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https://www.readbyqxmd.com/read/29665470/application-of-supercritical-fluid-chromatography-coupled-to-mass-spectrometry-to-the-determination-of-fat-soluble-vitamins-in-selected-food-products
#1
Jean-Marie Oberson, Esther Campos-Giménez, Johann Rivière, Frédéric Martin
In the present manuscript, we describe a fully optimized and validated method suitable to analyse nine compounds (retinyl acetate, retinyl palmitate, retinol, α-tocopherol, α-tocopheryl acetate, cholecalciferol, ergocalciferol, phylloquinone, menaquinone-4) representing the major contributors to the fat-soluble vitamin activity of selected food products (infant formulas, adult nutritionals, infant cereals and mixed meals). Sample preparation involves direct solvent extraction using enzyme-assisted matrix disintegration and methanolic protein precipitation...
April 10, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/29626813/elevated-co-2-induces-a-global-metabolic-change-in-basil-ocimum-basilicum-l-and-peppermint-mentha-piperita-l-and-improves-their-biological-activity
#2
Soad Al Jaouni, Ahmed M Saleh, Mohammed A M Wadaan, Wael N Hozzein, Samy Selim, Hamada AbdElgawad
Many studies have discussed the influence of elevated carbon dioxide (eCO2 ) on modeling and crop plants. However, much less effort has been dedicated to herbal plants. In this study, a robust monitoring for the levels of 94 primary and secondary metabolites and minerals in two medicinal herbs, basil (Ocimum basilicum L.) and peppermint (Mentha piperita L.), grwon under both ambient (aCO2 , 360 ppm) and eCO2 (620 ppm) was performed. We also assessed how the changes in herbal tissue chemistry affected their biological activity...
March 29, 2018: Journal of Plant Physiology
https://www.readbyqxmd.com/read/29487228/structure-of-the-plant-photosystem-i
#3
REVIEW
Ido Caspy, Nathan Nelson
Plant photosystem I (PSI) is one of the most intricate membrane complexes in nature. It comprises two complexes, a reaction center and light-harvesting complex (LHC), which together form the PSI-LHC supercomplex. The crystal structure of plant PSI was solved with two distinct crystal forms. The first, crystallized at pH 6.5, exhibited P 21 symmetry; the second, crystallized at pH 8.5, exhibited P 212121 symmetry. The surfaces involved in binding plastocyanin and ferredoxin are identical in both forms. The crystal structure at 2...
February 27, 2018: Biochemical Society Transactions
https://www.readbyqxmd.com/read/29457959/biosynthesis-and-applications-of-prenylquinones
#4
Makoto Kawamukai
Prenylquinones are isoprenoid compounds with a characteristic quinone structure and isoprenyl tail that are ubiquitous in almost all living organisms. There are four major prenylquinone classes: ubiquinone (UQ), menaquinone (MK), plastoquinone (PQ), and rhodoquinone (RQ). The quinone structure and isoprenyl tail length differ among organisms. UQ, PQ, and RQ contain benzoquinone, while MK contains naphthoquinone. UQ, MK, and RQ are involved in oxidative phosphorylation, while PQ functions in photosynthetic electron transfer...
February 19, 2018: Bioscience, Biotechnology, and Biochemistry
https://www.readbyqxmd.com/read/29315587/comparisons-of-electron-transfer-reactions-in-a-cyanobacterial-tetrameric-and-trimeric-photosystem-i-complexes
#5
Ivan V Shelaev, Mahir D Mamedov, Fedor E Gostev, Arseny V Aybush, Meng Li, Jonathan Nguyen, Barry D Bruce, Victor A Nadtochenko
Photosystem I (PSI) is a Type-I reaction center and is the largest photosynthetic complex to be characterized. In cyanobacteria, PSI is organized as a trimer with a three-fold axis of symmetry. Recently, a tetrameric form of PSI has been identified in cyanobacteria. Plastids in plants and algae only contain monomeric PSI, suggesting that tetrameric PSI may be key in the transition from ancestral cyanobacterial trimeric PSI to plant/algal monomeric PSI. We have investigated the kinetics of electron transfer to the initial acceptor in PSI tetramer isolated from Chroococcidiopsis TS-821...
January 8, 2018: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/29106966/single-step-preparation-of-selected-biological-fluids-for-the-high-performance-liquid-chromatographic-analysis-of-fat-soluble-vitamins-and-antioxidants
#6
Giacomo Lazzarino, Salvatore Longo, Angela Maria Amorini, Valentina Di Pietro, Serafina D'Urso, Giuseppe Lazzarino, Antonio Belli, Barbara Tavazzi
Fat-soluble vitamins and antioxidants are of relevance in health and disease. Current methods to extract these compounds from biological fluids mainly need use of multi-steps and multi organic solvents. They are time-consuming and difficult to apply to treat simultaneously large sample number. We here describe a single-step, one solvent extraction of fat-soluble vitamins and antioxidants from biological fluids, and the chromatographic separation of all-trans-retinoic acid, 25-hydroxycholecalciferol, all-trans-retinol, astaxanthin, lutein, zeaxanthin, trans-β-apo-8'-carotenal, γ-tocopherol, β-cryptoxanthin, α-tocopherol, phylloquinone, lycopene, α-carotene, β-carotene and coenzyme Q10 ...
December 8, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29066393/mutations-in-algal-and-cyanobacterial-photosystem-i-that-independently-affect-the-yield-of-initial-charge-separation-in-the-two-electron-transfer-cofactor-branches
#7
Syed Lal Badshah, Junlei Sun, Sam Mula, Mike Gorka, Patricia Baker, Rajiv Luthra, Su Lin, Art van der Est, John H Golbeck, Kevin E Redding
In Photosystem I, light-induced electron transfer can occur in either of two symmetry-related branches of cofactors, each of which is composed of a pair of chlorophylls (ec2A/ec3A or ec2B/ec3B) and a phylloquinone (PhQA or PhQB). The axial ligand to the central Mg(2+) of the ec2A and ec2B chlorophylls is a water molecule that is also H-bonded to a nearby Asn residue. Here, we investigate the importance of this interaction for charge separation by converting each of the Asn residues to a Leu in the green alga, Chlamydomonas reinhardtii, and the cyanobacterium, Synechocystis sp...
October 21, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28831654/redox-potentials-of-ubiquinone-menaquinone-phylloquinone-and-plastoquinone-in-aqueous-solution
#8
Shinnosuke Kishi, Keisuke Saito, Yuki Kato, Hiroshi Ishikita
Quinones serve as redox active cofactors in bacterial photosynthetic reaction centers: photosystem I, photosystem II, cytochrome bc 1, and cytochrome b 6 f. In particular, ubiquinone is ubiquitous in animals and most bacteria and plays a key role in several cellular processes, e.g., mitochondrial electron transport. Their experimentally measured redox potential values for one-electron reduction E m(Q/Q(·-)) were already reported in dimethylformamide (DMF) versus saturated calomel electrode but not in water versus normal hydrogen electrode (NHE)...
November 2017: Photosynthesis Research
https://www.readbyqxmd.com/read/28814399/modeling-the-dose-effects-of-soybean-oil-in-salad-dressing-on-carotenoid-and-fat-soluble-vitamin-bioavailability-in-salad-vegetables
#9
RANDOMIZED CONTROLLED TRIAL
Wendy S White, Yang Zhou, Agatha Crane, Philip Dixon, Frits Quadt, Leonard M Flendrig
Background: Previously, we showed that vegetable oil is necessary for carotenoid absorption from salad vegetables. Research is needed to better define the dose effect and its interindividual variation for carotenoids and fat-soluble vitamins.Objective: The objective was to model the dose-response relation between the amount of soybean oil in salad dressing and the absorption of 1) carotenoids, phylloquinone, and tocopherols in salad vegetables and 2) retinyl palmitate formed from the provitamin A carotenoids...
October 2017: American Journal of Clinical Nutrition
https://www.readbyqxmd.com/read/28812579/reproducibility-and-relative-validity-of-a-food-frequency-questionnaire-to-estimate-intake-of-dietary-phylloquinone-and-menaquinones
#10
S R Zwakenberg, A I P Engelen, G W Dalmeijer, S L Booth, C Vermeer, J J M M Drijvers, M C Ocke, E J M Feskens, Y T van der Schouw, J W J Beulens
BACKGROUND/OBJECTIVES: This study aims to investigate the reproducibility and relative validity of the Dutch food frequency questionnaire (FFQ), to estimate intake of dietary phylloquinone and menaquinones compared with 24-h dietary recalls (24HDRs) and plasma markers of vitamin K status. SUBJECTS/METHODS: In a cross-sectional study among 63 men and 58 women, the FFQ was completed three times over a 1-year period and the reproducibility was calculated over these measurements...
December 2017: European Journal of Clinical Nutrition
https://www.readbyqxmd.com/read/28794209/phylloquinone-intake-is-associated-with-cardiac-structure-and-function-in-adolescents
#11
Mary K Douthit, Mary Ellen Fain, Joshua T Nguyen, Celestine F Williams, Allison H Jasti, Bernard Gutin, Norman K Pollock
Background: Associations between childhood vitamin K consumption and cardiac structure and function have not been investigated.Objective: We determined associations between phylloquinone (vitamin K-1) intake and left ventricular (LV) structure and function in adolescents.Methods: We assessed diet with three to seven 24-h recalls and physical activity (PA) by accelerometry in 766 adolescents (aged 14-18 y, 50% female, 49% black). Fat-free soft tissue (FFST) mass and fat mass were measured by dual-energy X-ray absorptiometry...
August 9, 2017: Journal of Nutrition
https://www.readbyqxmd.com/read/28733110/a-role-of-alpha-tocopherol-and-phylloquinone-in-the-modulation-of-uterine-contractility-and-reproductive-function-in-mouse-models
#12
Enitome E Bafor, Victory O Ebidame, Uloma B Elvis-Offiah, Osemelomen Omoruyi, Gerald I Eze, Osamwonyi Igbinuwen, Kadiri P Braimoh
BACKGROUND AND AIM: Alpha-tocopherol has been implicated in reproduction processes, and deficiency of phylloquinone has been associated with serious complications in pregnancy. This study was therefore aimed at investigating the effects of phylloquinone and alpha-tocopherol on uterine contractility and female reproductive function using mouse models. MATERIALS AND METHODS: Both in vivo and ex vivo animal models were employed and designed to assess changes on uterine contractility and reproductive functions in the non-pregnant uterus...
May 30, 2017: Medicina
https://www.readbyqxmd.com/read/28669508/quinones-in-the-a1-binding-site-in-photosystem-i-studied-using-time-resolved-ftir-difference-spectroscopy
#13
COMPARATIVE STUDY
Hiroki Makita, Leyla Rohani, Nan Zhao, Gary Hastings
Time-resolved step-scan FTIR difference spectroscopy at low temperature (77 K) has been used to study photosystem I particles with phylloquinone (2-methyl-3-phytyl-1,4-naphthaquinone) and menadione (2-methyl-1,4-naphthaquinone) incorporated into the A1 binding site. By subtracting spectra for PSI with phylloquinone incorporated from spectra for PSI with menadione incorporated a (menadione - phylloquinone) double difference spectrum was constructed. In the double difference spectrum bands associated with protein vibrational modes effectively cancel, and the bands in the spectrum are primarily associated with the neutral and reduced states of the two quinones in the A1 binding site...
September 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28566528/vegetables-and-mixed-dishes-are-top-contributors-to-phylloquinone-intake-in-us-adults-data-from-the-2011-2012-nhanes
#14
Stephanie G Harshman, Emily G Finnan, Kathryn J Barger, Regan L Bailey, David B Haytowitz, Cheryl H Gilhooly, Sarah L Booth
Background: Phylloquinone is the most abundant form of vitamin K in US diets. Green vegetables are considered the predominant dietary source of phylloquinone. As our food supply diversifies and expands, the food groups that contribute to phylloquinone intake are also changing, which may change absolute intakes. Thus, it is important to identify the contributors to dietary vitamin K estimates to guide recommendations on intakes and food sources. Objective: The purpose of this study was to estimate 1 ) the amount of phylloquinone consumed in the diet of US adults, 2 ) to estimate the contribution of different food groups to phylloquinone intake in individuals with a high or low vegetable intake (≥2 or <2 cups vegetables/d), and 3 ) to characterize the contribution of different mixed dishes to phylloquinone intake...
July 2017: Journal of Nutrition
https://www.readbyqxmd.com/read/28530393/structural-factors-that-alter-the-redox-potential-of-quinones-in-cyanobacterial-and-plant-photosystem-i
#15
Keisuke Kawashima, Hiroshi Ishikita
Using the cyanobacterial and plant photosystem I (PSI) crystal structures and by considering the protonation states of all titratable residues, redox potentials (Em ) of the two phylloquinones-A1A and A1B -were calculated. The calculated Em values were Em (A1A ) = -773 mV and Em (A1B ) = -818 mV for the plant PSI structure and Em (A1A ) = -612 mV and Em (A1B ) = -719 mV for the cyanobacterial PSI structure. Our analysis of the PSI crystal structures suggested that the side-chain orientations of Lys-B542 and Gln-B678 in the cyanobacterial crystal structure differ from these side-chain orientations in the plant crystal structure...
June 20, 2017: Biochemistry
https://www.readbyqxmd.com/read/28445289/vitamin-k-intake-and-the-risk-of-fractures-a-meta-analysis
#16
REVIEW
Guangliang Hao, Bei Zhang, Mingyong Gu, Chen Chen, Qiang Zhang, Guichun Zhang, Xuecheng Cao
The association between dietary vitamin K intake and the risk of fractures is controversial. Therefore we perform a meta-analysis of cohort or nested case-control studies to investigate the relationship between dietary vitamin K intake and the risk of fractures. A comprehensive search of PubMed and EMBASE (to July 11, 2016) was performed to identify cohort or nested case-control studies providing quantitative estimates between dietary vitamin K intake and the risk of fractures. Summary relative risk (RRs) with corresponding 95% confidence intervals (CIs) were pooled by using a random-effects model...
April 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28405861/pk-a-of-ubiquinone-menaquinone-phylloquinone-plastoquinone-and-rhodoquinone-in-aqueous-solution
#17
Ryo Hasegawa, Keisuke Saito, Tomohiro Takaoka, Hiroshi Ishikita
Quinones can accept two electrons and two protons, and are involved in electron transfer and proton transfer reactions in photosynthetic reaction centers. To date, the pK a of these quinones in aqueous solution have not been reported. We calculated the pK a of the initial protonation (Q(·-) to QH(·)) and the second protonation (QH(-) to QH2) of 1,4-quinones using a quantum chemical approach. The calculated energy differences of the protonation reactions Q(·-) to QH(·) and QH(-) to QH2 in the aqueous phase for nine 1,4-quinones were highly correlated with the experimentally measured pK a(Q(·-)/QH(·)) and pK a(QH(-)/QH2), respectively...
September 2017: Photosynthesis Research
https://www.readbyqxmd.com/read/28403946/vitamin-k-and-osteoporosis-myth-or-reality
#18
REVIEW
Andrea Palermo, Dario Tuccinardi, Luca D'Onofrio, Mikiko Watanabe, Daria Maggi, Anna Rita Maurizi, Valentina Greto, Raffaella Buzzetti, Nicola Napoli, Paolo Pozzilli, Silvia Manfrini
Vitamin K is a liposoluble vitamin. The predominant dietary form, phylloquinone or vitamin K1, is found in plants and green vegetables; whereas menaquinone, or vitamin K2, is endogenously synthesized by intestinal bacteria and includes several subtypes that differ in side chain length. Aside from its established role in blood clotting, several studies now support a critical function of vitamin K in improving bone health. Vitamin K is in fact required for osteocalcin carboxylation that in turn regulates bone mineral accretion; it seems to promote the transition of osteoblasts to osteocytes and also limits the process of osteoclastogenesis...
May 2017: Metabolism: Clinical and Experimental
https://www.readbyqxmd.com/read/28357617/interaction-of-various-types-of-photosystem-i-complexes-with-exogenous-electron-acceptors
#19
Anastasia A Petrova, Baina K Boskhomdzhieva, Georgy E Milanovsky, Olga A Koksharova, Mahir D Mamedov, Dmitry A Cherepanov, Alexey Yu Semenov
Interaction of photosystem I (PS I) complexes from cyanobacteria Synechocystis sp. PCC 6803 containing various quinones in the A1-site (phylloquinone PhQ in the wild-type strain (WT), and plastoquinone PQ or 2,3-dichloronaphthoquinone Cl 2 NQ in the menB deletion strain) and different numbers of Fe4S4 clusters (intact WT and FX-core complexes depleted of FA/FB centers) with external acceptors has been studied. The efficiency of interaction was estimated by measuring the light-induced absorption changes at 820 nm due to the reduction of the special pair of chlorophylls (P700(+)) by an external acceptor(s)...
September 2017: Photosynthesis Research
https://www.readbyqxmd.com/read/28356433/circulating-vitamin-k-is-inversely-associated-with-incident-cardiovascular-disease-risk-among-those-treated-for-hypertension-in-the-health-aging-and-body-composition-study-health-abc
#20
M Kyla Shea, Sarah L Booth, Daniel E Weiner, Tina E Brinkley, Alka M Kanaya, Rachel A Murphy, Eleanor M Simonsick, Christina L Wassel, Cees Vermeer, Stephen B Kritchevsky
Background: A role for vitamin K in coronary artery calcification (CAC), a subclinical manifestation of cardiovascular disease (CVD), has been proposed because vitamin K-dependent proteins, including the calcification inhibitor matrix Gla protein (MGP), are present in vascular tissue. Observational studies found that low circulating phylloquinone (vitamin K-1) was associated with increased CAC progression, especially in persons treated for hypertension. It is unknown whether hypertension treatment modifies this putative role of vitamin K in clinical CVD risk...
May 2017: Journal of Nutrition
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