The Structure of Hormaomycin and One of Its All-Peptide Aza-Analogues in Solution: Syntheses and Biological Activities of New Hormaomycin Analogues
作者:Uwe M. Reinscheid、Boris D. Zlatopolskiy、Christian Griesinger、Axel Zeeck、Armin de Meijere
DOI:10.1002/chem.200400977
日期:2005.1
Four newaza-analogues of hormaomycin 1, a secondary metabolite with interesting biologicalactivities produced by Streptomyces griseoflavus, were synthesized and subjected to preliminary tests of their antibiotic activity to provide new insights into the structure-activity relationship studies of this class of compounds. The solutionstructures of hormaomycin 1 and itsaza-analogue 2 a were determined
Use of .beta.-Methylphenylalanine (.beta.MeF) Residues To Probe the Nature of the Interaction of Substance P with Its Receptor: Effects of .beta.MeF-Containing Substance P Analogs on Rabbit Iris Smooth Muscle Contraction
作者:David M. Birney、Derek C. Cole、Craig E. Crosson、Brenda F. Kahl、Bart W. Neff、Ted W. Reid、Kaijun Ren、Robert D. Walkup
DOI:10.1021/jm00013a024
日期:1995.6
The effects of substituting (2S,3S)-beta-methylphenylalanine (S-beta MeF) or (2S,3R)-beta-methylphenylalanine (R-beta MeF) for the Phe(7) and/or Phe(8) residues of the tachykinin substance P (SP, RPKPQQFFGLM-NH2) upon the ability of SP to stimulate contraction of the rabbit iris smooth muscle were investigated. The eight beta MeF-containing SP analogs (four monosubstituted analogs, four disubstituted analogs) 1-8 were synthesized and found to be agonists of SP in the smooth muscle contraction assay, having EC(50) values ranging from 0.15 to 10.0 nM. Three analogs are significantly more active than SP [8R-(beta MeF)SP (4), 7S,8S-(beta MeF)(2)SP (5), and 7R,8S-(beta MeF)(2)SP (6)], three analogs are approximately equipotent with SP [7S-(beta MeF)SP (1), 7R-(beta MeF)SP (2), and 7S,8R-(beta MeF)(2)SP (8)], and two analogs are significantly less active than SP [8S-(beta MeF)SP (3) and 7R,8R-(beta MeF)(2)SP (7)]. The effects of the beta MeF substitutions upon the activity of SP are not additive and cannot be explained using simple conformational models which focus only on the side chain conformations of the beta MeF residues. It is postulated that the beta MeF residues induce minor distortions in the peptide backbone with resultant consequences upon peptide-receptor binding which are not dictated solely by the side chain conformations. This idea is consistent with H-1-NMR data for the monosubstituted analogs 1-4, which imply that the beta MeF substitutions cause slight distortions in the peptide backbone and that the beta MeF side chains are assuming trans or gauche(-) conformations.