As a result of screening for Dragendorff-positive substances of fungal origin, from wheat bran cultures, 2 new metabolites named nigerazine B (I) and A (II) were isolated from Asp. niger 1-639. The structure of the main component, nigerazine B, was determined to be N-methyl-trans-2,5 dimethyl-N'-cinnamoyl-piperazine from the physicochemical data and confirmed by synthesis. It was inactive against the microorganisms tested, but exhibited some inhibitory activity toward the root growth of lettuce seedlings.