Plasmid-linked Galactose Utilization by Lactobacillus acidophilus TK8912

A gramicidin S analog (Orn^1,1′]GS·4HCl) containing L-oroithine in place of L-valine at the 1,1′ positions was synthesized by the conventional solution method in order to examine whether this analog had antibacterial activity toward Gram-negative bacteria. In the synthesis of Orn^1,1′]GS·4HCl, two intermediate analogs (Orn^1,1′, Orn(For)^2,2′]GS·2HCl and Orn(Z)^1,1′]GS·2HCl) were obtained. Orn^1,1′]GS·4HCl and Orn,^1,1′, Orn(For)^2,2′]GS·2HCl showed no activity toward either Gram-negative or Gram-positive bacteria, whereas Orn(Z)^1,1′]GS 2HCl showed appreciable activity toward only Gram-positive bacteria.