9 research outputs found
beta-Peptido Sulfonamides: For-Met-Leu-Phe-OMe analogues containing taurine and chiral beta-amino-ethanesulfonic acid residues
No full textSynthesis and activity on human neuttrophil functions of fMLF-OMe analogs containing alkyl spacers at the central position
No full textPseudopeptides containing the 2-hydrazonoacyl fragment: analogs of the chemotactic agent HCO-Met-Leu-Phe-OMe
No full textIn order to further examine the properties of pseudopeptides containing the 2-hydrazonoacyl fragment, two new series of analogs of the prototypical chemotactic N-formyl-tripeptide HCO-Met-Leu-Phe-OMe were designed and synthesized. The first group contains the new fragment as the N-terminal residue and is represented by the N-aryl derivatives p-Cl-C6H4-NH-N=C(R)-CO-Leu-Phe-OMe (2 and 3) and by the corresponding N-aroyl analogs p-CH3-C6H4-CO-NH-N = C(R)-CO-Leu-Phe-OMe (4). The second group contains the new fragment in place of the central Leu residue and is represented by compounds HCO-Xaa-NH-N= C(R)-CO-Phe-OMe (7a and 7b) where Xaa is Nle and Met, respectively. The conformational and biochemical properties of the new products were examined
Peptide backbone folding induced by the C alpha-tetrasubstituted cyclic alpha-amino acids 4-amino-1,2-dithiolane-4-carboxylic acid (Adt) and 1-aminocyclopentane-1-carbozylic acid (Ac5c). A joint computational and experimental study
No full textPeptides containing the sulfonamide junction. Part 2. Structure and conformation of Z-Tau-Pro-DPhe-NHiPr.
No full textA New and Efficient Synthesis of Unnatural Amino Acids and Peptides by Selective 3,3-Dimethyldioxirane Side-Chain Oxidation
No full textSynthesis and activity of HCO-Met-Leu-Phe-OMe analogues containing beta-alanine or taurine at the central position
No full textPeptides containing 4-amino-1,2-dithiolane-4-carboxylic acid (Adt): Conformation of Boc-Adt-Adt-NHMe and NH…S interaction
No full textHybrid alpha/beta3-peptides with proteinogenic side chains. Monosubstituted analogues of the chemotactic tripeptide For-Met-Leu-Phe-OMe.
No full textThe alpha/beta3-mixed tripeptides R-CO-beta3-HMet-Leu-Phe-OMe (1a,b), R-CO-Met-beta3-HLeu-Phe-OMe (2a,b) and R-CO-Met-Leu-beta3-HPhe-OMe (3a,b) (a, R = tert-butyloxy-; b, R = H-), analogues of the potent chemoattractant For-Met-Leu-Phe-OMe, have been synthesized by classical solution methods and fully characterized. The activities of the new analogues as chemoattractants, superoxide anion producers and lysozyme releasers have been determined on human neutrophils. Whereas all of the three N-formyl derivatives are significantly less active than the parent tripeptide as chemoattractants, compound 1b has been found to be highly active as a superoxide anion producer and 3b as a lysozyme releaser. The results show that the replacement of the native Leu residue at the central position is, in each of the examined cases, the least favourable modification. The three N-Boc derivatives are, as expected, devoid of activity as agonists, but they are all good inhibitors of chemotaxis. Information on the solution conformation has been obtained by examining the involvement of the NH groups in intramolecular H-bonds using 1H NMR. The conformation of the N-Boc analogue 1a has also been determined in the crystal state by x-ray diffraction analysis. The molecule is extended at the beta3-HMet residue (phi1 = -87 degrees; theta1 = 172 degrees; psi1 = 126 degrees) and no intramolecular H-bond is present
