Determination of Phytoestrogen Composition in Soybean Cultivars in Serbia

The growing clinical interest and use of soybean-based food products and extracts to increase dietary phytoestrogen intake have led to medical interest in the precise determination of the phytoestrogen composition of soybean products. We have analyzed the composition of these compounds in 20 domestic and introduced varieties of genetically non-modified soybean genotypes grown under the same agroecological conditions. The isoflavone content of soybeans cultivated in this region of Serbia has not been previously reported. The assays were performed, after extraction with methanol-water (8:2, v/v), by C-18 reversed phase high-performance liquid chromatography coupled with photodiode array detection. The total phytoestrogen concentration was found to be between 2.24 and 3.79 mg g(-1) dry bean weight. The total concentration of daidzein and its derivatives ranged from 0.96 to 1.82 mg g(-1), total glyciteines from 0.34-0.53 mg g(-1), and all genistein derivatives from 0.86-1.67 mg g(-1) dry bean weight. Given the high biological potency of phytoestrogens and their metabolic conversion products, our data suggest that phytoestrogen content screening could be a useful tool in the selection of soybean genotypes with improved health promoting characteristics

Solubilization of fullerene C60 in micellar solutions of different solubilizers

Fullerene (C(60)), the third carbon allotrope, is a classical engineered material with the potential application in biomedicine. However, extremely high hydrophobicity of fullerene hampers its direct biomedical evaluation and application. In this work, we investigated the solubilization of fullerene using 9 different solubility enhancers: Tween 20, Tween 60, Tween 80, Triton X-100, PVP, polyoxyethylene (10) lauryl ether, n-dodecyl trimethylammonium chloride, myristyl trimethylammonium bromide and sodium dodecyl sulphate and evaluated its antioxidant activity in biorelevant media. The presence of C(60) entrapped in surfactant micelles was confirmed by UV/VIS spectrometry. The efficacy of each modifier was evaluated by chemometric analysis using experimental data for investigating the relationship between solubilization and particle size distribution. Hierarchical clustering and principal component analysis was applied and showed that non-ionic surfactants provide better solubilization efficacy (>85%). A correlation was established (r=0.975) between the degree of solubilization and the surfactant structure. This correlation may be used for prediction of C(60) solubilization with non-tested solubility modifiers. Since the main potential biomedical applications of fullerene are based on its free radical quenching ability, we tested the antioxidant potential of fullerene micellar solutions. Lipid peroxidation tests showed that the micellar solutions of fullerene with Triton and polyoxyethylene lauryl ether kept high radical scavenging activity, comparable to that of aqueous suspension of fullerene and BHT. The results of this work provide a platform for further solubilization and testing of pristine fullerene and its hydrophobic derivatives in a biological benign environment

Classification and discrimination of soybean (Glycine max (L.) Merr.) genotypes based on their isoflavone content

Isoflavones are phytoestrogens with various types of biological activity. Soybean (Glycine max (L.) Merr.) is the most abundant source of isoflavones in human nutrition. The present study aims to classify the different soybean genotypes according to their isoflavone contents. HPLC analysis of isoflavone content in 22 soybean genotypes was performed. The average content of individual isoflavones in the genotypes analyzed ranged from 2.8 mu g/g to 1069,9 mu g/g while the most abundant component among the 22 genotypes was malonyl-genistin. The majority of isoflavones had a significantly higher concentration (p lt 0.05) in the hybrid genotypes compared to parental genotypes implying heterosis. The principal component analysis (PCA) on isoflavone content and composition, including results in 83 genotypes, was conducted. The contents of daidzein and genistein were positively correlated, which could be explained by their biosynthetic pathways. Using the PCA, analyzed genotypes divided into six coherent groups regarding their specific isoflavone content. Malonyl-genistin and malonyl-daidzin were the most abundant components. Moreover, the significance of the cultivation year on the isoflavone content in soybean was pointed out. The overall results suggested the possibility of selection of suitable soybean extracts according to the content of malonyl-genistin

Effect of Quaternary Ammonium Gemini Surfactant Solution on the Rate Constant of the Ninhydrin–Lysine Reaction

The effect of solutions of double-chained quaternary ammonium gemini surfactants (16-s-16, s = 4–6) was characterized on the rate constant of the ninhydrin (nin) and lysine (Lys) reaction using a ultraviolet–visible (UV–vis) spectrophotometer. Rate constant (kψ) values were obtained at different geminis. However, kψ values obtained at several geminis were displayed in the form of the kψ–[gemini] rate profile, and the quantitative estimation of these results was elucidated employing a model of micellar catalysis referred to as pseudophase. The role of other experimental ingredients such as nin, Lys, pH, and temperature (T) was examined in geminis, and kψ values as a function of these parameters were determined. Data treatment confirms a fractional order in [nin] and a unity order in [Lys]. Using conductometric evaluation, the critical micellar concentration (cmc) of pure double-chained gemini surfactants (16–6–16, 16–5–16, and 16–4–16) and presence of nin and Lys were recorded. Results of the present experimental value were used to determine micellar binding constants (KA for Lys and KB for nin). The binding constants and second-order rate (km) affect the solvent properties at the micellar surface and hence are taken into consideration and discussed