Sesquiterpenoids from the rhizomes of Homalomena occulta.

ABSTRACT

Phytochemical investigation on the rhizomes of Homalomena occulta resulted in the isolation of five new sesquiterpenoids, namely cadinane-4ß,5α,10α-triol (1), 5(11)-epoxycadinane-4ß,5ß,10ß,11-tetraol (2), bullatantiol-1ß-methyl malate (3), 1ß,4ß,7α-trihydroxyeudesmane-1ß-methyl malate (6), and 1ß,4α,7-trihydroxyeudes-mane (7), together with five known sesquiterpenoids, bullatantriol (4), acetylbullatantriol (5), 1ß,4ß,7α-trihydroxyeudesmane (8), 1ß,4ß,7ß-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.