Glutamate receptor antagonists from the spider Argiope lobata venom

Homologous low molecular weight compounds blocking postsynaptic glutamate receptors were isolated from the Argiope lobata spider venom by ion-exchange chromatography and reverse-phase HPLC. Structures of nine different blocking agents were determined by NMR and mass spectroscopy. They can be divided into three groups: argiopin, argiopinins and pseudoargiopinines. The major principles of the structural organization of the novel class of antagonists of glutamate receptors were considered.