Chemical Characterization of Some Flavonoids from Trianthema prot ulacstrum and phoenix dactylefrera and Their Biological Activity

Abstract 

In the present work, the stems of Trianthema portulacastrum and Phoenix d actylefera pollens were extracted with 95% ethanol at ambient temperature. Qualitative tests on alcoholic extract of Trianthema portulacastrum stems re vealed the presence of flavonoids, alkaloids, tannins, saponins, steroids, carb ohydrates and glycosides. The crude extracts of Trianthema portulacastrum and Phoenix daclylefera w ere initially purified by column chromatography. Further purification was ac complished by TLC technique. In this way Trianthema portulacastrum gave two flavonoids (compounds I and II) while Phoenix dactylefera gave compo unds III and IV. The structures of these compounds were deduced on the bas is of their spectral data (UV, 1HNMR and MS).

Table of Contents

Dedication II

Acknowledgment III

Abstract IV

Chapter One

1- Introduction 1

1.1 General approach 1

1.2 Flavonoids occurrence and importance 2

1.3 Classification of flavonoid compounds 7

1.3-1 Flavones 8

1.3-2 Flavonols 10

1.3.3 Flavanones 11

1.3.4 Isoflavones 13

1.3-5 Anthocyanins 14

1.3-6 Chalcones 17

1.3.7 Aurones 18

1.4 Medicinal uses of flavonoid compounds 22

1.5 Techniques used in flavonoids analysis 24

1.5.1 Paper chromatography (PC) 24

1.5.2 Thin- layer chromatography (TLC) 25

1.5.3 Gas chromatography (GC) 28

1.5.4 High performance liquid chromatography (HPLC) 28

1.5.5 High speed counter current chromatography (HSCCC) 30

1.5.6 Column chromatography 31

1.6 Spectroscopic Methods 36

1.6.1 The Ultraviolet / Visible Spectroscopy (UV/Vis) 37

1.6.2 Mass Spectroscopy (MS) 42

1.6.3 Nuclear Magnetic Resonance (NMR) 43

1.7 The target species – Trainthema portulacastrum Linn 44

1.8 The target species – Phoenix dactylefera L 50

Chapter Two

2- Materials and methods 57

2.1- Materials 57

2.1.1 Plant material 57

2.1.2 Instruments 57

2.2 Methods 57

2.2.1 Preparation of test reagents for phytochemical screening 57

2.2.2 Preparation of plant extract for phytochemical screening 58

2.2.3 phytochemical screening 58

2.2.4 Extraction of flavonoids 61

2.2.5 Isolation of flavonoids 61

2.2.6 Antimicrobial assay 62

Chapter Three

3- Results and Discussion 65

3.1 Trianthema portulacustrum 65

3.1.1 Phytochemical screening 65

3.1.2 Biological activity 66

3.1.3 Isolation of flavonoids 67

3.1.4 Identification of compound I 67

3.1.5 Characterization of compound II 74

3.2 Phoenix dactylefera 79

3.2.1 Phytochemical screening 79

3.2.2 Antimicrobial susceptibility 80

3.2.3 Identification of compound III 81

3.2.4 Characterization of compound IV 85

Conclusion 91

Recommendations 91

References