Isolation of the two paragonial substances deposited into the spermatophores ofAcanthoscelides obtectus (Coleoptera,Bruchidae)

Summary Aqueous extracts from spermatophores ofAcanthoscelides obtectus (Coleoptera, Bruchidae) have been chromatographed on Sephadex G 25 and G 15 columns, the active fractions being further purified by preparative SiO₂ TLC. The isolation and properties of 2 biologically active compounds are reported. The paragonial substance A has a favourable action upon oogenesis, is a low molecular weight molecule (500–1000) and gives 1 single amino acid on hydrolysis, corresponding to glycin on TLC. The paragonial substance B is toxic, or an inhibitor of oogenesis at lower concentration, thus showing an antagonistic effect.