The biochemistry of natural pigments G. BRITTON UNiVERSITATSilBLIOTHEK CAMBRIDGE UNIVERSITY PRESS Cambridge London New York New Rochelle Melbourne Sydney
Contents 1 2 Preface Section I. Chemical and biochemical aspects Light and colour 1.1 Introduction.2 Colour and colour perception. Colour in living organisms.4 Light absorption.5 Spectroscopic methods in natural pigment research.6 The significance of colour in Nature 1.7 Conclusions and comments 1.8 Suggested further reading 1.9 Selected bibliography Carotenoids 2.1 Introduction 2.2 Structures and nomenclature 2. Properties 2.4 Distribution 2.5 Carotenoproteins 2.6 Biosynthesis 2.7 Regulation and control of biosynthesis 2.8 Metabolism of carotenoids by animals 2.9 Functions of carotenoids 2.10 Carotenoids as food colorants 2.11 Medical uses of carotenoids 2.12 Other polyene pigments 2.1 Conclusions and comments 2.14 Suggested further reading 2.15 Selected bibliography Quinones.1 Introduction.2 Structures ix 4 6 8 15 19 20 20 22 2 2 2 1 9 45 46 6 66 67 68 68 69 70 71 72
vi Contents. Properties 76.4 Occurrence and distribution 79.5 Contribution to colour 85.6 Biosynthesis 85.7 Functions and biological effects 97.8 Industrial and medicinal uses 99.9 Conclusions and comments 100.10 Suggested further reading 101.11 Selected bibliography 101 O-Heterocyclic pigments - the flavonoids 102 4.1 Introduction 102 4.2 Structures and nomenclature 102 4. Properties 107 4.4 Distribution 112 4.5 Contribution to plant colours 11 4.6 Biosynthesis 115 4.7 Metabolism of flavonoids by animals 125 4.8 Microbial degradation of flavonoids 125 4.9 Functions of flavonoids in plants 125 4.10 Use of anthocyanins as food colorants 126 4.11 Conclusions and comments 127 4.12 Suggested further reading 128 4.1 Selected bibliography 128 Tetrapyrroles 10 5.1 Introduction 10 5.2 General structural features 10 5. General light-absorption properties 12 5.4 Chlorophylls 1 5.5 Haem and haemoproteins 140 5.6 Free porphyrins in animals 152 5.7 Vitamin Bij 154 5.8 Linear tetrapyrroles-bilins 155 5.9 Biosynthesis and metabolism of tetrapyrroles 16 5.10 Disorders of porphyrin metabolism 18 5.11 Functions of tetrapyrrole pigments 184 5.12 Conclusions and comments 185 5.1 Suggested further reading 186 5.14 Selected bibliography 187 Other non-polymeric 7V-heterocyclic pigments 189 6.1 Introduction 189 6.2 Purines, pterins and flavins 189 6. Phenazines 204
Contents vu 6.4 Phenoxazines 6.5 Betalains 6.6 MiscellaneousN-heterocyclic pigments 6.7 Conclusions and comments 6.8 Suggested further reading 6.9 Selected bibliography Melanins 7.1 Introduction 7.2 Chemistry 7. Distribution 7.4 Biosynthesis 7.5 Factors affecting melanogenesis 7.6 Functions 7.7 Conclusions and comments 7.8 Suggested further reading 7.9 Selected bibliography 209 21 217 219 219 220 229 20 25 28 28 28 29 10 Section II. Functional aspects The importance of colour in Nature 8.1 Introduction 8.2 Colour and pattern in animals 8. Animal pigment cells - chromatophores 8.4 Animal colour changes 8.5 Colour in plants 8.6 Conclusions and comments 8.7 Suggested further reading 8.8 Selected bibliography Pigments in vision 9.1 Introduction 9.2 The eye ; 9. Visual pigments 9.4 Functioning of the visual pigments - the visual cycles 9.5 Some aspects of colour vision 9.6 Accessory pigments in vision 9.7 Conclusions and comments 9.8 Suggested further reading 9.9 Selected bibliography 24 24 244 245 248 252 254 255 255 262 268 276 277 281 281 282 Photosynthesis 28 10.1 Introduction 28 10.2 The photosynthetic apparatus of eukaryotes: the chloroplast 284
viii 11 Contents 10. Plant photosynthesis - a general outline 288 10.4 Light harvesting-the primary process of 289 photosynthesis 10.5 Secondary events -the photo synthetic electron 296 transport system 10.6 The dark reactions 00 10.7 Photosynthesis in eukaryotic algae 01 10.8 Photosynthesis in the prokaryotic blue-green algae 06 10.9 Bacterial photosynthesis 07 10.10 Pigment synthesis in relation to chloroplast 10 development 10.11 Development of the photosynthetic apparatus of 14 photosynthetic bacteria 10.12 Fate of photosynthetic pigments during chloroplast 15 degeneration 10.1 Conclusions and comments 10.14 Suggested further reading 10.15 Selected bibliography Other photofunctions of natural pigments 11.1 Introduction 11.2 Phytochrome 11. Phototaxis 11.4 Phototropism 11.5 Bacteriorhodopsin 11.6 Extra-ocular and extra-retinal photoreceptors in animals 11.7 Photoprotection 11.8 Bioluminescence 11.9 Conclusions and comments 11.10 Suggested further reading 11.11 Selected bibliography Problems Answers Index 16 17 17 19 19 19 2 24 25 27 0 6 7 8 40 48 55