Preface

**Section 4 Regulation of Secondary Metabolites Production 113**

**Medicament 115**

**Dehydrogenases 125** Andrea M.P. Romani

Chapter 8 **Physiology and Pathology of Mitochondrial**

Suthar

**VI** Contents

Chapter 7 **Microbial Biotransformation for the Production of Steroid**

Rutuja Rokade, Selvan Ravindran, Pooja Singh and Jitendra K.

Metabolites are the intermediate products of metabolism. Metabolites have various func‐ tions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, cat‐ alytic activity of their own, defense, and interactions with other organisms. A primary metabolite is directly involved in normal growth, development, and reproduction. A secon‐ dary metabolite is not directly involved in those processes but usually has an important eco‐ logical function. They are found in microorganisms, plants, and animals. Herbal plants, animals, and microorganisms such as bacteria, actinobacteria, cyanobacteria, fungi, and al‐ gae have attracted more attention in research that has led to the discovery of secondary me‐ tabolites. The exploration of secondary metabolites from various resources subsequently led to the development of drugs for the treatment of human diseases of microbial origin. Rou‐ tine screening of natural resources will introduce novel secondary metabolic products with a high pharmaceutical value. Thus, this book is very apt and needed.

This book consists of an introductory overview of secondary metabolites, which are classi‐ fied into four main sections: microbial secondary metabolites, plant secondary metabolites, secondary metabolites through tissue culture technique, and regulation of secondary metab‐ olite production. This book provides a comprehensive account on the secondary metabolites of microorganisms, plants, and the production of secondary metabolites through biotechno‐ logical approach like the plant tissue culture method. The regulatory mechanisms of secon‐ dary metabolite production in plants and the pharmaceutical and other applications of various secondary metabolites are also highlighted. The 8 chapters have been contributed by the authors around the world, including Austria, Portugal, Malaysia, the United Kingdom, India, Sri Lanka, and the United States.

This book is considered as necessary reading for microbiologists, biotechnologists, biochem‐ ists, pharmacologists, and botanists who are doing research in secondary metabolites. It should also be useful to MSc students, MPhil and PhD scholars, scientists, and faculty mem‐ bers of various science disciplines. We are thankful to all the contributors for their valuable work. We offer our special thanks and appreciation to Ms. Ivana Glavic, Publishing Process Manager/Author Service Manager, for her encouragement and help in bringing out the book in the present form.

We also thank Dr. D. Dhanasekaran, Bioprocess Technology Laboratory, Bharathidasan Uni‐ versity, Tiruchirappalli, India, for his valuable suggestions. We are also indebted to Intech Open and Bharathidasan University for their concern, efforts, and support in the task of publishing this volume.

> **Ramasamy Vijayakumar and Suresh S.S. Raja** Department of Microbiology Bharathidasan University Constituent College Tamilnadu, India

**Section 1**

**Microbial Secondary Metabolites**

**Microbial Secondary Metabolites**

**Chapter 1**

**Provisional chapter**

**An Introductory Chapter: Secondary Metabolites**

**An Introductory Chapter: Secondary Metabolites**

DOI: 10.5772/intechopen.79766

The metabolism can be defined as the sum of all the biochemical reactions carried out by an organism. Metabolites are the intermediates and products of metabolism and are usually restricted to small molecules. The term "secondary" introduced by A. Kossel in 1891 implies that while primary metabolites are present in every living cell capable of dividing, the secondary metabolites are present only incidentally and are not of paramount significance for organism's life. Though secondary metabolites are derived from primary metabolism, they do not make up basic molecular skeleton of the organism. Its absence does not immediately curtail the life of an organism, a feature contrary to primary metabolite, but survival of the organism is impaired to a larger extent. Its presence and synthesis are observed in ecologi-

The difference between primary and secondary metabolite is ambiguous since many of the intermediates in primary metabolism is overlapping with the intermediates of secondary metabolites [2]. Amino acids though considered a product of primary metabolite are definitely secondary metabolite too. Contrary to the observation that sterols are secondary metabolites that are indispensable part of many structural framework of a cell. The mosaic nature of an intermediate indicates common biochemical pathway being shared by primary and secondary metabolism [3]. The secondary metabolites serve as a buffering zone into which excess C and N can be shunted into to form inactive part of primary metabolism. The stored C and N can revert back to primary metabolite by the metabolic disintegration of secondary metabolite when on demand. There is dynamism and a delicate balance between the activities of the primary and secondary metabolism (**Figure 1**) being influenced by growth, tissue differentiation

> © 2016 The Author(s). Licensee InTech. This chapter is 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.

© 2018 The Author(s). Licensee IntechOpen. This chapter is 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.

Durairaj Thirumurugan, Alagappan Cholarajan, Suresh S.S. Raja and Ramasamy Vijayakumar

Durairaj Thirumurugan, Alagappan Cholarajan, Suresh S.S. Raja and Ramasamy Vijayakumar

cally disadvantaged species within a phylogenetic group [1].

and development of the cell or body, and also external pressures [4].

Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.79766

**1. Introduction**

#### **An Introductory Chapter: Secondary Metabolites An Introductory Chapter: Secondary Metabolites**

DOI: 10.5772/intechopen.79766

Durairaj Thirumurugan, Alagappan Cholarajan, Suresh S.S. Raja and Ramasamy Vijayakumar Durairaj Thirumurugan, Alagappan Cholarajan, Suresh S.S. Raja and Ramasamy Vijayakumar

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.79766
