Search

For simultaneous analysis of four fat-soluble tocopherols (α-, β-, γ-, and δ-) in edible oils, an efficient and green method using deep eutectic solvent-based liquid-phase microextraction (DES-LPME) coupled with reversed-phase high-performance liquid chromatography (RP-HPLC) was developed. The DESs formed by different quaternary ammonium salts and ethanol were used as the extractants. Tetrabutylammonium chloride (TBAC)-ethanol DES at a molar ratio of 1:2 achieved the best extraction efficiency. Under the optimized conditions, the detection limits were in the range of 2.1–3.0 ng mL−1. The intra-day and inter-day repeatability were in the ranges of 3.9–5.3% and 4.8–7.1%, respectively, and the recoveries for the real samples varied from 80.7% to 105.4%. The developed method was successfully employed for the determination of all four tocopherol homologues with an RP-HPLC system containing a COSMOSIL π-NAP column in five edible oils collected locally.

Hellenia speciosa (J.Koenig) S.R.Dutta, is a plant species belonging to the family Costaceae. It is widely distributed in China, India, Malaysia, Indonesia, tropical and subtropical Asia. In Ayurveda, the rhizome of the plant has been extensively used to treat fever, rash, asthma, bronchitis and, intestinal worms. The objective of the present study was to investigate the phytochemical constituents of the leaf of Hellenia speciosa using Gas Chromatography and Mass Spectroscopy analysis (GC-MS). The GC-MS analysis revealed the presence of 17 phytochemical components in the ethanolic leaf extract of Hellenia speciosa. The prevailing bioactive compounds present in Hellenia speciosa were Thymol (RT-10.019;3.59%), Caryophyllene (RT-11.854:0.62%), Caryophyllene oxide (RT-13.919;1.34%), Artumerone (RT-14.795;1.35%), Hexadecanoic acid methyl ester (RT-17.536; 2.77%), 9,12-Octadecanoic acid methyl ester (RT-19.163;1.35%), Squalene (RT- 24.980;1.19%), Piperine (RT-25.745;3.11%), Beta Tocopherol (RT-26.681;2.88%) Vitamin E (RT- 27.290;2.64%), Progesterone (RT-29.608;3.18%), Caparratriene (RT-29.861;9.72%), and Testosterone (RT-30.73;5.81%). The compounds were identified by comparing their retention time and peak area with that of the literature and by interpretation of mass spectra. The results and findings of the present study suggest that the plant can be used as a valuable source in the field of herbal drug discovery. The presence of bioactive compounds justifies the use of plant leaves for treating various diseases with fewer side effects and recommended the plant of pharmaceutical importance. However, further studies are needed to undertake its bioactivity and toxicity profile.

Seeds of 15 diverse rice accessions, representing aus, indica, temperate japonica and tropical japonica subpopulations, were produced under temperate climate conditions in Korea and used for vitamin E analysis and seed storage experiments at 45°C and 10.9% seed moisture content. High γ-tocotrienol was significantly positively correlated with seed longevity. In addition, a high β-tocopherol proportion relative to δ-tocopherol was significantly negatively correlated with seed longevity. Using high-density single-nucleotide polymorphism marker data, DNA haplotype analysis showed clear allelic variations in the region of two S-adenosylmethionine synthetase genes: LOC_Os04g42095 and LOC_Os11g15410, which regulate the conversion of δ-tocopherol into β-tocopherol. Four indica accessions with rare and subpopulation-specific alleles showed a 2.3-fold lower β-/δ-tocopherol ratio compared with accessions from other subpopulations.

OBJECTIVES: The aim of this study was to determine the effect of feeding cats with reduced renal function a high protein food while maintaining phosphorus concentration across foods containing varying protein levels. METHODS: The study was conducted using 23 cats of 5–13 years of age with chronic kidney disease. After a 1 month washout period, cats were randomly assigned to one of the 6 groups of approximately 4 cats to receive 3 treatment foods, each for 111 days, in a sequence following the William's Latin Square design. The treatment foods contained on a dry matter basis, low (25.94%), medium (31.91%) or high (36.77%) protein and had similar other nutrient levels including Phosphorus. Average body weights were determined after each treatment period. Blood and urine samples were collected at the end of each treatment period to compare changes in levels of metabolites associated with progression of kidney disease. RESULTS: The consumption of the foods with different protein levels did not have an effect on body weight. Urine pH was significantly higher after cats were fed high protein food (P = 0.0003). Blood chemistry results showed that cats had significantly increased level of blood urea nitrogen (BUN) after the consumption of the high protein food compared with the low protein food (P = 0.005). Increased urea levels were also confirmed from results of plasma metabolomics. Levels of microbial uremic toxins such as 3-indoxyl sulfate, 5-hydroxyindole sulfate, 6-hydroxyindole sulfate and 3-hydroxyindoline-one sulfate were significantly elevated after cats were fed high protein compared to both medium and low protein foods (P

The oaks Quercus robur L. and Quercus rubra L. are grown worldwide. The oak fruits (acorns) fallen on the ground during the autumn are usually considered as unusable, although some possible applications have been reported. In the present study, the possible recovery of tocopherols from acorns of two oak species Q. rubra (n = 14) and Q. robur (n = 15) was evaluated. Four tocopherols (Ts) (α-T, β-T, γ-T, and δ-T) in the oak fruits of Q. rubra and Q. robur were identified. The Q. robur acorns had abundant γ-T (28.18 ± 6.7 mg/100 g dw), while in Q. rubra β-T was predominant (17.28 ± 2.91 mg/100 g dw), nearly 95 and 90% of total detected tocopherols, respectively. The variability of tocopherol levels within the same species was lower for Q. rubra (16.5%) and higher for Q. robur (23.4%). The principal component analysis, applied to four tocopherol homologues, confirmed their feasibility to distinguish two strictly separated groups: one for species Q. rubra and the other for Q. robur. The predominance of β-T in Q. rubra acorns is a unique finding in the plant world; therefore, acorns of this oak species can be used as an unconventional natural source of this rare tocopherol homologue.

The wild mushroom Leucopaxillus candidus (Bres.) Singer was studied for the first time to obtain information about its chemical composition, nutritional value and bioactivity. Free sugars, fatty acids, tocopherols, organic and phenolic acids were analysed by chromatographic techniques coupled to different detectors. L. candidus methanolic extract was tested regarding antioxidant potential (reducing power, radical scavenging activity and lipid peroxidation inhibition). L. candidus was shown to be an interesting species in terms of nutritional value, with high content in proteins and carbohydrates, but low fat levels, with the prevalence of polyunsaturated fatty acids. Mannitol was the most abundant free sugar and β-tocopherol was the main tocopherol isoform. Other compounds detected were oxalic and fumaric acids, p-hydroxybenzoic and cinnamic acids. The methanolic extract revealed antioxidant activity and did not show hepatoxicity in porcine liver primary cells. The present study provides new information about L. candidus. The authors are grateful to Foundation for Science and Technology (FTC, Portugal) for financial support to CIMO (Pest-OE/AGR/UI0690/2014) and L. Barros (SFRH/BPD/107855/2015) grant.

Annona squamosa and Catunaregam nilotica seeds and oils were characterized for their approximate analysis and physico-chemical properties. The oil and protein contents were 26.8, 17.5 and 40.0, 22.2%, in A. squamosa and C. nilotica seeds, respectively. The oils were extracted using cold extraction (CE) and Soxhlet extraction (SE) methods. Fatty acids and tocopherols were determined by GC–MS and HPLC, respectively. Generally the physico-chemical properties and fatty acids were not significantly (P ≤ 0.05) affected by the extraction methods. The major fatty acids of A. squamosa oil extracted by CE and SE were oleic 49.2 and 50.5%, linoleic 22.3 and 22.7%, palmitic 15.6 and 15.2%, and stearic 10.6 and 9.3%, respectively. While the major fatty acids in C. nilotica oil extracted by CE and SE were oleic 10.5, and 10.4%, linoleic 63.1 and 63.4%, palmitic 9.7 and 9.8% and stearic 5.1 and 5.4%, respectively. The tocopherol content of CE and SE extracted oils from A. squamosa amounted to 16.6 and 15.5 and from C. nilotica amounted to 110.5 and 107.7 mg/100 g oil, respectively, with delta-tocopherol as the predominant tocopherol in A. squamosa oil, and beta-tocopherol in C. nilotica oil. The total amount of amino acids was found to be 7.266 and 14.202 g/100 g protein, in seeds of A. squamosa and C. nilotica, respectively.

Tocopherols (vitamin E) comprise a class of lipid-soluble antioxidants synthesized only in plants, algae, and some cyanobacteria. The majority of tocopherols in photosynthetic cells is in the α form, which has the highest vitamin E activity in humans, whereas the β, γ, and δ forms normally account for a small percentage of total tocopherols. The antioxidant activities of these forms of tocopherol differ depending on the experimental system, and their relative activities in vivo are unclear. In a screen for suppressors of the xanthophyll-deficient npq1 lor1 double mutant of Chlamydomonas reinhardtii , we isolated a vte3 mutant lacking α-tocopherol but instead accumulating β-tocopherol. The vte3 mutant contains a mutation in the homolog of a 2-methyl-6-phytyl-1,4-benzoquinone methyltransferase gene found in plants. The vte3 npq1 lor1 triple mutant with β-tocopherol survived better under photooxidative stress than did the npq1 lor1 mutant, but the vte3 mutant on its own did not have an obvious phenotype. Following transfer from low light to high light, the triple mutant showed a higher efficiency of photosystem II, a higher level of cell viability, and a lower level of lipid peroxide, a marker for oxidative stress, than did the npq1 lor1 mutant. After high-light transfer, the level of the photosystem II reaction center protein, D1, was also higher in the vte3 npq1 lor1 mutant, but the rate of D1 photodamage was not significantly different from that of the npq1 lor1 mutant. Taken together, these results suggest that the replacement of α-tocopherol by β-tocopherol in a xanthophyll-deficient strain of Chlamydomonas reinhardtii contributes to better survival under conditions of photooxidative stress.

Reduced levels of circulating sex hormone-binding globulin (SHBG) are implicated in the etiology of sex steroid-related pathologies and the metabolic syndrome. Dietary correlates of serum SHBG remain unclear and were studied in a convenient cross-sectional sample of healthy 30- to 40-y-old women (n = 255). By univariate analyses, serum SHBG correlated negatively with several indices of the metabolic syndrome, such as BMI, waist circumference, hip circumference (r = −0.36 to −0.44; P < 0.0001), fasting serum insulin (r = −0.41; P < 0.0001), serum triglycerides (r = −0.27; P < 0.0001), serum glucose (r = −0.23; P < 0.001), and plasma testosterone (r = −0.19; P = 0.002). Serum SHBG correlated positively with serum HDL-cholesterol (r = 0.33; P < 0.0001), plasma progesterone (r = 0.17; P = 0.007), and dietary intake of β-tocopherol (r = 0.17; P = 0.006), and negatively with that of fructose (r = −0.13; P = 0.04). Principal component analysis (PCA) extracted 12 nutrient factors with eigenvalues > 1.0 from 54 nutrients and vitamins in food records. Multivariate regression analyses showed that the PCA-extracted nutrient factor most heavily loaded with β-tocopherol and linoleic acid (P = 0.03) was an independent positive predictor of serum SHBG. When individual nutrients were the predictor variables, β-tocopherol (P = 0.002), but not other tocopherols or fatty acids (including linoleic acid), was an independent positive predictor of serum SHBG. Circulating insulin (P = 0.02) and waist circumference (P = 0.002), but not serum lipids, were negative independent predictors of SHBG in all regression models. Additional studies are needed in women of other age groups and men to determine whether consumption of foods rich in β-tocopherol and/or linoleic acid may increase serum SHBG concentrations and may thereby decrease the risk for metabolic syndrome and reproductive organ cancer.

In order to demonstrate whether the known biological effects of Aloe vera (L.) Burm. fil. could correlate with the antioxidant activity of the plant, the antioxidant activity of the aqueous leaf extract was investigated. The present study demonstrated that the aqueous extract from A. vera leaves contained naturally occuring antioxidant components, including total phenols, flavonoids, ascorbic acid, beta-carotene and alpha-tocopherol. The extract exhibited inhibitory capacity against Fe(3+)/ascorbic acid induced phosphatidylcholine liposome oxidation, scavenged stable DPPH(*), ABTS(*+) and superoxide anion radicals, and acted as reductant. In contrast, the leaf inner gel did not show any antioxidant activity. It was concluded that the known beneficial effects of Aloe vera could be attributed to its antioxidant activity and could be related to the presence of phenolic compounds and antioxidant vitamins.

The effect of irradiation (0–20 kGy) on hemp and sunflower seeds was assessed, with specific reference to the oxidatively labile lipid component (unsaturated fatty acids and tocochromanols). Total protein, lipid, and solids content of the seeds did not vary with irradiation dose. Lipid hydroperoxide concentration increased significantly in the sunflower seeds (48 mmol kg−1 lipid) and a significant increase in volatile secondary oxidation products was measured in both seeds (e.g. hexanal, heptanal, 1-penten-3-ol) with increasing irradiation dose. Irradiation at 5 kGy sterilised the seeds of all microbial contamination and irradiation doses of 20 kGy prevented germination. A loss of the antioxidant tocopherol was shown with increasing irradiation doses, although this was selective for specific tocopherol isoforms (α-tocopherol, β-tocopherol and γ-tocopherol).

A very well-known and appreciated mushroom, Agrocybe aegerita (Brig.) Sing, was the subject of chemical profiling, antioxidant assays and sensory evaluation test in cream cheese. Methanolic extract obtained from a wild sample of A. aegerita fruiting body was fully chemically identified. Sample was found to be rich in carbohydrates (84.51 g/100 g dw), ash and proteins (6.69 g/100 g dw and 6.68 g/100 g dw, respectively). Trehalose was the main free sugar while malic acid was the most abundant organic acid. Four isoforms of tocopherols were identified; gamma- tocopherol was the dominant isoform with 86.08 mu g/100 g dw, followed by beta- tocopherol, delta-tocopherol and alpha-tocopherol (8.80 mu g/100 g dw, 3.40 mu g/100 g dw and 2.10 mu g/100 g dw, respectively). Polyunsaturated fatty acids were predominant, with linoleic acid as the most prominent one (78.40 \%). Methanolic extract of chestnut mushroom exhibited high antioxidant activity. Sensory evaluation test included grading by panelists and comparing the overall acceptability of cream cheese alone and enriched cream cheese with dry powder of A. aegerita. General conclusion of the participants was that the newly developed product was more likeable in comparison to cream cheese alone. Due to the health-beneficial effects of antioxidants and wealth of chemically identified nutrients, A. aegerita is a promising starting material for incorporation on larger scale products. Ministry of Education, Science and Technological Development of Serbia {[}173032]; Foundation for Science and Technology (FCT, Portugal) {[}SFRH/BD/76019/2011]

SUMMARY Two different sunflower lines with increased beta-tocopherol concentration in the seeds, LG-15 and T589, have been developed. The objective of the present research was to conduct a comparative genetic study of the increased beta-tocopherol concentration in both lines. Plants of LG-15 were reciprocally crossed with plants of T589 in 2003. The F1, F2, BC to LG-15 and BC to T589 seed generations were produced in the same environment in 2004 and analyzed for tocopherol profile. The results indicated a strong environmental effect on the increased levels of beta-tocopherol concentration in LG-15 and T589, which averaged 30.5% and 25.8%, respectively, in 2003 and 43.2% and 54.0%, respectively, in 2004. The comparison of individual plant means and standard errors of individual plant means for the F2 and BC generations with those in the non-segregating parental and F1 generations indicated no transgressive segregation for beta-tocopherol concentration in F2 or BC seeds. These results suggested that increased beta-tocopherol concentration in both lines is the result of genetic alterations at the same locus.

During a study of the effect of vitamin E in activated mouse macrophages, we observed a reduction in the viability of cells treated with various forms of vitamin E. We show in this report that some tocopherols (both gamma- and delta-tocopherol) are cytotoxic to some but not all cell types. Mouse macrophages were especially sensitive (40 micromol/L), whereas human hepatocytes and bovine endothelial cells were almost completely refractory (90 micromol/L). The fully methylated tocopherol, alpha-tocopherol (alpha-Toc), was not cytotoxic in any cell type tested. The cytotoxicity observed with delta-tocopherol (delta-Toc) was associated with 2 markers of apoptosis. Vitamer-specific cytotoxicity was not due to differences in cellular uptake/accumulation because both alpha-Toc and delta-Toc accumulated equally in any cell type tested. In contrast, the cell-specific cytotoxicity was related in part to uptake/accumulation of the tocopherols. Macrophages accumulated nearly 5 times more tocopherol compared with hepatocytes cultured under similar conditions. To address the hypothesis that uptake accounted for the cell-specific sensitivity, we developed a macrophage "subtype" that was markedly resistant (150 micromol/L) to delta-Toc. Under many different cell culture conditions (including human serum) uptake/accumulation of tocopherols was reduced in this subtype by approximately 50%. Further selection and evaluation of this phenotype, however, demonstrated no cytotoxicity even when cellular levels were elevated. Our results show that undermethylated tocopherols are cytotoxic to macrophages and that there are independent and selectable processes that determine cellular tocopherol uptake/accumulation and delta-Toc cytotoxicity.

Tocopherols, synthesized by photosynthetic organisms, are micronutrients with antioxidant properties that play important roles in animal and human nutrition. Because of these health benefits, there is considerable interest in identifying the genes involved in tocopherol biosynthesis to allow transgenic alteration of both tocopherol levels and composition in agricultural crops. Tocopherols are generated from the condensation of phytyldiphosphate and homogentisic acid (HGA), followed by cyclization and methylation reactions. Homogentisate phytyltransferase (HPT) performs the first committed step in this pathway, the phytylation of HGA. In this study, bioinformatics techniques were used to identify candidate genes,slr1736 and HPT1, that encode HPT fromSynechocystis sp. PCC 6803 and Arabidopsis, respectively. These two genes encode putative membrane-bound proteins, and contain amino acid residues highly conserved with other prenyltransferases of the aromatic type. A Synechocystissp. PCC 6803 slr1736 null mutant obtained by insertional inactivation did not accumulate tocopherols, and was rescued by the Arabidopsis HPT1 ortholog. The membrane fraction of wild-type Synechocystis sp. PCC 6803 was capable of catalyzing the phytylation of HGA, whereas the membrane fraction from the slr1736 null mutant was not. The microsomal membrane fraction of baculovirus-infected insect cells expressing the Synechocystis sp. PCC 6803slr1736 were also able to perform the phytylation reaction, verifying HPT activity of the protein encoded by this gene. In addition, evidence that antisense expression of HPT1in Arabidopsis resulted in reduced seed tocopherol levels, whereas seed-specific sense expression resulted in increased seed tocopherol levels, is presented.

Flaxseed (Linum usitatissimum L.) oil was obtained via subcritical n-propane fluid extraction (SubFE) under different temperatures and pressures with an average yield of 28% and its composition, purity and oxidative stability were compared to oils obtained via conventional solvent extraction methods (SEMs). When the oxidative stability was measured by differential scanning calorimetry, the oil was found to be up to 5 times more resistant to lipid oxidation as compared to the SEM oils. Direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis showed characteristic and similar TAG profiles for SubFE and SEMs oils but higher purity for the SubFE oil. The flaxseed oil content of β-tocopherol, campesterol, stigmasterol and sitosterol were quantified via GC–MS. SubFE showed to be a promising alternative to conventional SEM since SubFE provides an oil with higher purity and higher oxidation stability and with comparable levels of biologically active components.

This study addresses issues regarding chemical and bioactive properties of nine wild edible mushrooms from native Nothofagus forest from Patagonia, Argentina. Macronutrients, sugars, fatty acids, tocopherols, organic acids, phenolic compounds and antioxidant properties were determined. Protein was found in high levels and varied between 3.35 g/100 g dw in Cyttaria hariotii and 22.29 g/100 g dw in Lepista nuda. All of them presented mannitol and trehalose as main sugars. Mannitol was significantly higher in Ramaria patagonica, although absent in Fistulina endoxantha, whereas trehalose predominated in Aleurodiscus vitellinus, Hydropus dusenii, Cortinarius magellanicus, C. hariotii, Grifola gargal and L. nuda, ranging from 1.15 to 10.26 g/100 g dw; it was absent in R. patagonica. The major fatty acid found was linoleic acid, followed by oleic acid and palmitic acid. All species presented oxalic and fumaric acids, while some also had malic, quinic and citric acids. Tocopherols composition was variable. Cortinarius magellanicus presented significantly higher contents of both α-tocopherol and β-tocopherol. R. patagonica presented the best results in all the antioxidant activity assays (EC50 values ≤ 1 mg/mL) and the highest content of phenolic compounds presenting gallic, p-hydroxybenzoic, p-coumaric and cinnamic acids. This study constitutes the first report on chemical composition and nutritional value of most of these edible mushroom species. Furthermore, it provides important information necessary to characterize and define the use of these species as gastronomic delicacies, functional foods and sources of bioactive compounds. info:eu-repo/semantics/publishedVersion

Coriander is commonly used for medicinal purposes, food applications, cosmetics and perfumes. Herein, the production of antioxidants in vegetative parts (leaves and stems) of in vivo and in vitro grown samples was compared. In vitro samples were clone A- with notorious purple pigmentation in stems and leaves and clone B- green. Seeds were also studied as they are used to obtain in vivo and in vitro vegetative parts. Lipophilic (tocopherols, carotenoids and chlorophylls) and hydrophilic (sugars, ascorbic acid, phenolics, flavonols and anthocyanins) compounds were quantified. The antioxidant activity was evaluated by radical scavenging activity, reducing power and lipid peroxidation inhibition. The in vivo sample showed the highest antioxidant activity mainly due to its highest levels of hydrophilic compounds. Otherwise, in vitro samples, mainly clone A, gave the highest concentration in lipophilic compounds but a different profile when compared to the in vivo sample. Clones A and B revealed a lack of B-carotene, B- and δ-tocopherols, a decrease in alpha-tocopherol, and an increase in Y-tocopherol and clorophylls in comparison to the in vivo sample. In vitro culture might be useful to explore the plants potentialities for industrial applications, controlling environmental conditions to produce higher amounts of some bioactive products.

The objective of this study has been to evaluate the stability of alpha-, (gamma+beta)-, and delta-tocopherols in rice bran oil chemically refined submitted to heating in a heater without air circulation and shielded from light, at temperatures of 100 degrees C and 180 degrees C. The collection of samples took place after 48, 96, 144, 192, 240, 336, and 432 h of heating and were stored in amber-colored flasks and frozen (-18 degrees C). The analyses of tocopherols took place in accordance with the method by Chen and Bergman (2005), with slight modifications, utilizing a system of high efficiency system of liquid chromatography. It was observed that the alpha-tocopherol is present at higher concentration in rice bran oil (328.4 mg/kg), followed by (gamma+beta)-tocopherol (99.1 mg/kg), and delta-tocopherol (7.7 mg/kg). The alpha-tocopherol in rice bran oil submitted to 100 degrees C showed a reduction of 28.65% at the end of 432 h of heating whereas when submitted to 180 degrees C temperature; its reduction was of 100% at the end of 240 h of heating. The contents of (gamma+beta)- and delta-tocopherol in rice bran oil at the end of 432 h of heating at 100 degrees C was of 79.9 and 6.4 mg/100 g, respectively.

In order to demonstrate whether the known biological effects ofAloe vera(L.) Burm. fil. could correlate with the antioxidant activity of the plant, the antioxidant activity of the aqueous leaf extract was investigated. The present study demonstrated that the aqueous extract fromA. veraleaves contained naturally occuring antioxidant components, including total phenols, flavonoids, ascorbic acid, β-carotene and α-tocopherol. The extract exhibited inhibitory capacity against Fe3+/ascorbic acid induced phosphatidylcholine liposome oxidation, scavenged stable DPPH•, ABTS•+and superoxide anion radicals, and acted as reductant. In contrast, the leaf inner gel did not show any antioxidant activity. It was concluded that the known beneficial effects ofAloe veracould be attributed to its antioxidant activity and could be related to the presence of phenolic compounds and antioxidant vitamins.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:48:47Z No. of bitstreams: 1 S0100-40422009000600028.pdf: 344488 bytes, checksum: 2e370fee136ec83aba312b384afe8315 (MD5) Made available in DSpace on 2013-08-22T18:48:47Z (GMT). No. of bitstreams: 1 S0100-40422009000600028.pdf: 344488 bytes, checksum: 2e370fee136ec83aba312b384afe8315 (MD5) Previous issue date: 2009-01-01 Made available in DSpace on 2013-09-30T19:10:47Z (GMT). No. of bitstreams: 2 S0100-40422009000600028.pdf: 344488 bytes, checksum: 2e370fee136ec83aba312b384afe8315 (MD5) S0100-40422009000600028.pdf.txt: 23627 bytes, checksum: 05061873eec465c7eb499b81abefe6e6 (MD5) Previous issue date: 2009-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:21:20Z No. of bitstreams: 2 S0100-40422009000600028.pdf: 344488 bytes, checksum: 2e370fee136ec83aba312b384afe8315 (MD5) S0100-40422009000600028.pdf.txt: 23627 bytes, checksum: 05061873eec465c7eb499b81abefe6e6 (MD5) Made available in DSpace on 2014-05-20T14:21:20Z (GMT). No. of bitstreams: 2 S0100-40422009000600028.pdf: 344488 bytes, checksum: 2e370fee136ec83aba312b384afe8315 (MD5) S0100-40422009000600028.pdf.txt: 23627 bytes, checksum: 05061873eec465c7eb499b81abefe6e6 (MD5) Previous issue date: 2009-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Phytochemical investigation of ethanolic leaves extracts of T. fagifolia led to the isolation of (+)-catechin, sitosterol-3-O-β-D-glucopyranoside, α- and β-tocopherol, a mixture of lupeol, α- and β-amyrin, sitosterol and a mixture of glicosid flavonoids (CP-13). The structures of these compounds were identified by ¹H and 13C NMR spectral analysis and comparison with literature data. Absolute configuration of the catechin was determinate by circular dichroism. Antioxidant activity (EC50), evaluated by 2,2-diphenyl-1-picrylhidrazyl (DPPH) assay system, decreased in the order: (+)-catechin > hydroalcoholic fraction > CP-13 > aqueous fraction > EtOH extract. Universidade Federal do Piauí (FUFPI) Departamento de Química Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Química Departamento de Química Orgânica Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Química Departamento de Química Orgânica

The objectif of this paper is determening the conte nt of tocopherols ( α - , β + γ and δ - ) using a HPLC method with a FL detector and fatty acids in six romanian cereal grain variet ies( wheat varieties: Ariesan, Dumbrava, Stil; maize varieties: Turda 201, Turda 1 60 and Turda 215)

Studies of vitamin E and cancer have focused on the alpha-tocopherol form of the vitamin. However, other forms of vitamin E, in particular gamma-tocopherol may have unique mechanistic characteristics relevant to lung cancer prevention. In an ongoing study of 1,088 incident lung cancer cases and 1,414 healthy matched controls, we studied the associations between 4 tocopherols (alpha-, beta-, gamma-, and delta-tocopherol) in the diet and lung cancer risk. Using multiple logistic regression analysis, the adjusted odds ratios (OR) and 95% confidence intervals (CI) of lung cancer for increasing quartiles of dietary alpha-tocopherol intake were 1.0, 0.63 (0.50-0.79), 0.58 (0.44-0.76) and 0.39 (0.28-0.53), respectively (p-trend0.0001). For dietary intake of beta-tocopherol, the OR and 95% CI for all subjects were: 1.0, 0.79 (0.63-0.98), 0.59 (0.45-0.78) and 0.56 (0.42-0.74), respectively (p-trend0.0001). Similar results for dietary gamma-tocopherol intake were observed: 1.0, 0.84 (0.67-1.06), 0.76 (0.59-0.97) and 0.56 (0.42-0.75), respectively (p- trend = 0.0002). No significant association between delta-tocopherol intake and lung cancer risk was detected. When the 4 tocopherols were summed as total tocopherol intake, a monotonic risk reduction was also observed. When we entered the other tocopherols in our model, only the association with dietary alpha-tocopherol intake remained significant; i.e., increasing intake of dietary alpha-tocopherol accounted for 34-53% reductions in lung cancer risk. To the best of our knowledge, this is the first report of the independent associations of the 4 forms of dietary tocopherol (alpha-, beta-, gamma- and delta-tocohperol) on lung cancer risk. Given the limitations with case-control studies, these findings need to be confirmed in further investigations.

SUMMARY Tocopherols are synthesized and accumulated by all plants and many cyanobacteria. The quenching and scavenging of reactive oxygen species and lipid peroxy radicals by tocopherols can result in the formation of various tocopherol oxidation compounds. A targeted GC/MS profiling method was developed to quantify all tocopherols and pathway intermediates, and 23 potential alpha- and gamma-tocopherol oxidation products. This method was used to study the response of wild-type Arabidopsis (Col) and the tocopherol biosynthetic mutants vte1, vte2 and vte4 during 12 h low- and high-light treatments (LL and HL, 90 and 1500 mumol photon m(-2) sec(-1), respectively) and a subsequent 12 h dark recovery period. All tocopherols and pathway intermediates exhibited HL-dependent increases except 2,3-dimethyl-6-phytyl-1,4-benzoquinone (DMPBQ) in vte1 and beta-tocopherol in Col. Profiling of potential tocopherol oxidation products during HL treatment indicated the presence of only alpha-tocopherolquinol (alpha-TQH(2)) in Col and only gamma-tocopherolquinol (gamma-TQH(2)) in vte4, both of which accumulated to similar levels and with similar kinetics the two genotypes. However, during dark recovery, the level of alpha-TQH(2) in Col decreased several times faster than that of gamma-TQH(2) in vte4, suggesting the presence of biochemical processes with higher specificity for alpha-TQH(2). (14)C-labeled alpha-tocopherolquinone (alpha-TQ) applied to isolated Col chloroplasts was converted to (14)C-alpha-tocopherol, demonstrating the existence of a plastid-based system for recycling oxidized alpha-tocopherol. The accumulation of (14)C-trimethylphytylbenzoquinone (TMPBQ) by isolated vte1 plastids treated with (14)C-labeled alpha-TQ is consistent with the tocopherolquinone-recycling pathway utilizing a yet to be identified plastid-localized dehydratase that converts tocopherolquinone to TMPBQ.

To investigate the role of reactive oxygen species (ROS) and the effect of vitamin E on proliferation of vascular smooth muscle cells (VSMCs) induced by homocysteine.DNA synthesis in the VSMCs cells was measured using [3H]-thymidine incorporation assay, and the cell number determined by trypan blue method. The level of ROS in the cells was determined using DCF-DA as the fluorescence probe.Homocysteine promoted VSMC DNA synthesis, proliferation, and ROS production. Cysteine resulted in increased ROS production in VSMCs, but had no significant effect on DNA synthesis and cell proliferation. Catalase significantly inhibited ROS production induced by homocysteine, but did not significantly inhibited homocysteine-mediated proliferation of VSMCs. While alpha-tocopherol and beta-tocopherol both suppressed increased ROS production induced by homocysteine in VSMCs, only alpha-tocopherol significantly inhibited homocysteine-mediated VSMC proliferation.ROS is not associated with VSMC proliferation, and vitamin E-induced suppression of VSMC proliferation is probably related to protein kinase C inhibition.

Tocopherols are essential micronutrients in human and animal nutrition due to their function as lipophilic antioxidants. They are exclusively synthesized by photosynthetic organisms including higher plants. Despite the attributed beneficial health effects and many industrial applications, research on the tocopherol biosynthetic pathway and its regulation in plants is still limited. In the work presented here we performed a detailed biochemical characterization of a gamma-tocopherol methyltransferase (gamma-TMT) from Arabidopsis thaliana and of a gamma-TMT purified from Capsicum annuum fruits, a tissue with high accumulation of tocopherols. The biochemical characteristics of both enzyme preparations were remarkably similar including substrate specificities. Both enzymes converted delta- and gamma- into beta- and alpha-tocopherol, respectively, but beta-tocopherol was not accepted as a substrate, pointing to a specific methylation at the C(5)-position of the tocopherol aromatic head group. A kinetic analysis performed with the Arabidopsis enzyme was consistent with an iso-ordered bi-bi type reaction mechanism. Our results emphasize the role of gamma-TMT in regulating the spectrum of accumulated tocopherols in plants.

A quick and direct method based on reversed phase high performance liquid chromatography with fluorescence detector for measuring tocopherols (α , β + γ and δ) has been developed. Oils are diluted in methanol: hexane: tetrahydrofuran (neither previous extraction of tocopherols nor saponification procedure are required) and after being vortexed and centrifuged, an aliquot of the overlay was injected directly into an Alltima C 18 column. Acetonitrile and methanol (50: 50) mixture was used as a mobile phase with a flow rate of 1 mL min-1. Quantification of tocopherols was performed by fluorescence detector at 290 nm excitation wavelength and 325 nm emission wavelength. Tocopherols were separated at 25°C in less than 10 min after injection. The method has good limit of detection (9 ng g-1 for α-tocopherol and 8 ng g-1 for β-, γ- and δ- tocopherols) and reproducibility (CV< 2.9 %). This method can be used to assess the influence of genetic modification of oil seeds on the distribution of tocopherols or the effect of tocopherols on the oxidative stability of edible plant oils.

This study is concerned with differences between breast-fed and bottle-fed infants in plasma and red blood cell (RBC)-levels and pattern of tocopherol analogues. Tocopherol levels were determined by High-Performance Liquid Chromatography (HPLC). The results were as follows: 1. In breast-fed infants the plasma contained larger amounts of the alpha and smaller amounts of the gamma form of tocopherol than in bottle-fed infants but the RBC contained the alpha form alone. 2. In the bottle-fed infants the plasma contained the alpha, gamma, and delta forms, but the RBC contained the alpha form alone. 3. In bottle-fed infants plasma alpha-tocopherol levels did not differ significantly from those in breast-fed infants but RBC alpha-tocopherol levels were far lower in the former. In contrast, plasma gammatocopherol levels were significantly higher in bottle-fed infants. 4. Cord blood plasma contained only the alpha and gamma forms with the patterns similar to those in adults. The delta form appeared in the plasma of bottle-fed neonates as early as 3 or 4 days after birth. 5. The transitional-form human milk obtained on the 5th postpartum day contained the alpha and gamma forms alone and resembled adult plasma. On the other hand, commercially available formulas contained all four forms, with the gamma form the highest, alpha and delta forms moderate, and only slight beta.