7-Amino-1-naphthol-3,6-disulphonic acid (2R-acid) as a chromophoric reagent for trivalent iron

1963 ◽  
Vol 194 (4) ◽  
pp. 271-276 ◽  
Author(s):  
Roshan Lal Seth ◽  
Arun K. Dey
Keyword(s):  
Trivalent Iron ◽  
Disulphonic Acid

Colour and Tinctorial Behaviour of Some Chromogens Derivatives of 4,4� � diaminostilbene�2,2`-disulphonic Acid

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Maria Elena Grad ◽  
Valentin Radioi ◽  
Simona Popa ◽  
Dorin Jurcau ◽  
alfa Xenia Lupea
Keyword(s):  
Colour Fastness ◽  
Colour Measurements ◽  
Cielab System ◽  
Disulphonic Acid ◽  
Derivatives Of

Some chromogenes derivatives of 4,4�-diamino-stilbene-2,2�-disulphonic acid were applied to cotton and wool and colour measurements in the CIELAB system were made. Colour differences were evaluated and some relationships between structure and colour were made. The effect on colour fastness caused by incorporating of different groups in the structure has been also investigated.

scholarly journals Diadenosine polyphosphate hydrolase from presynaptic plasma membranes of Torpedo electric organ

1997 ◽  
Vol 323 (3) ◽  
pp. 677-684 ◽  
Author(s):  
Jesús MATEO ◽  
Pedro ROTLLAN ◽  
Eulalia MARTI ◽  
Inmaculada GOMEZ DE ARANDA ◽  
Carles SOLSONA ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Pyridoxal Phosphate ◽  
Electric Organ ◽  
Competitive Inhibitor ◽  
Inhibitory Effect ◽  
Ic50 Value ◽  
Neural Origin ◽  
Disulphonic Acid ◽  
Torpedo Electric Organ ◽  
Enzyme Activators

The diadenosine polyphosphate hydrolase present in presynaptic plasma membranes from the Torpedo electric organ has been characterized using fluorogenic substrates of the form di-(1,N6-ethenoadenosine) 5´,5‴-P1,Pn-polyphosphate. The enzyme hydrolyses diadenosine polyphosphates (Apn A, where n = 3–5), producing AMP and the corresponding adenosine (n-1) 5´-phosphate, Ap(n-1). The Km values of the enzyme were 0.543± 0.015, 0.478±0.043 and 0.520±0.026 μM, and the Vmax values were 633±4, 592±18 and 576±45 pmol/min per mg of protein, for the etheno derivatives of Ap3A (adenosine 5´,5‴-P1,P3-triphosphate), Ap4A (adenosine 5´,5‴-P1,P4 -tetraphosphate) and Ap5A (adenosine 5´,5‴-P1,P5-pentaphosphate) respectively. Ca2+, Mg2+ and Mn2+ are enzyme activators, with EC50 values of 0.86±0.11, 1.35±0.24 and 0.58±0.10 mM respectively. The fluoride ion is an inhibitor with an IC50 value of 1.38±0.19 mM. The ATP analogues adenosine 5´-tetraphosphate and adenosine 5´-[γ-thio]triphosphate are potent competitive inhibitors and adenosine 5´-[α,β-methylene]diphosphate is a less potent competitive inhibitor, the Ki values being 0.29±0.03, 0.43±0.05 and 7.18±0.8 μM respectively. The P2-receptor antagonist pyridoxal phosphate 6-azophenyl-2´,4´-disulphonic acid behaves as a non-competitive inhibitor with a Ki value of 29.7±3.1 μM, and also exhibits a significant inhibitory effect on Torpedo apyrase activity. The effect of pH on the Km and Vmax values, together with inhibition by diethyl pyrocarbonate, strongly suggests the presence of functional histidine residues in Torpedo diadenosine polyphosphate hydrolase. The enzyme from Torpedo shows similarities with that of neural origin from neurochromaffin cells, and significant differences compared with that from endothelial vascular cells.

scholarly journals Simulated diabetic ketoacidosis therapy in vitro elicits brain cell swelling via sodium-hydrogen exchange and anion transport

2015 ◽  
Vol 309 (4) ◽  
pp. E370-E379 ◽  
Author(s):  
Keeley L. Rose ◽  
Andrew J. Watson ◽  
Thomas A. Drysdale ◽  
Gediminas Cepinskas ◽  
Melissa Chan ◽  
...  
Keyword(s):  
Diabetic Ketoacidosis ◽  
Hydrogen Exchange ◽  
Brain Slices ◽  
Anion Transport ◽  
Brain Cell ◽  
Cell Swelling ◽  
Sodium Hydrogen ◽  
Disulphonic Acid

A common complication of type 1 diabetes mellitus is diabetic ketoacidosis (DKA), a state of severe insulin deficiency. A potentially harmful consequence of DKA therapy in children is cerebral edema (DKA-CE); however, the mechanisms of therapy-induced DKA-CE are unknown. Our aims were to identify the DKA treatment factors and membrane mechanisms that might contribute specifically to brain cell swelling. To this end, DKA was induced in juvenile mice with the administration of the pancreatic toxins streptozocin and alloxan. Brain slices were prepared and exposed to DKA-like conditions in vitro. Cell volume changes were imaged in response to simulated DKA therapy. Our experiments showed that cell swelling was elicited with isolated DKA treatment components, including alkalinization, insulin/alkalinization, and rapid reductions in osmolality. Methyl-isobutyl-amiloride, a nonselective inhibitor of sodium-hydrogen exchangers (NHEs), reduced cell swelling in brain slices elicited with simulated DKA therapy (in vitro) and decreased brain water content in juvenile DKA mice administered insulin and rehydration therapy (in vivo). Specific pharmacological inhibition of the NHE1 isoform with cariporide also inhibited cell swelling, but only in the presence of the anion transport (AT) inhibitor 4,4′-diisothiocyanatostilbene-2,2′-disulphonic acid. DKA did not alter brain NHE1 isoform expression, suggesting that the cell swelling attributed to the NHE1 was activity dependent. In conclusion, our data raise the possibility that brain cell swelling can be elicited by DKA treatment factors and that it is mediated by NHEs and/or coactivation of NHE1 and AT.

Electrochemical and photoelectrochemical treatment of 1-aminonaphthalene-3,6-disulphonic acid

2005 ◽  
Vol 67 (1) ◽  
pp. 71-75 ◽  
Author(s):  
A SOCHA ◽  
E CHRZESCIJANSKA ◽  
E KUSMIEREK
Keyword(s):  
Disulphonic Acid

Electrical conduction in trivalent iron molybdates

1984 ◽  
Vol 3 (10) ◽  
pp. 921-924 ◽  
Author(s):  
S. C. Verma ◽  
H. B. Lal
Keyword(s):  
Electrical Conduction ◽  
Trivalent Iron
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