Essential Oils : Historical Significance, Chemical Composition, and Medicinal Uses and Benefits

The use of essential oils by civilizations constitutes a common practice since antiquity. In earlier times, China, India and the Middle East used herbs and oils in cooking, cosmetics, medicine and in religious rituals. These substances come from a secondary metabolism of plants and are associated with several functions necessary for their survival, such as the defense against microorganisms, predators and attraction of pollinators. Essential oils are composed of a complex mixture of biologically active substances, lipophilic and volatile, and in most cases derivatives of terpene compounds and in a lower occurrence - phenylpropanoids. They have been long recognized for their medicinal uses: antibacterial, antifungal, antiviral, insecticidal and their antioxidant properties. The increased interest in alternative natural substances is driving the research community to find new uses and applications of these substances. This book provides research on the historical significance, chemical composition and medicinal uses and benefits of essential oils. Some of the topics discussed include extraction methods of essential oils; an overview of the most relevant essential oil changes regarding plant phenology and plant development; the antibacterial properties of some essential oils; essential oils applications in agriculture; and the use of essential oils as additives in broiler diets. Content: ESSENTIAL OILS HISTORICAL SIGNIFICANCE, CHEMICAL COMPOSITION AND MEDICINAL USES AND BENEFITS ESSENTIAL OILS HISTORICAL SIGNIFICANCE, CHEMICAL COMPOSITION AND MEDICINAL USES AND BENEFITS CONTENTS PREFACE Chapter 1 ESSENTIAL OILS: PROPERTIES, APPLICATIONS, EXTRACTION METHODS, AND PERSPECTIVES Abstract Introduction References Chapter 2 PHENOLOGICAL CHANGES IN THE BIOSYNTHESIS AND CHEMICAL COMPOSITION OF THE ESSENTIAL OILS Abstract Introduction Sources of Variability Ecological Role of Volatile Organic Compounds Phenological Changes in the Biosynthesis of Essential OilsSecretory Structures The Importance of the Plant Organ Used for the Distillation The Role of Stress Genetic vs Environmental Modulation of the Essential Oil Production The Importance of the Plant Age Phenological Changes in the Chemical Composition of the Essential Oils Implications of the Variability on the Product Final Quality Genetic Control of the Essential Oil Composition Different Organs and Essential Oil Composition Plant Aging vs Composition Conclusion References Chapter 3 EXTRACTION TECHNIQUES AND PHARMACOLOGICAL POTENTIAL OF ESSENTIAL OILS FROM MEDICINAL AND AROMATIC PLANTS OF MAURITIUSAbstract 1. Introduction 2. Methods of Extraction 2.1. Supercritical Fluid Extraction Method 2.2. Short-Path Molecular Distillation 2.3. Microwave Assisted Extraction 2.3.1. In Situ Microwave-Generated Hydrodistillation 2.3.2. Microwave Steam Diffusion 2.4. Ultrasound Assisted Extraction 3. Characterization 3.1. Fast Gas Chromatography-Mass Spectrometry 3.2. Gas Chromatography Coupled to Tandem Mass Spectrometry 3.3. Gas Chromatography Coupled with Multivariate Curve Resolution4. Isolation 5. Reported Uses of EOs from Medicinal and Aromatic Plants of Mauritius 6. Biological Properties of EOs Conclusion References Chapter 4 EVALUATION OF ESSENTIAL OIL OF OCIMUM GRATISSIMUM L. FOR ANTIBACTERIAL ACTIVITY AND POTENTIAL TO MODIFY AMINOGLYCOSIDE TOXICITY Abstract Introduction Methodology Results and Discussion Acknowledgments References Chapter 5 CHEMICAL COMPOSITION AND ANTIMICROBIAL ACTIVITY OF PLINIA JABOTICABA (VELL.) KAUSEL ESSENTIAL OIL Abstract 1. Introduction 2. Materials and Methods2.1. Plant Material 2.2. Extraction Procedure 2.3. Analysis of Quantitative and Qualitative Composition of the Essential Oil 2.4. Antibacterial Activity against Cell-Wall Bacteria Microbiological Material Determination of Minimum Inhibitory Concentration (MIC) 2.5. Antibacterial Activity against No-Cell-Wall Bacteria (Mollicutes) Microbiological Material Determination of Minimum Inhibitory Concentration (MIC) 3. Results and Discussion 3.1. Essential Oil Composition 3.2. Antibacterial Activity Conclusion Acknowledgments References