Sesquiterpenoids from the rhizomes of Homalomena occulta.

Phytochemical investigation on the rhizomes of Homalomena occulta resulted in the isolation of five new sesquiterpenoids, namely cadinane-4β,5α,10α-triol (1), 5(11)-epoxycadinane-4β,5β,10β,11-tetraol (2), bullatantiol-1β-methyl malate (3), 1β,4β,7α-trihydroxyeudesmane-1β-methyl malate (6), and 1β,4α,7-trihydroxyeudes-mane (7), together with five known sesquiterpenoids, bullatantriol (4), acetylbullatantriol (5), 1β,4β,7α-trihydroxyeudesmane (8), 1β,4β,7β-trihydroxyeude-smane (9), and pterodontriol (10). Their structures were elucidated on the basis of spectroscopic evidences, including various 1D and 2D NMR and HR-ESI-MS. The structure of 1 was further confirmed by single-crystal X-ray diffraction analysis. Georg Thieme Verlag KG Stuttgart · New York.