Antagonistic effect of serum on bacteriostatic action of lupulone.

Summary1. Lecithin and cephalin are capable of neutralizing the inhibiting properties of lupulone. 2. Evidence is presented indicating that the antagonistic effect of serum on the bacteriostatic action of lupulone is due, at least in part, to its phosphatide content. 3. The inhibition of respiration by lupulone may be reversed by the subsequent addition of plasma.The authors wish to thank Elizabeth A. McComb of this laboratory for the determinations of phosphorus.