UV spectral properties of lipids as a tool for their identification

Angioni, Elisabetta; Lercker, Giovanni; Frega, Natale G.; Carta, Gianfranca; Melis, Maria Paola; Murru, Elisabetta; Spada, Simona; Banni, Sebastiano

doi:10.1002/1438-9312(200201)104:1<59::aid-ejlt59>3.0.co;2-i

Cited by 70 publications

(28 citation statements)

References 15 publications

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“…Indeed, the average body weight gain (% increase from 10 to 14 tra of the conjugated diene fatty acids were generated using Phoenix 3D HP Chemstation software (Hewlett-Packard). The spectra were taken to confi rm the identifi cation of the HPLC peaks ( 25 ). Separation of CLA isomers was achieved by separation of fatty acid methyl esters using a silver ion column ( 26 ).…”

Section: Resultssupporting

confidence: 53%

Hepatic retinol secretion and storage are altered by dietary CLA: common and distinct actions of CLA c9,t11 and t10,c12 isomers

Ortiz

Wassef

Shabrova

et al. 2009

Journal of Lipid Research

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The maintenance of normal retinoid (vitamin A and its derivatives) homeostasis is required to support many crucial biological functions ( 1-3 ). All retinoids in animals are derived from the diet as preformed dietary vitamin A (retinyl esters, retinol, and very small amounts of retinoic acid) from animal products or as ␤ -carotene from vegetables and fruits ( 4 ). Within the intestine, ingested vitamin A is packaged into chylomicrons as retinyl ester regardless of its dietary origin ( 5 ). In the bloodstream, lipolysis of the chylomicrons generates smaller lipoprotein particles called chylomicron remnants, still retaining retinyl ester ( 6, 7 ). Approximately 75% of retinoids within chylomicron remants are cleared by the liver, which is the major site of vitamin A storage and metabolism ( 8-10 ). To meet tissue retinoid needs, the liver secretes retinol into the circulation bound to its sole specifi c transport protein, retinol-binding protein (RBP; also known as RBP4) ( 11,12 ). RBP is a 21 kDa protein with a single binding site for one molecule of all-trans -retinol. It is mainly, but not exclusively, synthesized within the hepatocytes. RBP circulates in the blood as a 1:1 molar complex with another serum protein, transthyretin (TTR), preventing retinol-RBP excretion by the kidney ( 11, 12 ). In the fasting circulation, retinol-RBP represents approximately 99% of all serum retinoids. Blood levels of retinol-RBP in both humans and animals are maintained very constant except in extreme cases of nutritional intake of vitamin A, protein, calories, and zinc or in response to hormonal factors, stress, and in certain disease states ( 11,13,14 ).Abstract Conjugated linoleic acid (CLA) is a polyunsaturated fatty acid obtained from ruminant products. Previous studies in rats and pigs showed that a dietary equimolar mixture of c9,t11 and t10,c12 CLA isomers induces changes in serum and tissue levels of retinoids (vitamin A derivatives). However, the mechanism(s) responsible for these actions remain(s) unexplored. Given the numerous crucial biological functions regulated by retinoids, it is key to establish whether the perturbations in retinoid metabolism induced by dietary CLA mediate some of the benefi cial effects associated with intake of this fatty acid or, rather, have adverse consequences on health. To address this important biological question, we began to explore the mechanisms through which dietary CLA alters retinoid metabolism. By using enriched preparations of CLA c9,t11 or CLA t10,c12, we uncoupled the effects of these two CLA isomers on retinoid metabolism. Specifi cally, we show that both isomers induce hepatic retinyl ester accumulation. However, only CLA t10,c12 enhances hepatic retinol secretion, resulting in increased serum levels of retinol and its specifi c carrier, retinol-binding protein (RBP). Dietary CLA t10,c12 also redistributes retinoids from the hepatic stores toward the adipose tissue and possibly stimulates hepatic retinoid oxidation. Using mice lacking RBP, we also demonstrate that this ke...

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Section: Resultssupporting

confidence: 53%

Hepatic retinol secretion and storage are altered by dietary CLA: common and distinct actions of CLA c9,t11 and t10,c12 isomers

Ortiz

Wassef

Shabrova

et al. 2009

Journal of Lipid Research

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“…UV spectra of the eluate, generated by the Phoenix 3D HP Chemstation software, was obtained at every 1.28 s and electronically stored. The spectra were taken to confirm the identification of the peaks [2].…”

Section: Conjugated Linoleic Acid Unsaturated Fatty Acids and Retinolmentioning

confidence: 99%

Increasing pasture intakes enhances polyunsaturated fatty acids and lipophilic antioxidants in plasma and milk of dairy cows fed total mix ration

Terra

Marino

Manenti

et al. 2010

Dairy Sci. Technol.

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-Polyunsaturated fatty acids and lipo-soluble vitamins in the milk are considered as neutraceutical compounds due to their beneficial effects on human health. The aim of the present study was to evaluate the changes in fatty acid composition and fat-soluble antioxidant content in plasma and milk from cows fed with different dietary proportions from pasture. Cows from a farm in the Hyblean mountain region in Italy were randomly divided into three groups (12 animals per group): CTRL fed only a total mix ration (TMR); 30P fed a TMR supplemented with 30% dry matter (DM) from pasture and 70P fed a TMR supplemented with 70% DM of pasture. Blood and milk samples were collected, stored and analysed for their content of fatty acids and fat-soluble antioxidants. Fatty acid profiles were significantly modified by different diets. CLA, vaccenic acid (VA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) significantly (P < 0.05) increased in plasma as a function of the proportion of pasture added to the diet. In agreement with these data, a progressively significant (P < 0.05) increase in concentrations of VA, CLA and EPA was observed in the milk. Such changes in fatty acid composition were accompanied by a concomitant increase in the concentrations of α-tocopherol and β-carotene in both plasma and milk. The increase in EPA, DHA and CLA, β-carotene and α-tocopherol in plasma may not only have a beneficial impact for milk and meat quality, but may also result in an increased protection against inflammatory events. Article published by EDP SciencesRésumé -L'augmentation de la teneur en herbe de la ration améliore la teneur en acides gras polyinsaturés et en antioxydants lipophiles dans le plasma et le lait des vaches laitières en ration complète. Les acides gras polyinsaturés (AGPI) et les vitamines liposolubles du lait sont considérés comme des composés nutraceutiques en raison de leurs effets bénéfiques pour la santé. Le but de cette étude était d'évaluer les changements de composition en acides gras et de teneur en antioxydants liposolubles dans le plasma et le lait de vaches laitières recevant différentes proportions de pâture. Les vaches provenant d'une ferme de la région du mont Iblei en Italie, ont été réparties aléatoirement en trois groupes (12 animaux par groupe) : un groupe témoin recevant une alimentation en ration complète (TMR) ; un groupe recevant une alimentation TMR supplémentée à hauteur de 30 % de matière sèche en herbe ; un groupe recevant une alimentation TMR supplé-mentée à hauteur de 70 % de matière sèche en herbe. Des échantillons sanguins et du lait ont été collectés, conservés et analysés pour leur teneur en acides gras et en antioxydants liposolubles. Les profils en acides gras étaient modifiés de façon significative par les différents régimes. L'acide linoléique conjugué (CLA), l'acide vaccénique (VA), l'acide eisapentanoïque (EPA) et l'acide docohexanoïque (DHA) augmentaient significativement (P < 0,05) dans le plasma en fonction de la proportion de pâture. En accord avec ces rés...

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“…The mobile phase well used for the RP-HPLC system is the mixture of acetonitrile and acetone or the mixture of acetonitrile and dichloromethane (19,20). The detection of TG molecular species is carried out using 200-220 nm originating in carbonyl group (21), but these mobile phases have a big absorption around the wave length. In that case, tetrahydrofurane (THF), 2-propanol, ethanol or methyl-tert-butyl ether has been used instead of acetone or dichloromethane (22)(23)(24)(25) because these organic solvents have absorption less than 215 nm.…”

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confidence: 99%

Quantification Method for Triglyceride Molecular Species in Fish Oil with High Performance Liquid Chromatography-Ultraviolet Detector

et al. 2004

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Triglyceride (TG) is a principal component of fats and oils and consists of three fatty acids and one glycerol. Many kinds of fatty acids exist in natural fats and oils and partake in TG molecular construction. Consequently, in the case of the combinations of fatty acids are different between two TG molecular, these two TG molecular are distinguished as different kinds of TG molecular species (1). The analysis of TG molecular species is usually conducted with high performance liquid chromatography (HPLC), and silver ion column or reverse phase (RP) column is employed for the separation of TG molecular species (2,3). Silver ion column separates TG molecular species in order of the degree of unsaturation (4-6). On the contrary, RP column separates them in order of the polarity (7-9). Both of them have been well hired for the TG molecular species sep- JAPAN) Abstract: A new quantification method for triglyceride (TG) molecular species contained in fish oil was developed using high performance liquid chromatography (HPLC)-ultraviolet detector (UV) system. In this experiment, triacontyl silane column and a mixture of alcohol and acetonitrile were used for column and mobile phase, respectively. Fifteen kinds of TG molecular species exist in fish oil were collected and the calibration curves monitored at 210nm were acquired for each TG molecular species. Also, evaporative light scattering detector (ELSD), widely used for the detection of fish oil TG molecular species, was tandem jointed after UV to compare the calibration curves for each TG molecular species. As the results, the calibration curves by UV with isocratic elution system were linear lines, on the contrary, those by ELSD were not linear. The slope of each calibration curve by UV was not the same and there was a tendency that TG molecular species having big partition number indicates a small slope calibration curve. The HPLC-UV with gradient system was also examined, but a few of standard TGs did not provide linear calibration curve. Consequently, we concluded that isocratic HPLC-UV system would be an available method for the quantification of TG molecular species in fish oil. 285 JOSKey words: quantification, triglyceride molecular species, fish oil, HPLC-UV, triacontyl silane column (15) and expressed with the equation of PN=TC-2xDB, where TC is total carbon number of acyl group and DB is total number of double bond in TG. In this system, TG molecular species are eluted in order of PN and this rule can be adapted for every kind of oils and fats such as plant oil, animal fat, milk fat and fish oil (2,3). However, the separation of TG molecular species in milk fat and/or fish oil is not enough compared to those in plant oil or animal fat, because milk fat and/or fish oil consists of more kinds of TG molecular species than plant oil and animal fat (2,3). Therefore, some kinds of efforts, such as gradient elution system, are made in order to obtain fine separation of TG molecular species in milk fat or fish oil (16-18). The selection of the detector is al...

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UV spectral properties of lipids as a tool for their identification

Cited by 70 publications

References 15 publications

Hepatic retinol secretion and storage are altered by dietary CLA: common and distinct actions of CLA c9,t11 and t10,c12 isomers

Hepatic retinol secretion and storage are altered by dietary CLA: common and distinct actions of CLA c9,t11 and t10,c12 isomers

Increasing pasture intakes enhances polyunsaturated fatty acids and lipophilic antioxidants in plasma and milk of dairy cows fed total mix ration

Quantification Method for Triglyceride Molecular Species in Fish Oil with High Performance Liquid Chromatography-Ultraviolet Detector

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