Azadirachta indica is a tree in the mahogamy family maliaceae growing in tropical and sub-tropical regions. Alkaloid on the other hand are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. In the extraction of alkaloid from Azadirachta indica leaves, 200g of dry powdered Azadirachta indica leave was weigh and defatted with 200mls of n-hexane for 24 hours in a 500ml conical flask and decanted away. Solution of acetic acid and ethanol was added to the residue and was shake and allow to stand for 4 hours, filtered and the filtrate was evaporate to ¼ of its original volume. 80ml of Ammonium hydroxide was added drop wise to precipitate and was filtered off with filter paper. The alkaloid in the filter paper was place in 3 different places on a thin layer chromatographic plate and was place inside a chromatography tank in the solution of chloroform and methanol for 1 hour, dragendroff’s reagent was spread on the plate to detect only the alkaloid in the plate. CHAPTER ONE

1.0 INTRODUCTION

1.1 BACKGROUND

Azadirachta indica is a native tree of India. It is a tree in the mahogany family maliaceae growing in tropical and sub-tropical regions, its fruits and seed are the sources of Azaodirachta indica oil (zillur etal, 2006).

Azaodirachta indica is a fast growing tree that can reach a height of 15 – 20 metres (49 – 66ft) rarely to 35 – 40 metres (115 – 130ft) it is evergreen but in severe drought it may shed most of nearly all of its leaves. The Azaodirachta indica tree is noted for its drought resistance, normally it thrive in areas with sub-arid to sub-humid conditions with an annual rainfall 400 – 1,200 millimeters (16 – 47). It can grow in regions with annual rainfall below 400mm, but in such cases it depends largely on ground water levels. Azaodirachta indica can grow in many different types of soil but it thrives best on well drained deep and sandy soils. it can tolerate high to very high temperature and does not tolerate temperature below 4⁰C (39⁰F) (Zillui et al, 2004).

Alkaloids are group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids in addition to carbon, hydrogen, sulphur and more rarely other elements such as chlorine, bromine and phosphorus.

Alkaloids are produced by a large variety of organisms including bacteria, fungi, plant and animals and are part of the group of natural products (also called secondary metabolites). Many alkaloids can be purified from crude extract by acid-base extraction. Many alkaloids are toxic to other organisms. They often have pharmacological effects and are used as medications as recreational drugs, or in enthegogenic rituals. Examples are the local anesthetic and stimulant cocaine (Kausik, 2006).

The boundary between alkaloids and other nitrogen-containing natural compound is not clear cut. Compounds like amino acid peptides, proteins, nucleotides, nucleic acid, amines and antibiotics are usually not called alkaloids. Naturally compounds containing nitrogen in the exocyclic position (Mescaline serotonin, dopamine) are usually attributed to amines rather than alkaloids (Gangli, 2002).

The name alkaloid was introduced in 1819 by the German chemist Carl F.W Meissner. there is no unique method of naming alkaloids, Many individual names are formed by additing the suffix “ine” to the species or generic alkaloids. For example, atropine is isolated from the plant Atrop belladonia, strychinine is obtained from the seed of strychnione tree. If several alkaloids are extracted from one plant then their names often contain suffixes “idine”, “anine”, “aline”, etc (Lewis, 2005).

There are three alkaloids extracted from neem leaf Viz Gudunine, nimbin and nimbidin. Because of the structure diversity of alkaloids, there is no single method of their extraction from natural raw materials. Most alkaloids are soluble in organic solvents but not in water, and the opposite tendency of their salts. most plants contain several alkaloids. Their mixture is extracted first and then individual alkaloids are separated. Plants are thoroughly ground before extraction. Most alkaloids are present in the raw plants in the form of salts of organic acids. The extracted alkaloids may remain salts or change into bases. The nimbin contains acetoxy, a lactone, an estare, a methoxy and an aldehyde group. Nimbidin contains sulphur. Gudunin contains meliacins. Guducin shown potent anti inflammatory activity in experimental animals while nimbin and nimbidin have been found to have anti viral activity. They affect potato virus x, vaccinal virus and fowl POX virus (Leland, 2006).

1.2 AIMS OF THE STUDY

The aim of this research project is to determine the alkaloids found in Azaodirachta indica plant.

1.3 STATEMENT OF THE PROBLEM

The major problem associated with alkaloid is that many alkaloid are toxic to human, adequate measures are taken to know the toxicity and the amount of toxic substance present in the alkaloid. Alkaloid potends a tremendous potential as medicinal drugs and the study of their properties and application is an endless quest in providing remedies to human and animal ailment

1.4 SIGNIFICANCE OF THE STUDY

The importance of this study is to determine and isolate the alkaloids present in Azadirachta indica leave.

1.5 SCOPE OF THE STUDY

The scope of this study is limited to the determination of alkaloid from Azadirachta indica leaves.

CHAPTER TWO

2.0 LITERATURE REVIEW

2.1 ALKALOIDS

Alkaloids is a specific class of chemical compounds found in plant and occasionally in animal are notable chiefly for their physiological activity, many have long histories as poisons, narcotic, hallucinogens and medical agents. Generally, alkaloids are basic or alkaline substances that is they neutralize acids, their molecules contain chiefly atoms of carbon, hydrogen and nitrogen which is the source of their basicity (Begley, 2007).

Alkaloid vary wide in structure and properties. Some are relatively simple with as few as five carbon atom e.g xanthine others such as solanine are complicated with as many as 44 carbon atom.

2.2 OCCURANCE OF ALKALOID

Alkaloid occur most commonly in the form of their salts in solution in the cell sap of younger tissues as in living parenchyma cells and more commonly stored in the solid state in older tissues such as bark cells. Although they often occur in greater concentration in one organ than in another, they are distributed in all parts of the alkaloid bearing plant in greater or lesser concentration. Alkaloid probably are formed in the green tissues such as the leaf and are then carried in the sap to various parts of the organism such as bark and seeds, for temporary or permanent storage. In other plants such as tobacco alkaloids, are synthesized in the roots alone and from there are transported to other parts of the plant (Leland, 2006).

Alkaloids are distributed in the flowering seed plants especially in the dicotylendons. They occur in certain families more than in others, these include the poppy family, barberry family and to a lesser extent in the bean family (leguninosae).

2.3 GENERAL PROPERTIES OF ALKALOID

Alkaloid are non-volatile and odourless but have a bitter characteristics taste (Strychine is the most bitter substance known, whereas cocaine is practically without bitterness). Most alkaloid are colourless but occasionally the alkaloid base is colourless and the salts are coloured. nearly all alkaloid are optically active and can fluoresce. Most alkaloid and their salts are crystalline solids and they are insoluble in water and more soluble in organic solvent (Bartlett, 2009).

Alkaloids are often divided into the following major groups

1) “True alkaloids” which contain nitrogen in the heterocycle and originate from amino acids. Their characteristic examples are atropine, nicotine, and morphine.

2) Protoalkaloids which contain nitrogen and also originate from amino acids examples include mescaline, adrenaline and ephedrine.

3) Polyamine alkaloids they are derivatives of putrescine, spermidine and spermine

4) Peptide and cyclopeptide alkaloids

Pseudoalkaloids – alkaloids like compounds that do not originate from amino acid. This group includes, terpene-like and steroid-like alkaloids as well as purine-like alkaloids such as caffeing some alkaloids do not have the carbon skeleton characterization of their group. So galantamine and homoaforphines do not contain isoquinoline fragment, but are in isoquinoline alkaloids (Begley, 2007).NALYSIS OF ALKALOID IN AZADIRACHTA INDICA LEAF