A new sesquiterpene lactone from Elephantopus tomentosus

A new sesquiterpene lactone, named tomenphantopin H (1), together with two known germacranolides, 2β-methoxy-2-deethoxy-8-O-deacylphantomolin-8-O-tiglinate (2) and 2-deethoxy-2-hydroxyphantomolin (3), was isolated from the whole plant of Elephantopus tomentosus Linn. The new compound was completely elucidated using a combination of 1D and 2D NMR techniques (COSY, HMQC, and HMBC) and HR-ESI-MS analyses. All compounds exhibited antibacterial activity.