scholarly journals Colour indicator for enantiomeric excess and assignment of the configuration of the major enantiomer of an amino acid ester

2002 ◽  
pp. 174-175 ◽  
Author(s):  
Richard A. van Delden ◽  
Ben L. Feringa
Keyword(s):  
Amino Acid ◽  
Acid Ester ◽  
Enantiomeric Excess ◽  
Amino Acid Ester

ChemInform Abstract: Determination of Enantiomeric Excess for Amino Acid Ester Salts Using FAB Mass Spectrometry.

ChemInform ◽  
2010 ◽  
Vol 29 (47) ◽  
pp. no-no
Author(s):  
M. SAWADA ◽  
H. YAMAOKA ◽  
Y. TAKAI ◽  
Y. KAWAI ◽  
H. YAMADA ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Acid Ester ◽  
Enantiomeric Excess ◽  
Amino Acid Ester ◽  
Fab Mass Spectrometry

Determination of enantiomeric excess for amino acid ester salts using FAB mass spectrometry

1998 ◽  
pp. 1569-1570 ◽  
Author(s):  
Masami Sawada ◽  
Yoshio Takai ◽  
Hitoshi Yamada ◽  
Masami Sawada ◽  
Hiroshi Yamaoka ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Acid Ester ◽  
Enantiomeric Excess ◽  
Amino Acid Ester ◽  
Fab Mass Spectrometry

Eco-Friendly Synthesis of Peptides Using Fmoc-Amino Acid Chlorides as Coupling Agent Under Biphasic Condition

2020 ◽  
Vol 27 ◽  
Author(s):  
Santosh Y. Khatavi ◽  
K. Kantharaju
Keyword(s):  
Amino Acid ◽  
Acid Chloride ◽  
Acid Ester ◽  
Analytical Techniques ◽  
Peptide Bond ◽  
Amino Acid Ester ◽  
Acid Chlorides ◽  
Peptide Bond Formation ◽  
Green Protocol ◽  
Additional Base

Background: Agro-waste derived solvent media act as a greener process for the peptide bond formation using Nα - Fmoc-amino acid chloride and amino acid ester salt with in situ neutralization and coupling under biphasic condition. The Fmoc-amino acid chlorides are prepared by the reported procedure of freshly distilled SOCl2 with dry CH2Cl2. The protocol found many added advantages such as neutralization of amino acid ester salt and not required additional base for the neutralization, and directly coupling take place with Fmoc-amino acid chloride gave final product dipeptide ester in good to excellent yields. The protocol occurs with complete stereo chemical integrity of the configuration of substrates. Here, we revisited Schotten-Baumann condition, instead of using inorganic base. Objective: To develop green protocol for the synthesis of peptide bond using Fmoc-amino acid chloride with amino acid esters salt. Methods: The final product isolated is analyzed in several spectroscopic and analytical techniques such as FT-IR, 1H-, 13CNMR, Mass spectrometry and RP-HPLC to check stereo integrity and purity of the product. Conclusion: The present method developed greener using natural agro-waste (lemon fruit shell ash) derived solvent medium for the reaction and not required chemical entity.

A novel route for aspartame production by combining enzymatic and chemical reactions for industrial use

2020 ◽  
Vol 85 (2) ◽  
pp. 464-466
Author(s):  
Kenzo Yokozeki ◽  
Isao Abe
Keyword(s):  
Aqueous Solution ◽  
Amino Acid ◽  
Chemical Reactions ◽  
Acid Ester ◽  
Amino Acid Ester ◽  
Acyl Transferase ◽  
Enzymatic Production ◽  
Production Route ◽  
Industrial Use ◽  
Hcl Removal

ABSTRACT Here, we report a novel industrial aspartame production route, involving the enzymatic production of α-l-aspartyl-l-phenylalanine β-methylester from l-aspartic acid dimethylester and l-phenylalanine by α-amino acid ester acyl transferase. The route also involves the chemical transformation of α-l-aspartyl-l-phenylalanine β-methylester to α-l-aspartyl-l-phenylalanine methylester hydrochloride (aspartame hydrochloride) in an aqueous solution with methanol and HCl, followed by HCl removal to form aspartame.

scholarly journals Transdermal Delivery Systems for Ibuprofen and Ibuprofen Modified with Amino Acids Alkyl Esters Based on Bacterial Cellulose

2021 ◽  
Vol 22 (12) ◽  
pp. 6252
Author(s):  
Paula Ossowicz-Rupniewska ◽  
Rafał Rakoczy ◽  
Anna Nowak ◽  
Maciej Konopacki ◽  
Joanna Klebeko ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Bacterial Cellulose ◽  
Acid Ester ◽  
Active Pharmaceutical Ingredient ◽  
Amino Acid Ester ◽  
Isopropyl Ester ◽  
Isopropyl Esters ◽  
Transdermal Application

The potential of bacterial cellulose as a carrier for the transport of ibuprofen (a typical example of non-steroidal anti-inflammatory drugs) through the skin was investigated. Ibuprofen and its amino acid ester salts-loaded BC membranes were prepared through a simple methodology and characterized in terms of structure and morphology. Two salts of amino acid isopropyl esters were used in the research, namely L-valine isopropyl ester ibuprofenate ([ValOiPr][IBU]) and L-leucine isopropyl ester ibuprofenate ([LeuOiPr][IBU]). [LeuOiPr][IBU] is a new compound; therefore, it has been fully characterized and its identity confirmed. For all membranes obtained the surface morphology, tensile mechanical properties, active compound dissolution assays, and permeation and skin accumulation studies of API (active pharmaceutical ingredient) were determined. The obtained membranes were very homogeneous. In vitro diffusion studies with Franz cells were conducted using pig epidermal membranes, and showed that the incorporation of ibuprofen in BC membranes provided lower permeation rates to those obtained with amino acids ester salts of ibuprofen. This release profile together with the ease of application and the simple preparation and assembly of the drug-loaded membranes indicates the enormous potentialities of using BC membranes for transdermal application of ibuprofen in the form of amino acid ester salts.

scholarly journals Nicotinamide riboside–amino acid conjugates that are stable to purine nucleoside phosphorylase

2020 ◽  
Vol 18 (15) ◽  
pp. 2877-2885
Author(s):  
Faisal Hayat ◽  
Marie E. Migaud
Keyword(s):  
Amino Acid ◽  
Acid Ester ◽  
Purine Nucleoside Phosphorylase ◽  
Amino Acid Ester ◽  
Purine Nucleoside ◽  
Nucleoside Phosphorylase ◽  
Amino Acid Conjugates ◽  
Nicotinamide Riboside

O5′ amino acid ester conjugates of nicotinamide riboside, generated via a reduced intermediate, are stable to purine nucleoside phosphorylase.

Platinum(II) complexes of reduced amino acid ester Schiff bases: synthesis, characterization, and antitumor activity

2012 ◽  
Vol 40 (1) ◽  
pp. 413-424 ◽  
Author(s):  
Li-Jun Li ◽  
Cheng Wang ◽  
Yu Qiao ◽  
Xiao-Yan Yang ◽  
Xing-Xing Hua ◽  
...  
Keyword(s):  
Amino Acid ◽  
Antitumor Activity ◽  
Schiff Bases ◽  
Acid Ester ◽  
Amino Acid Ester

Agarose-chymotrypsin as a catalyst for peptide and amino acid ester synthesis in organic media

1989 ◽  
Vol 11 (11) ◽  
pp. 811-816 ◽  
Author(s):  
Rosa M. Blanco ◽  
Jos� M. Guis�n ◽  
Peter J. Halling
Keyword(s):  
Amino Acid ◽  
Acid Ester ◽  
Amino Acid Ester ◽  
Organic Media ◽  
Ester Synthesis
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