Antimicrobial activities of amine- and guanidine-functionalized cholic acid derivatives

Compounds in a series of cholic acid derivatives, designed to mimic the act ivities of polymyxin B and its derivatives, act as both potent antibiotics and effective permeabilizers of the outer membranes of gram-negative bacter ia. Some of these compounds rival polymyxin B in antibacterial activity aga inst gram-negative bacteria and are also very active against gram-positive organisms. Other compounds interact synergistically with hydrophobic antibi otics to inhibit bacterial growth.