A convenient route for the synthesis of Fmoc-protected phosphinic dipeptide building blocks is described. The protected amino acid isosteres benzyloxycarbonyl aminomethyl phosphinic acid (glycine surrogate), benzyl α-isopropyl acrylate (valine surrogate), and benzyl α-isobutyl acrylate (leucine surrogate) were synthesized starting from commercially available materials. Reaction of either the va...

α-amino nitriles are synthesized in a one-pot, three-component coupling of aldehydes (or ketones), aniline, and trimethylsilyl cyanide using a catalytic amount of choline chloride.2zncl2 as a bio lewis acidic ionic liquid. mild lewis acidic characteristic of this ionic liquid allows efficient synthesis of α-amino nitriles from acid sensitive aldehydes.

quorum sensing controls the luminescence of vibrio fischeri through the transcriptional activator luxr and the specific autoinducer signal produced by luxi. amino acid sequences of these two genes were analyzed using bioinformatics tools. luxi consists of 193 amino acids and appears to contain five α-helices and six ß-sheets when analyzed by sspro8. luxi belongs to the autoinducer synthetase fa...

N-Protected amino acids can be easily converted into chiral α-amino aldehydes in a one-pot reaction by activation with CDI followed by reduction with DIBAL-H. This method delivers Boc-, Cbz- and Fmoc-protected amino aldehydes from proteinogenic amino acids in very good isolated yields and complete stereointegrity.

A new class of N-linked protein glycosylation - arginine rhamnosylation - has recently been discovered as a critical modification for the function of bacterial elongation factor P (EF-P). Herein, we describe the synthesis of suitably protected α- and β-rhamnosylated arginine amino acid "cassettes" that can be directly installed into rhamnosylated peptides. Preparation of a proteolytic fragment ...

An efficient method for synthesis of cyclohexyl and cyclohexenyl α-amino acids via palladium-catalyzed three-component assemblies followed by ring-closing metathesis (RCM) is described. The present catalytic reaction is successfully extended to substituted benzylidene azlactones 2a-j RCH=(1,3-oxazole): R = alkyl or aryl. The amphiphilic bis-allylation of these substrates has been achieved by re...

Pd-catalyzed C-H functionalization of mandelic acid and α-phenylglycine is reported. We have developed different protocols for the arylation, iodination, acetoxylation, and olefination of these substrates based on two different (Pd(II)/Pd(IV) and Pd(II)/Pd(0)) catalytic cycles. Four crucial features of these protocols are advantageous for practical applications. First, the α-hydroxyl and amino ...

amino acid dehydrogenases (l-amino acid: oxidoreductase deaminating ec 1.4.1.x) are members of the wider superfamily of oxidoreductases that catalyze the reversible oxidative deamination of an amino acid to its keto acid and ammonia with the concomitant reduction of either nad+, nadp+ or fad. these enzymes have been received much attention as biocatalysts for use in biosensors or diagnostic kit...

abstract bee venom is a complex mixture of proteins, peptides and low molecular components: proteins (enzymes) :( phospholipase, a2phospholipase b, hyaluronidase α – glucosidase) - , peptides (melittin, apamine mcd peptide,adolapine ,procamine a and b, protease inhibitors)- low molecular components: biogenic amines:( histamine, dopamine and noradrenalin) - pheromones: complex ethers- sugars :( ...