Chemistry
Derived Lipids
Derived lipids are a diverse group of compounds formed from the chemical modification of simple lipids. They include phospholipids, glycolipids, and cholesterol, which play essential roles in cell structure, signaling, and energy storage. These lipids are characterized by their varied structures and functions, contributing to the complexity and versatility of biological systems.
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8 Key excerpts on "Derived Lipids"
eBook - ePubFood Lipids
Sources, Health Implications, and Future Trends
- Jose M. Lorenzo, Paulo Eduardo Sichetti Munekata, Mirian Pateiro, Francisco J. Barba, Rubén Domínguez, Mirian Pateiro Moure, Ruben Dominguez(Authors)
- 2022(Publication Date)
- Academic Press(Publisher)
O’Keefe, 2008 ). Despite the evident problems with the accepted definitions, a more precise definition is difficult, since lipids are complex and heterogeneous molecules.Regarding the biological activity, lipids serve several functions in organisms, such as they serve as the structural component of living organisms (essential for biomembranes such as cellular and mitochondrial membrane), the basic structure of intracellular constituents (lipoproteins), they are involved in metabolism (a constituent of bile salts, steroid hormones, fat-soluble vitamins, etc.) and thermal regulation (insulators due to deposition in subcutaneous and around the organs), and they also serve as energy storage (9 kcal/g) (Dawson, Lan, & Rao, 2009 ). Therefore, this class of compounds is of great importance for human nutrition due to large evidence fromin vitro animal and clinical studies that associate its consumption with adequate growth, development, and normal tissue activity (Simopoulos, 2011 ; Valenzuela, 2009 ). Also, some of the lipids are essential for humans, including fat-soluble vitamins and provitamins or some fatty acids. This means that they must be provided by the diet since humans lack enzymatic system for their synthesis (Pateiro, Domínguez, Munekata, Barba, & Lorenzo, 2019 ). Particularly for humans, linoleic and α-linolenic acids (from the omega-6 and omega-3 families, respectively) are the only known essential fatty acids due to the lack of desaturase enzymes. Additionally, fat-soluble vitamins and sterols (cholesterol and phytosterols) are the components relevant to human metabolism (Pateiro et al., 2019 ). Therefore, the contribution of these lipids to the diet is essential for proper nutrition. Others such as eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and omega-6 arachidonic acid are also considered as “semiessential” due to their functional importance. In this sense, very long-chain omega-3 polyunsaturated fatty acids present highly important biological functions (Robinson et al., 2017 ), since they are vital in the prevention of cardiovascular diseases, diabetes, and Alzheimer's disease; possess antiinflammatory properties; improve and regulate ocular function; and are vital for immune and nervous system development (Pateiro et al., 2021 ; Shahidi & Ambigaipalan, 2018 ; Valenzuela, 2009
eBook - PDFAnimal Clinical Chemistry
A Practical Handbook for Toxicologists and Biomedical Researchers, Second Edition
- G.O. Evans(Author)
- 2009(Publication Date)
- CRC Press(Publisher)
183 9 Lipids 9.1 BIOCHEMISTRY AND PHYSIOLOGY The collective term lipids is used to describe molecules that have diverse chemical and functional relationships; they all have poor solubility in water but are soluble in organic solvents. They can be broadly divided into sterols, including choles-terol, fatty acids, or molecules containing fatty acids—for example, triglycerides and phospholipids, the fat-soluble vitamins, eicosanoids, and sphingolipids. A more recent comprehensive classification of lipids proposes that they are divided into eight categories: fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, ste-rol lipids, prenol lipids, saccharolipids, and polyketides, based on the hydrophobic and hydrophilic properties of the lipids (Fahy et al. 2005). This classification should prove useful as the analytical approaches using liquid chromatography and mass spectrometry provide more information on lipids and their interactions in the field of lipidomics (Wenk 2005). Cholesterol is the major sterol in the body and occurs mainly as the nonesterified free form, which is a fundamental component of cell membranes and the precursor for steroid hormones and bile acids. Cholesteryl esters present in the tissues and plasma are mainly formed by cholesterol esterification with long chain fatty acids; these cholesterol esters act as a storage pool. Most of the requirements for cholesterol are met by endogenous synthesis, mainly in the liver, with the exogenous supplemen-tation from the diet. Fatty acids have a basic structure, R-COOH, and the important fatty acids have long chains with an even number of carbon atoms (C12–C20), which may be described as saturated (e.g., stearic acid, C18:1), monounsaturated (e.g., oleic acid, C18:2), and polysaturated (e.g., linoleic, C18:2, and linolenic, C18:3, acids).
eBook - PDF- Khetarpaul, Neelam(Authors)
- 2021(Publication Date)
- Daya Publishing House(Publisher)
Chapter 1 Definition and Classification of Lipids I Definitions of Lipid Lipids come from the Greek lipos, meaning fat. Although lipid analysts tend to have a firm understanding of what is meant by the term “lipid”, there is no widely-accepted definition. Fats and oils are classified as “lipids” which is a category that embraces a broad variety of chemical substances. In addition to triglycerides, it also includes monoand diglycerides, phosphatides, cerebrosides, sterols, terpenes, fatty alcohols, fatty acids, fat-soluble vitamins, and other substances. Generally, lipids are usually described as a group of naturally occurring compounds, which are hydrophobic and have in common a ready solubility in such organic solvents as hydrocarbons, chloroform, benzene, ethers and alcohols. They include a diverse range of compounds, like fatty acids and their derivatives, carotenoids, terpenes, phospholipids, steroids, bile acids and waxes. It should be apparent that many of these compounds have little by way of structure or function to relate them. In fact, a definition of this kind is positively misleading, since many of the substances that are now widely regarded as lipids may be almost as soluble in water as in organic solvents. Lipids are fatty acids and their derivatives, and substances related biosynthetically or functionally to these compounds. This treats cholesterol (and plant sterols) as a lipid, and could be interpreted to include bile acids, tocopherols and certain other compounds. It also enables classification of such compounds as gangliosides as lipids, although they are more soluble in water than in organic solvents. However, it does not include such natural substances as steroidal hormones, petroleum This ebook is exclusively for this university only. Cannot be resold/distributed. products, some fat-soluble vitamins, carotenoids or terpenes, except in rare circumstances. If “lipids” are defined in this way, fatty acids must be defined also.
eBook - PDF- Jose Perez-Castineira(Author)
- 2020(Publication Date)
- De Gruyter(Publisher)
The importance of the different roles played by lipids in vivo led biochemists to launch the LIPID MAPS (“LIPID Metabolites and Pathways Strategies”) initiative in 2002 that set off the development of lipidomics. Lipidomics aims at the identification, characterization, and quantification of the lipidome, that is, the entire spectrum of lipids and derived metabolites in a biological system [4, 6]. In 2005, an updated defi- nition as well as a comprehensive classification of these molecules was introduced based on their biochemical properties. Lipids were defined as “hydrophobic or am- phipathic small molecules that may originate entirely or in part by carbanion-based condensations of thioesters and/or by carbocation-based condensation of isoprene units” [7]. Additionally, the term simple lipids was proposed for those that yield up to two types of products upon hydrolysis (e.g. fatty acids, sterols, and acylglycerols), and complex lipids for those yielding three or more products (e.g. glycerophoshopilids and glycosphingolipids). Naturally occurring lipids were classified into eight categories that cover eukaryotic and prokaryotic sources (Table 4.1, Figure 4.1), each category being subdivided into classes and subclasses. The LIPID MAPS initiative also proposed an appropriate nomenclature as well as guidelines for drawing the structures of these bio- molecules [7, 8]. Another commonly accepted definition describes simple lipids as Table 4.1: Comprehensive lipid classification for lipidomics. Category Abbreviation Example Fatty acids FA Hexadecanoic acid Glycerolipids GL -hexadecanoyl--(Z-octadecenoyl)-sn-glycerol Glycerophospholipids GP -hexadecanoyl--(Z-octadecenoyl)-sn-glycero-- phosphocholine Sphingolipids SP N-(hexadecanoyl)-sphing--enine--phosphocholine Sterol lipids ST Cholest--en-β-ol Prenol lipids PR E,E-farnesol Saccharolipids SL -tetradecanoyl--dodecyl--O-β-D-galactosyl-sn-glycerol Polyketides PK Aflatoxin B Source [7, 8]. 80 4 Lipids
eBook - PDF- Rodrigo Valenzuela Baez(Author)
- 2013(Publication Date)
- IntechOpen(Publisher)
Conclusions Lipids are a large and wide group of molecules that are present in all living organism and also in foods and characterized by particular physicochemical properties, such as their non polarity and their solubility in organic solvents. Some lipids, in particular fatty acids and sterols, are essential for animal and plant life. Lipids are key elements in the structure, biochemistry, physiology, and nutritional status of an individual, because are involved in: i) the cellular structure; ii) the cellular energy reserve, iii) the formation of regulatory metabolites, and; iv) in the regulation and gene expression, which directly affects the functioning of the body. Another important aspect related to lipids is their important involvement, either in the treatment and/or the origin of many diseases which can affect humans. Structural and functional characteristics of lipids, discussed in this chapter, will allow you to integrate those metabolic aspects of these important and essential molecules in close relationship of how foods containing these molecules can have a relevant influence in the health or illness of an individual. Author details Rodrigo Valenzuela B. Nutrition and Dietetics School, Faculty of Medicine, University of Chile, Santiago Chile Alfonso Valenzuela B. Lipid Center, Nutrition and Food Technology Institute, University of Chile, Faculty of Medicine, University of Los Andes, Santiago Chile Acknowledgement The authors are grateful from FONDECYT, FONDEF and INNOVA-Chile the support of their research. Overview About Lipid Structure 17 10. References [1] Carpenter K. (1998). Early ideas on the nutritional significance of lipids, J. Nutr . 128, 423S-426S. [2] Oreši č M. (2009). Metabolomics, a novel tool for studies of nutrition, metabolism and lipid dysfunction. Nutrition, Metabolism and Cardiovascular Diseases , Vol 19, pp. 816-24. [3] Burlingame B, Nishida C, Uauy R. et al. (2009).
eBook - PDFAdvanced Chemical Biology
Chemical Dissection and Reprogramming of Biological Systems
- Howard C. Hang, Matthew R. Pratt, Jennifer A. Prescher, Howard C. Hang, Matthew R. Pratt, Jennifer A. Prescher(Authors)
- 2023(Publication Date)
- Wiley-VCH(Publisher)
243 11 Chemical Biology of Lipids Scotland Farley, Alix Thomas, Aurélien Laguerre, and Carsten Schultz Oregon Health and Science University, Department of Chemical Physiology and Biochemistry, 3181 SW Sam Jackson Park Road, L334, Portland, OR 97239, USA 11.1 Introduction Of the four classes of biomolecule that make up every cell – proteins, nucleic acids, carbohydrates, and lipids – lipids, for most of the time we have known about them, have been relegated to an inert, structural role. Slowly, it became understood that the “lipid bilayer” is far from a uniform or constant structure, characterized by tens of thousands of individual lipid species, myriad different conformations within and around the cell, and multiple complex biophysical phases, all of which interface with each other and the biomolecules around them to facilitate cellular processes. Even more recently, another layer of lipid function has emerged, as we have come to understand that lipids, in addition to their crit- ical structural functions, also have important signaling roles both intracellularly and extracellularly [1–4]. For instance, the highly phosphorylated lipid phosphatidyli- nositol 4,5-bisphosphate (PIP 2 ) is a crucial cofactor of many ion channels and other transmembrane proteins [5]. Add another phosphate and you have the signaling lipid phosphatidylinositol 3,4,5-trisphosphate (PIP 3 ), a rare and transiently formed species that transmits growth factor receptor signals by recruiting kinases to the plasma membrane [6]. Extracellularly abundant lipids such as lysophosphatidic acid (LPA) activate G-protein-coupled receptors on cell surfaces to induce diverse effects such as cytoskeleton reorganization, cell migration, proliferation, survival, and cell–cell com- munication [7]. Lipids are involved in many diseases including atherosclerosis and genetically transmitted lipid storage diseases such as Niemann–Pick C (NPC) with often dramatic outcomes for the patients.
eBook - PDF- Papita H Gourkhede(Author)
- 2023(Publication Date)
- Arcler Press(Publisher)
BIOCHEMISTRY OF LIPIDS CHAPTER8 CONTENTS 8.1. Introduction .................................................................................... 214 8.2. Diversity in Lipid Structure ............................................................. 217 8.3. Properties of Lipids In Solution ....................................................... 219 8.4. Engineering of Membrane Lipid Composition ................................. 223 8.5. Role of Lipids in Cell Function ........................................................ 227 8.6. Lipid Metabolism in Plants.............................................................. 237 8.7. Plant Lipid Geography .................................................................... 238 8.8. Future Directions of Lipids .............................................................. 239 8.9. Conclusion ..................................................................................... 241 References ............................................................................................. 242 Biochemistry and its Application 214 Including fats, oils, hormones, and certain components of membranes that are grouped together, lipids, are a diverse group of organic compounds because they do not interact appreciably with water. As fat in adipose cells, one type of lipid, the triglycerides provides thermal insulation and serves as the energy-storage depot for organisms. Between cells, tissues, and organs, some lipids such as steroid hormones serve as chemical messengers and others between biochemical systems within a single cell communicate signals. The membranes of cells and organelles (structures within cells) are microscopically thin structures formed from two layers of phospholipid molecules. 8.1. INTRODUCTION To separate individual cells from their environments and to compartmentalize the cell interior into structures, membranes function to carry out special functions.
eBook - PDFAdvanced Nutrition
Macronutrients, Micronutrients, and Metabolism, Second Edition
- Carolyn D. Berdanier, Lynnette A. Berdanier(Authors)
- 2015(Publication Date)
- CRC Press(Publisher)
261 10 Lipids The third macronutrient group consists of lipids. They are energetically more dense than carbo-hydrates having more than twice the energy value of carbohydrate per gram. Americans consume approximately 32%–42% of their total energy intake as lipid. Lipids make up a group of compounds that are, in general, insoluble in water and soluble in nonaqueous solvents. They are present in varying amounts in all living cells. Nerve cells and adipose cells are rich in lipid; muscle cells and epithelial cells have less. In addition to being a very important source of energy, lipids serve a variety of other needs. They perform a basic role in the structure and function of biological membranes. In the body, they are the precursors of a variety of hormones and also act as some important cell signals. CLASSIFICATION Lipids are relatively soluble in such solvents as ether, chloroform, benzene, and some alcohols. Additionally, some lipids are saponifiable; others are not. Saponifiable lipids, when treated with alkali, undergo hydrolysis at the ester linkage, resulting in the formation of an alcohol and a soap (fatty acids combined with hydroxide). Triacylglycerol (TG) (triglyceride), for example, when treated with sodium hydroxide, is hydrolyzed yielding a mixture of soaps and free glyc-erol. Traditionally, saponifiable lipids have been classified into three groups (A, B, C), each with subgroups. A. Simple lipids: esters of fatty acids with various alcohols 1. Fats: esters of fatty acids with glycerol (acylglycerols) 2. Waxes: esters of fatty acids with long chain alcohols 3. Cholesterol esters B. Compound lipids: esters of fatty acids that contain substituent groups in addition to fatty acids and alcohol 1. Phospholipids: esters of fatty acids, alcohol, a phosphoric acid residue, and usually an amino alcohol, sugar, or other substituent 2. Glycolipids: esters of fatty acids that contain carbohydrates and nitrogen (but not phos-phoric acid).
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