ABSTRACT
14-Isovaleryloxy-O-methyl-1,2-dehydrocacalol (1) and cycloart-23-ene-3,25-diol, beta-sitosterol, and stigmasterol, along with five new cacalolides, 1-hydroxy-2-methoxy-1,2,3,4-dehydro-6-dehydroxycacalone (2), 1-hydroxy-2-methoxy-1,2,3,4-dehydrocacalone (3), 1,2-dimethoxy-1,2,3,4-dehydro-6-dehydroxycacalone (4), 1,2-dimethoxy-1,2,3,4-dehydrocacalone (5), and 2-methoxy-O-methyl-1-oxo-2,3-dehydrocacalol (6), were isolated from Senecio madagascariensis collected from Colombia. The structures of the new compounds were determined using one- and two-dimensional NMR techniques. In addition, the structure of 2 was corroborated by derivatizations and single-crystal X-ray diffraction studies.
Subject(s)
Asteraceae/chemistry , Sesquiterpenes/isolation & purification , Crystallography, X-Ray , Magnetic Resonance Spectroscopy , Molecular Structure , Sesquiterpenes/chemistry , Spectrometry, Mass, Fast Atom BombardmentABSTRACT
The roots of Croton sarcopetalus afforded three new diterpenoids (2-4) with a novel carbon skeleton that seems to be derived biosynthetically from a pimarane precursor. The essential oil of the roots gave trans-methylisoeugenol as the main constituent, along with 22 further compounds.
