Synthesis and evaluation of strand and turn modified ring-extended gramicidin S derivatives

In this paper, we describe the crystal structure of previously reported ring-extended gramicidin S (GS) derivative 2 (GS14K4), containing a d-amino acid residue in one of the β-strand regions. This structure is in agreement with a previously reported modeling study of the same molecule. The polar side chain of the additional d-amino acid residue...

Tuning hydrophobicity of highly cationic tetradecameric Gramicidin S analogues using adamantane amino acids

Ring extended Gramicidin S analogues containing adamantane amino acids and six cationic residues were designed and evaluated. Systematic replacement of the hydrophobic residues with adamantane amino acids resulted in a small set of compounds with varying amphipathic character. It was found that the amphipathicity of these compounds is correlated...

Structural and biological evaluation of some loloatin C analogues

Loloatin C is a cyclic cationic antimicrobial peptide which is active against Gram positive as well as certain Gram negative bacteria. Unfortunately, it is equally potent against human erythrocytes. To probe the structure-activity relationship of this promising antibiotic peptide, amino acid substitution and/or incorporation of a constraint...