Rapid capillary electrophoresis analysis of glutathione and glutathione disulfide in roots and shoots of plants exposed to copper.

INTRODUCTION: Glutathione and glutathione disulfide can be determined by capillary zone electrophoresis; however, the frequent use of acidic precipitation of protein from samples prior to analysis generates an acidic matrix of strength and pH that may cause changes in the method sensitivity, comigration of species or changes in the equilibria that relate both species in cells or fluids. OBJECTIVE: To optimise electrophoretic conditions for glutathione and glutathione disulfide determination, and to improve pre-analytical treatment for better visualization of the signals of both peptides in an acidic matrix. METHODOLOGY: The method consisted of direct photometric detection at 185 nm and 300 mm borate at pH 7.6 as background electrolyte. The variables under study were voltage applied, injection time, capillary length and electrolyte pH. Seedlings were hydroponically grown and the peptides were extracted with metaphosphoric acid. RESULTS: The resulting acidic matrix was previously treated with the same background electrolyte to prevent comigration and to improve signal resolution. The optimised method showed good reproducibility and linearity, with correlation coefficients above 0.999 and detection limits below 3 microM, and determination of both analytes in less than 3 min. Analyte recovery in the process was in the 88-104% range. The concentration range found in hydroponically grown tomato plants, irrespective of copper level, was 45-100 nmol/g fresh weight for glutathione and below 56 nmol/g fresh weight for glutathione disulfide. CONCLUSION: The results obtained here support the applicability of the method to the fast and simultaneous determination of glutathione and glutathione disulfide in tissue of shoots and roots of plants grown under either normal or stressful conditions.

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