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).

The in vitro cytotoxic activity of hexane, ethyl acetate and butanol extracts of the sea-cucumber Isostichopus badionotus (Holothuroidea) was tested against normal cells (Vero), human cervical carcinoma (HeLa) and breast adenocarcinoma (MCF-7 and MDA-MB-231) ATCC cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Hexane extracts from body walls and viscera showed high cytotoxic activity against HeLa cells (IC50's = 48.5 and 42.5 g mL-1 , respectively), while the ethyl acetate extract of body walls was considered low active (IC50 = 98.3 μg mL-1). In addition, the body walls hexane extract showed a good selectivity index value of 12.0.