The aerial parts of Trixis pallida afforded seven known trixanolides (18-24
) together with 17 new trixanolides (1-17). Their structures were determine
d by 1D and 2D NMR techniques, while the absolute configuration of the trix
ane skeleton was determined using the Mosher method and turned out to be en
antiomeric to that reported using the Horeau method. This result is further
discussed from the biosynthetic point of view.