Biobased Surfactants

Synthesis, Properties, and Applications

Douglas G. Hayes, Daniel K. Solaiman, Richard D. Ashby

• Publisher: Academic Press and AOCS Press
• Year: 2019
• Print ISBN: 9780128127056
• eBook ISBN: 9780128127063
• Edition: 2
• Topic: Physical Sciences
• Subtopic: Organic Chemistry

Biobased Surfactants: Synthesis, Properties, and Applications, Second Edition, covers biosurfactant synthesis and applications and demonstrates how to reduce manufacturing and purification costs, impurities, and by-products. Fully updated, this book covers surfactants in biomedical applications, detergents, personal care, food, pharmaceuticals, cosmetics, and nanotechnology. It reflects on the latest developments in biobased surfactant science and provides case scenarios to guide readers in efficient and effective biobased surfactant application, along with strategies for research into new applications.This book is written from a biorefinery-based perspective by an international team of experts and acts as a key text for researchers and practitioners involved in the synthesis, utilization, and development of biobased surfactants.- Describes new and emerging biobased surfactants and their synthesis and development- Showcases an interdisciplinary approach to the topic, featuring applications to chemistry, biotechnology, biomedicine, and other areas- Presents the entire lifecycle of biobased surfactants in detail

Section III

Biobased Surfactants

Chapter 7

Phospholipid-Based Surfactants

Jingbo Li^⁎,†; Yongjin He^⁎,‡; Sampson Anankanbil^⁎; Zheng Guo^{⁎ ⁎} Department of Engineering, Faculty of Science and Technology, Aarhus University, Aarhus, Denmark
^† Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
^‡ College of Life Science, Fujian Normal University, Fuzhou, China

Abstract

In this chapter, in addition to a summary of updated understanding and progresses for biosynthesis (pathway), biological functions, and physicochemical properties of phospholipids (PLs), we review latest progresses in separation, analysis and characterization of PLs, strategy for chemo- or enzymatic modifications of PLs, particularly in the synthesis of lyso-PLs and structured PLs. Intensive discussion is given to the design and synthesis of functional PLs such as new phenophospholipids and applications of PLs as surfactants in different industrial sectors, such as food, pharma, and cosmetics.

Keywords

Phospholipids; Glycerophospholipids; Surfactants; Lecithin; Biosynthesis; Lipase; Deoil; Structured phospholipids; Lysophospholipids; Phosphatidylcholine (PC); Phospholipase A1; A2; C; D; Phenophospholipids

Acknowledgments

Jingbo Li would like to thank the International Postdoctoral Grant from Independent Research Fund Denmark (7026-00039B) for financial support.

7.1 Introduction

Phospholipids (PLs, also refer to glycerophospholipids) are a subclass of lipids that generally consist of a glycerol backbone with I,2-positions connected to two fatty acyl groups via ester bonds. The third glycerol position is connected to a phosphate group. The phosphate group bears two ester bonds to glycerol backbone and a polar head group, such as choline, ethanolamine, inositol, serine, and glycerol. The polar head groups correspond to the subspecies of PLs: phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylserine (PS), and phosphatidylglycerol (PG), respectively. Structurally, all PLs are amphiphilic molecules, serving as the molecular basis for their biological functions and as emulsifiers in food, cosmetic, or drug products.

The fundamental biological function of PLs is to form cellular membranes and act as a barrier for entry of compounds into cells. PLs also function as precursors of second messengers such as diacylglycerol (DG) and inositol-1,4,5-P₃ (inositol trisphosphate). A third, and usually overlooked, function of PLs is the storage of energy in the form of fatty acyl components (Vance and Vance, 2008). Other specific functions are associated with specific organs and involve unique molecular species of PLs. Pulmonary surfactant PLs are essential for life. They are composed of a complex lipoprotein-like mixture that lines the inner surface of the lung to prevent alveolar collapse at the end of expiration (Agassandian and Mallampalli, 2013). PS is a component of the lipid‑calcium-phosphate complex for deposition during bone formation (Merolli and Santin, 2009), regulation of apoptosis (programmed cell death) (Devitt et al., 2003), and blood coagulation (Lentz, 2003). A better understanding of the biological functions in the human body not only helps us to know the role and mechanism of PLs to maintain structure and function but also facilitates the development of ingredients or drug excipients of phospholipid analogues for better health or to address dysfunction or diseases occurring in tissues or organs.

In 1956, using rat liver as an enzyme source, Kennedy and Weiss (1956) elucidated a pathway for the de novo biosynthesis of PE and PC. The PE and PC branches of this “Kennedy” pathway are based upon the formation of characteristic high-energy intermediates: cytidine diphosphate (CDP)-ethanolamine, for the synthesis of PE, and CDP-choline, for the synthesis of PC (Gibellini and Smith, 2010). After the Kennedy and Weiss study, a few researches shed some light on the importance and regulation of individual pathways, but progress in biochemical and molecular analysis was slow. Many enzymes in these pathways are membrane- associated and therefore difficult to purify, and kinetic analysis of reactions with insoluble substrates and products was not straightforward (Kent, 1995). However, with the advances in gene analysis, expression, and purification of protein and structural analysis of enzymes, the biosynthesis pathways of PLs are much more clear, and the branching pathways for biosynthesis of specific phospholipid species have been deciphered (Lykidis, 2007).

With respect to PLs, the food engineers and application scientists have different contents from biologists or pharmaceutical researchers, which generally refer to “lecithins.” The word “lecithin” comes from the Greek “λέκιθος,” meaning “egg, the start of life.” Nowadays, lecithins often refer to “a complex mixture of acetone-insoluble phosphatides, which consist chiefly of PC, PE, PS, and PI, combined with various amounts of other substances such as triglycerides, fatty acids, and carbohydrates as isolated from a crude vegetable oil source. It contains > 50% of acetone-insoluble matter” (van Hoogevest and Wendel, 2014). Soybean, sunflower, and rapeseed are the major sources of vegetable lecithins. In general, PLs are excellent surface-active amphiphilic molecules, which are widely used as emulsifier, wetting agent, solubilizer, and as the major compone...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• Introduction
• Section I: Introduction, Importance, and Relevance of Biobased Surfactants
• Section II: Biosurfactants: Biosynthesis and Applications
• Section III: Biobased Surfactants
• Glossary
• Index