An improved synthesis of a family of amino acids that contain ω-aminoalkyl groups and of a new family containing ω-carboxyalkyl groups linked to the R-amine is described. The synthesis was performed by alkylation of suitably monoprotected alkylenediamines and protected ω-amino acids with triflates of R-hydroxy acid esters. The reaction proceeded with inversion of configuration yielding opticall...

Microorganisms such as bacteria, fungi and some plants secrete an abundance of suites of low molecular weight, high-affinity iron(iii)-chelating acylated siderophores. The peptide composition of a suite of amphiphilic siderophores generated by a Vibrio species, isolated from oligotrophic open ocean water, contained the same iron(iii)-scavenging polar head group and is attached to a fatty acid. ...

A variety of chiral N-phosphinyl α-imino esters have been synthesized for the first time from ketoesters and phosphinylamide, which were then reduced by L-selectride to give the corresponding N-phosphinyl-protected α-amino esters. The reduction proceeded very well with excellent chemical yields (88-98%) as well as high diastereoselectivities (96:4 to 99:1). Some of these products could be obtai...

an experiment was conducted to reevaluate the digestible lysine requirement of arian male broilers by comparing the performance of chicks fed different levels of cottonseed meal (csm) on a total amino acid (aa) versus a digestible aa basis. four hundred and thirty two (432) arian male broiler chicks were allotted to 18 treatments with four repli-cates of six chicks each in a completely randomiz...

A new class of peptidomimetic is reported in which one of the amide C=O bonds of the peptide backbone is replaced by an oxetane ring. They are synthesised by conjugate addition of various α-amino esters to a 3-(nitromethylene)oxetane, reduction of the nitro group and further coupling with N-Z protected amino acids to grow the peptide chain. Structural insights are provided by X-ray diffraction ...

Abbreviations: ACC: 1-Amino-cyclopropane-1-carboxylic acid ADC: arginine decarboxylase AgNO3: silver nitrate AVG: aminoethoxyvinylglycine BA: 6-benzylaminopurine DFMA: α-DL-difluromethyl arginine DFMO: α-DL-difluromethyl ornithine IAA: indole acetic acid NAA: α-naphthalene acetic acid ODC: ornithine decarboxylase PA: polyamine Put: putrescine SAM: S-adenosyl-Lmethionine STS: silver thiosulphate...

Unnatural chiral α-amino acids are widely used in fields of organic chemistry, biochemistry and medicinal chemistry, and their synthesis has attracted extensive attention. Although the asymmetric synthesis provides some efficient protocols, noble and elaborate catalysts, ligands and additives are usually required which leads to high cost. Distinctly, it is attractive to make unnatural chiral α-...

The X-ray crystal structure of arginase from Schistosoma mansoni (SmARG) and the structures of its complexes with several amino acid inhibitors have been determined at atomic resolution. SmARG is a binuclear manganese metalloenzyme that catalyzes the hydrolysis of l-arginine to form l-ornithine and urea, and this enzyme is upregulated in all forms of the parasite that interact with the human ho...

Genetic code redundancy would yield, on the average, the assignment of three codons for each of the natural amino acids. The fact that this number is observed only for incorporating Ile and to stop RNA translation still waits for an overall explanation. Through a Structural Bioinformatics approach, the wealth of information stored in the Protein Data Bank has been used here to look for unambigu...