Synthetic Aspects of Biologically Active Cyclic Peptides: Gramicidin S and Tyrocidines

active ester activity of gramicidin AM-toxin amino acid amino acid residues amino group analogs containing analogs of gramicidin antibacterial activity antibiotic azide Bacillus brevis bacteria Biochem biological activity biosynthesis Chem chemical synthesis chromatography cidin compound conformation cyclic monomer cyclic peptides d-amino D-Phe D-phenylalanine decapeptide dehydroalanine dimer enzyme ethanol formation gramicidin S analogs heavy enzyme hydrogen bonds hydrophobic ibid inhibition interaction isolated Izumiya kind permission Kyoritsu Shuppan L-Leu L-leucine L-Orn L-Pro L-proline L-Val L. C. Craig leucine light enzyme linear decapeptide linear pentapeptide linear peptide Makisumi membrane Minimum inhibitory concentration mixture molecular molecule monomer N-hydroxysuccinimide natural gramicidin obtained ornithine Ovchinnikov p-nitrophenyl ester pentapeptide peptide antibiotics peptide bond peptide chain permission of Kyoritsu poly-(Orn protein protons pyridine Reproduced by kind Schwyzer showed shown in Fig side chains similar soluble spectra ẞ-sheet structure ẞ-turn studies synthesis of gramicidin tyrocidine valine Waki yield µg/ml