Sesamin from the roots of YErba mansa (Anemposis californica)

Anemopsis californica, a plant native to the southwestern United States and Northern Mexico, has a long history of use by Native Americans to treat infection. The goal of these studies was to identify chemical constituents of this sparsely studied plant. A crude extract of A. californica was shown to inhibit the growth of clinical isolates of Mycobacterium avium and Mycobacterium marinum. This extract underwent several steps of bioactivity-directed fractionation and purification with normal and reversed phase chromatography. Sesamin (1), a tetrahydrofuran derivative, was isolated from the active fractions, and characterized by NMR spectroscopy and X-ray crystallography. The compound demonstrated a MIC of 20µg/mL against several mycobacterium species. This is the first report of sesamin produced by a plant in the Saururaceae plant family. Efforts to characterize additional bioactive compounds from A. californica are ongoing.