Deracemization and Stereoinversion to Aromatic <scp>d</scp>-Amino Acid Derivatives with Ancestral <scp>l</scp>-Amino Acid Oxidase
作者:Shogo Nakano、Yuki Minamino、Fumihito Hasebe、Sohei Ito
DOI:10.1021/acscatal.9b03418
日期:2019.11.1
pure amino acid derivatives could be foundational compounds for peptide drugs. Deracemization of racemates to l-amino acid derivatives can be achieved through the reaction of evolved d-aminoacidoxidase and chemical reductants, whereas deracemization to d-aminoacid derivatives has not progressed due to the difficulty associated with the heterologous expression of l-amino acidoxidase (LAAO). In this
One-Pot Biocatalytic Synthesis of Substituted<scp>d</scp>-Tryptophans from Indoles Enabled by an Engineered Aminotransferase
作者:Fabio Parmeggiani、Arnau Rué Casamajo、Curtis J. W. Walton、James L. Galman、Nicholas J. Turner、Roberto A. Chica
DOI:10.1021/acscatal.9b00739
日期:2019.4.5
d-Tryptophan and its derivatives are important precursors of a wide range of indole-containing pharmaceuticals and naturalproducts. Here, we developed a one-pot biocatalytic process enabling the synthesis of d-tryptophans from indoles in good yields and high enantiomeric excess (91% to >99%). Our method couples the synthesis of l-tryptophans catalyzed by Salmonella enterica tryptophan synthase with
The facile synthesis of a series of tryptophan derivatives
作者:Georg Blaser、John M. Sanderson、Andrei S. Batsanov、Judith A.K. Howard
DOI:10.1016/j.tetlet.2008.02.120
日期:2008.4
of 5- and 6-substituted tryptophan derivatives that are difficult to prepare using alternative enzymatic approaches. Acylation of an activated amino acid, derived from serine in situ, is coupled with an enzymatic resolution step to furnish enantiopure analogues bearing a range of electron withdrawing and releasing substituents. Isolation of a dehydroalanine derivative as a by-product from some reactions
Truncated somatostatin analogs and intermediates therefor, processes for their preparation, and pharmaceutical compositions containing the analogs
申请人:AMERICAN HOME PRODUCTS CORPORATION
公开号:EP0021585A1
公开(公告)日:1981-01-07
Compounds of formula:
Compounds of formula :
in which X, is hydrogen, des-amino, H-Ala-Gly or H-Ala-D-Ala; X2 is a Trp, Leu, Met or p-Cl-Phe; X3 is a D-Trp or 5-or 6-fluoro-D-Trp; and the A groups are hydrogen or a direct bond between the two sulphur atoms; and pharmaceutically acceptable salts thereof, are disclosed which are selective inhibitors of growth hormone and glucagon release without materially altering blood serum levels of insulin. They are prepared by classical or solid phase synthetic methods via appropriate protected peptide precursors. Pharmaceutical compositions are also disclosed.
Complete Stereoinversion of <scp>l</scp>-Tryptophan by a Fungal Single-Module Nonribosomal Peptide Synthetase
作者:Yang Hai、Matthew Jenner、Yi Tang
DOI:10.1021/jacs.9b08898
日期:2019.10.16
Single-module nonribosomal peptide synthetases (NRPSs) and NRPS-like enzymes activate and transform carboxylic acids in both primary and secondary metabolism and are of great interest due to their biocatalytic potentials. The single-module NRPS IvoA is essential for fungal pigment biosynthesis. Here, we show that IvoA catalyzes ATP-dependent unidirectional stereo inversion of L-tryptophan to D-tryptophan with complete conversion. While the stereoinversion is catalyzed by the epimerization (E) domain, the terminal condensation (C) domain stereoselectively hydrolyzes D-tryptophanyl-S-phosphopantetheine thioester and thus represents a noncanonical C domain function. Using IvoA, we demonstrate a biocatalytic stereoinversion/deracemization route to access a variety of substituted D-tryptophan analogs in high enantiomeric excess.