Ampelozizyphus amazonicus Ducke is a tree commonly found in the Amazon region and an extract of its stem bark is popularly used as an antimalarial and anti-inflammatory agent and as an antidote to snake venom. Ursolic acid; five lupane type triterpenes: betulin, betulinic acid, lupenone, 3ß-hydroxylup-20(29)-ene-27,28-dioic acid, and 2α,3ß-dihydroxylup-20(29)-ene-27,28-dioic acid, and three phytosteroids: stigmasterol, sitosterol and campesterol, have been isolated from stem extracts of A. amazonicus Ducke. Their structures were characterized by spectral data including COSY and HMQC. In an in vitro biological screening of the isolated compounds, 3ß-hydroxylup-20(29)-ene-27,28-dioic acid was cytotoxic against the SKBR-3 human adenocarcinoma cell line (1 to 10 mg/mL), while 2α,3ß-dihydroxylup-20(29)-ene-27,28-dioic acid exhibited cytotoxicity against both SKBR-3 human adenocarcinoma and C-8161 human melanoma tumor cell lines (>0.1 mg/mL). In the present study, different extracts and some fractions of this plant were also investigated for trypanocidal activity due to the presence of pentacyclic triterpenes. The triterpene classes are potent against Trypanosoma cruzi. The bioassays were carried out using blood collected from Swiss albino mice by cardiac puncture during the parasitemic peak (7th day) after infection with the Y strain of T. cruzi. The results obtained showed that A. amazonicus is a potential source of bioactive compounds since its extracts and fractions isolated from it exhibited in vitro parasite lysis against trypomastigote forms of T. cruzi at concentrations >100 µg/mL. Fractions containing mainly betulin, lupenone, 3ß-hydroxylup-20(29)-ene-27,28-dioic acid, and 2α,3ß-dihydroxylup-20(29)-ene-27,28-dioic acid showed more activity than crude extracts.

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Ochratoxin A was produced, at concentrations of about 200 mg kg1 of dry beans (Phaseolus vulgaris L.) of each of five Brazilian commercial varieties. Both intact and decorticated kernels of the varieties Preto, Branco, Rosinha, Roxo and Carioca (22% moisture) were inoculated withAspergillus alutaceous and incubated at 25°C for 28 days. Results from thin-layer and column chromatography, mass, infrared, 1H-nuclear magnetic resonance and UV-spectrometry showed that 1) the common bean is a highly stimulatory substrate for the bioproduction of ochratoxin A and 2) the putative toxin extracted by the method of Soares & Rodriguez-Amaya was in fact ochratoxin A. Removal of the seed coat resulted in increased OTA production for all varieties, particularly for the Rosinha, Roxo and Carioca.