The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Michael Rychlik - One of the best experts on this subject based on the ideXlab platform.
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improved stable isotope dilution assay for dietary Folates using lc ms ms and its application to strawberries
Frontiers in chemistry, 2018Co-Authors: Lisa Striegel, Soraya Chebib, M Netzel, Michael RychlikAbstract:Folates play an important role in the human body and a deficiency of this vitamin can cause several diseases. Therefore, a reliable analytical method is crucial for the determination of folate vitamers in strawberries and other dietary folate sources. A stable isotope dilution LC-MS/MS method for analyzing Folates in food was developed and validated. The folate vitamers Pteroylmonoglutamic acid, tetrahydrofolate, 5-methyltetrahydrofolate, and 5-formyltetrahydrofolate were quantified using C-13-labeled internal standards. Validation of the assay was accomplished by determining linearity, precision, recovery, limit of detection, and limit of quantification and revealed to be a precise, sensitive, and accurate method to determine folate vitamers. Strawberries are worldwide consumed and known to be a good dietary source of nutritive compounds. Using this method, folate concentrations in selected commercial strawberry cultivars and experimental breeding lines grown in Germany and Australia were investigated. Total Folates varied from 59 to 153 mu g/100 g on fresh weight basis. Furthermore, folate content after lyophilizing or freezing did not show any significant differences compared to fresh strawberries. However, significant losses of total Folates in pureed strawberries could be observed after 5 days of storage with only 16% of the original concentration retained. In summary, some of the investigated strawberry cultivars/breeding lines can be considered as rich dietary sources of natural Folates.
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stable isotope dilution assays for clinical analyses of Folates and other one carbon metabolites application to folate deficiency studies
PLOS ONE, 2016Co-Authors: Markus Kopp, Rosalie Morisset, Peter Koehler, Michael RychlikAbstract:: Folate deficiency is generally accepted as a potential direct or indirect risk factor for diseases including spina bifida, coronary heart diseases, malfunctions of the central nervous system, and cancer. The direct inclusion of Folates in the methylation cycle, including the remethylation of homocysteine and regeneration of S-adenosylmethionine, underlines the importance of these vitamins and other components of one-carbon metabolism. Therefore, the aim of the present study was to develop a multiple stable isotope dilution assay (SIDA) for the respective analytes in plasma and tissue samples to allow for a closer look at the interaction between a severe folate deficiency and local folate status, as well as further interactions with circulating S-adenosylmethionine, S-adenosylhomocysteine, and homocysteine. The analytical methods were based on SIDAs coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis using the deuterated Folates [2H4]-5-methyltetrahydrofolic acid, [2H4]-5-formyltetrahydrofolic acid, [2H4]-tetrahydrofolic acid, [2H4]-10-formylfolic acid, and [2H4]-folic acid and the deuterated one-carbon metabolites [2H4]-homocysteine, [2H4]-S-adenosylhomocysteine, and [2H3]-S-adenosylmethionine as internal standards. Three analytical methods have been developed for the analysis of homocysteine, S-adenosylmethionine, S-adenosylhomocysteine, and six folate vitamers. Validation data for the analysis of C1-metabolites in plasma and tissue samples or folate analysis in tissue samples revealed excellent sensitivity, precision, and recovery for all analytes studied. The miniaturized methods using sample volumes as low as 50 μL and weighed portions of 5-25 mg will allow the assessment of the status of Folates and additional biomarkers of impaired one-carbon metabolism during folate deficiency.
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Folates in fruits and vegetables contents processing and stability
Comprehensive Reviews in Food Science and Food Safety, 2016Co-Authors: Nicolas Delchier, Michael Rychlik, Anna-lena Herbig, Catherine M G C RenardAbstract:Folates play a key role in human one-carbon metabolism and are provided by food. It is well established that Folates are beneficial in the prevention of neural tube defects and cardiovascular and neurodegenerative diseases. Fruits and vegetables, and especially green vegetables, are the main sources of Folates. In parallel, fruits and vegetables, with high contents of Folates, are mostly consumed after processing, such as, canning, freezing, or home-cooking, which involve folate losses during their preparation. Hence, it is important to know the percentage of folate losses during processing and, moreover, the mechanisms underlying those losses. The current knowledge on folate losses from fruit and vegetables are presented in this review. They depend on the nature of the respective fruit or vegetable and the respective treatment. For example, steaming involves almost no folate losses in contrast to boiling. Two main mechanisms are involved in folate losses: (i) leaching into the surrounding liquid and (ii) oxidation during heat treatment, the latter of which depending on the nature of the vitamer considered. In this respect, a vitamer stability decreases in the order starting from folic acid followed by 5-HCO-H4folate, 5-CH3-H4folate, and, finally, H4folate. Further studies are required, especially on the diffusion of the vitamers in real foods and on the determination of folate degradation products.
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Folates in fruit and vegetables: contents, processing and stability.
Comprehensive Reviews in Food Science and Food Safety, 2016Co-Authors: Catherine Renard, Nicolas Delchier, Anna-lena Herbig, Michael RychlikAbstract:Folates play a key role in human one-carbon metabolism and are provided by food. It is well established that Folates are beneficial in the prevention of neural tube defects and cardiovascular and neurodegenerative diseases. Fruits and vegetables, and especially green vegetables, are the main sources of Folates. In parallel, fruits and vegetables, with high contents of Folates, are mostly consumed after processing, such as, canning, freezing, or home-cooking, which involve folate losses during their preparation. Hence, it is important to know the percentage of folate losses during processing and, moreover, the mechanisms underlying those losses. The current knowledge on folate losses from fruit and vegetables are presented in this review. They depend on the nature of the respective fruit or vegetable and the respective treatment. For example, steaming involves almost no folate losses in contrast to boiling. Two main mechanisms are involved in folate losses: (i) leaching into the surrounding liquid and (ii) oxidation during heat treatment, the latter of which depending on the nature of the vitamer considered. In this respect, a vitamer stability decreases in the order starting from folic acid followed by 5-HCO-H4folate, 5-CH3-H4folate, and, finally, H4folate. Further studies are required, especially on the diffusion of the vitamers in real foods and on the determination of folate degradation products.
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Effects of industrial processing on folate content in green vegetables.
Food Chemistry, 2013Co-Authors: Nicolas Delchier, Michael Rychlik, Christiane Ringling, Julie Le Grandois, Dalal Aoude-werner, Rachel Galland, Stéphane Georgé, Catherine M G C RenardAbstract:Folates are described to be sensitive to different physical parameters such as heat, light, pH and leaching. Most studies on Folates degradation during processing or cooking treatments were carried out on model solutions or vegetables only with thermal treatments. Our aim was to identify which steps were involved in Folates loss in industrial processing chains, and which mechanisms were underlying these losses. For this, the Folates contents were monitored along an industrial canning chain of green beans and along an industrial freezing chain of spinach. Folates contents decreased significantly by 25% during the washing step for spinach in the freezing process , and by 30% in the green beans canning process after sterilisation, with 20% of the initial amount being transferred into the covering liquid. The main mechanism involved in folate loss during both canning green beans and freezing spinach was leaching. Limiting the contact between vegetables and water or using steaming seems to be an adequate measure to limit Folates losses during processing.
Willy E Lambert - One of the best experts on this subject based on the ideXlab platform.
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Regulation of C1 Metabolism in Arabidopsis: The N-terminal Regulatory Domain of Cystathionine {gamma} Synthase Is Cleaved in Response to Folate Starvation.
Plant Physiology, 2017Co-Authors: Karen Loizeau, Bernadette Gambonnet, Guo Fang Zhang, Dominique Van Der Straeten, Gilles Curien, Willy E Lambert, Fabrice Rébeillé, Samuel Jabrin, Stephane RavanelAbstract:In all organisms, control of folate homeostasis is of vital importance to sustain the demand for one carbon (C1) units that are essential in major metabolic pathways. In this study we induced folate deficiency in Arabidopsis cells by using two antifolate inhibitors. This treatment triggered a rapid and important decrease in the pool of Folates with significant modification in the distribution of C1-substituted folate coenzymes, suggesting an adaptive response to favor a preferential shuttling of the flux of C1-units to the synthesis of nucleotides over the synthesis of methionine (Met). Metabolic profiling of folate-deficient cells indicated important perturbation of the activated methyl cycle because of the impairment of Met synthases that are deprived of their substrate 5-methyl-tetrahydrofolate. Intriguingly, S-adenosylmethionine (AdoMet) and Met pools declined during the initial period of folate starvation but were further restored to typical levels. Re-establishment of Met and AdoMet homeostasis was concomitant with a previously unknown post-translational regulation that consists in the removal of 92 amino acids at the N-terminus of cystathionine gamma-synthase (CGS), the first specific enzyme for Met synthesis. Rescue experiments and analysis of different stresses indicated that CGS processing is specifically associated with perturbation of the Folates pool. Also, CGS processing involves chloroplastic serine-type proteases that are expressed in various plant species subjected to folate starvation. We suggest that a metabolic effector, to date unidentified, can modulate CGS activity in vivo through an interaction with the N-terminal domain of the enzyme and that removal of this domain can suppress this regulation.
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Folates from metabolically engineered rice a long term study in rats
Molecular Nutrition & Food Research, 2015Co-Authors: Filip Kiekens, Dieter Blancquaert, Willy E Lambert, Dominique Van Der Straeten, Lindsey Devisscher, Jeroen Van Daele, Veronique Stove, Joris R Delanghe, Christophe P StoveAbstract:Scope The biological impact of Folates from folate rice, a metabolically engineered (biofortified) rice line, rich in Folates, was investigated. Its consumption may be helpful to fight folate deficiency. Our objective was to investigate the potential of folate rice to supply the organism with Folates and evaluate its biological effectiveness using a rat model. Methods and results Five groups of 12 Wistar rats were monitored during a 7/12-wk depletion/repletion trial. Animals receiving folate-free diet (0 μg/rat/day) and those additionally receiving wild-type rice (on average 0.11 μg/rat/day) suffered from decreased hematocrit and lower folate concentrations in both plasma and RBCs. This resulted in serious morbidity and even lethality during the trial. In contrast, all animals receiving a daily supplement of folate rice or folic acid fortified rice (on average 3.00 μg/rat/day and 3.12 μg/rat/day, respectively) and those receiving a positive control diet (11.4 to 25.0 μg/rat/day), survived. In these groups, the hematocrit normalized, plasma and RBC folate concentrations increased and pronounced hyperhomocysteinemia was countered. Conclusion Using an animal model, we demonstrated that biofortified folate rice is a valuable source of dietary folate, as evidenced by folate determination in plasma and RBCs, the alleviation of anemia and counteraction of pronounced hyperhomocysteinemia.
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ultra performance liquid chromatography tandem mass spectrometry uplc ms ms for the sensitive determination of Folates in rice
Journal of Chromatography B, 2010Co-Authors: Veerle De Brouwer, Sergei Storozhenko, Christophe P Stove, Dominique Van Der Straeten, Jeroen Van Daele, Willy E LambertAbstract:Abstract High-performance liquid chromatography, coupled to tandem mass spectrometry (HPLC–MS/MS) has been established as the method of choice for the sensitive and simultaneous determination of different Folates in a particular matrix, especially when only minute quantities of material are available. Using a previously developed and validated HPLC–MS/MS method as a starting point, we here report on the development and validation of an ultra-performance liquid chromatography (UPLC–MS/MS) method for analysis of Folates in rice, which allows higher throughput and better resolution. UPLC was performed under gradient conditions on an Acquity HSS T3 column, followed by tandem mass spectrometry detection. The method was validated based on linearity, sensitivity, precision, accuracy and matrix effects. The limits of detection and the lower limits of quantification varied between 0.06 and 0.45 μg/100 g and 0.12 and 0.91 μg/100 g, respectively. Two linear calibration curves were established, one for the low and the other for the high concentration range. Analysis of the distribution and levels of Folates in wild-type and folate-biofortified rice showed up to 50-fold enrichment in biofortified rice, with total folate levels of up to 900 μg/100 g rice. This is the first successful implementation of a UPLC method for the rapid and sensitive quantitative determination of Folates in plant material.
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Folates and folic acid from fundamental research toward sustainable health
Critical Reviews in Plant Sciences, 2010Co-Authors: Dieter Blancquaert, Karen Loizeau, Sergei Storozhenko, Veerle De Brouwer, Willy E Lambert, Fabrice Rébeillé, Stephane Ravanel, Hans De Steur, Jacques Viaene, Dominique Van Der StraetenAbstract:Folates are of paramount importance in one-carbon metabolism of most organisms. Plants and microorganisms are able to synthesize Folates de novo, making them the main dietary source for humans and animals, which are dependent on food or feed supplies for Folates. Folate deficiency is an increasing problem in the developing, as well as in the developed regions of the world, affecting millions of people. Different strategies, such as food fortification and folic acid supplementation, remain far from accessible for the poor rural populations in developing countries. Increasing knowledge concerning folate biosynthesis, transport and catabolism does not only deepen our insight on the regulation of folate metabolism but also provides the keys towards folate enhancement through metabolic engineering in bacteria, as well as in plants. Recently, promising results were obtained using such an approach, but further fundamental research is a prerequisite to develop a practicable solution to fight folate deficiency. In parallel, progress in the development and improvement of folate analysis has been made. Here, we provide the state-of-the-art of folate biosynthesis, catabolism, and salvage. Finally, we report on progress in folate biofortification and discuss the agroeconomical aspect of biofortified crop plants.
Dominique Van Der Straeten - One of the best experts on this subject based on the ideXlab platform.
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Folates in plants research advances and progress in crop biofortification
Frontiers in chemistry, 2017Co-Authors: Vera Gorelova, Fabrice Rébeillé, Lars Ambach, Christophe P Stove, Dominique Van Der StraetenAbstract:Folates, also known as B9 vitamins, serve as donors and acceptors in one-carbon (C1) transfer reactions. The latter are involved in synthesis of many important biomolecules, such as amino acids, nucleic acids and vitamin B5. Folates also play a central role in the methyl cycle that provides one-carbon groups for methylation reactions. The important functions fulfilled by Folates make them essential in all living organisms. Plants, being able to synthesize Folates de novo, serve as an excellent dietary source of Folates for animals that lack the respective biosynthetic pathway. Unfortunately, the most important staple crops such as rice, potato and maize are rather poor sources of Folates. Insufficient folate consumption is known to cause severe developmental disorders in humans. Two approaches are employed to fight folate deficiency: pharmacological supplementation in the form of folate pills and biofortification of staple crops. As the former approach is considered rather costly for the major part of the world population, biofortification of staple crops is viewed as a decent alternative in the struggle against folate deficiency. Therefore strategies, challenges and recent progress of folate enhancement in plants will be addressed in this review. Apart from the ever-growing need for the enhancement of nutritional quality of crops, the world population faces climate change catastrophes or environmental stresses, such as elevated temperatures, drought, salinity that severely affect growth and productivity of crops. Due to immense diversity of their biochemical functions, Folates take part in virtually every aspect of plant physiology. Any disturbance to the plant folate metabolism leads to severe growth inhibition and, as a consequence, to a lower productivity. Whereas today’s knowledge of folate biochemistry can be considered very profound, evidence on the physiological roles of Folates in plants only starts to emerge. In the current review we will discuss the implication of Folates in various aspects of plant physiology and development.
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Folates from metabolically engineered rice a long term study in rats
Molecular Nutrition & Food Research, 2015Co-Authors: Filip Kiekens, Dieter Blancquaert, Willy E Lambert, Dominique Van Der Straeten, Lindsey Devisscher, Jeroen Van Daele, Veronique Stove, Joris R Delanghe, Christophe P StoveAbstract:Scope The biological impact of Folates from folate rice, a metabolically engineered (biofortified) rice line, rich in Folates, was investigated. Its consumption may be helpful to fight folate deficiency. Our objective was to investigate the potential of folate rice to supply the organism with Folates and evaluate its biological effectiveness using a rat model. Methods and results Five groups of 12 Wistar rats were monitored during a 7/12-wk depletion/repletion trial. Animals receiving folate-free diet (0 μg/rat/day) and those additionally receiving wild-type rice (on average 0.11 μg/rat/day) suffered from decreased hematocrit and lower folate concentrations in both plasma and RBCs. This resulted in serious morbidity and even lethality during the trial. In contrast, all animals receiving a daily supplement of folate rice or folic acid fortified rice (on average 3.00 μg/rat/day and 3.12 μg/rat/day, respectively) and those receiving a positive control diet (11.4 to 25.0 μg/rat/day), survived. In these groups, the hematocrit normalized, plasma and RBC folate concentrations increased and pronounced hyperhomocysteinemia was countered. Conclusion Using an animal model, we demonstrated that biofortified folate rice is a valuable source of dietary folate, as evidenced by folate determination in plasma and RBCs, the alleviation of anemia and counteraction of pronounced hyperhomocysteinemia.
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Rice folate enhancement through metabolic engineering has an impact on rice seed metabolism, but does not affect the expression of the endogenous folate biosynthesis genes
Plant Molecular Biology, 2013Co-Authors: Dieter Blancquaert, Sergei Storozhenko, Willy Lambert, Jeroen Van Daele, Christophe Stove, Dominique Van Der StraetenAbstract:Folates are key-players in one-carbon metabolism in all organisms. However, only micro-organisms and plants are able to synthesize Folates de novo and humans rely entirely on their diet as a sole folate source. As a consequence, folate deficiency is a global problem. Although different strategies are currently implemented to fight folate deficiency, up until now, all of them have their own drawbacks. As an alternative and complementary means to those classical strategies, folate biofortification of rice by metabolic engineering was successfully achieved a couple of years ago. To gain more insight into folate biosynthesis regulation and the effect of folate enhancement on general rice seed metabolism, a transcriptomic study was conducted in developing transgenic rice seeds, overexpressing 2 genes of the folate biosynthetic pathway. Upon folate enhancement, the expression of 235 genes was significantly altered. Here, we show that rice folate biofortification has an important effect on folate dependent, seed developmental and plant stress response/defense processes, but does not affect the expression of the endogenous folate biosynthesis genes.
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ultra performance liquid chromatography tandem mass spectrometry uplc ms ms for the sensitive determination of Folates in rice
Journal of Chromatography B, 2010Co-Authors: Veerle De Brouwer, Sergei Storozhenko, Christophe P Stove, Dominique Van Der Straeten, Jeroen Van Daele, Willy E LambertAbstract:Abstract High-performance liquid chromatography, coupled to tandem mass spectrometry (HPLC–MS/MS) has been established as the method of choice for the sensitive and simultaneous determination of different Folates in a particular matrix, especially when only minute quantities of material are available. Using a previously developed and validated HPLC–MS/MS method as a starting point, we here report on the development and validation of an ultra-performance liquid chromatography (UPLC–MS/MS) method for analysis of Folates in rice, which allows higher throughput and better resolution. UPLC was performed under gradient conditions on an Acquity HSS T3 column, followed by tandem mass spectrometry detection. The method was validated based on linearity, sensitivity, precision, accuracy and matrix effects. The limits of detection and the lower limits of quantification varied between 0.06 and 0.45 μg/100 g and 0.12 and 0.91 μg/100 g, respectively. Two linear calibration curves were established, one for the low and the other for the high concentration range. Analysis of the distribution and levels of Folates in wild-type and folate-biofortified rice showed up to 50-fold enrichment in biofortified rice, with total folate levels of up to 900 μg/100 g rice. This is the first successful implementation of a UPLC method for the rapid and sensitive quantitative determination of Folates in plant material.
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Folates and folic acid from fundamental research toward sustainable health
Critical Reviews in Plant Sciences, 2010Co-Authors: Dieter Blancquaert, Karen Loizeau, Sergei Storozhenko, Veerle De Brouwer, Willy E Lambert, Fabrice Rébeillé, Stephane Ravanel, Hans De Steur, Jacques Viaene, Dominique Van Der StraetenAbstract:Folates are of paramount importance in one-carbon metabolism of most organisms. Plants and microorganisms are able to synthesize Folates de novo, making them the main dietary source for humans and animals, which are dependent on food or feed supplies for Folates. Folate deficiency is an increasing problem in the developing, as well as in the developed regions of the world, affecting millions of people. Different strategies, such as food fortification and folic acid supplementation, remain far from accessible for the poor rural populations in developing countries. Increasing knowledge concerning folate biosynthesis, transport and catabolism does not only deepen our insight on the regulation of folate metabolism but also provides the keys towards folate enhancement through metabolic engineering in bacteria, as well as in plants. Recently, promising results were obtained using such an approach, but further fundamental research is a prerequisite to develop a practicable solution to fight folate deficiency. In parallel, progress in the development and improvement of folate analysis has been made. Here, we provide the state-of-the-art of folate biosynthesis, catabolism, and salvage. Finally, we report on progress in folate biofortification and discuss the agroeconomical aspect of biofortified crop plants.
Margaretha Jagerstad - One of the best experts on this subject based on the ideXlab platform.
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challenges in the determination of unsubstituted food Folates impact of stabilities and conversions on analytical results
Journal of Agricultural and Food Chemistry, 2015Co-Authors: Hanna S Strandler, Johan Patring, Margaretha Jagerstad, Jelena JastrebovaAbstract:Tetrahydrofolate is the parent molecule of the folate coenzymes required for one carbon metabolism. Together with other unsubstituted Folates such as dihydrofolate and folic acid, tetrahydrofolate represents the third pool of dietary Folates following 5-methyltetrahydrofolate and formyl Folates. Low intake of dietary Folates and poor folate status are common problems in many countries. There is a critical need for reliable methods to determine folate in foods to accurately estimate folate intakes in populations. However, current values for Folates in foods in databanks are often underestimated due to the high instability of several folate forms, especially tetrahydrofolate. The present review highlights the occurrence of unsubstituted Folates in foods and their oxidation mechanisms and chemical behavior as well as interconversion reaction between tetrahydrofolate and 5,10-methylenetetrahydrofolate. The review shows also the important role of antioxidants in protecting Folates during analysis and describes...
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occurrence stability and determination of formyl Folates in foods
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Margaretha Jagerstad, Jelena JastrebovaAbstract:The B-vitamin folate has specific tasks as a one-carbon (C1) group supplier in the building and repair of DNA and RNA as well as in the methylation of homocysteine to methionine. Folate occurs in all living cells as a dynamic pool of several interconvertible forms carrying different C1 groups. Along the food chain, this dynamic pool of Folates constantly changes due to either enzymatic or chemical interconversions during food processing and storage. These interconversions make it difficult to determine individual folate forms in foods. The formyl Folates, the second most predominant forms of food Folates, after 5-methyltetrahydrofolate, are particularly prone to interconvert at low pH. Today, this knowledge is often neglected, leading to risks for analytical underestimation of formyl Folates. The purpose of the review is to explore the stability and interconversions of formyl Folates in foods as well as to analyze the pitfalls in the determination of formyl Folates.
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folate binding protein in milk a review of biochemistry physiology and analytical methods
Critical Reviews in Food Science and Nutrition, 2012Co-Authors: Linnea Nygrenbabol, Margaretha JagerstadAbstract:Folate-binding protein (FBP) was discovered in cow's milk around 40 years ago. Bovine FBP belongs to a family of several folate-binding proteins. In milk, it is a soluble whey protein with the ability to sequester folate from blood plasma. Bovine FBP is a well-characterized protein in terms of amino acid sequence and binding characteristics. Affinity and binding kinetics towards various folate forms have been intensively studied because they are crucial in using bovine FBP as an analytical tool. Shortly after the identification of bovine FBP, a competitive protein-binding assay for measuring serum and blood folate concentrations was introduced. Another analytical application of bovine FBP is in affinity chromatography, as a clean-up/concentration step for analysis of Folates in foods and biological samples by liquid chromatographic methods. Concentrations of FBP in milk and dairy products have been determined by ELISA and Surface Plasmon Resonance-biosensor techniques. Since the initial reports of FBP in ...
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increasing natural food Folates through bioprocessing and biotechnology
Trends in Food Science and Technology, 2005Co-Authors: Margaretha Jagerstad, Vieno Piironen, Caroline Walker, Emilia Carnovale, Marie HolasovaAbstract:Abstract The present study summarises results on processing effects for Folates obtained from an EU-funded folate project (QLK1-1999-00576). Yeast fermentation, malting, germination and Lactobacillus bacteria can be combined and further optimised to potentially enhance the folate content in bread, vegetables, dairy products and beer by 2–3 fold. Further research, exploration and development of folate producing lactic acid bacteria and yeast strains for food applications should be encouraged. Milling technologies can be further developed and by careful selection of raw materials and ingredients, food processing can be designed and optimised to increase folate content (and specific forms) using minimal processing.
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hplc determination of Folates in raw and processed beetroots
Food Chemistry, 2003Co-Authors: Jelena Jastrebova, Cornelia M Witthoft, Anders Grahn, Ulla Svensson, Margaretha JagerstadAbstract:Abstract A sensitive HPLC method with fluorescence detection and gradient elution has been developed for the determination of Folates in vegetables. The method involved extraction of Folates from food matrix by heat treatment, deconjugation of folate polyglutamates to monoglutamates by incubation with hog kidney conjugase and purification of food extracts by solid-phase extraction with strong-anion exchange cartridges. The chromatographic separation of Folates was achieved on Zorbax SB C 8 column, which was found to be superior over conventional C 18 column in terms of selectivity and sensitivity. Validation of the method included linearity tests, the addition of standard Folates for the determination of recovery, repeatability and stability tests. The method developed was applied to analysis of raw and processed beetroots; 5-methyltetrahydrofolate was found to be the main folate form in beetroots. Cultivar differences and growing conditions were found to have a pronounced effect on the folate content in beetroots. Processing resulted in considerable losses of Folates, whereas losses during storage appeared to be moderate.
Sergei Storozhenko - One of the best experts on this subject based on the ideXlab platform.
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Rice folate enhancement through metabolic engineering has an impact on rice seed metabolism, but does not affect the expression of the endogenous folate biosynthesis genes
Plant Molecular Biology, 2013Co-Authors: Dieter Blancquaert, Sergei Storozhenko, Willy Lambert, Jeroen Van Daele, Christophe Stove, Dominique Van Der StraetenAbstract:Folates are key-players in one-carbon metabolism in all organisms. However, only micro-organisms and plants are able to synthesize Folates de novo and humans rely entirely on their diet as a sole folate source. As a consequence, folate deficiency is a global problem. Although different strategies are currently implemented to fight folate deficiency, up until now, all of them have their own drawbacks. As an alternative and complementary means to those classical strategies, folate biofortification of rice by metabolic engineering was successfully achieved a couple of years ago. To gain more insight into folate biosynthesis regulation and the effect of folate enhancement on general rice seed metabolism, a transcriptomic study was conducted in developing transgenic rice seeds, overexpressing 2 genes of the folate biosynthetic pathway. Upon folate enhancement, the expression of 235 genes was significantly altered. Here, we show that rice folate biofortification has an important effect on folate dependent, seed developmental and plant stress response/defense processes, but does not affect the expression of the endogenous folate biosynthesis genes.
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ultra performance liquid chromatography tandem mass spectrometry uplc ms ms for the sensitive determination of Folates in rice
Journal of Chromatography B, 2010Co-Authors: Veerle De Brouwer, Sergei Storozhenko, Christophe P Stove, Dominique Van Der Straeten, Jeroen Van Daele, Willy E LambertAbstract:Abstract High-performance liquid chromatography, coupled to tandem mass spectrometry (HPLC–MS/MS) has been established as the method of choice for the sensitive and simultaneous determination of different Folates in a particular matrix, especially when only minute quantities of material are available. Using a previously developed and validated HPLC–MS/MS method as a starting point, we here report on the development and validation of an ultra-performance liquid chromatography (UPLC–MS/MS) method for analysis of Folates in rice, which allows higher throughput and better resolution. UPLC was performed under gradient conditions on an Acquity HSS T3 column, followed by tandem mass spectrometry detection. The method was validated based on linearity, sensitivity, precision, accuracy and matrix effects. The limits of detection and the lower limits of quantification varied between 0.06 and 0.45 μg/100 g and 0.12 and 0.91 μg/100 g, respectively. Two linear calibration curves were established, one for the low and the other for the high concentration range. Analysis of the distribution and levels of Folates in wild-type and folate-biofortified rice showed up to 50-fold enrichment in biofortified rice, with total folate levels of up to 900 μg/100 g rice. This is the first successful implementation of a UPLC method for the rapid and sensitive quantitative determination of Folates in plant material.
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Folates and folic acid from fundamental research toward sustainable health
Critical Reviews in Plant Sciences, 2010Co-Authors: Dieter Blancquaert, Karen Loizeau, Sergei Storozhenko, Veerle De Brouwer, Willy E Lambert, Fabrice Rébeillé, Stephane Ravanel, Hans De Steur, Jacques Viaene, Dominique Van Der StraetenAbstract:Folates are of paramount importance in one-carbon metabolism of most organisms. Plants and microorganisms are able to synthesize Folates de novo, making them the main dietary source for humans and animals, which are dependent on food or feed supplies for Folates. Folate deficiency is an increasing problem in the developing, as well as in the developed regions of the world, affecting millions of people. Different strategies, such as food fortification and folic acid supplementation, remain far from accessible for the poor rural populations in developing countries. Increasing knowledge concerning folate biosynthesis, transport and catabolism does not only deepen our insight on the regulation of folate metabolism but also provides the keys towards folate enhancement through metabolic engineering in bacteria, as well as in plants. Recently, promising results were obtained using such an approach, but further fundamental research is a prerequisite to develop a practicable solution to fight folate deficiency. In parallel, progress in the development and improvement of folate analysis has been made. Here, we provide the state-of-the-art of folate biosynthesis, catabolism, and salvage. Finally, we report on progress in folate biofortification and discuss the agroeconomical aspect of biofortified crop plants.
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Folate fortification of rice by metabolic engineering
Nature Biotechnology, 2007Co-Authors: Sergei Storozhenko, Veerle De Brouwer, Maarten Volckaert, Oscar Navarrete, Dieter Blancquaert, Guo Fang Zhang, Willy Lambert, Dominique Van Der StraetenAbstract:Rice, the world's major staple crop, is a poor source of essential micronutrients, including Folates (vitamin B9). We report folate biofortification of rice seeds achieved by overexpressing two Arabidopsis thaliana genes of the pterin and para-aminobenzoate branches of the folate biosynthetic pathway from a single locus. We obtained a maximal enhancement as high as 100 times above wild type, with 100 g of polished raw grains containing up to four times the adult daily folate requirement.
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Folates in plants biosynthesis distribution and enhancement
Physiologia Plantarum, 2006Co-Authors: Fabrice Rébeillé, Sergei Storozhenko, Stephane Ravanel, Samuel Jabrin, Roland Douce, Dominique Van Der StraetenAbstract:Folates are crucial intermediates for a set of reactions that involve the transfer of single-carbon units (C1 metabolism). They are directly involved in the synthesis of nucleic acids, methionine, pantothenate, glycine and serine, and indirectly, through S-adenosyl methionine, in all methylation reactions. Humans cannot synthesize Folates de novo. In these organisms, folate deficiency has severe effects on health and affects large population groups around the world. Because plants are the main source of dietary Folates, there are great concerns to select plant food having high concentrations of Folates or to engineer their folate metabolism to increase the initial amount. All these attempts rely on what we know about the metabolism of Folates. During these last 10 years, the complex pathway leading to the synthesis of Folates has been deciphered. Our knowledge about folate synthesis and distribution during plant growth and development also increased substantially. However, important aspects of folate metabolism remain unclear, such as catabolism, transport and regulation of the homeostasis. The aim of this review was to summarize our recent findings, to describe the few attempts reported in the literature to engineer folate level in plants, and to discuss potential strategies that could be used for enhancement.