Unnatural Amino Acids

  title={Unnatural Amino Acids},
  author={Loredano Pollegioni and Stefano de Servi},
  booktitle={Methods in Molecular Biology},
Ammonia-lyases catalyze a wide range of processes leading to , -unsaturated compounds by elimination of ammonia. In this chapter, ammonia-lyases are reviewed with major emphasis on their synthetic applications in stereoselective preparation of unnatural amino acids. Besides the synthesis of various unnatural -amino acids with the aid of phenylalanine ammonia-lyases (PALs) utilizing the 3,5-dihydro5-methylidene-4H-imidazol-4-one (MIO) prosthetic groups, the biotransformations leading to various… 

Unnatural α-Amino Acid Synthesized through α-Alkylation of Glycine Derivatives by Diacyl Peroxides.

A protocol for catalyst- and additive-free α-alkylation reactions of glycine derivatives with diacyl peroxides, which proceed by a pathway involving addition of alkyl radicals to imine intermediates, indicating its utility for late-stage functionalization.

Asymmetric Synthesis of Protected Unnatural α-Amino Acids via Enantioconvergent Nickel-Catalyzed Cross-Coupling.

It is established that a chiral catalyst based on nickel can achieve the enantioconvergent coupling of readily available racemic alkyl electrophiles with a wide variety ofAlkylzinc reagents (1:1.1 ratio) to afford protected unnatural α-amino acids in good yield and ee.

General Synthesis of Amino Acid Salts from Amino Alcohols and Basic Water Liberating H2.

An atom-economical and environmentally friendly method to transform amino alcohols to amino acid salts using just basic water, without the need of pre-protection or added oxidant, catalyzed by a

Site-Selective Cu-Catalyzed Alkylation of α-Amino Acids and Peptides toward the Assembly of Quaternary Centers.

The CuI -catalyzed selective α-alkylation of α-amino acid and peptide derivatives with 2-alkyl-1,3-dioxolanes is reported. This oxidative coupling is distinguished by its site-specificity, high

Synthesis of β- and γ-hydroxy α-amino acids via enzymatic kinetic resolution and cyanate-to-isocyanate rearrangement.

A new strategy for stereoselective preparation of all four isomers of β- and γ-hydroxy α-amino acids is presented, based on enzymatic kinetic resolution and cyanate-to-isocyanate rearrangement as key steps.

Cobalt-Catalyzed Three-Component Difluoroalkylation-Peroxidation of Alkenes.

The Co(acac)2-catalyzed three-component difluoroalkylation-peroxidation of alkenes with diffluorohaloactates and hydroperoxides has been developed and can be extended to other halide compounds to give the alkylation- peroxidation products.

Advances in Enzymatic Synthesis of D-Amino Acids

The aims of this review are to report the advances in synthesis of D-AAs gathered in the past few years based on five main classes of enzymes, and to improve the intrinsic atomic economy and cost-effectiveness.

Pd-Catalyzed Asymmetric Hydroalkylation of 1,3-Dienes: Access to Unnatural α-Amino Acid Derivatives Containing Vicinal Quaternary and Tertiary Stereogenic Centers.

The synthetic utility of the current methodology was demonstrated through product transformations to access other biologically important compounds such as chiral β-amino alcohol and α-quaternary cyclic α-aminos acid derivatives.

Nonnatural amino acid synthesis by using carbon-hydrogen bond functionalization methodology.

A method of palladium-catalyzed synthesis of protected unnatural amino acids by C-H bond functionalization that employs readily available starting materials derived from chiral pool is reported.



Synthesis of new Cα-tetrasubstituted α-amino acids

Although such aldehydes are prone to give aldol products under the reaction conditions used, the group was able to obtain the target cyclic amino acids in low to moderate yields and in some cases with good diastereoselectivity.

Enhancing the utility of unnatural amino acid synthetases by manipulating broad substrate specificity.

It is demonstrated that the unnatural synthetases can be permissive to many unnatural amino acid substrates and can be converted into a permissive l-4-benzoylphenylalanine synthetase with a single mutation without compromising fidelity.

Addition of a photocrosslinking amino acid to the genetic code of Escherichia coli

An orthogonal aminoacyl-tRNA synthetase/tRNA pair is evolved that makes possible the in vivo incorporation of p-benzoyl-l-phenylalanine into proteins in Escherichia coli in response to the amber codon, TAG.

An Unnatural Amino Acid that Mimics a Tripeptide β-Strand and Forms β-Sheetlike Hydrogen-Bonded Dimers

Unnatural amino acid 2 (5-HO2CCONH-2-MeO-C6H3-CONHNH2) duplicates the hydrogen-bonding functionality of one edge of a tripeptide β-strand. It is composed of hydrazine, 5-amino-2-methoxybenzoic acid,

Synthesis of novel unnatural amino acid as a building block and its incorporation into an antimicrobial peptide.

  • J. OhK. Lee
  • Chemistry, Biology
    Bioorganic & medicinal chemistry
  • 1999

De novo design of selective antibiotic peptides by incorporation of unnatural amino acids.

To develop antimicrobial peptides exhibiting increased potency and selectivity against Gram positive, Gram negative, and Mycobacterium bacteria coupled with reduced hemolytic activity, peptides containing unnatural amino acids have been designed, synthesized, and evaluated.

Addition of p-azido-L-phenylalanine to the genetic code of Escherichia coli.

We report the selection of a new orthogonal aminoacyl tRNA synthetase/tRNA pair for the in vivo incorporation of a photocrosslinker, p-azido-l-phenylalanine, into proteins in response to the amber

A novel beta-turn mimic useful for mapping the unknown topology of peptide receptors.

Ethers of cis or trans D-4-hydroxyproline (Hype), adjacent to octahydroindole-carboxylic acid (Oic), introduce a beta-turn into the backbone of peptides when positioned respectively at the i+1 and

Adding new chemistries to the genetic code.

The development of new orthogonal aminoacyl-tRNA synthetase/tRNA pairs has led to the addition of approximately 70 unnatural amino acids to the genetic codes of Escherichia coli, yeast, and mammalian cells, which provide new opportunities to generate proteins with enhanced or novel properties and probes of protein structure and function.

A Repertoire of Novel Antibacterial Diastereomeric Peptides with Selective Cytolytic Activity*

The data reveal that modulating hydrophobicity and positive charge is sufficient to confer antibacterial activity and cell selectivity, and proposes a new strategy for the design of a repertoire of short, simple, and easily manipulated antibacterial peptides as potential drugs in the treatment of infectious diseases.