A new dimeric alkaloid, psylloborine A (3), was identified from the 22-pointed ladybird beetle Psyllobora vigintiduopunctata (L.). Psylloborine A exhibits an unusual heptacyclic ring system, derived from two azaphenalene units. Structural assignment was based on NMR-spectroscopic methods, using E.COSY experiments for the analysis of the highly complex spin systems. (C) 1998 Elsevier Science Ltd. All rights reserved.