977 resultados para Sesquiterpene lactones, phenolic fraction
Resumo:
A new antifungal phenolic glycoside, 3,4,5-trimethoxyphenyl-1-O-β-D- (5-O-syringoyl)-apiofuranosyl-(1→6)-β-D-glucopyranoside (1), together with four known iridoids, geniposidic acid (2), geniposide (3), 6α-hydroxygeniposide (4) and 6β-hydroxygeniposide (5); two lignans, (+)-lyoniresinol-3α-O-β-D-glucopyranoside (6), (-)-lyoniresinol- 3α-O-β-D-glucopyranoside (7); and two phenolic acids, chlorogenic (8) and salicylic acids (9) and D-manitol (10), were isolated from the ethanolic extract of the stems of Alibertia sessilis. Structures of 1 and of the known compounds were determined by spectroscopic analysis. All compounds isolated were evaluated for their antifungal activities against two phytopathogenic fungi strains Cladosporium cladosporioides and C. sphaerospermum by direct bioautography. ©2007 Sociedade Brasileira de Química.
Resumo:
The effects of isolated compounds from Brazilian lichens and their derivatives on H 2O 2 and NO production were studied using murine macrophages as a part of an attempt to understand their possible immunomodulatory properties. The compound cytotoxicity was studied using MTT assay. Macrophage stimulation was evaluated by the determination of NO (Griess assay) and H 2O 2 (horseradish peroxidase/phenol red) in supernatants of peritoneal macrophage cultures of Swiss mice. This research demonstrated stimulatory activities of some phenolic compounds isolated from lichens and their derivatives on H 2O 2 and NO production. Structure-activity relationships suggest several synthetic directions for further improvement of immunological activity.
Resumo:
The Acidithiobacillus ferrooxidans periplasmic space is known to have proteins involved in the respiratory chains. There are no reports about the expression of the periplasmic proteins in A. ferrooxidans cells attached to chalcopyrite. In this preliminary work, it was compared the periplasmic protein profiles of A. ferrooxidans planktonic and attached cells after exposure to chalcopyrite for 2 hours. The bacterial response to chalcopyrite was investigated by a proteomic approach (two- dimensional gel electrophoresis and mass spectrometry). Four proteins differentially expressed between planktonic and attached cells after exposure to chalcopyrite were identified. Two of these proteins, repressed in chalcopyrite- attached cells, were both identified as superoxide dismutase, whereas the single strand binding protein (SSB) and the PspA/IM30 protein were induced. These results showed that A. ferrooxidans chalcopyrite- attached and planktonic cells show differential expression of the periplasmic proteins and that a proteomic approach can provide a valuable tool to detect proteins related to the A. ferrooxidans response to attachment to the mineral substrates. © (2009) Trans Tech Publications.
Resumo:
The ability to control the carbon nanotube (CNT) dispersion in polymers is considered the key to most applications of nanotube/polymer composites. The carbon nanotube dispersion into water with different surfactants, as well as its incorporation into phenolic resins, was investigated. Ultrasonication of liquid suspensions was used to prepare stable dispersions. In order to evaluate the best surfactant to be used, light scattering and UV-Visible spectroscopy were employed. The structure of CNT reinforced of phenolic resin was analyzed in function of the concentration and type of surfactant, sonication power and time. It was also evaluated the influence in the dispersion by using the glass temperature transition properties being obtained by dynamic mechanical analyses and impact energy. © 2011 Sociedade Brasileira de Química.
Resumo:
Avocados possess high nutritional value with proven effectiveness in preventing cardiovascular diseases, attributed primarily to their unsaturated fatty acids content. This fruit is also rich in carotenoids and vitamins, particularly vitamin E. This work evaluates the antioxidant capacity and total phenolic content of hydrothermally-treated Fuerte avocado. Fruits were selected and hydrothermally treated at 45°C for 5, 10, 15 and 20 min. They were then stored in a refrigerator (10 ± 10°C and 90±5% relative humidity) and evaluated over a 15-day period. The total phenolic content increased up to the sixth day of storage, and decreased thereafter, without differences between the treatments. The percentage of antioxidant capacity of the control and the hydrothermally-treated samples for 5 and 10 min increased during storage. Untreated fruits showed the highest percentage of antioxidant capacity. However, the antioxidant capacity of avocado fruits subjected to these treatments declined starting on the twelfth day of storage, possibly due to the fruits' senescence. Hydrothermal treatments for 15 and 20 min delayed fruit senescence while the antioxidant capacity continued to increase up to the fifteenth day of storage. No significant correlation was found between antioxidant capacity and total phenolic content. The antioxidant capacity of ripe Fuerte avocado was higher than that of unripe or overripe avocado.
Resumo:
The recovery of phenolic compounds of Eugenia pyriformis using different solvents was investigated in this study. The compounds were identified and quantified by reverse-phase high-performance liquid chromatography coupled with ultraviolet-visible diode-array detector (RP-HPLC-DAD/UV-vis). Absolute methanol was the most effective extraction agent of phenolic acids and flavonols (588.31 mg/Kg) from Eugenia pyriformis, although similar results (p ≤ 0.05) were observed using methanol/water (1:1 ratio). Our results clearly showed that higher contents of phenolic compounds were not obtained either with the most or the least polar solvents used. Several phenolic compounds were identified in the samples whereas gallic acid and quercetin were the major compounds recovered. © 2012 Association of Food Scientists & Technologists (India).
Resumo:
Relief is regarded as the abiotic factor most strongly influencing pedogenic processes at a local scale. The spatial correlations between the composition of the clay fraction (iron - Fe and aluminum - Al oxides, kaolinite and organic matter - OM) and contents of available phosphorus (P) of an Oxisol were evaluated at hillslope scale under sugarcane cultivation. A total of 119 samples were collected at intersection points on a 100. ×. 100. m georeferenced grid of regularly spaced points 10. m apart in the 0.2-0.4. m depth in an area consisting of two landform components namely: component I (an area with a linear hillslope curvature), and component II (one with a concave-convex hillslope curvature). Soil OM and available P contents were subjected to descriptive statistics and geostatistical analyses in order to assess their variability and spatial dependence. All attributes studied were spatially dependent. Available phosphorus had positive spatial correlation with high crystalline goethite, hematite and gibbsite. Identifying small hillslope curvatures is useful with a view to better understanding their relationships with soil organic matter and available phosphorus, as well as kaolinite and Fe and Al oxide attributes. A simple correlation analysis by itself is inadequate to relate attributes, which requires a supplemental, geostatistical technique. © 2012 Elsevier B.V..
Resumo:
Annona crassiflora Mart. is a typical fruit of the Brazilian cerrado, considered to be a species of economic interest, mainly for its use in cooking, which is widespread among the inhabitants of that region, and can be found in many typical local dishes, especially sweets, jellies, liqueurs, soft drinks, ice creams and juices. Thus, the objective of this study was to determine the bioactive substance contents and the antioxidant capacity of the lipid fraction of A. crassiflora Mart. seeds in the interest of better identifying the quality of this raw material from the Brazilian cerrado. After the receipt of the fruits, the seeds were removed manually and, then, the lipid fraction was obtained by cold extraction with chloroform:methanol:water (2:1:0.8, v/v/v) and analyzed for the composition of phytosterols, tocopherols, fatty acids, total carotenoids, antioxidant activity and oxidative stability index. The lipid fraction showed significant quantity of bioactive substances, especially phytosterols, tocopherols and unsaturated fatty acids, as well as significant antioxidant capacity and oxidative stability, influenced by the content of phytosterols and the composition of fatty acids present in the analyzed fraction. © 2012 Elsevier B.V.
Resumo:
The use of cooling, without using adequate hygienic practices in primary milk production, allows for the growth of psychrotrophic microorganisms that produce the thermoresistant lipases that give milk a rancid flavor. This study aimed to verify how the variation in temperature influences the lipolytic metabolism of the psychrotrophic organisms. Samples of raw milk were collected and submitted to laboratorial analysis as follows: psychrotrophic bacteria count, lipolytic bacteria count, and free fatty acids dosage. Each sample was divided into 3 aliquots and then incubated at 4, 8, and 12 °C, respectively. For each temperature, analyses were repeated after 12, 24, and 48 h of storage. Despite the psychrotrophs growth increase, according to temperature rise, the lipolytic metabolism was not consistent and presented the lower index at 8 °C, suggesting an intensification of the proteolytic compensatory activity at this temperature. © 2013 Institute of Food Technologists®.
Resumo:
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.
Resumo:
This study aimed to assess the nutritional composition of the fruit and the physicochemical and bioactive properties of jatoba (Hymenaea courbaril L.) pulp and seed oils. The lipid content of both fractions was below 6%. There was a significant presence of minerals, especially, sodium, potassium and phosphorus. The main macronutrient in pulp and seed was crude fiber, and considerable amounts of Vitamin C, 51.87 and 121.45. mg/100. g respectively, were found. The physicochemical properties demonstrated the good quality of the oils. The oxidative stability index was influenced by the composition of fatty acids reaching a value of 45.97. h for the jatoba pulp oil. The most abundant bioactive compounds were α-tocopherol (886.37 and 993.63. mg/kg) and β-sitosterol (61.83 and 91.09. mg/kg) for pulp and seed oils, respectively. Among the unsaturated fatty acids in the pulp, the oleic (46.09%) and linolenic acid (14.54%) stood out. The pulp and seed oils can be considered a valuable source for new industrial, cosmetic and pharmaceutical products. © 2013 Elsevier B.V.
Resumo:
The present study therefore assessed the deleterious effects of MLs (ivermectin, abamectin, doramectin and moxidectin) on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females that naturally detached from experimentally infested cattle in two experiments. The following reproductive parameters of engorged female ticks were analyzed: female weight, egg mass weight, percentage of hatchability, percentage of reduction in oviposition, percentage of reduction in hatchability, reproductive efficiency and percent control/efficacy of formulations with respect to reproductive parameters. In the experiment I, statistical analysis of the data grouped into 5-days intervals revealed that pour-on application of abamectin (500. mcg/kg) had significantly (p≤. 0.05) reduced engorged female weight, egg mass weight and percent hatchability on days 6-15, 6-20 and 11-20 post-treatment (p. t.) compared to the respective data for detached and pre-selected engorged females in the control group. The abamectin, demonstrated 33.41% of reduction in oviposition, 6.77% in hatchability and abamectin efficacy was of 13.99%. In the experiment II, statistically significant reductions (p≥. 0.05) were observed in animals treated subcutaneous with ivermectin (630. mcg/kg), doramectin (700. mcg/kg) and moxidectin (1000. mcg/kg) relative to the control for days 6-40, 6-48 and 6-40 p. t., respectively. Ivermectin reduced hatchability only on days 16-20 p. t., whereas doramectin significantly reduced (p≤. 0.05) hatchability on days 6-10 and 16-35 p. t. For moxidectin, deleterious effects on hatchability were observed on days 16-35 p. t. The percent reductions in oviposition of engorged female ticks were 46.31%, 62.17% and 61.02% with ivermectin, doramectin and moxidectin treatments, respectively. The percent efficacy of the formulations on the reproductive parameters of engorged female ticks was 21.22% for ivermectin, 36.03% for doramectin and 35.45% for moxidectin. Among the MLs assessed, doramectin and moxidectin had the highest acaricidal efficacies and the most deleterious effects on the reproductive parameters of engorged R. (B.) microplus females. However, future studies will be necessary to assess the extent to which these effects, along with acaricidal activity, can be used to control the ectoparasite in cattle. © 2013 Elsevier Inc..
Resumo:
Exercise capacity and quality of life (QOL) are important outcome predictors in patients with systolic heart failure (HF), independent of left ventricular (LV) ejection fraction (LVEF). LV diastolic function has been shown to be a better predictor of aerobic exercise capacity in patients with systolic dysfunction and a New York Heart Association (NYHA) classification >II. We hypothesized that the currently used index of diastolic function E/e' is associated with exercise capacity and QOL, even in optimally treated HF patients with reduced LVEF. This prospective study included 44 consecutive patients aged 55±11 years (27 men and 17 women), with LVEF,0.50 and NYHA functional class I-III, receiving optimal pharmacological treatment and in a stable clinical condition, as shown by the absence of dyspnea exacerbation for at least 3 months. All patients had conventional transthoracic echocardiography and answered the Minnesota Living with HF Questionnaire, followed by the 6-min walk test (6MWT). In a multivariable model with 6MWT as the dependent variable, age and E/e' explained 27% of the walked distance in 6MWT (P=0.002; multivariate regression analysis). No association was found between walk distance and LVEF or mitral annulus systolic velocity. Only normalized left atrium volume, a sensitive index of diastolic function, was associated with decreased QOL. Despite the small number of patients included, this study offers evidence that diastolic function is associated with physical capacity and QOL and should be considered along with ejection fraction in patients with compensated systolic HF.
Resumo:
Results are presented from a search for the rare decays Bs0→μ+μ- and B0→μ+μ - in pp collisions at √s=7 and 8 TeV, with data samples corresponding to integrated luminosities of 5 and 20 fb-1, respectively, collected by the CMS experiment at the LHC. An unbinned maximum-likelihood fit to the dimuon invariant mass distribution gives a branching fraction B(Bs0→μ+μ-)=(3.0-0.9+1.0) ×10-9, where the uncertainty includes both statistical and systematic contributions. An excess of Bs0→μ+μ- events with respect to background is observed with a significance of 4.3 standard deviations. For the decay B0→μ+μ- an upper limit of B(B0→μ+μ-)<1.1×10 -9 at the 95% confidence level is determined. Both results are in agreement with the expectations from the standard model. © 2013 CERN. Published by the American Physical Society under the terms of the.
Resumo:
The color characteristics and the phenolic composition related to color of young red wines elaborated with the hybrid grape cultivar BRS Violeta, developed for its adaptation to sub-tropical climates in Brazil, have been studied. These wines are characterized with a deep red-purplish color, reaching color intensity averaging 24 units. In spite of being young red wines elaborated with short maceration time, their content in total polyphenols was very high (around 3692. mg/L, as gallic acid equivalents), especially when compared to similar Vitis vinifera young red wines. Within polyphenols, anthocyanins predominated (around 2037. mg/L, as malvidin 3,5-diglucoside equivalents) and they were almost exclusively anthocyanidin 3,5-glucosides (ca. 97%), mainly built from B-ring tri-substituted anthocyanidins (delphinidin. >. petunidin. ≈. malvidin) and having high proportion of p-coumaroylated derivatives (ca. 28%) that confer higher stability. The content of hydroxycinnamic acid derivatives was also remarkable (ca. 95. mg/L, as caffeic acid equivalents) and unknown glucose derivatives of p-coumaric acid accounted for ca. 42% of total HCAD. Finally, these found flavonols were mainly based on myricetin whereas kaempferol derivatives were missing, their total content being within the ranges usually found for V. vinifera wines, but reaching their top values (ca. 91. mg/L, as quercetin 3-glucoside equivalents). All the aforementioned data suggest that Violeta wine could be considered an important dietary source of healthy polyphenols with a moderate alcoholic content (ca. 11.6%). © 2013 Elsevier Ltd.