ABSTRACT

The antimicrobial activity and phytochemical screening of the leaves of Piper guineense Schumach, Psidium guajava Linn, Gongrenema latifolium Endl and Terminalia catappa Linn was carried out. The four plant species indicated the presence of alkaloid, phenol, tannin, spaonin and flavonoid which are bioactive component. The percentage of the phytochemcials are as follows alkaloid (0.46.139%), phenol (0.37-1.66%, saponin (0.31-0.67%), flavonoid (0.23-0.55%) and tannin (0.13-037%). The antimicrobial activity of the ethanolic and aqueous extracts of the leaves of the plant species were tested against four microorganisms, Candida albican, Klebsiella pneumonia, Escherchia coli and Bacillus subtilis. The sensitivity of the microorganisms was determined using disk diffusion method. Ethanolic plant extract and aqueous extract inhibited the growth of these pathogens. The zone of inhibition of the growth of these microorganisms by the plant extract depends on the concentration of the extract. Ethanolic plant extract had high sensitivity than the aqueous plant extract which shows less. Gongronema latifolium contained more alkaloids (1.39±0.03%) than other phytochemicals and Terminalia catappa had less tannin (0.13±0.00%) than other phytochemicals. The ethanolic extracts of Gongronema latifolium had the highest inhibitory activity (24.00±2.00mm) which shows more sensitivity against the test organisms while the aqueous extracts of Terminalia catappa has low inhibitory activity (8.33±0.58mm) which showed less sensitivity against the test organism. This result reveals that these plant species have potentials as source of raw materials in the pharmaceutical industry.   

TABLE OF CONTENTS

Cover page

Title page i

Certification ii

Dedication iii

Acknowledgement iv

Table of content v

List of tables vii

List of plates viii

Abstract ix

CHAPTER ONE 

1.0 Introduction 1

1.1.2 Aims and objective of the research 3

1.1.3 Justification of the study 4

CHAPTER TWO

2.0 Literature review 5

2.1 Phytochemical screening of plants 5

2.1.2 Antimicrobial activity of plants 7

2.3 Botany of plants 9

2.3.1 Botany of Terminalia catappa  9

2.3.2 Botany of Gongronema latifolium 10

2.2.3 Botany of Piper guineenses 10

2.2.4 Botany of Psidium guajava 11

CHAPTER THREE

3.0 Source of materials 12

3.1 Sample preparation 12

3.2 Phytochemical screening 12

3.2.1 Qualitative analysis of phytochemicals 13

3.2.1.1 Test of tannins 13

3.2.1.2 Test of saponin 13

3.2.1.3 Test of flavonoids 13

3.2.1.4 Test of alkaloids 14

3.2.1.5 Test of Phenols 14

3.3 Quantitative determination of the phytochemcials 14

3.3.1 Determination of alkaloids ` 14

3.3.2 Determination of flavonoids 15

3.3.3 Determination of tannins 16

3.3.4 Determination of saponin 17

3.3.5 Determination of Phenols 18

3.4 Antimicrobial activity of the leaves of the plants Terminalia catappa,

Piper Guineenses, Gongronema Latifolium and Psidium Guajava. 19

3.4.1 Sample Preparation 19

3.4.2 Production of extracts 19

3.4.3 Sources of test organism 19

3.4.4 Antimicrobial activity test 20

3.4.5 Determination of Minimum Inhibition Concentration 20

3.4.6 Statistical Analysis 21

CHAPTER FOUR

4.0 Results 25

4.1 Phytochemical components 25

4.1.1 Qualitative analysis 25

4.1.2 Quantitative analysis 26

CHAPTER FIVE

5.0 Discussion and conclusion 33

5.1 Discussion 33

5.2 Conclusion 36

References