33 resultados para Two-Hybrid System Techniques
Resumo:
Papaya (Carica papaya L.) is a typical crop of tropical areas, and Brazil is one of the leading world producers. In recent decades, papaya culture has expanded to different regions of the country, but the number of cultivars available is still limited. In the present study, a complete diallel cross was carried out using eight accessions of papaya from the UENF/Caliman germplasm bank. Four genotypes belong to the Formosa heterotic group and four, to the Solo group. This study aimed to evaluate the occurrence and viability of exploring heterosis in heterotic intragroup hybrids. Fifty-six hybrid progenies were generated and evaluated. Among the Formosa intragroup hybrids, two hybrid combinations (MR x J4 and MR x SK) showed heterosis for all traits, as well as good average total fruit production. Among the Solo intragroup hybrids, three hybrid combinations (WM x GG, WM x SS and WM x SM) stand out for fruit production and high content of soluble solids. In Formosa x Solo hybrids, all hybrid combinations with the parent JS (JS x WM, JS x GG, JS x SS and JS x SM) showed high fruit quality and good average for fruit production. The heterotic profile of the hybrids tested allowed the identification of promising hybrids within Formosa and Solo heterotic groups. The analysis of the canonical variables also allowed the visualization of distinct groups of hybrids, depending on the provenance of the parents.
Resumo:
The modern technological ability to handle large amounts of information confronts the chemist with the necessity to re-evaluate the statistical tools he routinely uses. Multivariate statistics furnishes theoretical bases for analyzing systems involving large numbers of variables. The mathematical calculations required for these systems are no longer an obstacle due to the existence of statistical packages that furnish multivariate analysis options. Here basic concepts of two multivariate statistical techniques, principal component and hierarchical cluster analysis that have received broad acceptance for treating chemical data are discussed.
Resumo:
This paper is the first part of an article aimed to present theoretical basis as well as some applications of two infrared reflection techniques: specular reflection and reflection-absorption. It is emphasyzed how the Kramers-Krönig analysis of reflection data can be useful in both retrieving optical constants and making spectral analysis possible. Examples of vitreous, powdered and liquid samples are given.
Resumo:
This paper is the second part of an article aimed to present theoretical basis as well as some applications of two infrared reflection techniques: specular reflection and reflection-absorption. It is emphasyzed how much spectral simulation can aid spectral analysis. The usefulness of reflection-absorption spectroscopy as a thin film caracterization technique is stressed. Optical effects such as LO-TO splittings and their observation as Berreman effect are also addressed.
Resumo:
Analysis of diazepam (DZP) and its active metabolite nordiazepam (NDZP) in plasma is commonly performed in clinical medicine to ensure proper therapeutic effects while minimizing the incidence of toxicity. This study aimed to optimize analytical parameters and compare two pre-treatment techniques, liquid-liquid (LLE) and solid phase extraction (SPE), as well as liquid chromatographic conditions to analyze simultaneously DZP and NDZP in plasma from 20 patients treated with a daily dose of 10 mg. Both techniques showed to be well in line with the international criteria for analytical validation, which permitted to quantify DZP (66.2 - 1148.6 ng mL-1) and NDZP (138.5 - 808.6 ng mL -1) in all samples. The correlation coefficients between SPE and LLE were respectively 0.9729 for DZP and 0.9643 for NDZP.
Resumo:
The phytochemical investigation of Sida galheirensis led to the isolation of 5,4'-dihydroxy-3,7,3´-trimethoxyflavone, 17³-ethoxyphaeoforbide, a rare natural product, 6,7-dimethoxycoumarin, ortho-hydroxybenzoic acid, sitosterol-3-O-beta-D-glucopyranoside, stigmasterol-3-O-beta-D-glucopyranoside, 5,7,4'-trihydroxyflavone, 5,7,3',4'-tetrahydroxyflavone, kaempferol-3-O-beta-D-(6"-E-p-coumaroyl) glucopyranoside and luteolin 7-O-beta-D-glucopyranoside. Their structures were assigned based on spectroscopic analyses, including two-dimensional NMR techniques. Antioxidant activities of hexane, CHCl3, EtOAc, BuOH and EtOH extracts of Sida galheirensis were measured using the 1,2-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay. This is also the first work reporting the chemical investigation of Sida galheirensis.
Resumo:
By the year 2005 the world biochemical market will reach an estimated $ 100 billion and separation processes are a vital link between lab discoveries and the fulfillment of this commercialization potential. The practical application of aqueous two-phase systems (ATPS) to extraction processes has been exploited for several years for the recovery of biological products. Unfortunately, this has not resulted in an extensive presence of the technique in commercial processes. In this paper a critical overview of the fundamental thermodynamic properties related to formation of aqueous two-phase systems and their application to extraction and purification of bioparticules is presented.
Resumo:
The phytochemical investigation of the flowers of Pterogyne nitens (Caesalpinioideae) resulted in the isolation and identification of nine phenolic derivatives, quercetin 3-O-sophoroside, taxifolin, astilbin, ourateacatechin, caffeic, ferulic, sinapic, chlorogenic and gallic acid, besides two guanidine alkaloids, pterogynine, pterogynidine. This is the first time these compounds have been reported in P. nitens flowers. As this is a monospecific genus, these secondary metabolites may have taxonomical significance. Their structures were assigned on the basis of spectroscopic analyses, including two-dimensional NMR techniques.
Resumo:
The phytochemical investigation of the wood extracts of Senna reticulata (Leguminoseae) yielded six anthraquinones: chrysophanol, physcion, aloe-emodin, 1,3,8-trihydroxyanthraquinone, 3-methoxy-1,6,8-trihydroxyanthraquinone, emodin and the chrysophanol-10,10' bianthrone. The triterpenes a and b-amirin, the steroids b-sitosterol and stigmasterol as well as the flavonoid kaempferol were also identified. The structures were established by spectral analysis, including two-dimensional NMR techniques. It is the first report of 1,3,8-trihydroxyanthraquinone and 3-methoxy-1,6,8-trihydroxyanthraquinone in higher plants.
Resumo:
The phytochemical investigation of Xylopia langsdorffiana led to the isolation of corytenchine, xylopinine, discretamine, xylopine, ent-atisan-16α-hydroxy-18-oic acid, 13² (S) hydroxy-17³-ethoxyphaephorbide and quercetin-3-α-rhamnoside. Their structures were assigned based on spectroscopic analyses, including two-dimensional NMR techniques. Antioxidant activities of discretamine were measured using the 1,2-diphenyl- 2-picryl-hydrazyl (DPPH) free radical scavenging assay.
Resumo:
The phytochemical investigation of Byrsonima gardneriana led to the isolation of five triterpenes and one flavonoid: D:B-Friedoolean-5-en-3-one (1), friedoolean-14-en-3-one (2), friedelan-3-one (3), lup-20(29)-en-3-ol (4), 3β-hydroxiolean-12-ene (5) and 3,3',4',5,7-pentahydroxyflavan (6). Their structures were assigned based on spectroscopic analyses, including two-dimensional NMR techniques and comparison with published spectral data. Antioxidant activities of ethanol extract and phases were measured using the 1,2-diphenyl- 2-picryl-hydrazyl (DPPH) free radical scavenging assay, evaluation of total phenolic content and trolox equivalent antioxidant capacity (TEAC).
Resumo:
We investigated the phenolic constituents and antioxidant activity of geopropolis from two species of stingless Amazonian bees, Melipona interrupta and Melipona seminigra. The chemical investigation of geopropolis from Melipona interrupta led to the isolation of 5,7,4'-trihydroxyflavonone, 3,5,6,7,4'-pentahydroxyflavonol, naringenine-4'-O-b-D-glucopyranoside and myricetin-3-O-b-D-glucopyranoside. Their structures were assigned based on spectroscopic analyses, including two-dimensional NMR techniques. Antioxidant activity of methanol and ethanol extracts of M. interrupta and M. seminigra were measured using the 1,2-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay. This is also the first work reporting the chemical investigation of stingless bee species from the Amazonian region.
Resumo:
This study evaluates the application of an intelligent hybrid system for time-series forecasting of atmospheric pollutant concentration levels. The proposed method consists of an artificial neural network combined with a particle swarm optimization algorithm. The method not only searches relevant time lags for the correct characterization of the time series, but also determines the best neural network architecture. An experimental analysis is performed using four real time series and the results are shown in terms of six performance measures. The experimental results demonstrate that the proposed methodology achieves a fair prediction of the presented pollutant time series by using compact networks.
Resumo:
Phytochemical investigation of Eugenia copacabanensis allowed for the isolation and identification of following compounds: β-sitosterol, β-sitosterol-glucoside, eight triterpenes, (mixture of α- and β-amyrins, ursolic acid, 30-hydroxy-ursolic acid, betulin, friedelin, friedelan-3,4-lactone, and taraxerol), a mixture of three sesquiterpenes, (clovandiol, globulol, and viridiflorol), three flavonoids (kaempferol-3-O-β-D-rhamnoside, quercetin-3-O-α-L-arabinoside, and quercetin), and a mixture of four coumaroyl esters (octacosanyl, heptacosanyl, hexacosanyl, and tetracosanyl coumarates). The structures of these compounds were assigned based on comparison with literature data and spectroscopic analysis, including analysis by two-dimensional NMR techniques. Total phenolic content and total flavonoids were evaluated. Antioxidant activities of methanol extracts and fractions were measured by the 1,2-diphenyl-2-picryl-hidrazyl free radical scavenging assay.
Resumo:
In this work, we used an aqueous two-phase system (ATPS) consisting of the ionic liquid [C4mim][Cl] and the salt K2HPO4 to partition α-lactalbumin, β-lactoglobulin, and lactoferrin whey proteins. Extraction efficiency values above 87% indicate that the proteins primarily migrated to the ionic liquid-rich phase (top phase). Partition coefficient values ranged from 6.17 to 8.93 for a-lactalbumin, from 22.80 to 34.55 for β-lactoglobulin, and from 26.46 to 40.06 for lactoferrin. Therefore, the saline ATPS with the ionic liquid examined in this study can be considered to be a promising alternative for extracting whey proteins.