Thin-layer chromatography of mycobactins and mycolic acids for the identification of clinical mycobacteria

Forty seven strains of mycobacteria (35 strains isolated from clinical specimens and 12 reference strains) were analyzed for mycobactin and mycolate production by thin-layer chromatography (TLC). Different growth conditions had little or no effect on the production of individual mycobactins and the reproducibility of mycobactin Rf values. Mycolate profiles of isolated strains were compared with those of reference strains. Clinical isolates belonging to the same species showed the same profiles. The combined evaluation of mycobacterial products by TLC allowed the identification of pathogenic and opportunist cultivable mycobacteria. on routine examination, the analysis of mycobactin and mycolate production constitutes an adequate procedure for the characterization and identification of myobacteria.

Physiological responses of pressed baker's yeast cells pre-treated with citric, malic and succinic acids

The dough-leavening power of baker's yeast, Saccharomyces cerevisiae, is strongly influenced by conditions under which the pressed yeast is maintained prior to bread dough preparation. In this study, the influence of the yeast cell's pre-treatment with organic acids (malic, succinic, and citric acids) was investigated at a wide range of pH values when the pressed yeast samples were exposed to 30 degrees C. Increased fermentative activity was observed immediately after pre-treatment of the cells with organic acids. When the pH of the pressed yeast containing added citric acid was raised from 3.5 to 7.5, increases in both fermentative and maltase activities were obtained. Improvements in viability and levels of total protein were also observed during storage in the presence of citric acid, notably at pH 7.5. Glycerol-3-phosphate dehydrogenase activity and levels of internal glycerol also increased in the presence of citrate. on the other hand, pressed yeast samples containing succinic acid at pH 7.5 showed decreased viability during storage despite the maintenance of high levels of fermentative activity, similar to pressed yeast containing malic acid at pH 4.5 and 7.5. Decreases in intracellular levels of trehalose were observed during storage in all cases. Overall, the results of this study revealed the potential benefits of adding organic acids to pressed yeast preparations for baking purposes.

Synthesis and characterization of solid molybdenum(VI) complexes with glycolic, mandelic and tartaric acids. Photochemistry behaviour of the glycolate molybdenum complex

The complexes (NH4)(2)[ MoO2( C2H2O3)(2)]center dot H2O, (NH4)(2)[MoO2(C8H6O3)(2)] and (NH4)(2) [MoO3(C4H4O6)]center dot H2O were prepared by reaction of MoO3 with glycolic, mandelic and tartaric acids, respectively. The complexes were characterized by elemental and thermal analysis, IR spectroscopy and X- ray diffraction. Crystals of the glycolate and tartarate complexes are orthorhombic and the mandelate complex is monoclinic. Elemental and thermal analysis data showed that the glycolate and tartarate complexes are monohydrated. Hydration water is not present in the structure of the mandelate complex. IR spectra showed COO- is involved in coordination as well as the oxygen atom of the deprotonated hydroxyl group of the alpha-carbon. The glycolate molybdenum complexes with general formula M-2[MoO2(C2H2O3)(2)]center dot nH(2)O, where M is an alkali metal and n=1 or 1/2, were also prepared and characterized. Aqueous solutions of the glycolate complex become blue and mandelate and tartarate complexes change to yellow or brown when exposed to UV- radiation.

Apparent digestibility of protein, energy, and amino acids in some selected feed ingredients for pacu Piaractus mesopotamicus

The apparent digestibility coefficients (ADCs) of amino acids (AA), protein, and energy in six feed ingredients (Brazilian fish meal, soybean meal, corn gluten meal, alcoholic yeast, corn, and wheat bran) we evaluated for pacu juveniles. In general, all ingredients showed high digestibility values for all AA, and differences among ADCs of individual amino acid were detected (P < 0.01). Corn gluten, soybean, and fish meals had the highest ADCs of AA. The ADCs of protein in fish meal, yeast, and corn gluten meal should not be used as AA digestibility indicators, because those showed differences up to 6.7% between the ADCs of protein and AA. All ingredients had lower ADCs of energy than corn gluten meal (P < 0.01). Lysine was the first limiting amino acid in fish meal, corn gluten meal, wheat bran, and corn, and the second limiting amino acid in soybean meal, as methionine was the first limiting amino acid in soybean meal and yeast. However, the soybean meal was the best quality protein source, as it had the highest digestible essential amino acid index. This demonstrated that digestible amino acid values can be used to formulate practical diets for pacu, preventing potential deficiencies or excess that might cause environmental and economic losses.

Soil microbial biomass and organic matter fractions during transition from conventional to organic farming systems

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Activity of Extracts and Fatty Acids of Canavalia ensiformis (Leguminosae) Against the Symbiotic Fungus of the Leaf-Cutting Ants Atta sexdens

The inhibitory effect of leaves extracts of Carnavalia ensiformis on the development of the symbiotic fungus of the leaf-cutting ants Atta sexdens (Forel) was evaluated. The hexane extract showed highest activity at concentration of 1000 μg/mL. Chromatographic separations of this extract have led to the isolation of a mixture of fatty acids which showed the same activity of the crude extract.

Invited review Giardia duodenalis: Inter-strain variability of proteins, antigens, proteases, isoenzymes and nucleic acids

Giardia duodenalis isolates from asymptomatic or symptomatic patients and from animals present similarities and differences in the protein composition, antigenic profile, pattern of proteases and isoenzymes, as well as in nucleic acids analysis. In the present overview, these differences and similarities are reviewed with emphasis in the host-parasite interplay and possible mechanisms of virulence of the protozoon.

Evaluating of the activity antioxidant and fatty acids profile of lychee seeds (Litchi chinensis SONN.)

Purpose: The purpose of this paper is to characterize lychee seeds regarding their centesimal composition, and also to evaluate their antioxidant potential and fatty acid profile. Design/methodology/approach: To obtain the extract, dehydrated and grinded seeds were extracted with ethyl alcohol for 30 min, at a proportion of 1:3 of seeds:ethyl alcohol, under continuous agitation, at room temperature. Afterwards, the mixture was filtered and the supernatant subjected to a rotoevaporator at 40oC aiming to determine, by direct weighing, the extract dry matter yield. Findings: The largest found values went to the total carbohydrates (72.75 percent). In the oil from the lychee seeds there was a high percentage of unsaturated fatty acids, the main component being linoleic, considered an essential fatty acid. Research limitations/implications: Implies the identification of compounds biativos extracted from seeds of tropical and subtropical fruits, and to prevent certain types of diseases. Originality/value: The article tries to identify new source of phenolic compounds extracted from fruit. © Emerald Group Publishing Limited.

Characterization and fatty acids profile of the oils from Amazon nuts and walnuts: Characterization and fatty acids profile of the oilseeds

Purpose: The purpose of this paper is to characterize oils extracted from Bertholletia excelsa, Lecythis pisonis, Dipteryx lacunifera, Carya illinoensis and Juglans regia, regarding their characterization and fatty acid profile. Design/methodology/approach: The oils were extracted from oilseeds by cold pressing and physico-chemical characterization was performed by using standard methods for oils and fats. The oxidative stability and fatty acid profile also were determined. Findings: According to the results, the physico-chemical properties of oils from nuts and walnuts were comparable to those of good quality conventional oils. The oil seeds are a good source of unsaturated fatty acids, especially oleic and linoleic acids. Research limitations/implications: Implies the identification of fatty acid profile and physico-chemical properties of oils extracted from nuts and walnuts, and to prevent certain types of diseases. Originality/value: The paper identifies a new source of essential fatty acids extracted from oilseeds. © Emerald Group Publishing Limited.

Characterization of flavonoids and phenolic acids in Myrcia bella cambess. Using FIA-ESI-IT-MSn and HPLC-PAD-ESI-IT-MS combined with NMR

The leaves of Myrcia DC. ex Guill species are used in traditional medicine and are also exploited commercially as herbal drugs for the treatment of diabetes mellitus. The present work aimed to assess the qualitative and quantitative profiles of M. bella hydroalcoholic extract, due to these uses, since the existing legislation in Brazil determines that a standard method must be developed in order to be used for quality control of raw plant materials. The current study identified eleven known flavonoid-O-glycosides and six acylated flavonoid derivatives of myricetin and quercetin, together with two kaempferol glycosides and phenolic acids such as caffeic acid, ethil galate, gallic acid and quinic acid. In total, 24 constituents were characterized, by means of extensive preparative chromatographic analyses, along with MS and NMR techniques. An HPLC-PAD-ESI-ITMS and FIA-ESI-IT-MSn method were developed for rapid identification of acylated flavonoids, flavonoid-O- glycosides derivatives of myricetin and quercetin and phenolic acids in the hydroalcoholic M. bella leaves extract. The FIA-ESI-IT-MS techinique is a powerful tool for direct and rapid identification of the constituents after isolation and NMR characterization. Thus, it could be used as an initial method for identification of authentic samples concerning quality control of Myrcia spp extracts. © 2013 by the authors.

Heavy Metals Extracted by DTPA and Organic Acids from Soil Amended with Urban or Industrial Residues

Understanding soil responses to the application of urban or industrial residues is necessary. In the current experiment, both sources of residues were applied to the soil surface of a Hapludox soil for 8 years. The four residues studied were biodigested and centrifuged sewage sludge (LB and LC, respectively), steel slag from the metallurgic industry (E), and limed mud from the pulp and cellulose industry (LCal). The residues were applied at 0, 2, 4, and 8 Mg ha(-1) four times from 2002 to 2010 when soybean was cultivated in the summer and lopsided oat and sorghum were cultivated during the winter. The contents of heavy metals were evaluated with diethylenetriaminepentaacetic acid (DTPA) and organic acids. The LB was the residue that increased the contents of soil micronutrients and heavy metals to their greatest levels, although within limits that impair the risks of environmental contamination.

Phenolic compounds, carotenoids, tocopherols and fatty acids present in oils extracted from palm fruits

This review aimed to discuss the main bioactive compounds present in oils extracted from palm trees, indicating possible applications for the same. The bioactive compounds approached were: phenolic compounds, carotenoids, tocopherols, mono and polyunsaturated fatty acids. It is growing the search for food, especially from plant origin, characterized by the presence of such substances due to their benefi ts. Many studies show palm species as important sources of bioactive compounds and essential fatty acids. Therefore it is important to study the fruit characterization and composition of the oil from palm species of different regions that are still poorly investigated, seeking the possibility of its application in industry or the development of functional foods.

Cooperative effects of H+ and H- hydrido carbonyl ruthenium derivatives; role of homogeneous and heterogeneous protonic and lewis acids in catalytic hydrocarbonylation reactions

The role played by H+ hydrido iodocarbonyl and H- hydrido carbonyl ruthenium catalysts in the different catalytic steps of hydroformylation and hydroesterification of olefins, and in the homologation of alcohols has been investigated. The H- hydrido carbonyl species are mainly involved in the activation of olefins and in the hydrogenation of the acyl intermediates to aldehydes and alcohols, whereas the H+ hydrido iodocarbonyl derivatives are involved in the activation of alcohols and other oxygenated substrates, and in their carbonylation to esters. The cooperation between the two species, possible under particular reaction conditions, results in an improvement of the selectivity towards homologation (carbonylation plus hydrogenation) products. Heterogeneous Lewis acid promoters, easily recyclable from the reaction mixture, have also been successfully used in the hydrocarbonylation of alcohols, resulting in an increase of the carbonylation and homologation products. A reaction pathway in agreement with the experimental results is discussed. © 1989.