Vitamin from lipids

Normal-phase sorbents such as silica and Florisil are used to isolate low to moderate polarity species from nonaqueous solutions. Examples of applications include lipid classification, plant pigment separations, and separations of fat-soluble vitamins from lipid extracts, as well as the clean-up of organic solvent concentrates obtained from a previous SPE method or liquid-liquid extraction. Alumina is used to remove polar species from nonaqueous solutions. Examples include vitamins in feeds and food and antibiotics and other additives from feed. Normal-phase chromatography has been used for a number of years, and most applications for normal-phase column chromatography may be easily transferred over to normal-phase SPE. 

Gel permeation ehromatography (GPC)/normal-phase HPLC was used by Brown-Thomas et al. (35) to determine fat-soluble vitamins in standard referenee material (SRM) samples of a fortified eoeonut oil (SRM 1563) and a eod liver oil (SRM 1588). The on-line GPC/normal-phase proeedure eliminated the long and laborious extraetion proeedure of isolating vitamins from the oil matrix. In faet, the GPC step permits the elimination of the lipid materials prior to the HPLC analysis. The HPLC eolumns used for the vitamin determinations were a 10 p.m polystyrene/divinylbenzene gel eolumn and a semipreparative aminoeyano eolumn, with hexane, methylene ehloride and methyl tert-butyl ether being employed as solvent. 

The provision of fat-soluble vitamins and lipids is difficult, if not impossible, in various diseases. This is especially true for diseases that are accompanied by a lot of oxidative stress, for example, mucoviscidosis. The requirements of fat-soluble antioxidative substances are certainly high in these cases and can barely be covered by intramuscular injections because fat-soluble vitamins can hardly, if at all, be absorbed from oily preparations. Alternatively, the vitamins can administered via the buccal mucosa the fat-soluble substances have to be packaged in such a way that they can be transported in a watery compartment and are thus able to largely dissolve in the saliva. When they have an adequate size, they can then penetrate the buccal mucosa. One approach is the development of the so-called nanocolloids, that is, particles with a polar nucleus, in which the fat-soluble vitamin is dissolved, and an apolar wrapping (monolayer). This structure makes an oral application of fat-soluble substances possible. First tests demonstrated that vitamin A palmitate, a-tocopherol, as well as coenzyme Qio are thus able to enter the systemic circulation via the buccal mucosa. 

Methods of extracting the fat-soluble vitamin from food matrices include alkaline hydrolysis, enzymatic hydrolysis, alcoholysis, direct solvent extraction, and supercritical fluid extraction of the total lipid component. 

The lung also possesses nonenzymatic antioxidants such as vitamin E, beta-carotene, vitamin C, and uric acid. Vitamin E is lipid-soluble and partitions into lipid membranes, where it is positioned optimally for maximal antioxidant effectiveness. Vitamin E converts superoxide anion, hydroxyl radical, and lipid peroxyl radicals to less reactive oxygen metabolites. Beta-carotene also accumulates in cell membranes and is a metabolic precursor to vitamin A. Furthermore, it can scavenge superoxide anion and react directly with peroxyl-free radicals, thereby serving as an additional lipid-soluble antioxidant. Vitamin C is widely available in both extracellular and intracellular spaces where it can participate in redox reactions. Vitamin C can directly scavenge superoxide and hydroxyl radical. Uric acid formed by the catabolism of purines also has antioxidant properties and primarily scavenges hydroxyl radical and peroxyl radicals from lipid peroxidation. 

All information available at present is presented in the 15 chapters of the special part. From lipides, vitamins, sterols, via medicaments, auxiliary substances of the industry, amino and nucleic acids, to anion- and cation-separation — every subject is dealt with. The possible new applications of the method in medical diagnosis and pharmacology are described in a special chapter. The authors of the respective chapters, after having employed the method for years, report also on the results of their own work some of this information has not been published before and will save time-consuming preliminary tests and studies of literature, for beginners and specialists and will give valuable hints. 

Frank, J., Budek, A., Lundh, T., Parker, R. S., Swanson, J. E., Lourenco, C. F., Gago, B., Laran-jinha, J., Vessby, B., Kamal-Eldin, A. (2006). Dietary flavonoids with a catechol structure increase alpha-tocopherol in rats and protect the vitamin from oxidation in vitro. J. Lipid Res., 47, 2718-2725. 

Superoxide dismutase and catalase are remarkably efficient, performing their reactions at or near the diffusion-limited rate (Section 8.4.2). Other cellular defenses against oxidative damage include the antioxidant vitamins, vitamins E and C. Because it is lipophilic, vitamin E is especially useful in protechng membranes from lipid peroxidahon. 

Most assays for 25(OH)D and l,25(OH)2D contain two or three of the following steps (1) deproteinization or extraction, (2) purification, and (3) quantification. Depro-teinization or extraction frees the metabolites from DPB and may partially purify the metabolites. Purification steps, most often column chromatography, separate the various forms of vitamin D, lipid, and interfering substances. The method of quantification depends on the metabolite being measured. 

The dry mass of pulse seeds consists of saccharides (14—63%), proteins (28 44%), and lipids (1-50%). The other constituents are mineral elements (mainly K and P) and vitamins from the B group. Soybean is the most valuable pod plant, due to its high quantity and good quality of protein. Soy products in the form of meat extenders and analogs are used all over the world. Soybean is also a raw material in the oil industry. 

Eand C. Because it is lipophilic, vitamin E is especially useful in protecting membranes from lipid peroxidation. 

Because vitamin E (found in vegetable and seed oils, whole grains, and green, leafy vegetables) is lipid-soluble, it plays an important role in protecting membranes from lipid peroxyl radicals. 

The antioxidant activity of alizarin was established in four different assays (1) suppression of light emission in the p-iodophenol enhanced chemiluminescent assay, (2) scavenging of superoxide anion (02 -) in a hypoxanthine-xanthine oxidase system, (3) protection of rat liver microsomes from lipid peroxidation by ADP/iron(II) ions, and (4) protection of bromobenzene-intoxicated mice from liver injury in vivo [141]. Alizarin was compared with Trolox (water soluble vitamin E), the flavonoid baicalin and green tea proanthocyanidins. In assay (1) the activity of alizarin was 76% of that of Trolox. In assay (2) the inhibition of 02 -induced chemiluminescence was 40%, 32%, 23% and 14% for Trolox, alizarin, green tea polyphenols and baicalin respectively. Alizarin was not significantly active in the lipid peroxidation assay but after baicalin the most active compound in the in vivo assay. This shows again the difficulty in the evaluation of antioxidant activity and the differences between in vitro and in vivo assays [141]. 

Princen, H. M. G., van Poppel, G., Vogelezang, C., Buytenhek, R., and Kok, J. (1992). Supplementation with vitamin E but not /3-carotene in vivo protects low density lipoprotein from lipid peroxidation in vitro Effect of cigarette smoking. Arterioscler. Thromb. 12, 554-562. 

Reversed-phase chromatography is the method of choice for the final step of vitamin K assays. It can easily separate vitamin Ki(20) from lipids with closely related polarities and from structural analogs used as internal standard. Similar to the other fat-soluble vitamins nonaqueous reversed-phased systems are preferable because of the increased solubility of vitamin Ki(20) and co-extracted lipids in the eluents that can be used. 

Several factors can be manipulated to control and reduce flavor deterioration in meat due to lipid oxidation. Factors related to raw material include vitamin E content and age, while factors related to processing include addition of antioxidants, heat treatment and packaging. Oxidation in meat and other muscle foods is promoted by any processing that disrupts the natural cellular compartmental separation that controls oxidation. Heating and grinding raw meat thus accelerate lipid oxidation. It is therefore important to maintain the integrity of heated meat products to retard flavor deterioration from lipid oxidation. 

Cadenas, 8., Rojas, C., Perez-Campo, R., Lopez-Torres, M., and Barja, G., 1995, Vitamin E protects from lipid peroxidation without depressing antioxidants in the guinea pig liver in vivo. Int. J. Biochem. In press. 

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