Characterization of antioxidant properties of aroma constituents isolated from medicinal plants

다국어 초록 (Multilingual Abstract)

Aroma extracts isolated from medicinal plants have been widely used in aromatherapy and their aroma components are believed to possess medicinal properties, as well as antioxidant activity. Aroma extracts isolated from medicinal plants such as clove buds, eucalyptus leaves, and various beans, were prepared and examined for antioxidant activity by three different assays. The antioxidative activity of aroma extracts of mung beans, soybeans, and cloves as well as major aroma chemicals like eugenol, eugenyl acetate, and thymol were comparable to that of the natural antioxidant, α-tocopherol (vitamin E). The aroma extracts isolated from soybeans, mung beans, kidney beans, and azuki beans inhibited the oxidation of hexanal for nearly one month at a level of 250 μL/mL. Mung bean and soybean extracts inhibited malonaldehyde (MA) formation from cod liver oil by 86% and 88%, respectively, at 250 μL/mL level. Aroma compounds contained in the extracts of soybean and mung bean were identified by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Among identified chemicals, eugenol, maltol, benzyl alcohol and 1-octen-3-ol inhibited the oxidation of hexanal by 100%, 93%, 84%, and 32%, respectively, for a period of 40 days at concentrations of 500 μg/mL. Eugenol, maltol, benzyl alcohol, and 1-octen-3-ol inhibited MA formation from cod liver oil by 91%, 78%, 78%, and 78%, respectively, at the 160 μg/mL level.

목차 (Table of Contents)

• Title page = i
• ACKNOWLEDGEMENTS = ii
• TABLE OF CONTENTS = iv
• LIST OF FIGURES = ix
• LIST OF TABLES = xii
• Abstract = 1
• INTRODUCTION = 3
• Aroma chemicals as natural antioxidants = 3
• Carbonyl compounds formed from lipid peroxidation = 4
• Analysis of malonaldehyde (MA) = 5
• Lipid/MA assay = 6
• Aldehyde/Carboxylic Acid Assay = 6
• Scope of The Present Study = 7
• References = 11
• Chapter I Antioxidative Activities of Aroma Extracts Isolated from Plants = 16
• Abstract = 18
• 1. Introduction = 19
• 2. Materials and methods = 21
• 2.1. Materials = 21
• 2.2. Isolation of essential oils from fresh beans = 22
• 2.3. Antioxidative tests of aroma extracts using aldehyde/carboxylic acid assay = 22
• 2.4. Antioxidative tests of aroma extracts using lipid/MA assay = 23
• I2.5. Identification of aroma chemicals in the extracts = 24
• 3. Results = 24
• 4. Discussion = 25
• References = 27
• Chapter II Determination of Antioxidant Properties of Aroma Extracts from Various Beans = 35
• Abstract = 37
• INTRODUCTION = 38
• MATERIALS AND METHODS = 39
• Beans. = 39
• Chemicals. = 39
• Isolation of Aroma Chemicals by Simultaneous Steam Distillation and Solvent Extraction (SDE). = 39
• Measurement of Total Aroma Compounds in Extracts = 40
• Aldehyde/Carboxylic Acid Assay = 41
• Lipid/MA Assay = 41
• Instrumental Analysis = 42
• RESULTS AND DISCUSSION = 43
• CONCLUSION = 45
• REFERENCES = 46
• Chapter III Antioxidant Properties of Aroma Compounds Isolated from Soybeans and Mung Beans. = 57
• Abstract = 59
• INTRODUCTION = 60
• MATERIALS AND METHODS = 61
• Beans. = 61
• Chemicals. = 61
• Isolation of Aroma Chemicals by Steam Distillation under Reduced Pressure (DRP) = 61
• Identification of Aroma Chemicals in the Extracts from Soybeans and Mung Beans = 62
• Aldehyde/Carboxylic Acid Assay = 62
• Lipid/MA Assay- = 62
• Instrumental Analysis-63
• RESULTS AND DISCUSSION = 64
• CONCLUSION = 66
• REFERENCES = 67
• Chapter IV Antioxidant properties of aroma extracts from clove buds [Syzygium aromaticum (L.) Merr. et Perry] and eucalyptus leaves (Eucalyptus polyanthemos Schauer) = 78
• Abstract = 80
• INTRODUCTION = 81
• MATERIALS AND METHODS = 82
• Plants. = 82
• Chemicals. = 83
• Isolation of Aroma Chemicals by Steam Distillation under Reduced Pressure (DRP) = 83
• Identification of Aroma Chemicals in the Extracts from Eucalyptus leaves. = 83
• Measurement of total aroma compounds in extracts = 84
• Aldehyde/Carboxylic Acid Assay = 84
• Lipid/MA Assay = 85
• Instrumental Analysis = 85
• RESULTS AND DISCUSSION = 86
• CONCLUSION = 92
• REFERENCES = 93
• Chapter V Inhibition of Malonaldehyde Formation in Blood Plasma Oxidation by Aroma Extracts Isolated from Medicinal Plants = 120
• Abstract = 122
• INTRODUCTION = 123
• MATERIALS AND METHODS = 124
• Plants. = 124
• Chemicals. = 125
• Plasma Preparation = 125
• Protein Analysis in Blood Plasma = 125
• Isolation of Aroma Chemicals by Steam Distillation under Reduced Pressure (DRP) = 125
• Measurement of total aroma compounds in extracts = 126
• Oxidation of Blood Plasma with Fenton's Reagent in the Presence or Absence of Aroma Extracts. = 126
• Analysis of MA as N-methylpyrazole = 127
• Recovery Test on MA from Blood Plasma. = 127
• Instrumental Analysis = 127
• RESULTS AND DISCUSSION = 128
• REFERENCES = 130
• CONCLUSIONS = 144
• CONCLUSIONS = 144