Flavonoids in the Living System

Abstract

Flavonoids and related phenols are ubiquitous in land plants (Mabry and Ulubelen, 1980), and as a common element of plants they have taken their place in importance in far ranging arrays of biological systems, being integral to the function of most living systems. The study of these compounds has attracted the attention of generations of chemists. In fact, as one of the first flavonoids described, hesperidin, the primary flavanone glycoside in citrus, was first reported by Lebreton nearly 170 years ago (Lebreton, 1828). Although there has been a long history of the use of medicinal plants rich in flavonoids, our recent interest in the biological properties of the flavonoids began with the findings of Szent-Györgyi who found that citrus flavonoids were important to proper capillary function (Rusznyak and Szent-Györgyi, 1936). Although the vitamin status that was briefly attributed to flavonoids was discontinued in 1950, subsequent research has clearly shown an ever increasing list of biological systems over which flavonoids exert significant control. The pace of this research has rapidly accelerated, and recently, a much clearer understanding has emerged of the significance of these compounds, not only in plants, but also in animal systems, and ultimately pertaining to human health. This volume is based primarily on an American Chemical Society symposium held in Orlando, FL in August, 1996. Some of the material was added later to highlight new findings regarding the biological properties of flavonoids. It is not intended to be a comprehensive treatment of flavonoid research, nevertheless it is hoped that it shows new perspectives and encourages new research into this broad subject area at the cellular and molecular levels.