A Novel 3,9-(1,2,3-Trioxocine)-Type Steroid of Rauia nodosa (Rutaceae)

A new natural product, a 3,9-(1,2,3-trioxocine)-type steroid, named rauianodoxy ( 6), was isolated from Rauia nodosa, together with five steroids: sistostenone ( 1), stigmastenone ( 2), sitosterol ( 3), stigmasterol ( 4) and ergosterol peroxide ( 5), one coumarin, O-geranylosthenol ( 7), and three alkaloids, N-methylflindersine ( 8), zantobungeanine ( 9) and veprissine ( 10). Compounds 5– 8 were isolated for the first time in the genus Rauia. These compounds were characterized on the basis of their spectral data, mainly one and two-dimensional NMR, and mass spectra, also involving comparison with the literature data. Theoretical studies at the DFT level reveal structural parameters for the 1,2,3-trioxole bridge compatible with known structures containing a similar group.