scholarly journals Synthetic Studies of Amino Acids by the Use of Copper Complex. II. The Condensation Reaction ofN-Pyruvylideneglycinatocopper(II) Complexes with various Aldehydes

1971 ◽  
Vol 44 (10) ◽  
pp. 2779-2786 ◽  
Author(s):  
Tetsuya Ichikawa ◽  
Sadao Maeda ◽  
Toshiro Okamoto ◽  
Younosuke Araki ◽  
Yoshiharu Ishido
Keyword(s):  
Amino Acids ◽  
Copper Complex ◽  
Condensation Reaction ◽  
Complex Ii ◽  
Synthetic Studies

Sodium borohydride: A versatile reagent in the reductive N-monoalkylation of α-amino acids and α-amino methyl esters

2002 ◽  
Vol 80 (7) ◽  
pp. 779-788 ◽  
Author(s):  
Giancarlo Verardo ◽  
Paola Geatti ◽  
Elena Pol ◽  
Angelo G Giumanini
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sodium Borohydride ◽  
Carbonyl Compounds ◽  
Condensation Reaction ◽  
Methyl Esters ◽  
Reducing Agent ◽  
Reductive Condensation ◽  
Versatile Reagent

α-Amino acids and α-amino methyl esters are easily converted to their N-monoalkyl derivatives by a reductive condensation reaction using several carbonyl compounds in the presence of sodium borohydride. This reducing agent has shown a wide versatility with minor but essential procedural variations. The reaction allows the α-monodeuterium labeling of the new N-substituent by use of sodium borodeuteride.Key words: α-amino acid, α-amino methyl esters, sodium borohydride, reductive N-monoalkylation, carbonyl compounds.

A bis-copper(II)–[D-βVal3,7]ascidiacyclamide complex enveloping two square pyramids and sharing an apex atom from a carbonate anion

2019 ◽  
Vol 75 (8) ◽  
pp. 1182-1187 ◽  
Author(s):  
Akiko Asano ◽  
Mitsinobu Doi
Keyword(s):  
Amino Acids ◽  
Water Molecule ◽  
Copper Complex ◽  
Structural Changes ◽  
Ring Expansion ◽  
Membered Ring ◽  
Water Molecules ◽  
Ring Size ◽  
Cd Spectra ◽  
Carbonate Anion

The four azole rings place structural restrictions on ascidiacyclamide (ASC). As a result, the structure of ASC exists in an equilibrium between two major forms (i.e. folded and square). [D-βVal3,7]Ascidiacyclamide (βASC) was synthesized by replacing two D-Val-Thz (Val is valine and Thz is thiazole) blocks with D-β-Valine (D-βVal-Thz). This modification expands the peptide ring; the original 24-membered macrocycle of ASC becomes a 26-membered ring. Circular dichroism (CD) spectra showed that, in solution, the structural equilibrium is maintained with βASC, but the folded form is dominant. A copper complex was prepared, namely [[D-βVal3,7]ascidiacyclamide(2−)]aqua-μ-carbonato-dicopper(II) monohydrate, [Cu2(C38H54N8O6S2)(CO3)(H2O)]·H2O, to determine the effect of the change in ring size on the coordinated structure. The obtained bis-CuII–βASC complex contains two water molecules and a carbonate anion. Two CuII ions are chelated by three N-donor atoms of two Thz–Ile–Oxz (Ile is isoleucine and Oxz is oxazoline) units. An O atom of the carbonate anion bridges two CuII ions, forming two square pyramids. These features are similar to the previously reported structure of the CuII–ASC complex, but the two pyramids are enveloped inside the peptide and share one apex. In the CuII–ASC complex, the apex of each square pyramid is an O atom of a water molecule, and the two pyramids are oriented toward the outside of the peptide. The incorporated β-amino acids of βASC make the space inside the peptide large enough to envelop the two square pyramids. The observed structural changes in the bis-CuII–βASC complex arising from ring expansion are particularly interesting in the context of the previously reported structure of the CuII–ASC complex.

Amalgamation and Scrutinizing of Leucine Derivatives Schiff bases Complexes as Antimicrobial Agent

2021 ◽  
Vol 25 ◽  
Author(s):  
Muhammad Pervaiz ◽  
Ikram Ahmad ◽  
Zohaib Saeed ◽  
Muhammad Sagir ◽  
Umer Younas ◽  
...  
Keyword(s):  
Amino Acids ◽  
Coordination Chemistry ◽  
Metal Complexes ◽  
Schiff Bases ◽  
Condensation Reaction ◽  
Amino Acid Derivatives ◽  
Comprehensive Review ◽  
Antimicrobial Potential ◽  
Donor Ability ◽  
Derivatives Of

: The enhanced applications of Schiff bases metal complexes of amino acid derivatives have captured the attention of researchers for the synthesis of leucine derivatives of Schiff bases metal complexes. Amino acids are considered to be essential part of food supplements as well as derivatives of Schiff bases in coordination chemistry due to their donor ability. The leucine derivatives Schiff bases ligand have been synthesized by condensation reaction between amine of leucine with aldehyde or ketone bearing molecules attached with them. These complexes were characterized by different spectroscopic tools in order to confirm their structural geometries. The structural geometries are considered to be very important in order to improve the antimicrobial potential of leucine derivative metal complexes. By taking into account the antimicrobial potential of titled compounds, a comprehensive review of leucine derivatives of Schiff bases metal complexes has been compiled.

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