Avaliaçäo da atividade antimicrobiana de metabólitos produzidos pelo fungo Nomuraea rileyi (Farlow) samson / Antimicrobial activity evaluation of metabolits produced by the Nomuraea rileyi (Farlow) samson fungus

Metabólitos do fungo entomopatogênico Nomuraea rileyi produzidos em culturas submersas em caldo Sabouraud sacarose extrato de levedura foram extraídos com diclorometano. O extrato bruto foi fracionado por cromatografia em coluna e em camada espessa de fluxo contínuo utilizando benzeno-clorofórmio-acetato de etila 18:1:1 (v:v:v) como eluentes. Amostras de Saccharomyces cerevisiae e de bactérias (18 cepas hospitalares e 5 estirpes fitopatogênicas) foram testadas frente ao metabólito empregando-se o método de difusäo em ágar pelo sistema de discos (Kirby-Bauer). Aproximadamente (40 por cento) (9/23) das amostras bacterianas ensaiadas tiveram seu crescimento inibido na presença do metabólito produzido pelo fungo Nomuraea rileyi, sugerindo uma possível atividade antibacteriana deste metabólito

Bacterial chemistry-III: preliminary studies on Trypanosomal activities of Chromobacterium violaceum products

It has been found that the pigment-I from Chromobacterium violaceum, 3 [1,2 dihydro 5 (5 hydroxy 1H indol 3 yl) 2 oxo 3H pyrrol-3 ylidiene] 1,3 dihydro 2H indol 2 one, has trypanocide activity. The formylated derivatives, pigment-III, immobilized 100% of the Trypanosoma cruzi at a level of 46 micronM after 48h of interaction with a total growth inhibition in the same period. Pigment I exhibited low toxicity and a DNA synthesis inhibition similar to that of Nifurtimox, a known trypanocide compound

Bacterial chemistry - IV. Complete characterization of violacein: an antibiotic and trypanocide pigment from chromobacterium violaceum

Chromobacterium violaceum, Brazilian or Chilean strain, produces a pigment 3 [1,2-dihydro-5 (5-hydroxy-JH-indo) 2-oxo-3H-pyrrol-3-ylidene] 1,3-dihydro-2H-indol-2-one (Violacein). Violacein was isolated from acetone extract in both cases and identified by ultraviolet-visible., infrared, nuclear magnetic rosonance spectroscopy and by mass spectrometry. A derivative of violacein, the tetracetyl-violacein was synthetized in order to confirm the violacein structure. The biosynthesis of C=violacein is also reported