672-86-6Relevant academic research and scientific papers
D-METYROSINE COMPOSITIONS AND METHODS FOR PREPARING SAME
-
, (2020/10/20)
The disclosure provides processes for preparing a compound of formula I, comprising reacting a compound of formula II with an aqueous acid in a solvent and at a temperature sufficient for at least about 48 hours to produce a compound of formula I: wherein, R1-R5 are defined herein. Also provided are D-metyrosine prepared according to the processes described herein and compositions comprising the D-metyrosine provided herein.
Chiral ligand-exchange resolution of underivatized amino acids on a dynamically modified stationary phase for RP-HPTLC
Remelli, Maurizio,Faccini, Stefania,Conato, Chiara
, p. 313 - 318 (2014/06/09)
The synthesis of Spi(τ-dec), derived from the selective alkylation of L-spinacine (4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid) at the τ-nitrogen of its heteroaromatic ring, with a linear hydrocarbon chain of 10 carbon atoms, is described here for the first time. Spi(τ-dec) was successfully employed in the past to prepare home-made chiral columns for chiral ligand-exchange high-performance liquid chromatography. In the present article a new method is described, using Spi(τ-dec) as a chiral selector in high-performance thin-layer chromatography (HPTLC): commercial hydrophobic plates were first coated with Spi(τ-dec) and then treated with copper sulfate. The performance of this new chiral stationary phase was tested against racemic mixtures of aromatic amino acids, after appropriate optimization of both the conditions of preparation of the plates and the mobile phase composition. The enantioselectivity values obtained for the studied compounds were higher than those reported in the literature for similar systems. The method employed here for the preparation of chiral HPTLC plates proved practical, efficient, and inexpensive. Chirality 26:313-318, 2014. 2014 Wiley Periodicals, Inc.
Novel open-chain and cyclic conformationally constrained (R)- and (S)-α,α-disubstituted tyrosine analogues
Obrecht,Lehmann,Ruffieux,Schonholzer,Muller
, p. 1567 - 1587 (2007/10/02)
A series of novel open-chain and cyclic conformationally constrained (R)- and (S)-α,α-disubstituted tyrosine analogues 1a-e were synthesized in good yields and high optical purities. The absolute configurations of these tyrosine analogues were unambiguously determined based on the X-ray structures of the precursor diastereoisomeric peptides of type 4 and 5. Four of these structures are deseribed, showing β-turn type-I geometries for dipeptides 4b, 5b, and 4c and an extended conformation for peptide 5c. The conversion of the free amino acids 1a-c into suitably protected building blocks 11a-d and 15d,e for peptide synthesis is discussed.
Kinetic Resolution of Unnatural and Rarely Occuring Amino Acids: Enantioselective Hydrolysis of N-Acyl Amino Acids Catalyzed by Acylase I
Chenault, H. Keith,Dahmer, Juergen,Whitesides, George M.
, p. 6354 - 6364 (2007/10/02)
Acylase I (aminoacylase; N-acylamino-acid amidohydrolase, EC 3.5.1.14, from porcine kidney and the fungus Aspergillus) is broadly applicable enzymatic catalyst for the kinetic resolution of unnatural and rarely occuring α-amino acids.Its enantioselectivity for the hydrolysis of N-acyl L-α-amino acids is nearly absolute, yet it accepts substrates having a wide range of structure and functionality.This paper reports the initial rates of enzyme-catalyzed hydrolysis of over 50 N-acyl amino acids and analogues, the stabilities of the enzymes in aqueous and aqueous/organic solutions, and the effects of different acyl groups and metal ions on the rates of enzymatic hydrolysis.Eleven α-amino and α-methyl α-amino acids were resolved on a 2-29-g scale.Crude L- and D-amino acid products had generally >90percent ee.The utility of resolved amino acids as chiral synthons was illustrated by the preparation of (R)- and (S)-1-butene oxide and the diastereoselective (cis:trans, 7-8:1) iodolactonization of three 2-amino-4-alkenoic acid derivatives.
