50
4.1 Introduction
Lipids comprise a very diverse group of compounds that not only forms the membrane bilayer but also plays multiple critical roles in cellular functions. They provide hydrophobic environment for membrane protein functions and interactions,
and fatty acids and triglycerides serve as energy reservoirs. They also play prominent roles in the regulation of cellular bioenergetics through integrating oxidative
metabolism (Michalik et al. 2006), modulating systemic energy balance through
eicosanoid and lysolipid production (Vegiopoulos et al. 2010), and regulating mitochondrial electron transport chain flux and coupling efficiency (Breen et al. 2005).
Moreover, many classes of lipids such as eicosanoids, lysolipids, diacylglycerols,
phosphatidic acids, and ceramides serve as secondary messengers in cellular signaling pathways (Gross and Han 2011).
Lipids are defined as amphiphilic biological substances consisting of fatty acids
and their derivatives and the substances that are biosynthetically or functionally
related to these compounds (Christie 1993). Lipid molecules exhibit high structural
diversity due to variable chain length; a multitude of oxidative, reductive, substituContents
4.1 Introduction ........................................................................................................................ 50
4.2 Seaweed Lipids .................................................................................................................. 52
4.2.1 Glycerophospholipids ............................................................................................ 52
4.2.2 Saccharolipids ........................................................................................................ 54
4.2.3 Glycerolipids .......................................................................................................... 55
4.2.4 Betaine Lipids ........................................................................................................ 55
4.2.5 Sphingolipids ......................................................................................................... 56
4.2.6 Fatty Acyls ............................................................................................................. 56
4.2.7 Sterols .................................................................................................................... 59
4.3 Seaweed Lipidomics: An Update ....................................................................................... 60
4.4 Tools and Techniques in Seaweed Lipidomics .................................................................. 61
4.4.1 Sampling and Lipid Extraction .............................................................................. 61
4.4.2 Analytical Platforms for Lipidomics ...................................................................... 63
4.4.3 Lipidomic Data Analysis ....................................................................................... 66
4.5 Application of Lipidomics to the Seaweed Systems Biology ............................................ 76
4.5.1 Elucidation of Lipidomic Profiling and Identification of Novel Lipids ................ 80
4.5.2 Lipidomic Changes in Seaweed Acclimation Strategies
to Abiotic/Biotic Stress ........................................................................................... 83
4.6 Integration of Lipidomics with Allied Omics Platforms ................................................... 85
4.7 Conclusion ......................................................................................................................... 89
References ................................................................................................................................... 90
P. Kumari
4.1 Introduction
Lipids comprise a very diverse group of compounds that not only forms the membrane bilayer but also plays multiple critical roles in cellular functions. They provide hydrophobic environment for membrane protein functions and interactions,
and fatty acids and triglycerides serve as energy reservoirs. They also play prominent roles in the regulation of cellular bioenergetics through integrating oxidative
metabolism (Michalik et al. 2006), modulating systemic energy balance through
eicosanoid and lysolipid production (Vegiopoulos et al. 2010), and regulating mitochondrial electron transport chain flux and coupling efficiency (Breen et al. 2005).
Moreover, many classes of lipids such as eicosanoids, lysolipids, diacylglycerols,
phosphatidic acids, and ceramides serve as secondary messengers in cellular signaling pathways (Gross and Han 2011).
Lipids are defined as amphiphilic biological substances consisting of fatty acids
and their derivatives and the substances that are biosynthetically or functionally
related to these compounds (Christie 1993). Lipid molecules exhibit high structural
diversity due to variable chain length; a multitude of oxidative, reductive, substituContents
4.1 Introduction ........................................................................................................................ 50
4.2 Seaweed Lipids .................................................................................................................. 52
4.2.1 Glycerophospholipids ............................................................................................ 52
4.2.2 Saccharolipids ........................................................................................................ 54
4.2.3 Glycerolipids .......................................................................................................... 55
4.2.4 Betaine Lipids ........................................................................................................ 55
4.2.5 Sphingolipids ......................................................................................................... 56
4.2.6 Fatty Acyls ............................................................................................................. 56
4.2.7 Sterols .................................................................................................................... 59
4.3 Seaweed Lipidomics: An Update ....................................................................................... 60
4.4 Tools and Techniques in Seaweed Lipidomics .................................................................. 61
4.4.1 Sampling and Lipid Extraction .............................................................................. 61
4.4.2 Analytical Platforms for Lipidomics ...................................................................... 63
4.4.3 Lipidomic Data Analysis ....................................................................................... 66
4.5 Application of Lipidomics to the Seaweed Systems Biology ............................................ 76
4.5.1 Elucidation of Lipidomic Profiling and Identification of Novel Lipids ................ 80
4.5.2 Lipidomic Changes in Seaweed Acclimation Strategies
to Abiotic/Biotic Stress ........................................................................................... 83
4.6 Integration of Lipidomics with Allied Omics Platforms ................................................... 85
4.7 Conclusion ......................................................................................................................... 89
References ................................................................................................................................... 90
P. Kumari