New Insecticidal Tetradecahydroxanthenediones from <i>Callistemon viminalis</i>

Abstract

Two novel epimeric compounds, viminadione A ( 1 ) and viminadione B ( 2 ), have been isolated by bioassay-guided fractionation of the aerial parts of Callistemon viminalis and their structures (including relative stereochemistry at C-7, C-8, and C-9) elucidated by spectroscopic methods. Viminadione A ( 1 ) exhibits moderate insecticidal activity in comparison with natural pyrethrum extract. Viminadione B ( 2 ) is less active.