The Biosynthesis of Mycotoxins

The Biosynthesis of Mycotoxins: A Study in Secondary Metabolism focuses on the biosynthetic analysis of mycotoxins, which are inherently a heterogeneous group of metabolites that are formed along the terpene route and the route polyketide, as well as from amino acids. This book discusses the unique biological properties and structural complexity of the highly specialized secondary microbial metabolites.
Organized into 12 chapters, this book starts with an overview of the characteristics of secondary metabolites, including their problematic function and the combination of their structural diversity with their restricted biological occurrence. This text then explains the sporadic occurrence of the mycotoxins as fungal metabolites. Other chapters explore ergochromes, which are a group of light yellow mycotoxins that are isolated from ergot, mold fungi, and lichens. The final chapter discusses the biosynthesis of several unrelated fungal metabolites for which toxicological data are reported.
Biochemists, organic chemists, mycologists, enzymologists, plant pathologists, toxicologists, and graduate students will find this book useful.

Contenu

List of Contributors

Foreword

Preface

1 Mycotoxins as Secondary Metabolites

I. Introduction

II. Diversity

III. Occurrence

IV. Regulation

V. Function

References

2 Biosynthesis of Ergot Toxins

I. Introduction

II. The Alkaloids of Ergot

III. Biosynthesis of the Ergoline System

IV. Biosynthesis of Lysergic Acid Derivatives

V. Enzymology and Physiology of Ergot Alkaloid Biosynthesis

VI. Conclusion

References

3 The Biosynthesis of Trichothecene Mycotoxins

I. Introduction

II. Biosynthesis of Trichothecenes

III. Biosynthesis of the Roridins and Verrucarins

References

4 The Biosynthesis of Aflatoxin and Its Congeners

I. Introduction

II. Structural Types Biogenetically Related to the Anatoxins

III. The Biosynthetic Study of Aflatoxin and Its Congeners

IV. The Sequence of the Aflatoxin Biosynthetic Pathway: Elucidation by Using Blocked Mutants, Enzyme Inhibitors, and Conversion of Potential Precursors

V. Biosynthetic Scheme

References

5 The Biosynthesis of the Ergochromes

I. Introduction

II. Hypotheses on Ergochrome Biosynthesis

III. Methodology

IV. Investigation of Ergochrome Biosynthesis with Labeled Precursors

V. Biosynthesis of Related Secoanthraquinones

VI. Biomimetic Reactions

References

6 The Biosynthesis of Neurotropic Mycotoxins

I. Introduction

II. Citreoviridin

III. Maltoryzine

IV. Aspergillic Acid and Related Pyrazine Oxides

V. Fumitremorgin, Verruculogen, and Roquefortine

VI. Paxilline, Paspaline, and Related Metabolites

VII. Tryptoquivalines

VIII. Slaframine

References

7 The Biosynthesis of Patulin and Penicillic Acid

I. Introduction

II. Biogenetic Theories

III. Methodology Followed during the Study

IV. Origin of the Aromatic Precursors

V. Secondary Transformations of the Aromatic Precursors

VI. Cleavage of the Aromatic Precursors

VII. Derailment Metabolites

VIII. Metabolic Grids and Concluding Remarks

References

8 The Biosynthesis of the Cytochalasans

I. Introduction

II. Structure

III. Biosynthesis

IV. Biosynthetic Scheme

Addendum

References

9 The Biosynthesis of Gliotoxin and Related Epipolythiodioxopiperazines

I. Introduction

II. Survey of Structural Types

III. The Biosynthesis of Gliotoxin

IV. The Biosynthesis of the Aranotins

V. The Biosynthesis of Sporidesmin

VI. Conclusions

Addendum

References

10 The Biosynthesis of Cyclopiazonic Acid and Related Tetramic Acids

I. Introduction

II. The Structures of Naturally Occurring Tetramic Acids

III. The Biosynthesis of Tetramic Acids

IV. Enzymes in the Biosynthesis of a-Cyclopiazonic Acid

V. The Mechanism of the Oxidative Cyclization of ß-Cyclopiazonic Acid

VI. Metabolic Development of Penicillium cyclopium during a-Cyclopiazonic Acid Production

VII. Links between Primary Metabolism and the Synthesis of a-Cyclopiazonic Acid

VIII. Summary

References

11 The Biosynthesis of Anthraquinonoid Mycotoxins from Penicillium islandicum Sopp and Related Fungi

I. Introduction

II. Chemical Studies of the Anthraquinonoid Mycotoxins

III. Biosynthetic Origin of Anthraquinonoid Mycotoxins

IV. Metabolic Relationship of the Anthraquinonoids Produced by Penicillium islandicum and Related Fungi

V. Biomimetic Synthesis of Anthraquinonoids

References

12 The Biosynthesis of Some Miscellaneous Mycotoxins

I. Introduction

II. Ochratoxin and Related Dihydroisocoumarins

III. Citrinin

IV. Citromycetin

V. Zearalenone and Related Metabolites

VI. Rubratoxins and Related Metabolites

VII. Xanthocillins

VIII. Toxic Furanosesquiterpenoids

IX. Diplosporin

X. Griseofulvin

References

Index