Recent Advances in Polyphenol Research

Plant polyphenols are secondary metabolites that constitute one of the most common and widespread groups of natural products. They are crucial constituents of a large and diverse range of biological functions and processes, and provide many benefits to both plants and humans. Many polyphenols, from their structurally simplest representatives to their oligo/polymeric versions, are notably known as phytoestrogens, plant pigments, potent antioxidants, and protein interacting agents.

This sixth volume of the highly regarded Recent Advances in Polyphenol Research series is edited by Heidi Halbwirth, Karl Stich, Véronique Cheynier and Stéphane Quideau, and is a continuance of the series' tradition of compiling a cornucopia of cutting-edge chapters, written by some of the leading experts in their respective fields of polyphenol sciences. Highlighted herein are some of the most recent and pertinent developments in polyphenol research, covering such major areas as:

• Chemistry and physicochemistry

• Biosynthesis, genetics & metabolic engineering

• Roles in plants and ecosystems

• Food, nutrition & health

• Applied polyphenols

This book is a distillation of the most current information, and as such, will surely prove an invaluable source for chemists, biochemists, plant scientists, pharmacognosists and pharmacologists, biologists, ecologists, food scientists and nutritionists.

Auteur

About the Editors Heidi Halbwirth is Associate Professor at Technische Universität Wien in Vienna, Austria. Her research activities have concentrated on plant secondary metabolism in horticulturally relevant plants with a strong focus on the enzymes involved and their structure-function relationships. Her particular research passion is flower colour, which allows the study of fundamental aspects of plant biochemistry and physiology. Karl Stich is Professor at Technische Universität Wien in Vienna, Austria. His field of expertise is the biochemistry of plants, and applied biochemistry in the field of plant protection with a strong focus on the secondary metabolism of plants. He is a longstanding member of Groupe Polyphenols and was awarded the 11th GP Medal for his scientific contributions to the elucidation of the flavonoid pathway. Véronique Cheynier, former president of the " Groupe Polyphénols " (2012-2016), is research director at the French National Institute for Agricultural Research (INRA) in Montpellier, France. Her research interests concern the study of the structure of polyphenolic compounds, notably vegetable tannins and anthocyanin pigments, their reactions during plant transformation processes, and their influence on the quality of foods and beverages, especially wine. Stéphane Quideau, former president of the " Groupe Polyphénols " (2008-2012), is full professor of Organic and Bioorganic Chemistry at the University of Bordeaux, France. His research laboratory is specialized in plant polyphenol chemistry and chemical biology, with a focus on the studies of ellagitannin chemical reactivity and synthesis, and interactions of bioactive polyphenols with their protein targets.

Contenu
Contributors xiii

Preface xvii

Acknowledgements xxi

1 The Lignans: A Family of Biologically Active Polyphenolic Secondary Metabolites 1
*Anna K.F. Albertson and JeanPhilip Lumb*

1.1 Introduction 1

1.2 Biosynthesis of Lignans 3

1.3 Synthetic Approaches to Lignans and Derivatives 7

1.4 Conclusion 60

References 65

2 Anthocyanin Accumulation is Controlled by Layers of Repression 71
*Andrew C. Allan, Kathy E. Schwinn, and Richard V. Espley*

2.1 Introduction 71

2.2 MYBs and bHLHs Directly Activate Anthocyanin Production 72

2.3 Exciting Phenotypes in Horticulture are often caused by Variations in the Expression of Key MYBs 73

2.4 Is There a Cost to the Plant of over accumulation of Anthocyanins? 74

2.5 Controlling Anthocyanin Levels 75

2.6 The MYB Activator is Degraded at Night 76

2.7 MYB Activator Competes with MYB Repressors 77

2.8 miRNA Targeted Degradation of MYB Transcript 78

2.9 Turnover of Anthocyanin Vacuolar Content by Peroxidases 78

2.10 Summary 79

References 79

3 The Subtleties of Subcellular Distribution: Pointing the Way to Underexplored Functions for Flavonoid Enzymes and End Products 89
*Brenda S.J. Winkel*

3.1 Multienzyme Complexes and Metabolic Networks 89

3.2 New Insights from Global Surveys of Protein Interactions 90

3.3 The Flavonoid Metabolon 91

3.4 Subcellular Distribution of Flavonoid Enzymes and Evidence for Alternative Metabolons 94

3.5 Posttranslational Modifications An Underexplored Area of Flavonoid Metabolism 98

3.6 Why Do We Need to Know? 99

3.7 Future Prospects 99

References 100

4 Transcriptional and Metabolite Profiling Analyses Uncover Novel Genes Essential for Polyphenol Accumulation 109
*Wilfried Schwab, Ludwig Ring, and Chuankui Song*

4.1 Introduction 109

4.2 Transcriptional and Metabolite Profiling Analyses in Strawberry Fruit 110

4.3 Characterization of Peroxidase 27 113

4.4 Competition of the Lignin and Flavonoid/Anthocyanin Pathways as Demonstrated by the Activity of Peroxidase 27 115

4.5 Candidate Genes Putatively Correlated with Phenolics Accumulation in Strawberry Fruit 115

4.6 Acylphloroglucinol Biosynthesis in Strawberry Fruit 118

4.7 Glucosylation of Acylphloroglucinols 120

4.8 Conclusion

References 124

5 Dietary (Poly)Phenols and Vascular Health 127
*Christine Morand, Nicolas BarberChamoux, LaurentEmmanuel Monfoulet, and Dragan Milenkovic*

5.1 Introduction 127

5.2 Vascular Health: A Prerequisite to Prevent Cardiometabolic Diseases and Cognitive Decline 128

5.3 Diet and Vascular Health 130

5.4 (Poly)Phenols: A Major Family of Dietary Plant Bioactive Compounds 131

5.5 Fate of (Poly)Phenols in the Body and Biological Activities 133

5.6 Nutritional Effects of Flavonoids in Protecting Cardiovascular Health 135

5.7 Limitation of Knowledge and Strategy for Research 138

5.8 Findings from Translational Research on Citrus Flavanones and Vascular Health 139

5.9 Conclusion 142

References 142

6 CellularSpecific Detection of Polyphenolic Compounds by NMRand MSBased Techniques: Application to the Representative Polycyclic Aromatics of Members of the Hypericaceae, the Musaceae and the Haemodoraceae 149
*Dirk Hölscher,*

6.1 Introduction 149

6.2 The Plant Genus Hypericum 150

6.3 Phenylphenalenones: Plant Secondary Metabolites of the Haemodoraceae 151

6.4 Phenalenone Type Phytoalexins 157

6.5 Laser Microdissection and Cryogenic NMR as a Combined Tool for Cell TypeSpecific Metabolite Profiling 160

6.6 Matrix free UV Laser Desorption/Ionization (LDI) at the SingleCell Level: Distribution of Secondary Metabolites of Hypericum Species 163 6.7 LDI MSIBased Detection of PhenalenoneType Phytoalexins in a Bana...