Valérie Rolland-Fulcrand

Rapid solid phase synthesis of α-amino acids

Abstract A solid phase synthetic method for amino acids is developed. The N-acetyl-dehydroalanine is quatitatively bound to Wang resin by the Mitsunobu method. Then a Michael addition is achieved on the double bond with different nucleophiles. Non proteinic N-acetyl-α-amino acids are obtained after cleavage from the resin by mild acid treatment (Scheme 1).

Efficient chemoenzymatic synthesis of enantiomerically pure β-heterocyclic amino acid derivatives

Abstract Enantiomerically pure ( S )-pyrazolyl alanine and its derivatives are nonproteinogenic amino acids with antidiabetic activity. A short and effective enantioselective synthesis of these compounds is described, using a kinetic resolution by an acylase from Aspergillus sp.

Synthesis of enantiomerically pure (3R,4R,5R)-4-hydroxy isoleucine lactone

Abstract A short four-step synthesis of (3 R ,4 R ,5 R )-4-hydroxyisoleucine lactone with total control of stereochemistry is reported, the key intermediate being the didehydroamino acid derivative arising from an aldol dehydration reaction between a glycine anion equivalent and butan-2,3-dione.

CHEMOENZYMATIC SYNTHESIS OF THE TWO ENANTIOMERS OF 7-AZATRYPTOPHAN

Abstract 7-Azatryptophan is an unnatural α-amino acid with a very potent fluorescent activity. It is used as a vehicle for probing the structure and dynamics of proteins and peptides. Diastereoselective alkylation, diastereoselective protonation and enzymatic resolution have been tested for preparing enantiomerically pure 7-azatryptophan.

Detection of enzyme activity at trace levels: A new perspective for the direct screening of active catalytic antibodies

A very low level of enzyme activity (10−11 mol) has been detected using a PCR method following a vector hybridisation of a supported oligonucleotide. This methodology could be very useful for direct active catalytic antibody screening from a combinatorial library.

Enzymatic peptide synthesis by new supported biocatalysts

SummaryIt is well known that proteases can be successfully used for peptide synthesis in aqueous medium or in water-containing organic solvents. Copolymerized of acrylated derivatives ofα-chymotrypsin and polyethylene glycol (PEG) have been prepared and used as biocatalysts for the synthesis of model peptides in organic solvents containing a very low quantity of water. Trypsin has been similarly treated and used as a new biocatalyst particularly for the coupling of non-specific substrates.

Chemo-Enzymatic Synthesis of New Non Ionic Surfactants from Unprotected Carbohydrates

ABSTRACT The synthesis of new non ionic surfactants is reported. They were prepared from unprotected carbohydrates, amino acids, and fatty alcohols. These modules were linked by enzymatic esterification and transesterification reactions catalysed by lipases and proteases in organic media.

Enzymatic esterification and transesterification of N-protected Glu or Asp and synthesis of sweetener aspartam analogues by a new glutamic acid specific endopeptidase

Esterification and transesterification reactions are carried out in water miscible organic solvents by using a new glutamic acid specific endopeptidase, isolated from Bacillus lichenifonnis. Sweetener aspartam analogues syntheses are also described.