Bioactive Metabolites Produced by Penicillium sp.1 and sp.2, Two Endophytes Associated with Alibertia macrophylla (Rubiaceae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Secondary Metabolites of Miconia rubiginosa

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tropical biodiversity: has it been a potential source of secondary metabolites useful for medicinal chemistry?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The role of matrix effects on the quantification of abscisic acid and its metabolites in the leaves of Bauhinia variegata L. using liquid chromatography combined with tandem mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fungal pyogranulomatous encephalitis in a dog with leishmaniosis

É relatado um caso de encefalite piogranulomatosa em um cão fêmea de um ano de idade, da raça Fila Brasileiro. Ao exame macroscópico do cérebro, evidenciou-se área amolecida e hemorrágica no córtex frontal direito e na superfície de corte do hemisfério esquerdo, afetando a substância branca e áreas corticais profundas. O diagnóstico de encefalite piogranulomatosa micótica multifocal foi realizado através de exame histopatológico, que mostrou a presença de macrófagos, células gigantes, focos de hemorragia e hifas septadas de coloração marrom, com distribuição difusa e invadindo a luz de vasos. A identificação de formas amastigotas no imprint de linfonodo poplíteo confirmou o diagnóstico de leishmaniose. A infecção micótica no cérebro deste cão foi relacionada com a ocorrência concomitante de leishmaniose, uma doença imunossupressora.

Transcriptome profiling of Paracoccidioides brasiliensis yeast-phase cells recovered from infected mice brings new insights into fungal response upon host interaction

Paracoccidioides brasiliensis is a fungal human pathogen with a wide distribution in Latin America. It causes paracoccidioidomycosis, the most widespread systemic mycosis in Latin America. Although gene expression in P. brasiliensis had been studied, little is known about the genome sequences expressed by this species during the infection process. To better understand the infection process, 4934 expressed sequence tags (ESTs) derived from a non-normalized cDNA library from P. brasiliensis (isolate Pb01) yeast-phase cells recovered from the livers of infected mice were annotated and clustered to a UniGene (clusters containing sequences that represent a unique gene) set with 1602 members. A large-scale comparative analysis was performed between the UniGene sequences of P. brasiliensis yeast-phase cells recovered from infected mice and a database constructed with sequences of the yeast-phase and mycelium transcriptome (isolate Pb01) (https://dna.biomol.unb.br/Pb/), as well as with all public ESTs available at GenBank, including sequences of the P. brasiliensis yeast-phase transcriptome (isolate Pb18) (http:// www.ncbi.nlm.nih.gov/). The focus was on the overexpressed and novel genes. From the total, 3184 ESTs (64.53%) were also present in the previously described transcriptome of yeast-form and mycelium cells obtained from in vitro cultures (https://dna.biomol.unb.br/Pb/) and of those, 1172 ESTs (23.75% of the described sequences) represented transcripts overexpressed during the infection process. Comparative analysis identified 1750 ESTs (35.47% of the total), comprising 649 UniGene sequences representing novel transcripts of P. brasiliensis, not previously described for this isolate or for other isolates in public databases. KEGG pathway mapping showed that the novel and overexpressed transcripts represented standard metabolic pathways, including glycolysis, amino acid biosynthesis, lipid and sterol metabolism. The unique and divergent representation of transcripts in the cDNA library of yeast cells recovered from infected mice suggests differential gene expression in response to the host milieu.

Quantitative determination of anti-fungal and insecticide amides in adult plants, plantlets and callus from Piper tuberculatum by reverse-phase high-performance liquid chromatography

A rapid, sensitive and reliable reverse-phase HPLC method was used for the quantitative determination of the anti-fungal and insecticide amides, dihydropiplartine (1), piplartine (2), Delta(alpha,beta)-dihydropiperine (3) and pellitorine (4) in plants in natura, in plantlets in vitro and ex vitro, and in callus of Piper tuberculatum. Well-resolved peaks were obtained with good detection response and linearity in the range of 15.0-3000 mug/mL. The plants in natura contained compounds 1-4, the plantlets ex vitro and in vitro accumulated compounds 1-2 and 1-4, respectively, while only amide 4 was found in callus. Copyright (C) 2003 John Wiley Sons, Ltd.

BINDING OF PARACOCCIDIOIDES-BRASILIENSIS TO LAMININ THROUGH SURFACE GLYCOPROTEIN GP43 LEADS TO ENHANCEMENT OF FUNGAL PATHOGENESIS

Extracellular matrix protein laminin binds specifically to yeast forms of Paracoccidioides brasiliensis and enhances adhesion of the fungus to the surface of epithelial Madin-Darby canine kidney cells in vitro. Immunoblotting of fungal extracts showed that the gp43 glycoprotein is responsible for adhesion. This was confirmed by binding assays using purified gp43, with a K-d of 3.7 nM. The coating of P. brasiliensis yeast forms with laminin before injection into hamster testicles enhanced the fungus virulence, resulting in a faster and more severe granulomatous disease. These results indicate that interaction of fungi with extracellular matrix elements may constitute a basis for the evolution of fungal infection toward regional spreading and dissemination.

Circadian rhythm of anti-fungal prenylated chromene in leaves of Piper aduncum

Leaves of Piper aduncum accumulate the anti-fungal chromenes methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate (1) and methyl 2,2-dimethyl-8-(3'-methyl-2'-butenyl)-2H-1-chromene-6-carboxylate (2). The enzymatic formation of 2 from dimethylallyl diphosphate and I was investigated using cell-free extracts of the title plant. An HPLC assay for the prenylation reaction was developed and the enzyme activity measured in the protein extracts. The prenyltransferase that catalyses the transfer of the dimethylallyl group to C-2' of 1 was soluble and required dimethylallyl diphosphate as the prenyl donor. In the leaves, the biosynthesis of the prenylated chromene 2 was time-regulated and prenyltransferase activity depended upon circadian variation. Preliminary characterisation and purification experiments on the prenyltransferase from P. aduncum have been performed. Copyright (C) 2005 John Wiley & Sons, Ltd.

PHENYLBUTANOID AND TAXANE-LIKE METABOLITES FROM NEEDLES OF TAXUS-BREVIFOLIA

The structures for brevifoliol and three baccatin VI derivatives were revised to possess the novel 11(15 --> 1)-abeotaxane tricylic skeleton based on X-ray crystallographic studies. Four more new rearranged taxane derivatives related to brevifoliol and the unusual phenylbutanoid, (-)-rhododendrol, were isolated from the needles of Taxus breuifolia. Their structures were established as 10 beta-benzoxy-5 alpha-(3'-dimethylamino-3'-phenyl)-propanoxy-1 beta-hydroxy- 7 beta,9 alpha,13 alpha-triacetoxy-11(15 --> 1)-abeotaxa-4(20),11-diene; 10 beta-benzoxy-1 beta-hydroxy-5 alpha-(3'-methylamino-3'-phenyl)- propanoxy-7 beta,9 alpha,l3 alpha-triacetoxy-11(15 --> 1)-abeotaxa-4(20),11-diene; 10 beta-benzoxy-5 alpha-cinnamoxy-1 beta-hydroxy-7 beta,9 alpha,13 alpha-triacetoxy-1 1(15 --> 1)-abeotaxa-4(20),11-diene; 10 beta-benzoxy-1 beta,5 alpha-dihydroxy-7 beta,9 alpha,13 alpha-triacetoxy-11(15 --> 1)-abeotaxa-4(20),11-diene and 2(R)-hydroxy-4-(4'-hydroxyphenyl)-butane.

Glyceraldehyde-3-phosphate dehydrogenase of Paracoccidioides brasiliensis is a cell surface protein involved in fungal adhesion to extracellular matrix proteins and interaction with cells

The pathogenic fungus Paracoccidioides brasiliensis causes paracoccidioidomycosis, a pulmonary mycosis acquired by inhalation of fungal airborne propagules, which may disseminate to several organs and tissues, leading to a severe form of the disease. Adhesion to and invasion of host cells are essential steps involved in the infection and dissemination of pathogens. Furthermore, pathogens use their surface molecules to bind to host extracellular matrix components to establish infection. Here, we report the characterization of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of P. brasiliensis as an adhesin, which can be related to fungus adhesion and invasion. The P. brasiliensis GAPDH was overexpressed in Escherichia coli, and polyclonal antibody against this protein was obtained. By immunoelectron microscopy and Western blot analysis, GAPDH was detected in the cytoplasm and the cell wall of the yeast phase of P. brasiliensis. The recombinant GAPDH was found to bind to fibronectin, laminin, and type I collagen in ligand far-Western blot assays. of special note, the treatment of P. brasiliensis yeast cells with anti-GAPDH polyclonal antibody and the incubation of pneumocytes with the recombinant protein promoted inhibition of adherence and internalization of P. brasiliensis to those in vitro-cultured cells. These observations indicate that the cell wall-associated form of the GAPDH in P. brasiliensis could be involved in mediating binding of fungal cells to fibronectin, type I collagen, and laminin, thus contributing to the adhesion of the microorganism to host tissues and to the dissemination of infection.

Chemical evolution in the Asteraceae. The Oxidation-Reduction mechanism and production of secondary metabolites

This work describes the application of partial least squares (PLS) regression to variables that represent the oxidation data of several types of secondary metabolite isolated from the family Asteraceae. The oxidation states were calculated for each carbon atom of the involved compounds after these had been matched with their biogenetic precursor. The states of oxidation variations were named oxidation steps. This methodology represents a new approach to inspect the oxidative changes in taxa. Partial least square (PLS) regression was used to inspect the relationships among terpenoids, cournarins, polyacetylenes, and flavonoids from a data base containing approximately 27,000 botanical entries. The results show an interdependence between the average oxidation states of each class of secondary metabolite at tribe and sub tribe levels.