The mode of action of levallorphan as an inhibitor of cell growth.

It has been reported! by Simon 1) that several synthetic analogs of the morphine series are strong inhibitors of bacterial growth. Simon attributes this effect to selective inhibition of ribosomal RNA synthesis (2, 3). We have studied the effects of the most potent of these drugs, levallorphan tartrate, on macromolecular synthesis in Escherichia coli. This d!rug was selected for study because it is not classified as a narcotic and! because it is more soluble than its narcotic analog, levorphanol. of this drug on energy metabolism. We find that the drug brings about the disappearance of intracellular nucleotide triphosphates. A brief report of these results has been published (4).