Walrobsins A (1) and B (2), two limonoids featuring an unprecedented 5-oxatricyclo[5.4.11,4]hendecane ring system, were isolated from the root barks of Walsura robusta. Their structures, including their absolute configurations, were determined by analyses of HR-ESIMS, 1D/2D NMR, and X-ray
Screening active natural products, rapid identification, and accurate isolation are of great important for modern natural lead compounds discovery1. We hereby reported the isolation of seven new neotecleanin-type limonoids (1-7), seven new limonoids with