Isolation of α-linolenic acid biohydrogenation products by combined silver ion solid phase extraction and semi-preparative high performance liquid chromatography
| Autor: | John S. Church, Payam Vahmani, Óscar López-Campos, William J. Meadus, Pascale Duff, Michael E. R. Dugan, Cletos Mapiye, T.D. Turner, David C. Rolland |
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| Rok vydání: | 2015 |
| Předmět: |
chemistry.chemical_classification
Chromatography Elution Conjugated linoleic acid Solid Phase Extraction Clinical Biochemistry alpha-Linolenic Acid Fatty acid Cell Biology General Medicine Reversed-phase chromatography Biochemistry High-performance liquid chromatography Analytical Chemistry Hexane chemistry.chemical_compound chemistry Linoleic Acids Conjugated Solid phase extraction Chromatography High Pressure Liquid Polyunsaturated fatty acid |
| Zdroj: | Journal of Chromatography B. 980:34-40 |
| ISSN: | 1570-0232 |
| DOI: | 10.1016/j.jchromb.2014.11.038 |
| Popis: | Polyunsaturated fatty acids typically found in cattle feed include linoleic (LA) and α-linolenic acid (ALA). In the rumen, microbes metabolize these resulting in the formation of biohydrogenation products (BHP), which can be incorporated into meat and milk. Bioactivities of LA-BHP, including conjugated linoleic acid (cis (c) 9,trans (t) 11-18:2 and t10,c12-18:2) and trans fatty acid isomers (t9-, t10- and t11-18:1) have been investigated, but effects of several BHP unique to ALA have not been extensively studied, and most ALA-BHP are not commercially available. The objective of the present research was to develop methods to purify and collect ALA-BHP using silver ion (Ag(+)) chromatography in sufficient quantities to allow for convenient bioactivity testing in cell culture. Fatty acid methyl esters (FAME) were prepared from perirenal adipose tissue from a cow enriched with ALA-BHP by feeding flaxseed. These were applied to Ag(+)-solid phase extraction, and eluted with hexane with increasing quantities of acetone (1, 2, 10, 20%) or acetonitrile (2%) to pre-fractionate FAME based on degree of unsaturation and double bond configuration. Fractions were collected, concentrated and applied to semi-preparative Ag(+)-high performance liquid chromatography (HPLC) for the isolation and collection of purified isomers, which was accomplished using isocratic elutions with hexane containing differing amounts of acetonitrile (from 0.015 to 0.075%). Purified trans-18:1 isomers collected ranged in purity from 88 to 99%. Purity of the ALA-BHP dienes collected, including c9,t13-18:2, t11,c15-18:2 and t10,c15-18:2, exceeded 90%, while purification of other dienes may require the use of other complementary procedures (e.g. reverse phase HPLC). |
| Databáze: | OpenAIRE |
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