title: Antigiardial activity of triterpenoids from root bark of Hippocratea excelsa.
abstract: Two new triterpenoids, 21 beta-hydroxyolean-12-en-3-one (1) and a seco-dinor derivative of pristimerine named dzununcanone (2), were isolated from the root bark of Hippocratea excelsa. Their structures were assigned on the basis of spectroscopic evidence, mainly 1H and 13C 1D and 2D NMR including DEPT, COSY, ROESY, HSQC, and HMBC experiments, as well as EIMS and HREIMS. The known 21alpha-hydroxy-3-oxofriedelane (3), a compound new to the species, and the known methide quinones pristimerine (4) tingenone (5), and xuxuarine Ebeta (7) were also isolated. The antiprotozoal activities were determined against Giardia intestinalis. Pristimerine and tingenone were the most active antigiardial compounds, with IC50 values of 0.11 and 0.74 microM, respectively, compared with metronidazole, the current drug of choice (IC50 1.23 microM).
authors: Laboratorio de Química OrgAnica de Investigación, Facultad de Química, Universidad Autónoma de YucatAn, Calle 41 No. 421, Col. Industrial, C. P. 97105, Mérida, YucatAn, México. quijano@servidor.unam.mx
authors: Gonzalo J
authors: GJ
authors: Mena-Rejón
authors: Aida R
authors: AR
authors: Pérez-Espadas
authors: Rosa E
authors: RE
authors: Moo-Puc
authors: Roberto
authors: R
authors: Cedillo-Rivera
authors: I L
authors: IL
authors: Bazzocchi
authors: I A
authors: IA
authors: Jiménez-Diaz
authors: Leovigildo
authors: L
authors: Quijano
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D016829:Giardia lamblia / Q000187:drug effects*; D031320:Hippocrateaceae / Q000737:chemistry*; D008800:Mexico; D015394:Molecular Structure; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: C521032:21 beta-hydroxyolean-12-en-3-one; D000981:Antiprotozoal Agents; D014315:Triterpenes; C521033:dzununcanone