Fatty Acids and Glycerides

ISBN-13: 9781468425673 / Angielski / Miękka / 2012 / 469 str.

A. Kuksis

Opis

The advances in lipid biochemistry over the past 25 to 30 years have been dramatic and exciting. The elucidation of the pathways of fatty acid biosynthesis and oxidation, the delineation of the biogenesis of cholesterol from small-molecular- weight precursors, the structure proof of simple and complex lipids from plants, animals, and microorganisms, are excellent examples of the spectacular advances made during the golden era of lipid biochemistry. The multifaceted discoveries in these diverse areas of study could be attributed to development of highly sophisticated column chromatographic techniques for separation and purification of simple and complex lipids. The advent of thin-layer chromatography as well as gas- liquid chromatography provided an explosive impetus to research developments in this field. Concomitant advances in mass spectrometry allowed an interface with gas-liquid chromatography which spawned even greater insight into the structure of lipids. These eventful days of lipid chemistry nearly 25 years ago led to a relatively quiescent period wherein scientists applied these newly available techniques to investigation of the behavior of isolated (lipid) enzyme systems and to unraveling the intricacies of the metabolic behavior of lipids in the intact cell or whole organisms. Then, in the early 1960s, a decided change in research emphasis developed with the advent of a simple, reproducible procedure for the isolation of cell membranes.

Spis treści

1 Separation and Determination of Structure of Fatty Acids.- 1.1. Introduction.- 1.2. Preparation and Isolation of Fatty Acids.- 1.2.1. Generation of Free Acids.- 1.2.2. Preparation of Derivatives.- 1.2.3. Transesterification of Bound Acids.- 1.3. Preliminary Fractionation of Fatty Acids.- 1.3.1. Conventional TLC.- 1.3.2. Argentation TLC.- 1.3.3. Other Methods.- 1.4. Identification of Fatty Acids by Gas—Liquid Chromatography.- 1.4.1. Short-Chain Acids.- 1.4.2. Saturated Normal- and Branched-Chain and Cyclic Acids.- 1.4.3. Ethylenic Acids.- 1.4.4. Acetylenic Acids.- 1.4.5. Oxygenated Acids.- 1.5. Identification of Fatty Acids by Gas Chromatography/Mass Spectrometry.- 1.5.1. Saturated Normal- and Branched-Chain and Cyclic Acids.- 1.5.2. Ethylenic and Acetylenic Acids.- 1.5.3. Oxygenated Acids.- 1.5.4. Stable Isotope-Labeled Fatty Acids.- 1.6. Ancillary Methods of Fatty Acid Identification.- 1.6.1. Chemical Methods.- 1.6.2. Spectrometric Methods.- 1.6.3. Enzymatic Methods.- 1.7. Summary and Conclusions.- 1.8. References.- 2 Synthesis and Analysis of Stable Isotope- and Radioisotope-Labeled Fatty Acids.- 2.1. Introduction.- 2.2. Synthesis of Stable Isotope-Labeled Fatty Acids.- 2.2.1. Experimental Techniques.- 2.2.2. Saturated Fatty Acids.- 2.2.3. Monounsaturated Fatty Acids.- 2.2.4. Polyunsaturated Fatty Acids.- 2.2.5. Perdeutero Fatty Acids.- 2.2.6. 13C-Labeled Fatty Acids.- 2.3. Synthesis of Radioisotope-Labeled Fatty Acids.- 2.3.1. 14C-Labeled Fatty Acids.- 2.3.2. 3H-Labeled Fatty Acids.- 2.3.3. Biosynthesis of 14C- and 3H-Labeled Lipids.- 2.4. Analysis of Radioisotope-Labeled Fats.- 2.4.1. Liquid Scintillation Counting.- 2.4.2. Radio-Gas Chromatography.- 2.4.3. Thin-Layer Chromatography.- 2.4.4. Determination of Radiochemical Purity.- 2.4.5. Chemical Degradation Methods.- 2.4.6. Storage of Radioisotope-Labeled Fatty Acids.- 2.5. Analysis of Stable Isotope-Labeled Fatty Acids.- 2.5.1. Mass Spectrometry.- 2.5.2. Infrared Spectrometry.- 2.5.3. Nuclear Magnetic Resonance.- 2.6. Summary.- 2.7. References.- 3 Separation and Determination of the Structure of Acylglycerols and Their Ether Analogues.- 3.1. Introduction.- 3.2. Nomenclature.- 3.3. Selected Methods for Modifying or Degrading Glycerolipids.- 3.3.1. Methanolysis.- 3.3.2. Saponification.- 3.3.3. Phospholipase C Hydrolysis.- 3.3.4. Acetolysis.- 3.3.5. Thermal Cleavage.- 3.3.6. Reductive Hydrogenolysis.- 3.3.7. Grignard Hydrolysis.- 3.3.8. Oxidative Cleavage of Double Bonds.- 3.3.9. Hydrogenation.- 3.4. Derivatization Procedures.- 3.4.1. Acetates.- 3.4.2. Isopropylidenes.- 3.4.3. Trimethylsilyl Ethers.- 3.4.4. Tertiarybutyldimethylsilyl Ethers.- 3.4.5. Other Derivatives.- 3.5. Determination of the Structural Components of Glycerolipids.- 3.5.1. Glycerol.- 3.5.2. Fatty Alcohols.- 3.5.3. Monoalkyl- and Monoalk-1-enylglycerols.- 3.6. Extraction and Purification of Lipids.- 3.7. Thin-Layer Chromatography.- 3.7.1. Plate Preparation.- 3.7.2. Detection of Neutral Lipids.- 3.7.3. Recovery of Lipids from Silica Gel.- 3.7.4. Separations on Silica Gel.- 3.7.5. Separations on Silica Gel Impregnated with Borate or Arsenite.- 3.7.6. Separations on Silica Gel Impregnated with Silver Nitrate.- 3.7.7. Reversed-Phase TLC.- 3.7.8. Quantitation.- 3.8. Liquid Chromatography.- 3.9. Gas Chromatography.- 3.9.1. Column Packings.- 3.9.2. General Separation Characteristics.- 3.9.3. Equivalent Chain Length.- 3.9.4. Separation of Neutral Lipids.- 3.9.5. Quantitative Gas Chromatography.- 3.10. Mass Spectrometry.- 3.10.1. Monoacylglycerols.- 3.10.2. Monoalkylglycerols.- 3.10.3. Monoalk-1-enylglycerols.- 3.10.4. Diacylglycerols.- 3.10.5. Alkylacylglycerols.- 3.10.6. Triacylglycerols.- 3.10.7. Other Modes of Ionization.- 3.11. Other Techniques.- 3.11.1. Infrared Spectroscopy.- 3.11.2. Nuclear Magnetic Resonance Spectroscopy.- 3.11.3. Optical Rotation and Stereospecific Analysis.- 3.11.4. Calculation Methods.- 3.12. Combined Techniques.- 3.13. Conclusions.- 3.14. References.- 4 Stereospecific Analysis of Triacylglycerols.- 4.1. Introduction.- 4.2. Physical and Chemical Methods for the Determination of Stereochemical Distribution of Fatty Acids in Triacylglycerols.- 4.3. Enzymatic Methods for Determination of Stereochemical Distribution of Fatty Acids in Triacylglycerols.- 4.3.1. Generation of Diacylglycerols.- 4.3.2. Stereospecific Selection of Diacylglycerols or Their Derivatives.- 4.3.3. Calculations and Checks on Accuracy.- 4.3.4. Studies with Radioactive Acylglycerols.- 4.4. Positional Distribution of Fatty Acids in Natural Triacylglycerols.- 4.4.1. Animal Fats.- 4.4.2. Human Tissues.- 4.4.3. Interorgan and Interspecies Comparisons.- 4.4.4. Plant Oils.- 4.4.5. Yeast and Microorganisms.- 4.5. Concluding Remarks.- 4.6. References.- 5 Stereospecific Synthesis of Enantiomeric Acylglycerols.- 5.1. Introduction.- 5.2. General Procedures for Specification of Absolute Configuration of Enantiomeric sn-Glycerol Derivatives.- 5.3. Sources and Practical Methods for Preparation of Enantiomeric sn-Glycerol Derivatives.- 5.3.1. d-Mannitol and l-Mannitol.- 5.3.2. Preparation of 1,2:5,6-Diisopropylidene-d- and -l-mannitols.- 5.3.3. Preparation of 1,2- and 2,3-Isopropylidene-sn-glycerols.- 5.3.4. Preparation of 1- and 3-Benzyl-sn-glycerols.- 5.3.5. Preparation of Enantiomeric Alkyl- and Alkenyl-sn-glycerols.- 5.4. Methods of Configurational Conversion and Inversion of sn-Glycerol Derivatives.- 5.4.1. Conversion of 1,2-Isopropylidene-sn-glycerol into 2,3-Isopropylidene-sn-glycerol.- 5.4.2. Inversion of 3-Benzyl-sn-glycerol into 1-Benzyl-sn-glycerol.- 5.4.3. Preparation of 1-Benzyl-sn-glycerol from d-Mannitol via l,3:2,5:4,6-O-Trimethylene-d-mannitol.- 5.5. Selection of Protective Groups for Stereospecific Synthesis of Acyl-, Alkyl-, and Alkylacyl-sn-glycerols.- 5.5.1. Isopropylidene Group.- 5.5.2. Benzylidene Group.- 5.5.3. Triphenylmethyl (Trityl) Group.- 5.5.4. Benzyl Group.- 5.5.5. 2,2,2-Trichloroethoxycarbonyl Group.- 5.5.6. Other Protective Groups.- 5.6. Stereospecific Acylation of Enantiomeric sn-Glycerol Derivatives.- 5.6.1. Selection of Acylating Reagents.- 5.6.2. Synthesis of Enantiomeric 1- and 3-Monoacyl-sn-glycerols.- 5.6.3. Synthesis of 2-Monoacyl-sn-glycerols.- 5.6.4. Synthesis of Enantiomeric 1,2- and 2,3-Diacyl-sn-glycerols.- 5.6.5. Synthesis of Enantiomeric 1,3-Diacyl-sn-glycerols.- 5.6.6. Synthesis of Enantiomeric Mixed-Acid Triacyl-sn-glycerols.- 5.7. Synthesis of Enantiomeric Isotope-Labeled Acyl- and Alkylacyl-sn-glycerols.- 5.7.1. Synthesis of Enantiomeric Isotope-Labeled Acyl-sn-glycerols.- 5.7.2. Synthesis of Enantiomeric Isotope-Labeled Alkylacyl-sn-glycerols.- 5.8. Methods of Isolation and Purification of Synthetic Acyl-sn-glycerols.- 5.8.1. Selection of Solvents.- 5.8.2. Distillation and Crystallization.- 5.8.3. Chromatography.- 5.9. Determination of Structure and Absolute Configuration of Synthetic and Natural Acyl-sn-glycerols.- 5.9.1. Chemical and Enzymatic Methods.- 5.9.2. Physical Methods.- 5.10. Summary and Conclusions.- 5.11. References.- 6 Metabolic Studies with Natural and Synthetic Fatty Acids and Enantiomeric Acylglycerols.- 6.1. Introduction.- 6.2. Activation of Fatty Acids.- 6.3. Biosynthesis of Phosphatidic Acid.- 6.3.1. Acylation of sn-Glycerol-3-phosphate.- 6.3.2. Acylation of Dihydroxyacetone Phosphate.- 6.3.3. Synthesis of Phosphatidic Acid from Monoacylglycerols and Diacylglycerols.- 6.3.4. Relative Contributions of the Pathways of Phosphatidic Acid Synthesis.- 6.4. Biosynthesis of Diacylglycerols.- 6.4.1. Synthesis of Diacylglycerols from Monoacylglycerols.- 6.4.2. Synthesis of Diacylglycerols from Phosphatidic Acid.- 6.4.3. Synthesis of Other Diacylglycerols.- 6.5. Biosynthesis of Triacylglycerols.- 6.5.1. Synthesis of Triacylglycerols from Diacylglycerols.- 6.5.2. Triacylglycerol Synthetase.- 6.5.3. Relative Contributions of the Major Pathways of Triacylglycerol Synthesis.- 6.6. Factors Influencing the Biosynthesis of Acylglycerols.- 6.6.1. Nutritional Factors.- 6.6.2. Hormonal Factors.- 6.6.3. Pharmacological Factors.- 6.7. Methods Employed in Studying the Biosynthesis of Acylglycerols.- 6.8. Kinetic Problems Encountered in Enzyme Assays Involving Lipid Substrates.- 6.9. Enzymatic Lipolysis of Acylglycerols.- 6.9.1. Pharyngeal Lipases.- 6.9.2. Pancreatic Lipase.- 6.9.3. Lipoprotein Lipase.- 6.9.4. Hormone-Sensitive Lipase.- 6.9.5. Monoacylglycerol Lipase.- 6.10. Summary and Conclusions.- 6.11. References.- 7 Composition of Selected Dietary Fats, Oils, Margarines, and Butter.- 7.1. Introduction.- 7.2. Methodology.- 7.2.1. Extraction Techniques.- 7.2.2. Esterification Techniques for Fatty Acids.- 7.2.3. Gas Chromatographic Analysis of Fatty Acid Methyl Esters.- 7.2.4. Sterol Derivatization.- 7.2.5. Gas Chromatographic Analysis of Sterols.- 7.2.6. Lipoxidase:cis,cis-Polyunsaturated Fatty Acid Analysis.- 7.3. Basic Processing.- 7.3.1. General Discussion.- 7.3.2. Additives.- 7.3.3. Mayonnaise and Salad Dressing.- 7.4. Source Oils.- 7.4.1. Soybean.- 7.4.2. Cottonseed.- 7.4.3. Peanut.- 7.4.4. Corn.- 7.4.5. Safflower.- 7.4.6. Sunflower.- 7.4.7. Rapeseed.- 7.4.8. Other Cruciferae.- 7.4.9. Olive.- 7.4.10. Sesame.- 7.4.11. Cocoa.- 7.4.12. Palm and Palm Kernel.- 7.4.13. Coconut.- 7.5. Confectionery Products.- 7.6. Nuts.- 7.7. Cooking Oils.- 7.8. Shortenings.- 7.9. Margarines.- 7.10. Dairy Products and Creamers.- 7.11. Animal Fats.- 7.12. Marine Products.- 7.13. Summary and Trends.- 7.14. References.- 8 Fatty Acid Composition of Glycerolipids of Animal Tissues.- 8.1. Introduction.- 8.2. Methods of Analysis.- 8.2.1. Isolation and Preparation of Fatty Acids.- 8.2.2. Quantitative Determination of Fatty Acids.- 8.2.3. Quality Control.- 8.3. Fatty Acids of Different Animal Species and Man.- 8.3.1. Differences among Homologous Tissues.- 8.3.2. Differences among Homologous Cell Types.- 8.3.3. Differences among Homologous Subcellular Fractions.- 8.3.4. Differences among Homologous Lipoproteins.- 8.4. Fatty Acids of Individual Animal Species and Man.- 8.4.1. Tissue Differences.- 8.4.2. Differences among Cell Types.- 8.4.3. Variations among Subcellular Fractions.- 8.4.4. Discrepancies among Plasma Lipoprotein Classes.- 8.4.5. Characteristics of Skin Surface and Fecal Lipids.- 8.5. Summary and Conclusions.- 8.6. References.