Selective inhibition of the bacterial peptidoglycan biosynthesis by the new types of liposidomycins

We examined the inhibitory activity against bacterial peptidoglycan biosynthesis, mammalian glycoprotein biosynthesis and growth of BALB/3T3 cells of four different types of liposidomycins which have the structure with or without sulfate and/or 3-methylglutaric acid moieties. Liposidomycins inhibited peptidoglycan biosynthesis about 30∼500 times more effectively than tunicamycin, whereas liposidomycins inhibited mammalian glycoprotein biosynthesis about 30∼300 times less effectively than tunicamycin. When the cytotoxic effect of liposidomycins and tunicamycin on the growth of mammalian cells were compared, liposidomycins did not show toxicity against BALB/3T3 cell at 25 μg/ml, though tunicamycin inhibited cell growth by 50% at 0.05 μg/ml. On the basis of these results, it is concluded that liposidomycins are selective antibiotics showing highly specific inhibition toward bacterial peptidoglycan biosynthesis.