Studies on the Chemical Constituents of the Leaves and Seeds of Hyptis Spicigera Lam

– Studies on the Chemical Constituents of the Leaves and Seeds of Hyptis Spicigera Lam –

ABSTRACT

The extracts of the leaves of H.spicigera were screened for the presence of secondary metabolites: alkaloids, glycosides, flavonoids, carbohydrates, tannins, sterols, terpenoids, and resins.

The results of the phytochemical screening showed all the extracts with the exception of hexane extract to contain the secondary metabolites analyzed in high and moderate amounts.

Antimicrobial activities of the crude extracts of H.spicigera against a broad spectrum of microorganisms namely: Staphylococcus aureus, Streptococcus pyogenes, Bacillus subtilis, Corynebacterium ulcerans, Salmonella typii, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Neisseria gonorrhea, and Candida albicans were carried out.

All the extracts showed bactericidal activity against the entire antibiotic-resistant microorganisms tested with some degree of variations against the standard drug, penicillin.

The methanolic extract of H.spicigera exhibited significant bactericidal activity at a low concentration of 2.5mg/ml while S.aureus, N.gonnorhea, and C.albicans were resistant at MBC of 5.0mg/ml.

The insecticidal properties of H.spicigera leaf extracts (hexane, ethyl acetate, and methanol) tested against Callosobruchus maculatus on cowpea were carried out.

Azadirachtin was used as a standard check along with the extracts tested.

Ethyl acetate extract showed the highest per cent mortality of 98% each at 72hrs, while 6% and 10% were recorded for the emergence of the C.maculatus. Ethyl acetate extract and azadirachtin standard check showed oviposition deterrent at 4.16% and 2.78% respectively.

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TABLE OF CONTENTS

Title page                               i

Declaration                           ii

Certification                            iii

Dedication                            iv

Acknowledgement           v

Abstract                                vii

Table of contents                      ix

CHAPTER ONE

1.0       Introduction                  1

• Aim 14
• Statement of the problem 15
• Significance of study 16
• Justification for the study 16
• Statement of research hypothesis/research question 18

CHAPTER TWO

• Literature Review 19
• Botanical description of spicigera 19
• Morphological description of spicigera plant 20
• Uses of spicigera 20
• Terpenoidal constituents 22
• Biological and ethnopharmacological applications 39
• Pesticidal properties 48
• Other essential oils from plants 52

CHAPTER THREE

3.0       Materials and Methods               64

3.2.1    Instrumentation                    64

• Spectroscopy 65
• Chromatography 65
• Collection of the plant material 65
• Extraction and isolation 65
• Lipid extraction 66
• Physicochemical analysis of spicigera seed oil 66
• Preparation of the fatty acid methyl ester for GC-MS analysis 67
• GC-MS analysis of derivatized oil 67
• Extraction of the volatile oils and GC-MS analysis 67
• Microorganisms and media 68
• Antimicrobial studies 69
• Minimum Bactericidal Concentration (MBC) 69
• Phytochemical screening of spicigera leaf extracts 70
• Biological activity of sample ZL-14 77

3.10.2  Determination of LD50                 78

• Insecticidal evaluation of the plant extracts 79
• Chromatographic Separations 80
• Thin-layer chromatography 80

3.12,2  Packing of column          80

CHAPTER FOUR

• Results and Discussion 81
• Yields of extracts 81
• Phytochemical screening results in 83
• Antimicrobial activities of spicigera 91
• Physicochemical properties of seed oil 93
• Fatty acid profile of spicigera seed oil 95
• Insecticidal evaluation of extracts 97
• Purification of ethylacetate fraction by HPLC 103
• GC-MS analysis of the volatile oils of spicigera leaves 105
• Chromatographic separation 109
• Structural elucidation ZL-14 113
• Structural elucidation EL-2 118
• Toxicity evaluation of ethylacetate and methanolic extracts         121
• Evaluation of the biological activity of ursolic acid derivative against trypanosomes       122

CHAPTER FIVE

5.0.      Summary, Conclusion, and suggestions for further work        125

References                    128

Appendices                     154

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INTRODUCTION

Background of Study

Natural products can either be of pre-biotic origin or originate from microbes, plants, or animal sources (Nakanishi, 1999).

As for chemicals, natural products include such classes of compounds as terpenoids, polyketides, amino acids, peptides, proteins, carbohydrates, lipids, nucleic acids, ribonucleic acid (RNA), deoxyribonucleic acid (DNA), and so forth.

Natural products do not just occur by accident or are products of the convenience of nature, but more than likely are a natural expression of the increase in complexity of organisms (Jarvis, 2000).

Interest in natural sources to provide treatments for pain palliatives, or curatives for a variety of maladies or recreational use reaches back to the earliest points of history.

Nature has provided many things for humankind over the years, including the tools for the first attempts at therapeutic intervention (Nakanishi, 1999).

The Nei Ching is one of the earliest health science anthologies ever produced and dates back to the thirtieth century B.C. (Nakanishi, 1999).

Some of the first records on the use of natural products in medicine were written in cuneiform in Mesopotamia on clay tablets and date to approximately 2600 B.C. (Cragg and Newman, 2001; Nakanishi, 1999).

Indeed, many of these agents continue to exist in one form or the other to this day and are used for the treatment of inflammation, influenza, cough, and parasitic infestation among others.

Chinese herb guides document the use of herbaceous plants as far back in time as 2000 B.C (Holt and Chandra, 2002).

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REFERENCES

Abaoba O.O.Efuwape B.M. (2001). Antibacterial properties of some Nigerian species.Biological Research Communications. 13:183-188
Abdullah, D., Ping, Q.N., Liu, G.J., (1996). Enhancing effect of essential oils on the Penetration of 5-fluorouracil through rat skin. Acta Pharm. Sin. 31, 214 – 221.
Abubakar M.S.,Abdulrahman E.M., and Owonubi M.O.(1995).The investigation of insecticidal activity of some Nigerian plants.Nigerian Society of Pharmacognosy Scientific Conference Jos, Nigeria.
Adams R.P.,(1983). Identification of essential oil components by Gas chromatography/Mass spectrometry. Allured Publishing Corporation, Carol Stream Illinois USA, pp. 50-150.
Adeniyi B.A., Asekun O.T., and Ekundayo O. (1999).Antimicrobial activity of the essential oil of seeds Hyptis suaveolens leaves.Fitoterapia.70:440-442
Aguirre F. (2004). A novel 8.7kDa protease inhibitor from chan seeds (Hyptis suaveolens L.)inhibits proteases from the larger grain borer Prostephanus truncatus(Coleoptera:Bostrichidae). Comparative Biochemistry and Physiology,138:81-89.