The heart of oxygenic photosynthesis is the water-splitting photosystem II (PSII), which forms supercomplexes with a variable amount of peripheral trimeric light-harvesting complexes (LHCII). Our knowledge of the structure of green plant PSII supercomplex is based on findings obtained from several representatives of green algae and flowering plants; however, data from a non-flowering plant are currently missing. Here we report a cryo-electron microscopy structure of PSII supercomplex from spruce, a representative of non-flowering land plants, at 2.8 Å resolution. Compared with flowering plants, PSII supercomplex in spruce contains an additional Ycf12 subunit, Lhcb4 protein is replaced by Lhcb8, and trimeric LHCII is present as a homotrimer of Lhcb1. Unexpectedly, we have found α-tocopherol (α-Toc)/α-tocopherolquinone (α-TQ) at the boundary between the LHCII trimer and the inner antenna CP43. The molecule of α-Toc/α-TQ is located close to chlorophyll a614 of one of the Lhcb1 proteins and its chromanol/quinone head is exposed to the thylakoid lumen. The position of α-Toc in PSII supercomplex makes it an ideal candidate for the sensor of excessive light, as α-Toc can be oxidized to α-TQ by high-light-induced singlet oxygen at low lumenal pH. The molecule of α-TQ appears to shift slightly into the PSII supercomplex, which could trigger important structure-functional modifications in PSII supercomplex. Inspection of the previously reported cryo-electron microscopy maps of PSII supercomplexes indicates that α-Toc/α-TQ can be present at the same site also in PSII supercomplexes from flowering plants, but its identification in the previous studies has been hindered by insufficient resolution.

• MeSH
• alfa-tokoferol * analýza   metabolismus   MeSH
• elektronová kryomikroskopie MeSH
• fotosyntéza MeSH
• fotosystém II (proteinový komplex) * metabolismus   MeSH
• rostliny metabolismus   MeSH
• tylakoidy metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alfa-tokoferol * MeSH
• fotosystém II (proteinový komplex) * MeSH

Non-traditional wild rice flakes were analysed for chemical composition, vitamin B compounds, α-tocopherol, mineral and trace elements. Dietary intakes of vitamins, minerals and trace elements were evaluated using FAO/WHO and Institute of Medicine regulations. Wild rice flakes proved to be significant contributors of pyridoxine, pantothenic and folic acids, niacin, thiamine, chromium, magnesium, manganese, phosphorus, zinc, copper, molybdenum and iron to essential dietary intakes values. Toxic dietary intake values for aluminium, cadmium, tin and mercury were less than 33%, which complies the limits for adults set by FAO/WHO for toxic elements intake related to the body weight of 65 kg for females and 80 kg for males taking 100 g of flakes as a portion. However, concentrations of Hg reaching between 3.67 and 12.20 µg/100 g in flakes exceeded the average Hg value of 0.27-1.90 μg/100 g in cereals consumed in the EU. It has to be respected in the future.

• Klíčová slova
• Daily intake, Mineral and trace elements, Vitamin, Wild rice flakes, Zizania aquatica L.,
• MeSH
• alfa-tokoferol analýza   MeSH
• dieta MeSH
• dospělí MeSH
• hmotnostní spektrometrie MeSH
• lidé MeSH
• minerály analýza   MeSH
• rýže (rod) chemie   metabolismus   MeSH
• stopové prvky analýza   MeSH
• těžké kovy analýza   MeSH
• vitamin B komplex analýza   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• výživová politika MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alfa-tokoferol MeSH
• minerály MeSH
• stopové prvky MeSH
• těžké kovy MeSH
• vitamin B komplex MeSH

UNLABELLED: The diversity in human diets that can be reached by proper use of different crops and varieties, including some underutilized ones, is a potentially powerful strategy to ensure food security and prevent serious health problems caused by current diets that are often not fulfilling nutritional requirements. In the framework of this research, the content of tocopherols and tocotrienols, thiamine, riboflavin, pyridoxine, and superoxide dismutase in nine varieties of quinoa, both colored and nonpigmented, obtained from 4 different countries, was investigated and compared to the content of the same vitamins and antioxidants in barley and wheat, both colored and nonpigmented, cultivated in the same experimental field. The aim of this work was to create a crop diversity strategy and encourage the consumption of underutilized crops to ensure that the human diet fulfills nutritional requirements. The contents of vitamin B1, B2, B6, tocopherol, and tocotrienol isomers and superoxide dismutase were determined via HPLC; imaging techniques were used to evaluate the seed color. Quinoa grains had the greatest concentration of tocopherol isomers and activity, represented mainly by α-tocopherol and γ-tocopherol. Wheat and barley seeds had substantial concentrations of tocopherols and tocotrienols. The concentration of riboflavin was greater in barley and wheat than in quinoa, the concentrations of pyridoxine and thiamine were variety-dependent in all grains. Quinoa grains had greater concentration of superoxide dismutase compared to wheat and barley. The richness of each variety and crop should be recognized and used integrally to improve the diet quality. PRACTICAL APPLICATION: Nutritional potential of crops was evaluated from the viewpoint of selected vitamins and antioxidants to create a well-balanced diet. Combined use of both traditional (wheat, barley) and underutilized crops (quinoa) is recommended. HPLC methods and image analysis were successfully used as viable tools for food quality determination.

• Klíčová slova
• antioxidant compounds, barley, quinoa, vitamins, wheat,
• MeSH
• alfa-tokoferol analýza   MeSH
• antioxidancia analýza   MeSH
• Chenopodium quinoa chemie   MeSH
• ječmen (rod) chemie   MeSH
• lidé MeSH
• nutriční hodnota MeSH
• pšenice chemie   MeSH
• semena rostlinná chemie   MeSH
• thiamin analýza   MeSH
• tokoferoly analýza   MeSH
• tokotrienoly analýza   MeSH
• vitamin A analýza   MeSH
• vitamin E analýza   MeSH
• vitaminy analýza   MeSH
• zemědělské plodiny MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alfa-tokoferol MeSH
• antioxidancia MeSH
• thiamin MeSH
• tokoferoly MeSH
• tokotrienoly MeSH
• vitamin A MeSH
• vitamin E MeSH
• vitaminy MeSH

A 2-year study explored metabolic and phenotypic plasticity of sun-acclimated Vitis vinifera cv. Pinot noir leaves collected from 12 locations across a 36.69-49.98°N latitudinal gradient. Leaf morphological and biochemical parameters were analysed in the context of meteorological parameters and the latitudinal gradient. We found that leaf fresh weight and area were negatively correlated with both global and ultraviolet (UV) radiation, cumulated global radiation being a stronger correlator. Cumulative UV radiation (sumUVR) was the strongest correlator with most leaf metabolites and pigments. Leaf UV-absorbing pigments, total antioxidant capacities, and phenolic compounds increased with increasing sumUVR, whereas total carotenoids and xanthophylls decreased. Despite of this reallocation of metabolic resources from carotenoids to phenolics, an increase in xanthophyll-cycle pigments (the sum of the amounts of three xanthophylls: violaxanthin, antheraxanthin, and zeaxanthin) with increasing sumUVR indicates active, dynamic protection for the photosynthetic apparatus. In addition, increased amounts of flavonoids (quercetin glycosides) and constitutive β-carotene and α-tocopherol pools provide antioxidant protection against reactive oxygen species. However, rather than a continuum of plant acclimation responses, principal component analysis indicates clusters of metabolic states across the explored 1,500-km-long latitudinal gradient. This study emphasizes the physiological component of plant responses to latitudinal gradients and reveals the physiological plasticity that may act to complement genetic adaptations.

• Klíčová slova
• carotenoids, climate, global radiation, grapevine, latitude, morphology, phenolic compounds, plasticity, ultraviolet radiation, α-tocopherol,
• MeSH
• absorpce radiace MeSH
• alfa-tokoferol analýza   MeSH
• analýza hlavních komponent MeSH
• antioxidancia metabolismus   MeSH
• biomasa MeSH
• fenoly analýza   MeSH
• karotenoidy analýza   MeSH
• listy rostlin anatomie a histologie   metabolismus   fyziologie   účinky záření   MeSH
• metabolom MeSH
• podnebí * MeSH
• ultrafialové záření MeSH
• Vitis anatomie a histologie   metabolismus   fyziologie   účinky záření   MeSH
• xanthofyly analýza   MeSH
• zeměpis MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa MeSH
• Názvy látek
• alfa-tokoferol MeSH
• antioxidancia MeSH
• fenoly MeSH
• karotenoidy MeSH
• xanthofyly MeSH

The reduction of analysis time, cost, and improvement of separation efficiency are the main requirements in the development of high-throughput assay methods in bioanalysis. It can be achieved either by ultra-high-performance liquid chromatography (UHPLC) using stationary phases with small particles (<2 μm) at high back pressures or by using opposite direction--monolithic stationary phases with low back pressures. The application of new types of monolithic stationary phases for UHPLC is a novel idea combining these two different paths. The aim of this work was to test the recently introduced second-generation of monolithic column Chromolith® HighResolution for UHPLC analysis of liposoluble vitamins in comparison with core-shell and fully porous sub-2 μm columns with different particle sizes, column lengths, and shapes. The separation efficiency, peak shape, resolution, time of analysis, consumption of mobile phase, and lifetime of columns were calculated and compared. The main purpose of the study was to find a new, not only economical option of separation of liposoluble vitamins for routine practice.

• Klíčová slova
• Bioanalysis, Core-shell, High-resolution monolith, LC, Liposoluble vitamins,
• MeSH
• alfa-tokoferol analýza   krev   MeSH
• lidé MeSH
• mateřské mléko chemie   MeSH
• poréznost MeSH
• syntetické pryskyřice chemie   MeSH
• velikost částic MeSH
• vitamin A analýza   krev   MeSH
• vysokoúčinná kapalinová chromatografie přístrojové vybavení   metody   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• alfa-tokoferol MeSH
• syntetické pryskyřice MeSH
• vitamin A MeSH

Breast milk is a main source of fat-soluble vitamins for newborns and it is needful to monitor the nutritional status prior to its application. In this work a novel, high-throughput and low-cost method for monitoring of retinol and alpha-tocopherol in breast milk was developed, validated and compared with reference method using monolithic column. For this purpose five various porous shell and monolithic columns were tested on the basis of relationship between HETP and linear mobile phase velocity, analysis time and consumption of solvents. Finally the core-shell analytical column Kinetex C18 (2.6 μm, 100 Å, 100×4.6 mm) was chosen as the best and optimal values of flow rate, injection volume and temperature of analysis were established. The detection of retinol and alpha-tocopherol was carried out at 325 and 295 nm, respectively by diode array detector. The LOD 0.004 μmol/L and 0.078 μmol/L, the LOQ 0.012 μmol/L and 0.182 μmol/L for retinol and alpha-tocopherol, respectively were calculated. The validation data showed good linearity, repeatability of retention time with RSD 0.22% and 0.12%, repeatability of peak area with RSD 6.94% and 1.75%, recovery 114.1-116.3% and 99.0-108.6% for retinol and alpha-tocopherol, respectively. Moreover, the newly developed method substantially decreased the solvent consumption by about 263 mL per 100 samples with the total time of analysis 1.75 min in comparison with analysis time 1.80 of the reference method.

• MeSH
• alfa-tokoferol analýza   MeSH
• časové faktory MeSH
• lidé MeSH
• limita detekce MeSH
• mateřské mléko chemie   MeSH
• reprodukovatelnost výsledků MeSH
• vitamin A analýza   MeSH
• vitaminy analýza   MeSH
• vysokoúčinná kapalinová chromatografie ekonomika   přístrojové vybavení   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• validační studie MeSH
• Názvy látek
• alfa-tokoferol MeSH
• vitamin A MeSH
• vitaminy MeSH

The liposoluble vitamins (retinol and α-tocopherol) concentration in human breast milk is of a cardinal knowledge especially for nutrition of prematurely born. It enables the feeding optimization of these important micronutrients for preterm infants. The novel rapid liquid-liquid extraction procedure for human breast milk investigation was developed and validated according to FDA guidelines. The recovery of retinol was 82-90% measured at three concentration levels 1.0, 2.5 and 5.0 μmol/L, for α-tocopherol 92-109% at concentration levels 2.5, 5.0 and 10.0 μmol/L. The repeatability of extraction procedure expressed as relative standard deviation was 3.26% for retinol and 4.79% for α-tocopherol. Developed extraction procedure was applied on 120 human breast milk samples. The separation of vitamins was completed using advantages of a monolithic column which accomplished demands of acceleration made by modern bio-analytical HPLC methodology. The analytes of interest were detected by diode-array detector at wavelengths 325 nm for retinol and 290 nm for α-tocopherol.

• MeSH
• alfa-tokoferol analýza   izolace a purifikace   MeSH
• časové faktory MeSH
• dospělí MeSH
• indikátory a reagencie chemie   MeSH
• lidé MeSH
• mateřské mléko chemie   MeSH
• metody pro přípravu analytických vzorků metody   MeSH
• mléčné bílkoviny chemie   izolace a purifikace   MeSH
• reprodukovatelnost výsledků MeSH
• vitamin A analýza   izolace a purifikace   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alfa-tokoferol MeSH
• indikátory a reagencie MeSH
• mléčné bílkoviny MeSH
• vitamin A MeSH

Dietary vitamin E supplementation provides a feasible option to extend the shelf life of meat. However, the costs of extra supplementation necessitate an accurate level of feeding to achieve the maximum return in product quality improvement. The current study aimed to quantify the effects of total dietary vitamin E intake on muscle α-tocopherol concentration in cattle and pigs, and to relate muscle α-tocopherol concentration to lipid oxidation and color of meat. Through computerized and manual searches, 13 studies with cattle and 10 with pigs were identified that have presented data on dietary vitamin E intake and muscle α-tocopherol concentration. Treatment means from 12 studies with beef and 14 with pork were used to evaluate the effects of muscle α-tocopherol concentration on lipid oxidation, as represented by thiobarbituric acid reactive substances in meat stored or retail displayed at chilled temperatures. With CIELAB a* (redness) values as an indicator of color development, the association between muscle α-tocopherol concentration and color could be evaluated with treatment means from 8 studies with beef and 5 with pork. Different treatments applied within studies resulted in 20 to 66 values available for the respective regression analyses. Relationships could be described effectively by different forms of the Mitscherlich model, which presented an initial value for y when x = 0, an asymptotic plateau, and the rate of change of y with increasing values of x. With the inclusion of experiment as a random effect, the relationship between total dietary vitamin E intake (x, IU/d for cattle and mg/d for pigs) and muscle α-tocopherol concentration (y, µg/g of meat) reached asymptotic plateau values at 5.71 and 4.83 µg/g of meat for cattle and pigs, respectively. The fractional accumulation rate (per total dietary vitamin E intake) of muscle α-tocopherol concentration was considerably greater in pigs (0.0130) than in cattle (0.00174). The form of the relationship between muscle α-tocopherol concentration and thiobarbituric acid reactive substances in pork was influenced by a single value, whereas muscle α-tocopherol concentrations could not be related to a* values in beef. This study presented viable models that could be applied in practice to calculate the amounts of supplemental dietary vitamin E needed to obtain the maximum profit from beef and pork.

• MeSH
• alfa-tokoferol analýza   MeSH
• barva MeSH
• kosterní svaly chemie   účinky léků   MeSH
• lipidy analýza   MeSH
• maso analýza   normy   MeSH
• peroxidace lipidů účinky léků   MeSH
• potravní doplňky MeSH
• prasata MeSH
• skot MeSH
• vitamin E farmakologie   MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alfa-tokoferol MeSH
• lipidy MeSH
• vitamin E MeSH

1. The influence of different forms of dietary selenium (Se) on vitamin E (alpha-tocopherol) and Se contents of egg yolk and chicken meat was investigated. 2. Eggs were collected from laying hens subjected to 4 different dietary treatments after 24 weeks of age. Treatments compared the effects of inorganic Se supplementation (selenite) to those of organic (Se-enriched yeast, Se-enriched alga Chlorella) supplements. In a second experiment the effect of the above organic dietary Se supplementation on the alpha-tocopherol contents of meat from broiler chickens was evaluated. 3. Dietary Se supplementation increased the alpha-tocopherol content of egg yolks from 297 mg/kg dry matter in treatment without supplementation to 311 mg/kg when selenium was supplemented as selenite, and to 370-375 mg/kg when organic supplements were used. The Se and alpha-tocopherol contents of breast and thigh meat in broilers were significantly increased by organic dietary Se supplementation. 4. The inclusion of organic dietary Se sources in the diets of laying hens and broilers would enhance the nutritional value (vitamin E and Se contents) of products (eggs and meat) for human consumption.

• MeSH
• alfa-tokoferol analýza   metabolismus   MeSH
• dieta veterinární   MeSH
• játra chemie   MeSH
• krmivo pro zvířata MeSH
• kur domácí MeSH
• maso analýza   MeSH
• nutriční hodnota MeSH
• potravní doplňky MeSH
• selen analýza   metabolismus   MeSH
• vaječný žloutek chemie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Názvy látek
• alfa-tokoferol MeSH
• selen MeSH

Among other side effects, administration of anticancer agents is accompanied by manifestations of gastrointestinal toxicity and disturbances of antioxidant balance. The monitoring of these toxic effects in clinical practice is impeded by a dearth of reliable laboratory methods. Therefore, a simple and rapid reversed-phase high-performance liquid chromatography procedure for selective and sensitive determination of retinol, a-tocopherol, and retinyl esters (retinyl-palmitate and retinyl-stearate) in blood serum has been developed and presented in this study. A Series 200 LC HPLC instrument from Perkin Elmer (Norwalk, USA) with diode-array detector (DAD) was used for the analysis. Separations of retinol, alpha-tocopherol, retinyl-palmitate, and retinyl-stearate were performed using a Chromolith Performance RP-18e, 100 x 4.6 mm monolithic column from Merck (Darmstadt, Germany). Gradient elution was used at a flow rate of 3 mL/min; the mobile phase was methanol-water (95:5, v/v) for 0-2.1 min and methanol-2-propanol (60:40, v/v) for 2.1-4.9 min. The total time of analysis was 6 min. The injection volume was 20 microL and the analysis was performed at ambient temperature. Detection of retinol, alpha-tocopherol, and retinyl esters was carried out at 325, 295, and 330 nm, respectively. For practical assessment of the method, the vitamin A absorption test was performed on seven healthy controls as well as on six patients with non-small cell lung carcinoma or head and neck carcinoma previously treated by chemotherapy and/or radiotherapy, six patients with rectal carcinoma before chemoradiotherapy, four patients with gastrointestinal stromal tumor (GIST) before treatment with imatinib, and a breast cancer patient with chemotherapy-induced diarrhea. Present data demonstrate the feasibility of large scale HPLC determination of vitamin E, vitamin A, and retinyl esters in human serum using a silica monolithic column, and this method may represent a valuable aid in the laboratory monitoring of the toxicity of anticancer therapy.

• MeSH
• absorpce MeSH
• alfa-tokoferol analýza   krev   MeSH
• benzamidy MeSH
• časové faktory MeSH
• chromatografie metody   MeSH
• estery analýza   krev   MeSH
• gastrointestinální stromální tumory farmakoterapie   MeSH
• imatinib mesylát MeSH
• kalibrace MeSH
• lidé MeSH
• monitorování léčiv metody   MeSH
• piperaziny škodlivé účinky   farmakologie   MeSH
• protinádorové látky škodlivé účinky   farmakologie   MeSH
• průjem chemicky indukované   MeSH
• pyrimidiny škodlivé účinky   farmakologie   MeSH
• reprodukovatelnost výsledků MeSH
• vitamin A analýza   krev   MeSH
• vysokoúčinná kapalinová chromatografie přístrojové vybavení   metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alfa-tokoferol MeSH
• benzamidy MeSH
• estery MeSH
• imatinib mesylát MeSH
• piperaziny MeSH
• protinádorové látky MeSH
• pyrimidiny MeSH
• vitamin A MeSH