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Composition of extraction products from alkylated high-sulphur coals

100%

Kozłowski M., Wachowska H., Yperman J.

Open Chemistry

2003

vol. 1

issue 4

366-386

Products of reductive and non-reductive methylation of two high-sulphur coals (Mequinenza and Illinois No. 6) have been extracted by dichloromethane. It has been established that the efficiency of the transformation of coal to the products soluble in CH2Cl2 is higher for coals subjected to non-reductive methylation by the Liotta method than for those after reduction in the potassium/liquid ammonia system. The extracts and the extraction residues were subjected to elemental analysis, IR spectroscopy, and AP-TPR (Atmospheric Pressure-Temperature Programmed Reduction) measurements. It has been shown that the main species undergoing extraction by CH2Cl2 are aliphatic compounds or aromatic structures of low degree of condensation. The effect of the extraction on the sulphur groups in coal has been discussed.

Quercetin influences BSA alpha-helical structures of native, ACR- and NaNO2-modified BSAs

86%

Rorbach-Dolata A., Żurawska-Płaksej E., Piwowar A.

Acta Poloniae Pharmaceutica - Drug Research

2018

vol. 75

issue 6

1339-1346

Quercetin (QUE) is a plant flavonoid with a multifarious spectrum of properties. It is a prominent component of the human diet, considered to be safe and beneficial for human health. Acrylamide (ACR) and sodium nitrate III (NaNO2) are also present in the diet and may demonstrate adverse and toxic effects on the macromolecules and tissues of the human organism. Albumin, the most abundant blood protein, is the most susceptible to the action of various exogenous factors, which may lead to structural damage and functional disturbances. The aim of this study was to estimate ACR- and NaNO2-induced changes in the secondary structure of bovine serum albumin (BSA), using circular dichroism (CD), and to determine the impact of quercetin on these modifications. BSA was incubated with ACR and NaNO2 solutions in the absence and presence of QUE in two different concentrations (3 mM and 500 µM), and changes in albumin alpha-helical structure were determined by CD. BSA secondary structure was vulnerable to alterations upon treatment with acrylamide and NaNO2, as well as quercetin. QUE, depending on concentration and incubation time, caused a decrease of around 13-19% in the alpha-helix content of BSA molecules, but also prevented the changes in the protein alpha-helical structure initiated by ACR and NaNO2. The most spectacular inhibition was revealed for QUE in lower concentrations after 24h of incubation with NaNO2. Although QUE reveals protective effect towards albumin modifications, it is difficult to unambiguously define whether this effect is advantageous, because quercetin itself causes alterations in BSA structure.

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1 Acta Poloniae Pharmaceutica - Drug Research

1 Open Chemistry

1 2018

1 2003

1 Kozłowski M.

1 Piwowar A.

1 Rorbach-Dolata A.

1 Wachowska H.

1 Yperman J.

1 Żurawska-Płaksej E.

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Composition of extraction products from alkylated high-sulphur coals

Quercetin influences BSA alpha-helical structures of native, ACR- and NaNO2-modified BSAs