**5. Antimicrobial peptides**

Antimicrobial peptides are a growing group of natural and synthetic peptides with a broad spectrum of targets including viruses, bacteria, fungi, and parasites [7]. Another interesting feature of this book is a comprehensive discussion on antimicrobial activity of defensin-like peptides [8]. These antimicrobial peptides act mainly by damaging the bacterial cell membranes and are found in many parts of the body. The chapter on defensins presents a discussion on mammalian defensins, their antimicrobial mechanisms, and its various evaluation techniques. This section also compares the antimicrobial activity of defensins in free form and immobilized on material surfaces along with pictorial representation of various immobilization methods. Furthermore, several of the concepts discussed can be easily adopted for the next-generation antimicrobial surfaces as coatings for medical devices and implants.

Peptide synthesis has come a long way from the invention of solid-phase synthesis to the present day. Each chapter in this book portrays one major aspect of peptides including its synthesis and applications. This book is intended to provide the researchers with various new methods for the synthesis of long and difficult sequence peptides.

**3**

**Author details**

Department of Chemistry, St. Teresa's College, Ernakulam, Kochi, India

© 2019 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,

\*Address all correspondence to: jayavarkey@yahoo.com

provided the original work is properly cited.

Jaya T. Varkey

*Introductory Chapter: Peptide Synthesis DOI: http://dx.doi.org/10.5772/intechopen.86505* *Introductory Chapter: Peptide Synthesis DOI: http://dx.doi.org/10.5772/intechopen.86505*

*Peptide Synthesis*

**4. Synthetic peptides**

CPPs are also included in this chapter.

**5. Antimicrobial peptides**

ligation (NCL) renders a highly effective and powerful method for the preparation of long-chain peptides [3]. This book introduces a novel "*O*-isoacylpeptide" method for the effective synthesis of long and difficult peptide sequences as in [4]. *O*-isoacylpeptides having ester bonds can be converted into the parent peptides under physiological condition *via* the *O* to *N* intramolecular migration. In addition a new approach called segment condensation with no racemization using the *O*-isoacylpeptide method is also introduced excellently [5]. This segment condensa-

This book gives a detailed review on synthesis and applications of synthetic peptides. Various aspects of solid-phase peptide synthesis including different resins, linkers, and synthesis techniques are discussed in detail. Applications of synthetic peptides as peptide vaccines, radio-theranostic agents, radio-labeled peptide analogues, and radio peptides for imaging therapy are featured as part of the synthetic peptide chapter. This chapter also presents an excellent discussion on cell-penetrating peptides (CPP) [6] as molecular carriers. It not only illustrates the use and applications of cell-penetrating peptides but also provides different aspects of various cell-penetrating techniques. A more in-depth description of factors affecting the mechanism of cellular uptake and various molecular detections of

Antimicrobial peptides are a growing group of natural and synthetic peptides with a broad spectrum of targets including viruses, bacteria, fungi, and parasites [7]. Another interesting feature of this book is a comprehensive discussion on antimicrobial activity of defensin-like peptides [8]. These antimicrobial peptides act mainly by damaging the bacterial cell membranes and are found in many parts of the body. The chapter on defensins presents a discussion on mammalian defensins, their antimicrobial mechanisms, and its various evaluation techniques. This section also compares the antimicrobial activity of defensins in free form and immobilized on material surfaces along with pictorial representation of various immobilization methods. Furthermore, several of the concepts discussed can be easily adopted for the next-generation antimicrobial surfaces as coatings for medical devices and

Peptide synthesis has come a long way from the invention of solid-phase synthesis to the present day. Each chapter in this book portrays one major aspect of peptides including its synthesis and applications. This book is intended to provide the researchers with various new methods for the synthesis of long and difficult

tion can be treated as a substitute for NCL method.

**2**

implants.

sequence peptides.
