Vitamin A and Carotenoids

Chemistry, Analysis, Function and Effects

By Victor R. Preedy

The Royal Society of Chemistry

Copyright © 2012 The Royal Society of Chemistry
All rights reserved.
ISBN: 978-1-84973-368-7

Contents

Vitamin A and Carotenoids in Context,
Chapter 1 Retinol, Retinoic Acid, Carotenes and Carotenoids: Vitamin A Structure and Terminology Gerald Wollard, 3,
Chapter 2 Vitamin A in the Context of Other Vitamins and Minerals Jennifer H. Lin and Kuang-Yu Liu, 23,
Chapter 3 The Importance of β-Carotene in the Context of Vitamin A Hans K. Biesalski and Donatus Nohr, 39,
Chapter 4 Vitamin A in the Context of Supplementation Frank T. Wieringa, Marjoleine A. Dijkhuizen and Jacques Berger, 55,
Chemistry and Biochemistry,
Chapter 5 The Chemistry of Vitamin A Alessandra Gentili, 73,
Chapter 6 Nomenclature of Vitamin A and Related Metabolites Niketa A. Patel, 90,
Analysis,
Chapter 7 Structural Analysis of Vitamin A Complexes with DNA and RNA H. A. Tajmir-Riahi and P. Bourassa, 97,
Chapter 8 Encapsulation of Vitamin A: A Current Review on Technologies and Applications Beatrice Albertini, Marcello Di Sabatino and Nadia Passerini, 113,
Chapter 9 Thermal Degradation of β-Carotene in Food Oils Alam Zeb, 129,
Chapter 10 Provitamin A Carotenoids: Occurrence, Intake and Bioavailability Torsten Bohn, 142,
Chapter 11 Vitamin A – Serum Vitamin A Analysis Ronda F. Greaves, 162,
Chapter 12 Liquid Chromatography-based Assay for Carotenoids in Human Blood Taiki Miyazawa, Kiyotaka Nakagawa and Teruo Miyazawa, 184,
Chapter 13 Capillary Liquid Chromatographic Analysis of Fat-soluble Vitamins and β-Carotene Sheng Zhang and Li Jia, 204,
Chapter 14 Assay of Carotenoid Composition and Retinol Equivalents in Plants Sangeetha Ravi Kumar and V. Baskaran, 221,
Chapter 15 LC-NMR for the Analysis of Carotenoids in Foods Chisato Tode and Makiko Sugiura, 250,
Chapter 16 LC-DAD-tandem MS Analysis of Retinoids and Carotenoids: Applications to Bovine Milk Alessandra Gentili and Fulvia Caretti, 261,
Chapter 17 HPLC-DAD-MS (ESI+) Determination of Carotenoids in Fruit Pasquale Crupi, Victor R. Preedy and Donato Antonacci, 282,
Chapter 18 Thin-layer Chromatographic Analysis of Pro-vitamin A Carotenoids Alam Zeb, 303,
Chapter 19 Extraction of Carotenoids from Plants: a Focus on Carotenoids with Vitamin A Activity Anita Oberholster, 316,
Chapter 20 Quantification of Carotenoids, Retinol, and Tocopherols in Milk and Dairy Products Beatrice Duriot and Benoit Graulet, 332,
Chapter 21 Simultaneous Ultra-high-performance Liquid Chromatography for the Determination of Vitamin A and Other Fat-soluble Vitamins to Assess Nutritional Status Fernando Granado-Lorencio, Inmaculada Blanco-Navarro and Belén Pérez-Sacristán,
Function and Effects,
Chapter 22 Distribution and Concentrations of Vitamin A and their Metabolites in Human Tissue Ewa Czeczuga-Semeniuk, Janusz W. Semeniuk and Adrianna Semeniuk, 381,
Chapter 23 Vitamin A Deficiency: An Overview Teresa Barber, Guillermo Esteban-Pretel, Maria Pilar Marín and Joaquín Timoneda, 396,
Chapter 24 Retinoic Acid Receptors and their Modulators: Structural and Functional Insights Albane le Maire, William Bourguet, Hinrich Gronemeyer and Angel R. de Lera, 417,
Chapter 25 Retinoic Acid in Development Don Cameron, Tracie Pennimpede and Martin Petkovich, 438,
Chapter 26 Retinol/Vitamin A Signaling and Self-renewal of Embryonic Stem Cells Jaspal S. Khillan, Himanshu Bhatia and Liguo Chen, 457,
Chapter 27 Retinoic Acids and their Biological Functions Joseph L. Napoli, 470,
Chapter 28 Vitamin A and Cancer Risk Siddhartha Kumar Mishra and Mi Kyung Kim, 485,
Chapter 29 Vitamin A and Immune Function Charles B. Stephensen, 501,
Chapter 30 Vitamin A and Brain Function Christopher R. Olson and Claudio. V. Mello, 516,
Chapter 31 The Importance of Vitamin A during Prgenancy and Childhood: Impact on Lung Function Hans K. Biesalski and Donatus Nohr, 532,
Subject Index, 555,

CHAPTER 1

Retinol, Retinoic Acid, Carotenes and Carotenoids: Vitamin A Structure and Terminology

GERALD WOOLLARD

Department of Chemical Pathology, Lab Plus, Auckland City Hospital, Auckland, New Zealand

E-mail: geraldw@adhb.govt.nz

1.1 Introductory Remarks

The fact that the terminology vitamin A is used colloquially in everyday conversations and in commercial products within the cosmetic industry tends to belie the fascinating nature of this compound and to understate the importance of retinol (and the carotenoids) in the biological world. There can hardly be a more intriguing set of compounds which are intrinsically related to so many fundamental biological processes. Any discussions concerning the structure of vitamin A are never complete without due regard to the carotenoids themselves.

To discuss the chemical and biochemical behavior of vitamin A and the carotenoids takes the reader on a journey from fundamental photosynthetic processes in plants and into the realm of human nutrition and pathology. Vitamin A is born out of these plant-derived products and transposed into a set of animal compounds which have their own specific carrier proteins [retinol-binding protein (RBP)] and nuclear receptors [retinoic acid receptor (RAR)]. This notion in itself is remarkable and models the idea of the interdependence of the natural world. The evolutionary process leading to retinoid/carotenoid biological complicity can be bewildering to consider in that parallel chemistries can be used by unrelated species for unrelated purposes.

1.2 Structure and Function of Carotenoids

It is instructive to consider briefly what carotenoids are and how their intended function dictates their structure. It gives an appreciation of their general chemical structure and what characteristics are essential. An example of a very familiar carotenoid, β-carotene is shown in Figure 1.1. A cursory glance at its basic structure shows the obvious feature of a long conjugated central chain with two rings (identical in β-carotene) at each end.

1.2.1 Central Carotenoid Chain

β-carotene represents a convenient prototype carotenoid to assist with the appreciation of carotenoid structure. It is ubiquitous in the natural plant and animal world, physiologically and nutritionally important in itself and as a precursor carotenoid for the production of other compounds. The general properties of carotenoids can be discussed by consideration of β-carotene.

1. The conjugated polyene structure is paramount to carotenoid function because the electrons in the double bonds are delocalized and have a lower ground energy state. This allows visible light to be absorbed.

2. Carotenoids act as chromophores with high extinction coefficients. They confer colour to fruit or flowers to attract birds and insects (for seed propagation) or by the birds themselves to enhance dichromatic behavior between the genders. Animals may modify this basic structure to extend the chromophore to make other carotenoids such as astaxanthin, the intense red pigment evident in salmon.

3. The ability to absorb light is at the very heart of the photosynthetic apparatus. The process is enormously complicated and will be discussed in detail later in this book. Basically, β-carotene itself or the other two important photosynthetic carotenoids lutein and...