Chlorothioketene, the Ultimate Reactive Intermediate Formed by Cysteine Conjugate β-Lyase-Mediated Cleavage of the Trichloroethene MetaboliteS-(1,2-Dichlorovinyl)-l-cysteine, Forms Cytosine Adducts in Organic Solvents, but Not in Aqueous Solution

1998 ◽  
Vol 11 (9) ◽  
pp. 1082-1088 ◽  
Author(s):  
Wolfgang Völkel ◽  
Wolfgang Dekant
Keyword(s):  
Aqueous Solution ◽  
Organic Solvents ◽  
Reactive Intermediate

scholarly journals Reverse vesicles as a new system for studying enzymes in organic solvents

1992 ◽  
Vol 285 (2) ◽  
pp. 373-376 ◽  
Author(s):  
A Sánchez-Ferrer ◽  
F García-Carmona
Keyword(s):  
Aqueous Solution ◽  
Organic Solvents ◽  
Reverse Micelles ◽  
Active Form ◽  
Ionic Surfactant ◽  
New Approach ◽  
Optically Transparent ◽  
Reverse Vesicles ◽  
Dodecyl Ether ◽  
New System

A new approach to the study of enzyme activity in organic solvents has been developed by using optically transparent reverse vesicles. Polyphenol oxidase was incorporated in an active form into the above ternary system formed by the non-ionic surfactant tetra(ethylene glycol) dodecyl ether/n-dodecane/water. The enzyme in this microenvironment, surprisingly, showed an apparent positive co-operativity which has never before been described either in aqueous solution or in reverse micelles. In addition, the Vmax. expressed was similar to that in water and twice that displayed in reverse micelles.

On the High Viscosity of Aqueous Solution of Lysozyme Induced by Some Organic Solvents

1996 ◽  
Vol 180 (2) ◽  
pp. 578-589 ◽  
Author(s):  
Elizabeth P.G. Arêas ◽  
José A.G. Arêas ◽  
James Hamburger ◽  
Warner L. Peticolas ◽  
Paulo S. Santos
Keyword(s):  
Aqueous Solution ◽  
Organic Solvents ◽  
High Viscosity

Preparation and Properties of Novel Aromatic Polyimides from 4,4′-Diamino-4″ -Hydroxytriphenylamine and Aromatic Tetracarboxylic Dianhydrides

2000 ◽  
Vol 12 (1) ◽  
pp. 197-203 ◽  
Author(s):  
Satoshi Akimoto ◽  
Mitsutoshi Jikei ◽  
Masa-aki Kakimoto
Keyword(s):  
Aqueous Solution ◽  
Weight Loss ◽  
Hydrogen Bonding ◽  
Glass Transition ◽  
Dimethyl Sulfoxide ◽  
Organic Solvents ◽  
Phthalic Anhydride ◽  
Glass Transition Temperatures ◽  
Aromatic Polyimides ◽  
Polymer Properties

Novel aromatic polyimides containing hydroxytriphenylamine units were prepared from 4,4′-diamino-4″-hydroxytriphenylamine 1 and various aromatic tetracarboxylic dianhydrides 2. The glass transition temperatures ( Tgs) of these polyimides were in the range of 274–388 °C and the 10% weight loss temperatures ( T d10s) were above 462 and 511 °C in air and nitrogen respectively. Polyimide 4f prepared from diamine 1 and 4,4′-hexafluoroisopropylidenebis(phthalic anhydride) (6FDA) was soluble not only in organic solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, 1, 3-dimethyl-2-imidazolidone and dimethyl sulfoxide but also in tetramethylammonium hydroxide aqueous solution. Other resulting polyimides were not soluble in organic solvents. The resulting polyimides 4 possessed Tgs about 20–70 °C higher and poorer solubilities than the previously reported polyimides prepared from 4,4′-diaminotriphenylamine and various aromatic tetracarboxylic dianhydrides. These results indicated that polymer properties such as thermal behaviour and solubilities were influenced by the intermolecular interaction of hydrogen bonding due to hydroxy units.

5-(Acridin-9-ylamino)uracil — A hydrolytically labile nucleobase modification in peptide nucleic acid

2013 ◽  
Vol 91 (12) ◽  
pp. 1202-1206 ◽  
Author(s):  
Augusto Matarazzo ◽  
Mohamed E. Moustafa ◽  
Robert H.E. Hudson
Keyword(s):  
Aqueous Solution ◽  
Nucleic Acid ◽  
Organic Solvents ◽  
Peptide Nucleic Acid ◽  
Small Degree ◽  
Starting Material ◽  
Neutral Aqueous Solution

5-Aminouracil (5-AU) is a readily available yet underutilized starting material for the synthesis of labelled nucleobase analogues. We have prepared the derivative of 5-AU with the amine-reactive chromophore 9-chloroacridine for the purpose of investigating its potential as a base-discriminating fluorophore. 9-Chloroacridine readily undergoes substitution by reaction with 5-AU to yield a fluorescent nucleobase that after standard manipulations produced a monomer suitable for incorporation into peptide nucleic acid (PNA) by fluorenylmethyloxycarbonyl (Fmoc)-based oligomerization chemistry. Although the monomer was stable in organic solvents, once incorporated into an oligomer the 5-substitution was found to be thermally labile and hydrolyzed to a small degree in neutral aqueous solution during study of its hybridization to cDNA. We have determined that 5-(acridin-9-ylamino)uracil and related derivatives produce the highly fluorescent acridone and 5-AU by hydrolysis in water.

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