(2R-trans)-2-butyl-5-heptylpyrrolidine as a potent sigma receptor ligand produced by Streptomyces longispororuber.

A potent sigma (sigma) receptor ligand was isolated from the culture broth of Streptomyces longispororuber #525. The active compound was identified to be (2R-trans)-2-butyl-5-heptylpyrrolidine by spectroscopic and chemical studies. The compound exhibited high affinity and selectivity for sigma receptors. The IC50 values toward sigma1, sigma2 and dopamine D2 receptors were 2.0, 22.7 and more than 40,000 nM, respectively. Its (2S-trans)- and (+/-)-cis-isomers, both synthesized, were also found to be high affinity sigma ligands.