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Turmeric ( Curcuma longa L.) is a medicinal plant, and its biological activities mainly arise from the main constituent, known as diferuloylmethane or curcumin. In the present paper, microwave-assisted extraction (MAE) was investigated for the recovery of curcumin from turmeric in comparison to conventional heat-assisted extraction (CHAE) technique. Various experimental conditions, such as solvent concentration (0-100%, v/v), MAE temperature (30-130 oC) and MAE time (0-20 min) were investigated to optimize the extraction of curcumin from turmeric. The identification and quantification of curcumin in extracts were performed by HPLC-DAD system. Antioxidant potential and radical scavenging abilities of microwave-assisted extract and conventional heat-assisted extract of turmeric (MAET and CHAET) were evaluated using different systems including total phenolic content (TPC), total antioxidant capacity (TAC), and radical scavenging activities. MAET and CHAET showed high antioxidant activity in all test systems, but the antioxidant properties of MAET were stronger than those of CHAET.

A fibre-optic sensor for p-aminophenol (PAP) based on the use of 25,26,27,28-tetrahydroxycalix[4]arene (CAL4) immobilised onto Amberlite XAD-16 and reflectance spectrometry has been developed. The sensor is based on the reaction of PAP with CAL4 in presence of an oxidant to produce an indophenol dye. The reflectance measurements were carried out at a wavelength of 620 nm since it yielded the largest divergence different in reflectance spectra before and after reaction with the analyte. A highly linear calibration curve (r(2) = 0.992) was observed in the PAP concentration range of 0.5-35 ppm (linear within 0.5-5.5 ppm) with a calculated limit of detection (LOD), defined as the lowest concentration level of analyte that the proposed method can detect to be statistically different from an analytical blank (i.e., yielding an analytical response greater than three times the standard deviation of a blank), of 0.109 ppm. The sensor response from different probes (n = 5) gave an RSD of 1.8% at 10.9 ppm PAP concentration. The response time of the optical one-shot sensor was 5 min for a stirred solution. The intra- and inter-assay variability (as relative standard deviation: RSD) was approximately 2 and 4%, respectively. The lifetime of the blank sensor (CAL4 adsorbed onto XAD-16) was at the order of weeks-months when protected from light, while of the analyte sensor (XAD-16 + CAL4, to which the oxidation product of PAP is coupled) was at the order of days when protected from air and light. Using the optical sensing probe, PAP in urine, pharmaceutical and pharmaceutical wastewater was determined. Although aminophenols showed serious interference, the method was not affected from common ions and from various important drug active constituents present in urine and pharmaceutical effluents such as acetaminophen, acetylsalicylic acid, sorbitol, and caffeine. The proposed technique was tested by replicate analysis of several complex samples with spiked PAP, with recoveries ranging between 97 and 102%. (C) 2008 Elsevier B.V. All rights reserved.

Countercurrent chromatography (CCC) is a generic term covering all forms of liquid-liquid chromatography that use a support-free liquid stationary phase held in place by a simple centrifugal or complex centrifugal force field. Biphasic liquid systems are used with one liquid phase being the stationary phase and the other being the mobile phase. Although initiated almost 30 years ago, CCC lacked reliable columns. This is changing now, and the newly designed centrifuges appearing on the market make excellent CCC columns. This review focuses on the advantages of a liquid stationary phase and addresses the chromatographic theory of CCC. The main difference with classical liquid chromatography (LC) is the variable volume of the stationary phase. There are mainly two different ways to obtain a liquid stationary phase using centrifugal forces, the hydrostatic way and the hydrodynamic way. These two kinds of CCC columns are described and compared. The reported applications of CCC in analytical chemistry and comparison with other separation and enrichment methods show that the technique can be successfully used in the analysis of plants and other natural products, for the separation of biochemicals and pharmaceuticals, for the separation of alkaloids from medical herbs, in food analysis, etc. On the basis of the studies of the last two decades, recommendations are also given for the application of CCC in trace inorganic analysis and in radioanalytical chemistry.

Genotype and environment (G x E) interactions are of major concern to plant breeders in breeding cultivars. The objective of this study was to determine the stability of grain yield in 12 wheat genotypes. Eleven lines selected from Tir wheat population (Triticum aestivum) were used in the study. The experiment was conducted in Van, Ercis, and Adilcevaz located in the eastern part of Turkey in 1997-98 and 1998-99. Two stability parameters were obtained as linear regression coefficient (b) of an entry mean on the average of all entries and deviation from regression (s(2)d), then stability was tested with the hypotheses b = 1.0 and s(2)d = 0. The results indicated that there were significant differences and interactions among genotypes, locations and years. The regression coefficient (b) values of the 11 genotypes used in this study ranged from 0.46 to 1.73; deviation from regression ranged from 69.9 to 2896.7. According to estimates of the two stability parameters, none of the genotypes were stable for grain yield. However, based on the linear regression coefficient and average grain yield, line 2 (Adilcevaz-40/1) and 11 (Van-Edremit/1) appeared to be promising because their yields were above the average in all of the environmental conditions of this study.

Summary: We report unusual MR serial imaging and electron microscopy findings in a 3-year-old boy who had Leigh syndrome with cytochrome-c oxidase (cox) deficiency. The MR imaging findings included periventricular white matter involvement, posteroanterior progression, and extension through the corpus callosum and internal capsule; however, no basal ganglia or brain stem abnormality was found, which was suggestive of leukodystrophy. The most noteworthy findings were the cystic foci with contrast enhancement in the affected white matter.

Consequently, distribution of humic acids between solid and liquid phases, mechanism of surface protonation and metal-humate complexation are introduced through this study.

The relationship between food and health has become increasingly significant as consumers now demand healthy, tasty and natural foods which perform a useful function in the body. In Turkey, rose hip (Rosa canina L.) is in popular use in foodstuffs such as marmalade, pestil (a traditional Turkish sweet) and syrup or in traditional medicine, mainly as herbal tea. The composition, total antioxidant capacity (TAC) and total phenolic content (TPC) of volatiles of rose hip samples were compared in relation to their stage of maturity and collection location. Rose hip fruit and seed were analyzed using a direct thermal desorption technique coupled with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOF/MS). The major components found in the volatile fraction released on extraction were free fatty acids. The various stages of maturity of rose hips (green, light yellow, yellow, orange and red coloured) and the place of collection (Istanbul, Mersin, York) resulted in some changes in volatile compound speciation, in TAC and TPC levels. Various extraction methods were compared; methanol extraction, traditional hot water infusion and boiling in water. Boiling in water for ten minutes was the method which demonstrated the highest extraction efficiency. TAC and TPC were determined using different electron transfer−based assays; the Cerium (IV) ions reducing antioxidant capacity, Cupric Reducing Antioxidant Capacity and Folin-Ciocalteu methods. The highest TAC and TPC were found in the red coloured (fully ripe) rose hip fruit, suggesting that colour is a suitable indicator for optimal harvesting time.