Nigriventrine: a low molecular mass neuroactive compound from the venom of the spider Phoneutria nigriventer.

Nigriventrine was isolated from the "armed" spider Phoneutria nigriventer, in which it constitutes about 0.4% of the total venom content. Its structure was determined to be [1,1'-(1-hydroxyhydrazine-1,2-diyl)bis(oxy)bis(4-hydroxy-2,6-dioxopiperidine-4 carboxylic acid)] by NMR, HR-ES/IMS and MS/MS methods. The intracerebroventricular application of nigriventrine in rat brain, followed by the detection of c-Fos protein expression, indicated that the compound was neuroactive in the motor cortex, sensory cortex, piriform cortex, median preoptic nucleus, dorsal endopiriform nucleus, lateral septal nucleus and hippocampus of rat brain. Nigriventrine causes convulsions in rats, even when peripherally applied.