1663-47-4Relevant academic research and scientific papers
Preparation of a novel aggregate like sugar-ball micelle composed of poly(methylglutamate) and poly(ethyleneglycol) modified by lactose and its molecular recognition by lectin
Toyotama,Kugimiya,Yamanaka,Yonese
, p. 169 - 172 (2001)
We report the preparation and characteristics of a novel micellar aggregate of an amphiphilic diblock copolymer, poly(methylglutamate) (PMG)-poly(ethyleneglycol) (PEG), whose terminus was modified by lactose lactone (LA). Due to the terminal LA moiety, th
Using hydrogen-bonding interactions to control the peptide secondary structures and miscibility behavior of poly(l -glutamate)s with phenolic resin
Kuo, Shiao-Wei,Chen, Chi-Jen
, p. 7315 - 7326 (2011)
We synthesized three low-molecular-weight poly(glutamate)s-poly(γ- methyl l-glutamate) (PMLG), poly(γ-ethyl l-glutamate) (PELG), and poly(γ-benzyl l-glutamate) (PBLG)-through living ring-opening polymerization of their α-amino acid-N-carboxyanhydride derivatives and then blended them with phenolic resin to control the secondary structures of these polypeptides. Each of the three binary blends exhibited a single glass transition temperature (differential scanning calorimetry) and a single-exponential decay of proton spin-lattice relaxation times in the rotating frame [T1ρH; solid state nuclear magnetic resonance (NMR) spectroscopy], characteristic of a miscible system. The strength of the interassociative interactions depended on the nature of the hydrogen bond acceptor groups, increasing in the order phenolic/PELG > phenolic/PMLG > phenolic/PBLG, as evidenced through analyses using Fourier transform infrared (FTIR) spectroscopy and the Painter-Coleman association model. The fractions of α-helical conformations (measured using FTIR and solid-state NMR spectroscopy) of PMLG and PELG decreased initially upon increasing the phenolic content but increased thereafter; in contrast, the fraction of α-helical conformations of PBLG increased continuously upon increasing the phenolic contents. Using variable-temperature infrared spectroscopy to investigate the changes in the conformations of the secondary structures of the peptide segments in these three binary blends, we found that the α-helical conformation in these three blend systems correlated strongly with the rigidity of side-chain groups, the strength of the intermolecular hydrogen bonding with the phenolic resin, the compositions of phenolic resin, and the temperature. More interestingly, the content of α-helical conformations of the polypeptides in these phenolic/PBLG blends increased upon increasing the temperature.
PROCESSES FOR PREPARATION OF (S)-TERT-BUTYL 4,5-DIAMINO-5-OXOPENTANOATE
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Paragraph 00352, (2019/03/12)
Provided are processes for the preparation of (S)-tert-butyl 4,5-diamino-5-oxopentanoate, or a salt, solvate, hydrate, enantiomer, mixture of enantiomers, or isotopologue thereof. Also provided are solid forms of various intermediates and products obtained from the processes.
PROCESS FOR THE PREPARATION OF N-CARBOXYANHYDRIDES
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Page/Page column 8, (2008/06/13)
The invention relates to a process for the preparation of N-carboxyanhydrides by reaction of the corresponding amino acid with phosgene, diphosgene and/or triphosgene in a solvent medium, characterized in that the reaction is a least partially carried out in the presence of an unsaturated organic compound which has one or more ethylenic double bonds. The N-carboxyanhydrides are thus obtained with better yields and an improved purity.
The Synthesis of the High-Potency Sweetener, NC-00637. Part 3: The Glutamyl Moiety and Coupling Reactions
Ager, David J.,Babler, Scott,Erickson, Robert A.,Froen, Diane E.,Kittleson, Jeannine,Pantaleone, David P.,Prakash, Indra,Zhi, Ben
, p. 72 - 85 (2013/09/04)
The synthesis of the high-potency sweetener, NC-00637 (1), required selective preparation of the γ-protected glutamic acid. Coupling of the three components could be performed in any order, but the final route involved N-acylation of the protected L-glutamic acid with the acid chloride derived from (S)-2-methylhexanoic acid. Activation of the α-carboxyl group allowed condensation with 5-amino-2-cyanopyridine (4). Saponification of the γ-ester 19 then provided the sweetener 1.
Friedel-Crafts α-aminoacylation of aromatic compounds with a chiral N- carboxy-α-amino acid anhydride (NCA); Part 2
Itoh, Osamu,Amano, Akira
, p. 423 - 428 (2007/10/03)
The N-carboxy-α-amino acid anhydrides (NCA) derived from L-Asp(OEt), L- Glu(OMe), L-Met, and L-Pro reacted with aromatic compounds (toluene or benzene) in the presence of AlCl3 to afford the corresponding α-aminoalkyl aryl ketones as hydrochloride salts in moderate yields. The β- and γ-amino acid esters, which were obtained from the reaction of the aromatic compounds with L-Asp(OEt)- and L-Glu(OMe)-NCA, were hydrolyzed by hydrochloric acid to the corresponding β- and γ-amino acids as hydrochloride salts. L-Phe-NCA did not react with benzene in the presence of AlCl3, instead an intramolecular acylation occurred to afford (S)-2-aminoin-danone hydrochloride. The chiralities of the original L-α-amino acids were most retained during these α-aminoacylation.
