The Systematic Identification Of Flavonoids

About 1958, the late Professor R. E. ALSTON and Professor B. L. TURNER, both of the Department ofBotany, The University ofTexas at Austin, initiated a general systematic investigation ofthe legurne genus Baptisia. They found that flavonoid patterns, as revealed by two-dimensional paper chromatography, were valid criteria for the recognition of the Baptisia species and for the documentation of their numerous natural hybrids. Later, they showed that the flavonoid chemistry could be used for the analysis of gene flow among populations. At that time no attempt was made to even partially identify the flavonoids which were detected chromatographically. Neverthe1ess, it soon became apparent that the full value of the chemical data for systematic purposes required knowledge of the structures of the flavonoids. In 1962, one of us (T.J.M.) in collaboration with Drs. ALSTON and TURNER beg an the chemical analysis of the more than 60 flavonoids which had been chromatographi cally detected in the 16 Baptisia species. In the intervening years, a number of chemists and botanists, inc1uding Drs. K. BAETCKE, B. BREHM, M. CRANMER, D. HORNE, J. KAGAN, B. KROSCHEWSKY, J. MCCLURE, H. RÖSLER, and J. WALLACE, participated in the devel opment of techniques and procedures for the rapid identification of known flavonoids and in the structure determination of new flavonoids. In addition, the flavonoid chem istry of many plants other than Baptisia was investigated.

This long awaited third edition of Phytochemical Methods is, as its predecessors, a key tool for undergraduates, research workers in plant biochemistry, plant taxonomists and any researchers in related areas where the analysis of organic plant components is key to their investigations. Phytochemistry is a rapidly expanding area with new techniques being developed and existing ones perfected and made easier to incorporate as standard methods in the laboratory. This latest edition includes descriptions of the most up-to-date methods such as HPLC and the increasingly sophisticated NMR and related spectral techniques. Other methods described are the use of NMR to locate substances within the plant cell and the chiral separation of essential oils. After an introductory chapter on methods of plant analysis, individual chapters describe methods of identifying the different type of plant molecules: phenolic compounds, terpenoids, organic acids, lipids and related compounds, nitrogen compounds, sugar and derivatives and macromolecules. Different methods are discussed and recommended, and guidance provided for the analysis of compounds of special physiological relevance such as endogenous growth regulators, substances of pharmacological interest and screening methods for the detection of substances for taxonomic purposes. It also includes an important bibliographic guide to specialized texts. This comprehensive book constitutes a unique and indispensable practical guide for any phytochemistry or related laboratory, and provides hands-on description of experimental techniques so that students and researchers can become familiar with these invaluable methods.

Revised and expanded throughout, this blue-ribbon reference emphasizes the latest developments in the identification, utilization, and analysis of flavonoids for the prevention of disease and maintenance of good health-examining the processes involved in the absorption, metabolism, distribution, and excretion of these compounds and the impact of biotransformation on flavonoid function.

Flavonoids are abundant secondary metabolites found in plants and fungi that have various roles in these organisms, including pigmentation, cell signalling, plant defence and inter-organism communication. Due to their abundance in nature, flavonoids are also important components of the human diet, and the last four decades have seen an intense study focused on the structure characterization of flavonoids and on their roles in mammal metabolism. This book reviews most of the well-established activities of flavonoids, and we also present more recent research studies on the area of flavonoids, including the chemical aspects of structure characterization of flavonoids, the biosynthesis of flavonoids in model plants as well as their role in abiotic stress situations and in agriculture, the role of flavonoids in metabolism and health and their importance in foods, from consumption to their use as bioactive components.

The flavonoids, one of the most numerous and widespread groups of natural constituents, are important to man not only because they contribute to plant colour but also because many members (e.g. coumestrol, phloridzin, rotenone) are physiologically active. Nearly two thousand substances have been described and as a group they are universally distributed among vascular plants. Although the anthocyanins have an undisputed function as plant pigments, the raison d'etre for the more widely distributed colourless flavones and flavonols still remains a mystery. It is perhaps the challenge of discovering these yet undisc10sed functions which has caused the considerable resurgence of interest in flavonoids during the last decade. This book attempts to summarize progress that has been made in the study of these constituents since the first comprehensive monograph on the chemistry of the flavonoid compounds was published, under the editorship of T. A. Geissman, in 1962. The present volume is divided into three parts. The first section (Chapters 1-4) deals with advances in chemistry, the main emphasis being on spectral techniques to take into account the re cent successful applications of NMR and mass spectral measurements to structural identifications. Recent developments in isolation techniques and in synthesis are also covered in this section. Advances in chemical knowledge of individual c1asses of flavonoid are mentioned inter aha in later chapters of the book.

This is the only book of its kind to provide an overview of the science of flavonoids in plants.

Based on the results of the latest congress of the European Association for the Study of the Liver (EASL), this volume makes excellent reading since it explores in detail the role of free radical reactions in liver diseases. Studies in recent years using various methods have shown that free radicals play an important role in toxic liver disorders. For this reason, the current scientific knowledge is presented in this balanced, clinical portrayal. The account refers to the many observations, experiencesand evaluations that have been made both clinically and experimentally. Two major areas discussed concern the pathophysiological changes by free radicals and the therapeutic possibilities that have come to light.