Sodium salts of ethyl N,N-dimethyl- and N,N-dimethylamidophosphoric acids I and II were obtained and their hydrolysis to respective acids was investigated. The salts and acids were characterized by spectral methods (MS, FT/IR, 1H, 13C, 31P NMR).
Teratogenic effects of the anticonvulsant drug valproic acid (VPA) on the development of rat embryos during early stage of organogenesis were studied using whole embryo culture technique. Embryos with 0-3 somites were exposed in culture to 10, 50 and 100 μg/ml VPA. Growth and development were retarded in embryos exposed to 50 and 100 μg/ml. Drug induced anomalies included open neural tube, irregular somites, and asymmetrically enlarged forebrain. The "no-observed-adverse-effect-level" (NOAEL) was 10 μg/ml VPA.
The effectiveness of penetration of erythrocyte membrane by sodium salt of 2,4-dichlorophenoxyacetic acid was analyzed. The experiment was executed in a dependence on different doses of the herbicide and at different times of incubation of red blood cells with 2,4-D-Na. It is known that the main mechanism of detoxification of the cell from xenobiotics including 2,4-D is to bind them with proteins contained in blood plasma. In the case of exposure of blood to high doses of 2,4-D-Na, the unbound part of xenobiotics may penetrate into erythrocytes and change the activity of numerous parameters of the cells. The results obtained by the use of high pressure liquid chromatography (HPLC) revealed that 2,4-D-Na is adsorbed by erythrocytes of 5% haematocrite in the amount of ~1% of the initial concentration. Moreover, it was observed that 2,4-D-Na is capable of accumulating in erythrocyte’s membrane and haemolysate in the amounts of 0.15% and 1.23% of the initial concentration, respectively. It was also stated that penetration of 2,4-dichlorophenoxyacetic acid into erythrocytes is not associated with incubation time (the similar concentrations of 2,4-D-Na were detected after different incubation times of 0.5 to 3 hours); however, it was related with concentrations of the herbicide. We suggest that 2,4-D-Na was transported with concentration gradient in human erythrocytes.
The aim of the present investigation was the evaluation of mercury distribution in the chicken tissues in the course of chronic mercury poisoning and the changes of mercury concentrations in the tissues after the administration of antidotum in the form of MESNA preparation.
Two structurally related compounds, phenyl dithiocarbamate sodium salt (I) and p-phenylene-bis (dithiocarbamate) sodium salt (II) were prepared by reaction of the parent aniline and p-phenylenediamine with CS2 in the presence of sodium hydroxide. These water soluble compounds were characterized by spectroscopic techniques, IR, 1H NMR and elemental analysis. The inhibitory effects of both compounds on both activities of mushroom tyrosinase (MT) from Agricus bisporus were studied at two temperatures, 27ºC and 37ºC. L-3, 4-dihydroxyphenylalanine (L-DOPA), and l-tyrosine were used as natural substrates for the catecholase and cresolase enzyme reactions, respectively. Kinetic analysis confirmed noncompetitive inhibition mode of I and mixed type of II on both activities of MT; I and II inhibit MT with inhibition constants (KI) of 300 μM and 4 μM, respectively. Analysis of thermodynamic parameters indicated predominant involvement of hydrophobic interactions in binding of I and electrostatic ones in binding of II to MT. It seems that II is a more potent MT inhibitor due to its two charged head groups able to chelate copper ions in the enzyme active site. Intrinsic fluorescence studies as a function of concentrations of both compounds showed unexpectedly quenching of emission intensity without any shift of emission maximum. Extrinsic ANS-fluorescence indicated that only binding of I induces limited changes in the tertiary structure of MT, in agreement with the postulated hydrophobic nature of the binding mechanism.
Zbadano reakcje wybranych roślin ozdobnych na podwyższoną zawartość sodu w podłożu. Do badań wykorzystano dwa gatunki roślin ozdobnych – szałwię błyszczącą (Salvia splendens Buc’hoz x Etl.) ‘Scarlet Piccolo’ oraz słonecznika zwyczajnego Helianthus annuus L. ‘Teddy Bear’. Rośliny uprawiano w zwapnowanym torfie wysokim wzbogaconym makroi mikroskładnikami. Zróżnicowanie zawartości sodu uzyskano, stosując dwie sole sodu (NaCl i Na2SO4) w dawkach odpowiadających po przeliczeniu 0–500 mg Na ⋅ dm–3. Zmiany właściwości chemicznych podłoża spowodowały zaburzenia gospodarki mineralnej roślin. Niezależnie od zastosowanej soli sodu wzrastająca zawartość Na miała negatywny wpływ na badane cechy morfologiczne roślin Salvia speldens. Badania wykazały, że słonecznik był bardziej tolerancyjny – negatywny wpływ zastosowanych soli sodu w przypadku tego gatunku nie zawsze był statystycznie udowodniony. Wyraźne obniżenie zawartości chlorofilu zaobserwowano jedynie w liściach szałwii. Bardziej niekorzystny wpływ na wartość ozdobną szałwii (wysokość i średnicę roślin mierzoną w połowie pędu głównego) i słonecznika (średnicę kwiatostanu) miał chlorek sodu.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.