical relationship and antioxidant activity of Iranian Verbascum species

80%

Jamshidi-Kia F., Saeidi K., Lorigooini Z., Maggi F., Jamshidi-Kia F., Saeidi K., Lorigooini Z., Maggi F.

Acta Biologica Cracoviensia s. Botanica

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2020

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vol. 62

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issue 2

4

Variations in xanthophyll composition in etiolated seedlings of Arabidopsis thaliana correlate with protochlorophyllide accumulation

80%

Myśliwa-Kurdziel B., Jemioła-Rzemińska M., Turek E., Strzałka K., Malec P.

|

2012

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vol. 59

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issue 1

57-60

EN

Protochlorophyllide (Pchlide) accumulation and xantophyll composition were studied in 5-day old etiolated seedlings of three ecotypes of Arabidopsis thaliana: Columbia (Col-0), Landsberg erecta (Ler) and Wassiliewska (Ws). The total Pchlide level as measured by fluorescence spectroscopy varied significantly between ecotypes. A rapid HPLC method revealed quantitative differences in carotenoid composition. It was found that in the Ler ecotype any enhanced accumulation of Pchlide correlates with an increased level of lutein, suggesting the role of enzymes involved in lutein synthesis in cross-regulation between chlorophyll and carotenoid biosynthetic pathways. The function of the dark-accumulated carotenoid pool in seedling de-etiolation is discussed.

5

Free fatty acids concentration in the Baltic Sea surface waters

80%

Pazdro K.

Oceanological Studies

|

1996

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vol. 25

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issue 3

25-38

EN

Free fatty acids concentrations and composition in dissolved and particulate fraction of the Baltic Sea surface waters (The Gulf of Gda?sk, the Gda?sk Deep and the Gotland Deep) and the Vistula waters were determined by means of fatty acids coumaryl esters HPLC analysis. Total concentrations of dissolved fatty acids were stated between 0.14 and 13 mg ?dm-3, whereas of particulate fatty acids between 16 and 50 mg ? dm-3. The concentrations depended strongly on the time and location of sampling. Palmitic acid was the dominant one in all inves-tigated samples. It was revealed that the total concentration as well as the percentage composi-tion of individual acids (especially polyunsaturated acids) in surface waters were related to the intensity of biological processes of the investigated area. The autochthonous phytoplankton blooms were the main source of fatty acids in the Baltic Sea surface waters.

6

Conditions for efficient induction and maintenance of callus cultures Vaccinium corymbosum var. Bluecrop and its accumulation of polyphenolic compounds

80%

Dembinska-Migas W., Luczkiewicz M., Migas P., Cisowski W.

Biotechnologia

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1998

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issue 2

174-185

EN

Zimmerman & Bromme and Schenk & Hildebrandt media with unchanged content of plant growth regulators in the basic medium, were used to develop the optimum conditions for efficient production of callus tissue of Vaccinium corymbosum var. Bluecrop. It has been determined that, of the auxins used, it was 2,4-D which has the most beneficial effect on callus tissue growth. Zeatin was found to regulate the water content of the tissue obtained. Quercetin-3-O-glucoside, as well as quercetin-3-O-galactoside were identified and analysed quantitatively in the callus tissue from in vitro cultures. Moreover, the following phenolic acids were identified in the callus with the use of chromatography: ferulic acid, p-hydroxybenzoic acid, p-coumaric acid, as well as gallic acid and protocatechuic acid which were also analysed quantitatively in the researched tissue material. Phytochemical monitoring of the propagated tissues for different production media (HPLC analysis) did not show any relationship between the plant growth regulators used and the analysed secondary metabolites.

7

Complexation of [2.2]paracyclophane with β- and γ-cyclodextrins studied by HPLC and NMR

80%

Dodziuk H., Bielejewska A., Schilf W., Ueda H.

Open Chemistry

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2011

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vol. 9

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issue 6

1056-1061

EN

The NMR spectra of [2.2]paracyclophane with β- or γ-cyclodextrin in DMF-d7 at room temperature do not show significant complexation, while HPLC of the complexes in mixed H2O:alcohol solvents demonstrate complexation with different stoichiometries. At 243 K in DMF solution the H3 and H5 NMR signals of γ-cyclodextrin (but not β) exhibit complexation-induced chemical shifts denoting complex formation. According to HPLC, at room temperature the [2.2]paracyclophane complex with β-cyclodextrin in 20% H2O:EtOH exhibits 1:2 stoichiometry with K 1 = 1×102 ± 2, K 2 = 9.0×104 ± 2×103 (K = 9×106) while that with γ-cyclodextrin in 50% H2O:MeOH exhibits 1:1 stoichiometry with K 1 = 4×103 ± 150 M−1. Thermodynamic parameters for both complexes have been estimated from the retention time temperature dependence. For the β-cyclodextrin complexation at 25°C ΔG 0CD is −39.7 kJ mol−1 while ΔH 0CD and ΔS 0CD are −88.2 kJ mol−1 and −0.16 kJ mol−1 K−1. For γ-cyclodextrin, the corresponding values are ΔG 0CD = −20.5 kJ mol−1, ΔH 0CD = −33.5 kJ mol−1 and ΔS 0CD = −0.04 kJ mol−1 K−1. [...]

8

Use of multivariate statistical techniques to optimize the separation of isoflavones by liquid chromatography

80%

Baranowska I., Magiera S., Baranowski J.

Open Chemistry

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2011

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vol. 9

|

issue 6

972-981

EN

The aim of this paper is to optimize and validate a high performance liquid chromatography (HPLC) method for separation and quantification of five isoflavones. A statistical central composite design was used to separate all peaks. These multivariate procedures were efficient in determining the optimal separation condition using resolution, capacity factor, asymmetry and number of theoretical plates. [...] The effective separation of the examined compounds was applied on a Develosil RP Aqueous AR 5 RP-30 column with a gradient mobile phase system and a DAD detector. The isolation and preconcentration of the isoflavones from urine and plasma samples were conducted by means of the solid-phase extraction (SPE). For optimize SPE conditions various sorbents were tested. Furthermore, high recoveries and good relative standard deviations were obtained when the samples were passed through the Oasis HLB column. The developed method was validated and successfully applied for determination of isoflavones in urine and plasma.

9

Improved HPLC method for total plasma homocysteine detection and quantification

80%

Sawuła W., Banecka-Majkutewicz Z., Kadziński L., Jakóbkiewicz-Banecka J., Węgrzyn G., Nyka W., Banecki B.

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2008

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vol. 55

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issue 1

119-126

EN

Recent clinical research has pointed at hyperhomocysteinemia as an independent risk factor in a number of cardiovascular and neurological diseases. We have improved a chromatographic method of total plasma homocysteine measurements in order to obtain higher sensitivity, reliability and reproducibility. The method demonstrates excellent linearity (R = 0.999), range (< 2-100 µM), precision (instrumental RSD 0.06 and method RSD 1.17), accuracy (recovery of 99.92 and RSD 1.27), reproducibility, quantification limit and ruggedness (e.g. pH from 2.0 to 2.5). Because even a small increase in homocysteine level can be a significant risk factor of cardiovascular diseases, such a precise method is required. The constructed method allows the measurement of plasma pyridoxal phosphate, PLP, the co-enzyme form of vitamin B6, on the same column and similar reagents. The developed method has been successfully applied to measure both total plasma and serum homocysteine in a group of acute stroke patients.

10

Changes in phytoplankton pigments composition during 2000 in different southern Baltic regions

80%

Ston J., Kosakowska A.

Oceanological Studies

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2002

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vol. 31

|

issue 1-2

75-89

EN

The results of differences in phytoplankton pigments composition are presented in this paper. Samples from the Southern Baltic taken during three cruises on r/v ?Oceania? (14.02 - 28.02.2000, 06.05 - 16.05.2000 and 20.09 - 01.10.2000) were examined. Qualification and quantification analyses of chlorophylls and carotenoids present in samples of naturally existing phytoplankton were based on the RP-HPLC technique. Seasonal and spatial variability in pigment characteristics was observed in the analysed seasons. Presence of: chlorophyll a, chlorophyll c1+c2, chlorophyll b, alloxanthin, zeaxanthin, fucoxanthin, peridinin, neoxanthin, diadinoxanthin - was noted in every season; violaxanthin and beta-carotene - only in May and September. Lutein was detected only in May samples. The quantity of May and September pigments exceeded 2-6 times the February pigments content. Vertical differentiation in the pigments amount was also noted. Spatial variability emphasized the influence of Vistula and Odra water masses. Different markers of phytoplankton species were found in each season: in February - cryptophytes (alloxanthin), May - diatoms (fucoxanthin) and September - cyanophytes and dinophytes (containing zeaxanthin and diadinoxanthin).

11

In vitro plant tissue cultures accumulate polyisoprenoid alcohols

80%

Skorupinska-Tudek K., Pytelewska A., Zelman-Femiak M., Mikoszewski J., Olszowska O., Gajdzis-Kuls D., Urbanska N., Syklowska-Baranek K., Hertel J., Chojnacki T., Swiezewska E.

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2007

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vol. 54

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issue 4

847-852

EN

In vitro cultivated plant cells and tissues were found to synthesize polyisoprenoids. Taxus baccata suspension cell cultures accumulated polyisoprenoids of the same pattern as the parental tissue; methyl jasmonate or chitosan treatment almost doubled their content. All the root cultures studied accumulated dolichols as predominant polyisoprenoids. Roots of Ocimum sanctum grown in vitro accumulated approx. 2.5-fold higher amount of dolichols than the roots of soil-grown plants. Dolichols dominated over polyprenols in all Triticum sp. tissues studied.

12

Ultrasound-assisted Matrix Solid Phase Dispersion for the HPLC-DAD analysis of amphenicols in shrimps

71%

Samanidou V. F., Makrygianni E. A.

Sample Preparation

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2014

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vol. 2

|

issue 1

EN

Ultrasound-assisted matrix solid phase dispersive extraction was applied for the selective isolation and clean-up of three amphenicol antibiotics, chloramphenicol (CAP), thiamphenicol (TAP) and florfenicol (FFC) from shrimp. The target antibiotics were separated on a LiChroCART-LiChrospher® 100 RP-18 (5 μm, 250 × 4 mm) analytical column in less than 9 min, with isocratic elution using a mixture of 70% ammonium acetate (0.05 M) and 30% acetonitrile (v/v). Matrix Solid Phase Dispersion protocol was optimized in terms of extraction sorbent and elution solvent. Two polymer based (Oasis and Nexus) sorbents and one silica based (Lichrolut C18) were compared and different elution solvents such as methanol, acetone, acetonitrile and isopropanol were evaluated based on the achieved recovery rates as well as on the cleanup efficiency. The extraction procedure was performed with and without sonication to evaluate the impact of ultrasounds. TAP and FFC were monitored at 234 nm and CAP at 280 nm by a photodiode array detector. The method was validated according to the European Union Decision 2002/657/EC in terms of linearity, selectivity, stability, accuracy, precision and sensitivity. Detection capability values (CCb) were 64.6 μg/kg for TAP and 1046.8 μg/kg for FFC and 63.8 μg/ kg for CAP.

13

Qualitative and quantitative analysis of gallic acid in Alchemilla vulgaris, Allium ursinum, Acorus calamus and Solidago virga-aurea by chip-electrospray ionization mass spectrometry and high performance liquid chromatography

71%

Condrat D., Mosoarca C., Zamfir A., Crişan F., Szabo M., Lupea A.

Open Chemistry

|

2010

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vol. 8

|

issue 3

530-535

EN

This study presents the results obtained from qualitative and quantitative analysis of gallic acid from hydro-alcoholic extracts (methanol, ethanol) of plants from Plantae regnum. Plant qualitative analysis was performed using a novel mass spectrometric (MS) method based on fully automated chip-nanoelectrospray ionization (nanoESI) high capacity ion trap (HCT) while quantitative analysis was carried out by high performance liquid chromatography (HPLC). These methods were applied to Alchemilla vulgaris - common lady’s-mantle (aerial part), Allium ursinum - bear’s garlic (leaves), Acorus calamus - common sweet flag (roots), Solidago virga-aurea - goldenrod (aerial part). Obtained results indicated that methanol extracts (96%, 80%) have a gallic acid content ranging between 0.0011–0.0576 mg mL−1 extract while the ethanol extracts (96%, 60%) exhibit a gallic acid concentration that varies between 0.0010–0.0182 mg mL−1 extract. [...]

14

New method for quantitative analysis of GD2 ganglioside in plasma of neuroblastoma patients

71%

Czaplicki D., Horwacik I., Kowalczyk A., Wieczorek A., Bolek-Marzec K., Balwierz W., Kozik A., Rokita H.

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issue 3

423-431

EN

Neuroblastoma, the most common extracranial solid tumour of childhood, is a malignancy of unknown origin and non-specific symptoms. One of the markers of the disease is GD2 ganglioside (disialoganglioside), which is abundantly expressed on the surface of neuroblastoma cells. Gangliosides are known to be shed by tumour cells and this phenomenon can be significant in cancer progression as they inhibit a number of immune responses both in vitro and in vivo. In search for novel markers useful in monitoring and prognosis of neuroblastoma, we developed and validated a new quantitative method of GD2 ganglioside analysis in human blood plasma. We evaluated the level of gangliosides in blood serum of 34 neuroblastoma patients using high-performance liquid chromatography. The technique was used to detect fluorescently labelled oligosaccharides derived from serum glycosphingolipids by enzymatic digestion with ceramide glycanase. The developed method allowed determination of GD2 concentrations at the picomole level and required only 40 µl of plasma, which should be particularly useful when the quantity of clinical material is limiting. Moreover, this method can be applied to study concentration of other gangliosides, as shown for GD3 ganglioside. Analysis of plasma samples from the 34 neuroblastoma patients did not reveal any correlations between the concentration of GD2 ganglioside and clinical parameters, including the results of therapy; it showed, however, that the concentration of GD2 ganglioside in the plasma of neuroblastoma patients decreased substantially in the course of treatment.

15

Nuclear Targeting Study of HPMA Copolymer-5-Fluorouracil Conjugate Based on the Subcellular Distribution in PC-3 Cells

71%

You L., Dai S., Huang Y., Ye L., Fu C.

Acta Poloniae Pharmaceutica - Drug Research

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2019

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vol. 76

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issue 2

205-213

EN

In recent decades, a large number of targeting drug delivery systems have been designed and evaluated for cancer therapy. An important part of these studies is to monitor the subcellular fate of macromolecules. Fluorescence labeling technique was the most adopted method. However, it had the disadvantages of alteration the properties of drugs as well as artifactual redistribution of ﬂuorescent markers caused by ﬁxation. In the present study, a more accurate method, HPLC analysis preceded by subcellular fractionation was developed and validated to study the distribution of a newly synthesized tumor cell targeting drug delivery system, HPMA copolymer-5-FU conjugates (P-FU) in PC-3 cells. P-FU was proved to accumulate more in nuclei than free 5-FU, whose concentration in the culture medium was approximately 1/20 that of 5-FU when attaining similar nucleus drug concentration. On the contrary, the overwhelming majority of drugs accumulated in nonnucleus when PC-3 cells were treated with free 5-FU. These results indicated that P-FU had nuclear targeting effect. The developed procedure allows an accurate subcellular fate screening for many macromolecules.

16

Development and validation of analytical method for assessment of calcium dobesilate in varied hydrogel compositions

71%

Lisik A., Pilch E., Słowiak L., Musiał W.

Acta Poloniae Pharmaceutica - Drug Research

|

2018

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vol. 75

|

issue 4

843-849

EN

Standardized analytical methods for testing pharmaceutical preparations are not readily available in the literature for calcium dobesilate hydrogels. The aim of the study was to develop and validate analytical method for methylcellulose gel containing calcium dobesilate as an active ingredient. Samples from dissolution experiments were assessed via HPLC with UV-VIS detector. The optimal composition of mobile phase included acetonitrile with water 1:1, acidified to 2.5 pH value. The applied column was Standard Purospher Star 18e 250 x 4.6 (5µm), and the maximum wavelength was set on 240 nm, at 25 °C. The total run time of analysis was set at 5 min and acquired retention time was 2.7 and 3.1 min for calcium dobesilate depending on the hydrogel formulation. Validity study of the method revealed that all obtained calibration curves showed good linearity (r2 > 0.9927). Linearity (100% level) was found to be 99.42, 100.12, 99.48, 99.89, 100.70, 100.08, 99.82, 100.23 for A, B, C, D, E, F, G and H formulation, respectively. Accuracy was in the range of 98-102% on three different spike levels for all eight formulations. Precision results was around 100% with RSD lower than 1% in all cases indicating that the method can be used as a validated method. Limit of quantitation (LOQ) was found to be 13.25 μg∙ml-1 for all eight formulations. The method is feasible for evaluation of hydrophilic gels with calcium dobesilate.

17

New HPLC method for in vitro dissolution study of antihypertensive mixture amlodipine and perindopril using an experimental design

71%

Gumieniczek A., Mączka P., Inglot T., Pietraś R., Lewkut E., Perczak K.

Open Chemistry

|

2013

|

vol. 11

|

issue 5

717-724

EN

A new HPLC method was developed for the determination of amlodipine and perindopril in their binary mixture as a part of a routine control of combined formulations. For the first time an HPLC method was used for an in vitro dissolution study of tablets containing the above drugs. The presented method was validated to meet official requirements and this validation included specificity, stability, linearity, precision and accuracy. Chromatography was carried out using a LiChrospher RP-18 column, a mixture containing acetonitrile and phosphate buffer of pH 3.0 (50:50, v/v) as mobile phase and UV detection at 225 nm. The dissolution test was performed using 900 mL of phosphate buffer at pH 5.5 containing 1% cetylpyridini chloride (CPC) at 37°C and 75 rpm, using the paddle method. Robustness procedure was done according to the plan defined by the Plackett-Burman design. The effects of acetonitrile content, pH of the buffer and flow rate of the mobile phase, column temperature, pH and CPC content in the dissolution medium as well as rotation speed of the paddle were considered. After that, both graphical and statistical methods were used for identification of significant and non-significant effects. [...]

18

Differences in the pharmacokinetics of flumequine after single and continuous oral administration in non-fasted broiler chickens

71%

Madej-Śmiechowska H., Orzoł A., Jasiecka-Mikołajczyk A., Ziółkowski H., Jaroszewski J. J.

Polish Journal of Veterinary Sciences

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2018

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vol. 21

|

issue 3

19

Simultaneous chiral separation and determination of carvedilol and 5′-hydroxyphenyl carvedilol enantiomers from human urine by high performance liquid chromatography coupled with fluorescent detection

71%

Magiera S., Adolf W., Baranowska I.

Open Chemistry

|

2013

|

vol. 11

|

issue 12

2076-2087

EN

A sensitive and specific high performance liquid chromatography coupled with fluorescent detection (HPLC-FL) and tandem mass spectrometry detection (HPLC-MS/MS) methods for separation and determination of carvedilol (CAR) enantiomers and 5′-hydroxyphenyl carvedilol (5′-HCAR) enantiomers has been developed and validated. The analysed compounds were extracted from human urine by solid phase extraction. Good enantioseparation of the studied enantiomers was achieved on CHIRALCEL® OD-RH column using 0.05% trifluoroacetic acid and 0.05% diethylamine in water and acetonitrile in a gradient elution. The mass spectrometric data were acquired using the multiple reaction monitoring mode by positive electrospray ionisation. The method was validated over the concentration range from 25.0 ng mL−1 to 200 ng mL−1 for the analysed compounds. The limit of quantification varied from 14.2 ng mL−1 to 24.2 ng mL−1. Both the repeatability and inter-day precisions were below 10.0%, and the accuracy varied from −13.2% to 3.77%. The extraction recoveries ranged from 79.2% to 108%. The present paper reports the method for the simultaneous determination of CAR enantiomers and their metabolite enantiomers (5′-HCAR) in human urine samples. This newly developed method was successfully used to analyse the aforementioned analytes in human urine samples obtained from patients suffering from cardiovascular disease. [...]

20

Dietary intake of specific phenolic compounds and their effect on the antioxidant activity of daily food rations

71%

Koch W., Baj T., Kukula-Koch W., Marzec Z.

Open Chemistry

|

2015

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vol. 13

|

issue 1

EN

The determination of phenolic acids’ and flavonoids’ content in daily food rations (DFRs) of a selected group of male and female students and the development of chromatographic conditions is the primary goal of the study. The presence of 7 phenolic components were confirmed in the prepared extracts from all diets reconstructed within a period of 3 years. The highest concentrations were determined for hesperidin (124 and 55.6 mg for women and men, respectively), naringin (47.6 mg in female and 37 mg in male diets) and chlorogenic acid (19.7 and 19.8 mg for women and men). The antioxidant potential of the daily food rations, measured with a DPPH test, was higher for women (range 47.1‒78.8%) than for men (range 34.5‒78.0%) and was found to strongly correlate with the total phenolics content of the samples (Folin-Ciocalteu test) (correlation coefficient 0.90).

Refine search results

The composition of pigments in relation to seasonal blooms of phytoplankton in the Gulf of Gdansk

Simultaneous determination of retinol, retinyl palmitate and β-carotene in rat serum treated with 7,12-dimethylbenz[a]anthracene and Hypericum Perforatum L. by high-performance liquid chromatography with diode-array detection

Phenolic profile, chemical relationship and antioxidant activity of Iranian Verbascum species

Variations in xanthophyll composition in etiolated seedlings of Arabidopsis thaliana correlate with protochlorophyllide accumulation

Free fatty acids concentration in the Baltic Sea surface waters

Conditions for efficient induction and maintenance of callus cultures Vaccinium corymbosum var. Bluecrop and its accumulation of polyphenolic compounds

Complexation of [2.2]paracyclophane with β- and γ-cyclodextrins studied by HPLC and NMR

Use of multivariate statistical techniques to optimize the separation of isoflavones by liquid chromatography

Improved HPLC method for total plasma homocysteine detection and quantification

Changes in phytoplankton pigments composition during 2000 in different southern Baltic regions