Martínez, RolandoKesternich, VictorCarracso, HéctorÁlvarez-Contreras, Carolina...[et al.].2014-02-252016-05-242014-02-252016-05-242006Journal of the Chilean Chemical Society. Vol. 51. N° 4, 2006.0717-9707http://dx.doi.org/10.4067/S0717-97072006000400003http://repositorio.unab.cl/xmlui/handle/ria/2366Indexación: ScieloABSTRACT The reaction in acidconditions of Leptocarpin 1, a compound with antitumor activity, formed two new isomeric products, 8b-angeloyl-1b,3b-dihydroxy-4,10-dimethyl,-D11(13) methylen-4Z,9Z-dieneheliangol-6,12-olide 2 and 8b-angeloyl-1b,3b-dihydroxy-4-methyl-D11(13),D11(14)-dimethylen-4Z-eneheliangol-6,12-olide 3, whose structures reported in this study were established by spectroscopy (1H-NMR, 13C-NMR, MS and IR) and confirmedthrough ROESY experiments and theoretical studies by molecular mechanics. The in vitro cytotoxicity of these isomeric compounds was less active than leptocarpin, showing the importance of the oxirane ring in the biological activity. Cytotoxic activity was measured in six cancer cell lines. Keywords: Conformational analysis; Heliangolide; Sesquiterpene lactones; Cytotoxicity.enConformational analysis; Heliangolide; Sesquiterpene lactones; Cytotoxicity.Artículo