Domingos Sávio Nunes

Optimization of Phenolics and Flavonoids Extraction Conditions and Antioxidant Activity of Roasted Yerba-Mate Leaves (Ilex paraguariensis A. St.-Hil., Aquifoliaceae) using Response Surface Methodology

This study focused on maximizing the extraction of total phenolics and flavonoids as well as the antioxidant activity measured by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay from roasted yerba mate (Ilex paraguariensis) as a function of time (5, 7.5 and 10 min) and temperature of extraction (60, 75 and 90°C). The data were subjected to Response Surface Methodology and the results showed that polynomial equations were significant, did not present lack of fit, and presented adjusted determination coefficients above 98%, proving their suitability for prediction purposes. Using the desirability function, the optimum operating conditions to obtain a higher extraction of antioxidants was found to be 10 min of extraction at 90°C, and the tea prepared under these experimental conditions presented 427.74 mg of gallic acid equivalents per liter and 80.02% of inhibition of the DPPH radical. The flavonoid content was highly correlated (r = 0.9046, p < 0.001) to the antioxidant capacity.

Chemical composition of volatiles from male and female specimens of Baccharis trimera collected in two distant regions of southern brazil: a comparative study using chemometrics

GC/MS/FID analyses of volatile compounds from cladodes and inflorescences from male and female specimens of Baccharis trimera (Less.) DC. collected in the states of Parana and Santa Catarina, Brazil, showed that carquejyl acetate was the primary volatile component (38% to 73%), while carquejol and ledol were identified in lower concentrations. Data were subjected to hierarchical cluster analysis and principal component analysis, which confirmed that the chemical compositions of all samples were similar. The results presented here highlight the occurrence of the same chemotype of B. trimera in three southern states of Brazil.

VOLATILE COMPONENTS FROM GALLS INDUCED BY Baccharopelma dracunculifoliae(Hemiptera: Psyllidae) ON LEAVES OF Baccharis dracunculifolia(Asteraceae)

The volatile components of the galls induced by the insect Baccharopelma dracunculifoliae (Hemiptera: Psyllidae) on leaves of Baccharis dracunculifolia (Asteraceae) were analyzed by gas chromatography-mass spectrometry (GC-MS) and gas chromatographyflame- ionisation detection (GC-FID), and then comparison with volatile oil samples from healthy leaves collected in the vicinity. The galls produced around 3.5% of the total organic volatiles whereas healthy leaves rendered an average yield of 0.6%. The observed higher proportions of germacrene D, bicyclogermacrene, limonene, and β-pinene in the galls suggest that all these compounds are important targets in the search for natural enemies of this Psyllid. Moreover, higher relative percentages of (E)-nerolidol and spathulenol were found in healthy leaves.

Chemical Composition of Essential Oils from Cladodes and Inflorescences from Male and Female Specimens of Baccharis milleflora

Abstract The results of analyses by GC-MS-FID of essential oils obtained from cladodes and inflorescences from male and female specimens of Baccharis milleflora are presented here for the first time in the literature. The essential oil of B. milleflora presented high variations in the chemical components, especially in viridiflorol contents that varied from 2.11 to 41.48 %, and an unidentified component labeled 212 (M+.) (0.62 to 11.87 %). Data were analyzed using unsupervised statistical techniques, namely Hierarchical Cluster Analysis and Principal Component Analysis, and it was possible to observe different chemical compositions for the different plant organs. The same trend was observed when maturity of the plant organs was considered. Viridiflorol was isolated and identified by spectroscopic analyses.

Isolation, Bioactivity and Structural Studies of 6-acetyl-7-hydroxy-2,2-dimethylchoromene from Calea hispida

The volatiles from Calea hispida leaves were analyzed by GC-MS-FID and presented as the main components (E)-nerolidol, beta-cubebene, spathulenol, alfa-cadinol and 6-acetyl-7-hydroxy-2,2-dimethylchromene, the latter being the major component (54.46%), which was crystallized and analyzed by X ray diffraction. Microbiological assays indicated activity of this chromene against Helicobacter pylori (ATCC 26695), what prompts a deeper investigation on this concern. The crystal structure study showed no difference to that reported before for this compound while quantum mechanics optimization indicated that the crystal structure is close to a minimum energy conformation, what includes the relative position of the hydroxyl to the acetyl moiety. In fact, potential energy scan and molecular dynamics showed that the intramolecular hydrogen bond within these two moieties is quite stable, both in gas phase and in solution.

COMPOSIÇÃO QUÍMICA DE DUAS VARIEDADES DE PRÓPOLIS DOS CAMPOS GERAIS DO PARANÁ

O presente estudo buscou desenvolver um metodo geral de fracionamento, permitindo obter de uma mesma amostra os oleos essenciais e, em seguida, o extrato aquoso e orgânico, destinado ao isolamento e analises quimicas utilizando duas amostras propolis provenientes da Regiao dos Campos Gerais do Parana. A analise dos oleos essenciais por CG/EM, permitiu a identificacao de mais de 28 compostos sendo os compostos majoritarios, o espatulenol, ( E )-nerolidol, 2,6-di-t-butil- p -cresol e o benzilbenzoato confirmados por RMN de 1 H e de 13 C. Os extratos foram analisados por UV-Vis e as substâncias isoladas por IV e RMN de 1 H e de 13 C. Essas analises demostraram que dois acidos aromaticos (benzoico e cinâmico) podem ser considerados como substâncias marcadoras das duas amostras de propolis analisadas.

Characterization of groundwater resources degradation at Santiago Island (Cabo Verde) ascribed to isotopic and geochemical signatures.

Overexploitation of coastal aquifers and pollution are among the main problems related to groundwater resources assessment and management in Santiago Island (Cabo Verde). Brackish groundwater for agriculture and human supply (e.g. Praia Baixo, Montenegro, and Charco) are being provided to populations as the only type of available water. Isotopic techniques combined with geochemical signatures provided information about salinization mechanisms (e.g. seawater intrusion, salt dissolution, and marine aerosols) of the groundwater systems, at Santiago Island. The isotopic composition of groundwater samples range from -4.98 to -2.61/oo in δO and from -44.6 to -14.9/oo in δH, with a mean isotope content of -3.88 ± 0.53/oo in δO and -25.9 ± 5.4/oo in δH vs V-SMOW (n = 115). Two groundwater groups were recognized based on the δO and δH isotopic composition and different geochemical evolution trends were identified: (i) mixture with seawater (the influence of marine aerosol cannot be excluded) and (ii) same isotopic “history” but different geochemical evolution, depending on weathering rates and rock permeability.

ESSENTIAL OIL OF BACCHARIS SEMISERRATA, A SOURCE OF SPATHULENOL - Doi: http://dx.doi.org/10.5212/Publi.Exatas.v.3i2.241245

The essential oils of the leaves of female (0.13%) and male (0.45%) specimens of Baccharis semiserrata collected in the state of Paraná, Brazil, were analyzed in detail using GC-FID and GC-MS techniques. Both samples have low monoterpene content and present the sesquiterpene spathulenol as their main component, reaching 50.75% in the oil originating from the male specimen and 42.65% in that of the female specimen. Other major sesquiterpenes found were (female-male): aromadendrene (9.61-2.33%), α-muurolene (8.88-2.38%) and δ-cadinene (9.52-3.93%). These data put this plant species forward as potential spathulenol source.