scholarly journals Synthesis of a Carboxylic Acid Extractant Containing an Amino Group and its Selective Extraction of In(III) and Ga(III)

2016 ◽  
Vol 23 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Yuji SASAKI ◽  
Misaki UTO ◽  
Tatsuya OSHIMA ◽  
Yoshinari BABA
Keyword(s):  
Carboxylic Acid ◽  
Selective Extraction ◽  
Amino Group ◽  
Acid Extractant

Azoverdin -an Isopyoverdin

1996 ◽  
Vol 51 (11-12) ◽  
pp. 772-780 ◽  
Author(s):  
R Michalke ◽  
K Taraz ◽  
H Budzikiewiez
Keyword(s):  
Carboxylic Acid ◽  
Succinic Acid ◽  
Peptide Chain ◽  
Side Chain ◽  
Carboxyl Group ◽  
Amino Group ◽  
Present Evidence ◽  
N Terminus

For azoverdin, the siderophore of Azomonas macrocytogenes ATCC 12334, a pyoverdintype structure has been suggested. We now present evidence that it is actually an isopyoverdin. Also the sequence of the peptide chain has to be revised. Azoverdin comprises, therefore, the chromophore (3S)-5-amino-1,2-dihydro-8,9-dihydroxy-3H -pyrimido[1,2a]quinoline- 3-carboxylic acid whose amino group is bound to a succinamide residue while the carboxyl group is attached to the N -terminus of L-Hse-[2-(R-1-amino-3-hydroxypropyl)-3,4,5,6- tetrahydropyrimidine-65-carboxylic acid]-N5-acetyl-N5,-hydroxy-ᴅ-Orn-ᴅ-Ser-N5-acetyl-N5- hydroxy-ʟ-Orn. In addition to azoverdin congeners with succinic acid (azoverdin A ) and with ʟ-Glu (azoverdin G ), resp., instead of the succinamide side chain could be isolated.

γ-Radiation-induced carboxylation of pyrrolidine

1976 ◽  
Vol 29 (12) ◽  
pp. 2603 ◽  
Author(s):  
A Davison ◽  
NT Barker ◽  
DF Sangster
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Carboxylic Acid ◽  
Hydroxyl Radicals ◽  
Hydrogen Abstraction ◽  
Major Product ◽  
Amino Group ◽  
Γ Radiation ◽  
Neutral Aqueous Solution ◽  
Radiation Induced

Amino acids produced in the γ-radiation-induced carboxylation of pyrrolidine and formate in neutral aqueous solution have been studied. Two products only were found in the ratio 1 : 5.5. The minor product, proline, and the major product, pyrrolidine-3-carboxylic acid, have been characterized. Their presence indicates that the predominant site of hydrogen abstraction from pyrrolidine by radiation-generated hydroxyl radicals is β to the amino group.

Transformation of the Carboxyl Group of an Amino Acid to Variously Substituted Imidazoles through a Davidson-Type Heterocyclization

Synthesis ◽  
2019 ◽  
Vol 51 (09) ◽  
pp. 1961-1968 ◽  
Author(s):  
Jim Küppers ◽  
Michaela Hympánová ◽  
Tim Keuler ◽  
Andreas Schneider ◽  
Gregor Schnakenburg ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
Amino Acid ◽  
Carboxylic Acid ◽  
Building Blocks ◽  
Carboxyl Group ◽  
Amino Group ◽  
Combinatorial Approach ◽  
X Ray ◽  
Imidazole Derivatives

The modification of amino acids leads to valuable building blocks for the synthesis of bioactive compounds. By keeping the amino group protected, the carboxylic acid functionality can be converted in two steps into an imidazole moiety via a Davidson-like heterocyclization. This reaction allows for a combinatorial approach, in which two positions at the heterocycle can be modified. Herein, we report the synthesis of such imidazole derivatives by employing N-protected cyclohexylalanine as the starting material. Different α-halo ketones were used and two points of diversity, positions 4 and 5, were examined. The structure of the final imidazole derivatives was confirmed by three X-ray crystal structure analyses and their protease inhibiting activities were evaluated.

Induction of One-Handed Helical Screw Sense in Achiral Peptide through the Domino Effect Based on Interacting Its N-Terminal Amino Group with Chiral Carboxylic Acid

2000 ◽  
Vol 122 (47) ◽  
pp. 11731-11732 ◽  
Author(s):  
Yoshihito Inai ◽  
Kenichi Tagawa ◽  
Akinori Takasu ◽  
Tadamichi Hirabayashi ◽  
Tatsuo Oshikawa ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Amino Group ◽  
Domino Effect ◽  
Terminal Amino

New Pyoverdin-Type Siderophores from Pseudomonas fluorescens

1990 ◽  
Vol 45 (10) ◽  
pp. 1437-1450 ◽  
Author(s):  
G. Mohn ◽  
K. Taraz ◽  
H. Budzikiewicz
Keyword(s):  
Carboxylic Acid ◽  
Pseudomonas Fluorescens ◽  
Carboxy Group ◽  
Culture Medium ◽  
Spectroscopic Methods ◽  
Amino Group ◽  
N Terminus ◽  
Short Hand ◽  
Degradation Studies

The structures of two new pyoverdins (GM-I and GM-II) isolated from the culture medium of Pseudomonas fluorescens have been elucidated by spectroscopic methods and degradation studies. The pyoverdins consist of a chromophore which could be identified as (1 S)-5-amino-2,3-dihydro-8,9-dihydroxy-1 H-pyrimido[1,2-a]quinoline-1-carboxylic acid substituted at the amino group with a 3-carboxypropanoyl or a succinamoyl residue and at the carboxy group with the N-terminus of D-Ala-D-Lys-Gly-Gly-D-threo-(OH)Asp-D-Glu-D-Ser-L-Ala-D-Ala-D-Ala-L-Ala-L-N5-(OH)Orn.According to the “short-hand” nomenclature proposed in [2]*** the two compounds should be characterized as pyoverdin-Q-akGGd'qsAaaAO′*-SUCA and pyoverdin-Q-akGGd'qsAaaAO′ *-SUC

Transformation of 1,2-Dithiole-3-thiones Into 1,6,6aλ4-Trithiapentalenes via Reaction with Bromoethanones

2006 ◽  
Vol 71 (5) ◽  
pp. 650-666 ◽  
Author(s):  
Richard Čmelík ◽  
Pavel Pazdera
Keyword(s):  
Carboxylic Acid ◽  
Thionyl Chloride ◽  
Reaction Mechanisms ◽  
Amino Group ◽  
Inverted Order ◽  
Derivatives Of

We report the reactions of derivatives of 5-amino-3-thioxo-3H-1,2-dithiole-4-carboxylic acid 1 with bromoethanones and acylation agents. Two different routes were used to obtain the products, 3-(acylmethylidene)-3H-1,2-dithioles 4. These compounds were synthesized by acylation of compounds 1 on the amino group, followed by the reaction with bromoethanones and excess of triethylamine. Another method was based on the inverted order of the mentioned reaction steps and in absence of a base. The treatment of 4 with thionyl chloride gave new unsaturated fused lactones 13 whereas thionation led to desired 1,6,6aλ4-trithiapentalenes 5. The structures of products and the reaction mechanisms are discussed.

Selective Extraction and Recovery of Cytochromecby Liquid−Liquid Extraction Using a Calix[6]arene Carboxylic Acid Derivative

Langmuir ◽  
2005 ◽  
Vol 21 (16) ◽  
pp. 7280-7284 ◽  
Author(s):  
Tatsuya Oshima ◽  
Hiroaki Higuchi ◽  
Keisuke Ohto ◽  
Katsutoshi Inoue ◽  
Masahiro Goto
Keyword(s):  
Carboxylic Acid ◽  
Acid Derivative ◽  
Selective Extraction ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction ◽  
Carboxylic Acid Derivative

Fibrinogen-Induced Polymerization Via the Process of Methylation

1979 ◽  
Vol 42 (05) ◽  
pp. 1398-1410
Author(s):  
A J Osbahr
Keyword(s):  
Carboxylic Acid ◽  
Thionyl Chloride ◽  
Acid Group ◽  
Fibrin Clot ◽  
Spectrophotometric Analysis ◽  
The Other ◽  
Amino Group ◽  
Methyl Sulfate ◽  
Carboxylic Acid Groups ◽  
Other Hand

SummaryFibrinogen is polymerized by a number of group specific reagents including diazomethane, thionyl chloride and di-methyl sulfate at pH 7.4. The relationship between the number of methyl groups incorporated into fibrinogen and the extent of polymerization was evaluated. With diazomethane and thionyl chloride as modifying agents, polymerization ensued in approximately IV2 hr with extensive modification of fibrinogen. On the other hand, m�thylation via di-methyl sulfate-induced polymer formation occurs in approximately 35 min with primarily carboxylic acid group esterification. The polymerized fibrinogen formed under these conditions exhibited properties that were closely similar with the physiological fibrin clot.Amino group determinations revealed the m�thylation of amino acid residues other than the expected esterification of carboxylic acid groups. Diazomethane induced both N- methylation of lysine, as well as O-methylation of tyrosine, as estimated from spectrophotometric analysis. On the other hand, thionyl chloride modified only a small number of amino groups, and di-methyl sulfate modification resulted in no significant amounts of amino group methylation during the process of modification induced polymerization of fibrinogen.The profile of the number of methoxyl groups incorporated into fibrinogen with time for diazomethane modification may reflect a conformational change in the protein due to a more nonspecific m�thylation. Both the reagent and the conditions of modification were found to be important in achieving a selective modification of fibrinogen.A possible interpretation of these results is the esterification of carboxylic acid groups in the fibrinogen with reduction in the prevailing carboxylate ion negative repulsion, thereby achieving an increased protein-protein interaction with a resulting polymerization.

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