Pamburus missionis root contained imperatorin and 7-hydroxy-8-(3′,7′-dimethylocta-2′,6′-dien)ylcoumarin and a new natural product, 3-(3-methyl-1-oxo-2-butenyl) 1H indole, its stem bark imperatorin and xanthotoxin and its fruit xanthyletin, xanthotoxin, isopimpinellin, scopoletin and luvangetin. The insecticidal activity of the stem bark is shown to be due to imperatorin and xanthyletin. © 1994.