PHYTOESTROGENS: OCCURRENCE IN FOODS, AND METABOLISM OF

0,78

MB

LIGNANS IN MAN AND PIGS

141

stron

6486

ID

University of Helsinki

2000

rok

TABLE OF CONTENTS

ABBREVIATIONS

LIST OF ORIGINAL COMMUNICATIONS

INTRODUCTION

REVIEW OF THE LITERATURE

1. PHYTOESTROGENS - ESSENTIAL ISSUES

1.1. Definition, origin and classification

1.2. Chemistry, estrogenicity and antiestrogenicity

1.2.1. Isoflavonoids

1.2.2. Dietary and mammalian lignans

1.3. Metabolism and pharmacokinetics of phytoestrogens

1.4. Physiological levels in human biological fluids

1.5. Phytoestrogens and disease

2. ISOFLAVONE CONTENT IN FOODS

2.1. Methods of analysis

2.2. Isoflavones in foods

2.3. Lignans in foods

2.4. Glycitein and coumestrol in foods

AIMS OF THE STUDY MATERIALS 6

1. Standards

1.1. Reference standards

1.2. Deuterated standards

2. Fluoroimmunoassay of ENL

3. Instrumentation

4. Sources of samples

4.1. Development of the method and food analyses.

4.2. Human and animal studies

5. Chemicals, reagents and preparation of glassware

6. Anion exchange material

METHODS

1. Quantification of phytoestrogens in foods

1.1. Pretreatment of food/diet samples

1.2. Enzymatic hydrolysis

1.3. Extraction

1.4. Acid hydrolysis

1.5. Ion exchange procedures

1.6. Derivatization

1.7. GC-MS

1.8. GC analysis of samples with high concentrations of isoflavonoids and lignans

2. Analysis of lignans in the biological samples 7

3. Calculations

4. Statistical methods

RESULTS

1. ID-GC-MS method for the determination of isoflavonoids, coumestrol and lignans in food

samples

1.1. Results of studies on the hydrolysis of phytoestrogens

1.2. Extraction

2. Validation of the method

2.1. Recoveries and accuracy

2.2. Imprecision

2.3. Specificity

2.4. Sensitivity

3. Results of quantitative assays

3.1. Phytoestrogens in foods and diets (I, II, III, IV, V, VI)

3.2. Concentrations of enterolactone in plasma and urine of subjects fed a strawberry meal (IV)

3.3. Quantification of lignans in intestinal samples and faeces from the pigs (V)

DISCUSSION

1. Food method

2. Quantitative assays in various foods and beverages

3. Metabolism of lignans 8

SUMMARY AND CONCLUSIONS

ACKNOWLEDGMENTS

REFERENCES