Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 5

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Influence of 2,5-dichloro-1,4-benzoquinone on jack bean urease activity. Inhibitory effect, total reducing capacity and DPPH radical scavenging activity

100%
Kot M., Olech Z.
Acta Biochimica Polonica
|
2011
|
tom 58
|
nr 4
Inhibition of jack bean activity by 2,5-dichloro-1,4-benzoquinone (DCBQ) was studied in phosphate buffer, pH 7.0. It was found that DCBQ acted as a strong, time and concentration dependent inactivator of urease. Under the experimental conditions obeyed the terms of pseudo-first-order reaction, urease was totally inactivated. Application of Wilson-Kitz method proved that the urease-DCBQ interaction followed a simple bimolecular process and the presence of intermediate complex was undetectable. The determined second order rate constant of the inactivation was 0.053 (μM min)-1. Thiols such as l-cysteine, glutathione and dithiothreitol (DTT) protected urease from inhibition by DCBQ but DCBQ-modified urease did not regain its activity after DTT application. The thiol protective studies indicated an essential role of urease thiol(s) in the inhibition. The irreversibility of the inactivation showed that the process was a result of a direct modification of urease thiol(s) by DCBQ (DCBQ chlorine(s) substitution). The decomposition of DCBQ in aqueous solution at natural light exposure was monitored by visible spectrophotometry, determination of the total reducing capacity (Folin-Ciocalteu method) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging ability. The DCBQ conversion resulted in a decrease of the inhibition power and was well correlated with the increase of the total reducing capacity and DPPH scavenging ability. These findings were attributed to DCBQ transformation by photolysis and the hydrolysis effect was found to be negligible.
2

Pojecie gospodarstwa rolnego oraz tryb nabywania nieruchomosci rolnych w swietle najnowszych zmian prawa cywilnego

100%
Olech Z., Skotarczak M.
Folia Universitatis Agriculturae Stetinensis. Oeconomica
|
2004
|
tom 43
51-57
3

Effect of thermal processing on antioxidant power and thiosulfinate content in Brussels sprouts juices

100%
Kot M., Olech Z.
Biotechnology and Food Science
|
2017
|
tom 81
|
nr 2
4
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

A spectrophotometric assay for total garlic thiosulfinates content. Kinetic aspects of reaction with chromogenic thiols

100%
Olech Z., Zaborska W.
Polish Journal of Food and Nutrition Sciences
|
2012
|
tom 62
|
nr 1
Garlic (Allium sativum) is a plant known for its antimicrobial, antithrombotic and antiatherosclerotic properties. Those features are attributed to thiosulfi nates, compounds formed in an enzymatic reaction occurring during garlic cloves crashing. A spectrophotometric method for the determination of thiosulfi nate concentration in garlic extracts and supplements was proposed. It is based on reactions between thiosulfi nates and selected chromogenic thiol compounds: 2-mercaptopyridine (2-MP), 4-mercaptopyridine (4-MP), 1-oxide-2-mercaptopyridine (MPO), 2-mercaptopyrimidine (MPM) and 2-nitro-5-thiobenzoic acid (NTB). Then kinetics of the reactions was studied. Rate constants and orders were determined. All reactions are fi rst order with respect to the thiol and fi rst order with respect to TS so the reactions of all tested thiols with garlic TS run in accordance with second order kinetics. Reaction rates vary among the thiol compounds: the constant rates differ from 6.7 (mol/L)-1.min-1 for 2-MP to 1129 (mol/L)-1.min-1 for NTB. Knowledge of the kinetic equation for the reactions and measurements of the initial rates allowed determining thiosulfi nate contents in garlic extracts and supplements.
5

Influence of walnut trees (Juglans regia L.) on soil urease activity (Short communication)

81%
Kot M., Bucki M., Olech Z.
Polish Journal of Agronomy
|
2020
|
tom 40
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.