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This study assessed the diversity of cultivable rock-associated fungi from Atacama Desert. A total of 81 fungal isolates obtained were identified as 29 Ascomycota taxa by sequencing different regions of DNA. Cladosporium halotolerans, Penicillium chrysogenum and Penicillium cf. citrinum were the most frequent species, which occur at least in four different altitudes. The diversity and similarity indices ranged in the fungal communities across the latitudinal gradient. The Fisher-α index displayed the higher values for the fungal communities obtained from the siltstone and fine matrix of pyroclastic rocks with finer grain size, which are more degraded. A total of 23 fungal extracts displayed activity against the different targets screened. The extract of P. chrysogenum afforded the compounds α-linolenic acid and ergosterol endoperoxide, which were active against Cryptococcus neoformans and methicillin-resistance Staphylococcus aureus respectively. Our study represents the first report of a new habitat of fungi associated with rocks of the Atacama Desert and indicated the presence of interesting fungal community, including species related with saprobes, parasite/pathogen and mycotoxigenic taxa. The geological characteristics of the rocks, associated with the presence of rich resident/resilient fungal communities suggests that the rocks may provide a favourable microenvironment fungal colonization, survival and dispersal in extreme conditions.

Paracoccidioidomycosis (PCM), a human mycosis caused by the dimorphic fungus Paracoccidioides brasiliensis, is a serious public health problem in several countries of Latin America. In our search we found that the crude extract of the endophytic fungus UFMGCB 551 was able to inhibit several clinical strains of P. brasiliensis, and was also active in the bioautographic assay against Cladosporium sphaerospermum. The endophytic fungus UFMGCB 551 was isolated from the plant Piptadenia adiantoides J.F. Macbr (Fabaceae). The fungus was identified as Fusarium sp. based on its macro- and micro-morphology, and on the sequence of the internally transcribed spacer regions (ITS) of its rRNA gene. The chromatographic fractionation of the fungal extract was guided by the bioautographic assay to afford three known trichothecene mycotoxins: T2-toxin (1) and a mixture of 8-n-butyrylneosolaniol (2) and 8-isobutyrylsolaniol (3). The minimal inhibitory concentrations (MIC) of the these compounds against eleven clinical strains of P. brasiliensis were evaluated and found to be in the range between 75 and 640 nmol l(-1) for 1 and 160-640 nmol l(-1) for the mixture of 2 and 3.

Piperaceae is a family of tropical plants known to have antifungal, antibacterial, tumour-inhibitory, antiviral, antioxidant, molluscicidal and leishmanicidal activities. In this work, extracts and fractions from aerial parts of Piper abutiloides (Piperaceae), a traditional medicinal plant, were evaluated against the fungal species Candida albicans, C. parapsilosis, C. krusei, C. glabrata, C. tropicalis, Cryptococcus neoformans and Sporothrix schenckii. The results have shown that the antifungal activity of this plant can be concentrated in the hexanic fraction after partitioning its hydroalcoholic extract between hexane and 90% aqueous methanol. The chromatographic fractionation of the bioactive part was monitored with a bioautographic assay using C. glabrata, and allowed the isolation of three antifungal compounds: pseudodillapiol, eupomatenoid-6 and conocarpan. These compounds presented different potencies against the fungi tested, with the strongest effect being observed for eupomatenoid-6 against C. glabrata, which presented a minimal inhibitory concentration value of 0.3 microg spot(-1). Conocarpan showed antifungal activity without apparent cytotoxic effect on normal human lymphocytes, as assessed by the proliferation assay with human peripheral blood mononuclear cells stimulated with phytohaemaglutinin. This work reveals for the first time the occurrence of these compounds in P. abutiloides and justifies further studies to clarify their mechanisms of action.

There is an urgent need for effective leishmanicidal drugs to replace or supplement those in current use. Our group has been bioprospecting many Brazilian plants looking for potential new ‘hits’ to combat leishmaniasis. We found that Baccharis platypoda was one of the Asteraceae species that displayed leishmanicidal activity. We now describe the isolation of the new clerodane diterpene (1), named platypodiol after its ethanolic leaf extract. Its structure was determined by detailed NMR and ESI-TOF/MS/MS experiments. Considering the few publications about this species, this result has increased the phytochemical knowledge about B. platypoda.

Due to its intricate internal biological structure the process of anaerobic digestion is difficult to control. The aim of any applied process control is to maximize methane production and minimize the chemical oxygen demand of the effluent and surplus sludge production. Of special interest is the start-up and adaptation phase of the bioreactor and the recovery of the biocoenose after a toxic event. It is shown that the anaerobic digestion of surplus sludge can be effectively modeled by means of a hierarchical system of neural networks and a prediction of biogas production and composition can be made several time-steps in advance. Thus it was possible to optimally control the loading rate during the start-up of a non-adapted system and to recover an anaerobic reactor after a period of heavy organic overload. During the controlled period an optimal feeding profile that allowed a minimum loading rate of 6 kg COD m−3 d−1 to be maintained was found. Maximum loading rates higher than 12 kg COD m−3 d−1 were often reached without destabilizing the system. The control strategy resulted simultaneously in a high level of gas production of about 3 m3biogas m−3reactor and a methane content in the biogas of about 70%. To visualize the effects of the control strategy on the reactor's operational space the data were processed using a data-mining program based on Kohonen Self-Organizing Maps. Copyright © 2003 Society of Chemical Industry

The ability of up-regulatory [recombinant (r) IFN-γ, rIFN-β and rTNF-α] and down-regulatory (rIL-4, rIL-10 and rIL-13) cytokines to control the expression of indoleamine 2,3-dioxygenase (INDO) and anti-Toxoplasma activity in the human fibrosarcoma cell line 2C4 was evaluated. Activation of fibroblasts with rIFN-γ, rIFN-β and rTNF-α resulted in augmentation of INDO expression and activity leading to 40.0, 25.0 and 27.0 % inhibition of tachyzoite growth, respectively. An additive effect was observed when host cells were incubated with rIFN-γ plus rTNF-α. With regard to the down-regulatory cytokines we observed that IL-4 as well as IL-13, but not IL-10, induced significant inhibition of IFN-γ-induced control of parasite replication, INDO mRNA expression and tryptophan catabolism. Similarly, IL-4 but not IL-10 inhibited the cell surface expression of HLA-DR and CD2 induced by IFN-γ. Consistent with these findings we were able to detect by reverse transcription-PCR the expression of mRNA for different chains of IL-4 and IL-13 receptors (IL-4Rα, IL-13Rα1 and IL-13Rα2) but not for IL-10 receptor in the 2C4 and other human lung fibroblast cell lines (LL24 and MRC5). Together our results indicate that IL-4 and IL-13, but not IL-10, are implicated in the negative regulation of IFN-γ-induced anti-Toxoplasma activity in human cells from fibroblast lineage.

The crude latex of Euphorbia splendens var. hislopii showed high molluscicidal activity against the snail Biomphalaria glabrata, one of the intermediate hosts of Schistosoma mansoni. Preliminary results indicate that at the concentrations used to kill snails the latex is not toxic to other organisms. Milliamine L, present in this latex, was shown to be one of the most potent molluscicidal substances known so far, with a DL100/24 h of 2.5 µg/L under laboratory conditions. Published results showed that the latex effectively controls snail populations under field conditions. In view of its potential use as a cheap and safe alternative to synthetic molluscicides, it is important to develop analytical procedures to standardize the latex in terms of its active components. Thus, a simple chromatographic method for the quantification of this ingenol ester in crude latex is described in the present work. As a first application of this method, the milliamine L concentration in latex samples collected over a one-year period was shown to remain close to 1.13 mg/mL. This constancy is in agreement with previous observations that the latex samples collected at different sites or periods of the year have similar molluscicidal activity. Copyright © 1999 John Wiley & Sons, Ltd.

The bioassay-guided fractionation of the CH 2 Cl 2 extract from the wood of Hyeronima oblonga (Euphorbiaceae) afforded two new alkaloids with a tetrahydroisoquinolinone nucleus described here for the first time. The compounds 3-methyl-4-methoxy-6-(1-oxoctyl)-5, 6, 7, 8-tetrahydro-1(2H)-isoquinolinone (Hyeronine A, 4a ) and 3-methyl-4-methyl-6-(1-oxohexyl)-5, 6, 7, 8-tetrahydro-1(2H) isoquinolinone (Hyeronine B, 4b ) displayed LC 50 of 4 ppm in the brine shrimp lethality assay.

An extract of the aerial parts from Alomia myriadenia Schultz-Bip. ex Baker (Asteraceae) showed significant cytotoxicity against a panel of human cancer cell lines in a screening of extracts from Brazilian Atlantic Forest plant species. Employing a bioassay-linked HPLC-electrospray/MS method, followed by semi-preparative HPLC, the active component was isolated and characterized as a mixture of epimers of the labdane diterpene 12S,16-dihydroxy-ent-labda-7,13-dien-15,16-olide.

A series of 2-aryl and 2,5-diarylfurans were synthesized and evaluated for their in vitro cytotoxicity against human cancer cells lines and on the proliferation of human peripheral blood mononuclear cells (PBMC) stimulated with phytohemaglutinin (PHA). Three compounds were found to present significant activity against the cancer cell lines without affecting the lymphocyte proliferation in PBMCs, indicating low toxicity to normal cells.

Four compounds active against the epimastigote forms of Trypanosoma cruzi, the causative agent of Chagas' disease, were isolated from the hexane extract of Pluchea quitoc L. (Compositae). The flavone casticin (1), identified on the basis of its spectroscopic characteristics, along with PQU19B, 19G and 28A, the structures of which are in the process of identification, did not show significant activity against the infective bloodstream trypomastigote forms of the parasite