Preface

Chapter 8 **Natural Products from Semi–Mangrove Plants in China 193**

Xiaopo Zhang

**VI** Contents

As Moustafa and Morsi remind us in Chapter One, it has been just over 100 years since a Rus‐ sian botanist, M. Tswett discovered chromatography. It seems timely to review the current status of the field of chromatography and appreciate the many improvements that have been made in the field. To do this thoroughly, of course, would require many volumes, but within the limits of space, the chapters that follow surely do indicate the range of techniques and some of the important applications. It is to be hoped that careful readers will reflect on these and consider other applications.

Accordingly, Chapters Two through Five look at different techniques of chromatography with a consideration of applications. These include ion-exchange chromatography (Chapter Two), the use of chromatography to characterize the bioactivity of compounds (Chapter Three), af‐ finity chromatography and the utilization in drug discovery (Chapter Four), and the use of column chromatography with chelating agents attached to useful substrates (Chapter Five).

Finally, this volume provides three examples of the range of utilization of chromatography in the study of natural products. This section provides useful and, it is hoped, inspirational ex‐ amples of how far the field of chromatography has come with respect to natural products since Tswett's discovery. These examples are considered in Chapters Six, Seven, and Eight.

This book is characterized by three important features. The authors represent an impressive collection of international workers from Brazil, China, Egypt, Poland, Turkey, and the United States. The majority of the chapters reflect the importance of collaborative efforts in contempo‐ rary research. Finally, some chapters are especially useful because of the experimental details that are provided.

And it is to be hoped that readers will find that the chapters are both informative and inspira‐ tional.

> **Dean F. Martin Barbara B. Martin**

**Chapter 1**

**Ion Exchange Chromatography - An Overview**

Chromatography is the separation of a mixture of compounds into its individual components based on their relative interactions with an inert matrix. However, chromatography is more than a simple technique, it is an important part of science encompassing chemistry, physical chemistry, chemical engineering, biochemistry and cutting through different fields. It is worth to be mentioned here that the IUPAC definition of chromatography is "separation of sample

M. Tswett (1872-1919), a Russian botanist, discovered chromatography in 1901 during his research on plant pigments. According to M. Tswett: "An essential condition for all fruitful research is to have at one's disposal a satisfactory technique". He discovered that he could separate colored leaf pigments by passing a solution through a column packed with adsorbent particles. Since the pigments separated into distinctly colored bands as represented in Figure 1, he named the new method "chromatography" (chroma – color, graphy –writing). Tswett emphasized later that colorless substances can also be separated using the same principle.

The separation results from the differential migration of the compounds contained in a mobile phase through a column uniformly packed with the stationary matrix. A mobile phase, usually a liquid or gas, is used to transport the analytes through the stationary phase while the matrix, or stationary phase, is generally an inert solid or gel and may be associated with various moieties, which interact with the analyte(s) of interest. Interac‐ tions between the analytes and stationary phase are non-covalent and can be either ionic or non-ionic in nature depending on the type of chromatography being used. Compo‐ nents exhibiting fewer interactions with the stationary phase pass through the column more

> © 2013 Moustafa and Morsi; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2013 Moustafa and Morsi; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

Yasser M. Moustafa and Rania E. Morsi

http://dx.doi.org/10.5772/55652

**1. Introduction**

Additional information is available at the end of the chapter

components after their distribution between two phases".

**1.1. Discovery and history of chromatography [1, 2]**

quickly than those that interact to a greater degree.
