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.