This book was developed from the proceedings of the first North American Tannin Conference held in Port. Angeles, Washington, August 1988. The objective of the conference was to bring together people with a common interest in condensed tannins and to promote interdisciplinary interactions that will lead to a better understanding of these important substances. Anot. her objective was the publicat. ion of this book because there has not been a monograph devoted to the chemistry and significance of tannins for several decades. The book is organized into sections dealing with the biosynthesis, structure, re actions, complexation with other biopolymers, biological significance, and use of tannins as specialty chemicals. The authors made a special attempt to focus on what we don't know as well as to provide a summary of what we do know in an effort to assist in planning future research. Our thanks go to the authors who so kindly contributed chapters and so pa tiently responded to our requests. We also thank Rylee Geboski and the Conference Assist. ance Staff, College of Forestry, Oregon State University, for their assistance in planning and conducting t. he conference, and Julia Wilson, Debbie Wolfe, Helen Coletka, and Nancy Greene of the Southern Forest Experiment Station, Pineville, Louisiana, who typed the chapt. ers. Linda Chalker-Scott was especially helpful in assisting us wit. h editing. Dick Hemingway is indebted t. o the staff of the Alexandria Forest."

This book was developed from the proceedings of the 2nd North American Tan nin Conference held in Houghton, Michigan, June, 1991. The objective of this con ference was to bring together people with a common interest in plant polyphenols and to promote interdisciplinary interactions that will lead to a bet ter understand ing of the importance of these substances. Another objective of this conference was to extend the 'tannin family' by making special efforts to encourage participation by scientists outside the United States, obtain more coverage of the hydrolyzable tannins, and further broaden the scope of coverage from the initial concentration on forestry and forest products. Com parison of the contents of this book with 'Chemistry and Significance of Condensed Tannins' that resulted from the proceedings of the 1st North American Tannin Conference shows the degree that these objectives were met. In developing the second conference, care was taken to assure that this book extends rather than duplicates the coverage of the first conference. Therefore, the two books should be taken together to obtain an up to date coverage of the broad area of chemistry and significance of plant polyphenols. Our thanks go to the authors who so kindly contributed chapters and so pa tiently responded to our requests. We thank the Conference Assistance Staff of Michigan Technological University for their help in planning and conducting the conference."

This volume summarizes current research on the influence of plant polyphenols on human health, promoting collaboration between chemists and biologists to improve our understanding of their biological significance, and expanding the possibilities for their use.

This volume contains the proceedings of the 3rd Tannin Conference, held in July 1998, with the objective of promoting collaboration between chemists and biologists to improve our understanding of the biological significance of plant polyphenols and to expand possibilities for their use. Special efforts were made to summarize late-1990s research on the influence of these compounds on human health. Some of the topics included are: hydrolyzable tannins; condensed tannins and related compounds; biotechnology; antioxidant properties and heart disease; conformation, complexation, and antimicrobial properties; polyphenols and cancer; polyphenols in commerce; polyphenols and ecology. A comparison of the contributions to the proceedings of the first, second, and third of these conferences shows important growth in the recognition of the significance of these compounds on the part of biologists and biochemists and increasing relevance in medically-oriented disciplines.