Abstract
Melinacidin is a crystalline mixture of closely related antibacterial agents produced by Acrostalagmus cinnabarinus var. melinacidinus. Melinacidin inhibits a variety of Gram-positive bacteria in vitro but is found to be toxic and ineffective in the treatment of experimental bacterial infections in mice. Melinacidin which inhibits the growth of KB and L-1210 cells in tissue culture appears to belong to the "3, 6-epidithiadiketopiperazine" group of antibiotics.