Philanthotoxin-433 (PhTX-433), a non-competitive glutamate receptor inhibitor

Abstract

A polyamine toxin present in the venom sac of the solitary digger wasp Philanthus triangulum, first noted by T. Piek, has been isolated, characterized, and synthesized. This toxin, philanthotoxin-433 (PhTX-433), having a butyryl/tyrosyl/polyamine structure, is a potent noncompetitive inhibitor of the quisqualate sub-type glutamate receptor as assayed by the twitch contraction of locust leg muscles. It is also an allosteric inhibitor of acetylcholine receptors of vertebrates. About sixty analogs of PhTX have been synthesized in order to clarify structure/activity relationships and to select candidates suitable for isolating the glutamate receptor by photoaffinity label and/or affinity label. © 1990 IUPAC