[Antibacterial peptides (18). Synthesis and antibacterial activity of alpha-acyltetrapeptides containing basic amino...

Three kinds of (formula; see text) were synthesized to investigate the relationship between the chemical structure and the antibacterial activities by acylation of the corresponding tetrapeptides. Acyl chlorides of (+)-6-Methyloctanoic acid (a component of colistin) and two kinds of other organic acid were employed as acylating agents. It was proved that one of three, (formula; see text) shows antibacterial activity against four kinds of Gram-negative bacteria and against Gram-positive bacteria, but that the other only have weak antibacterial activity.