ABSTRACT

The isolation and detection of alkaloid from the plant seed of Cassia occidentalis from leguminosae family was carried out using solvent extraction process. The dried powdered seed was soaked in a sample bottle using 1, 1- dichloromethane. After 3 days of occasional shaking, it was filtered, and the crude alkaloid was extracted using batch method.

Purification process of the crude alkaloid was not carried out. Thin layers chromatographic separation process was also not carried out. The crude alkaloid extracted from the seed of the plant was used. The test for alkaloid was carried out using Dragendorff’s reagent, Mayer’s reagent and Wagner and Lugol’s reagent. The following reagent shows a positive test. Dragendorff’s reagent yield a Reddish-brown precipitation, Mayer’s reagent yields a cream precipitate, while Wagner’s and Lugol’s reagent yields a Reddish-brown precipitate.

The presence of these precipitates indicates the presence of alkaloid in the seed of cassia occidentalis.

CHAPTER ONE

1.0   INTRODUCTION

1.1   BACKGROUND OF THE STUDIES

Alkaloids are larger groups of basic organic substance of natural origin usually plant which contains carbon, hydrogen and one or more nitrogen atoms. The nitrogen content is usually present in a heterocyclic ring such as in pyrrole, pyridine, pyrrolidine, quinoline or isoquinoline. It can be naturally occurring compounds containing basic nitrogen atoms (Finar I.L 2007).

According to Rogers M. F and Wink M. (1998), alkaloids are specific class of chemical compound found in plants and occasionally animals. Many have long historics as poison, narcotics hallucinogens and medicinal agents.

Generally, alkaloids are basic alkaline substances which can neutralizes acids. The basicity of alkaloids depends on lone pairs of electrons on their nitrogen atom thus forming salts with mineral acids such as HCL and H2SO4 and organic acids such as tartaric acid or malic acid. Alkaloids must be a product of plant or animal metabolism and must contain at least one nitrogen atoms that can be active as a base in acid-base reaction. Alkaloids could be classified either by the biological system in which they occur or by their chemical structure.

Hesse M. (2005), Said that most alkaloids contain oxygen but occasionally as in nicotine, this element is absence such oxygen free compounds are usually volatile. They vary widely in properties from one substance to the other. Some are relatively simple with a few as five carbon eg. xanthine, solanine is complicated with as many as 44 carbon atoms. Many compounds, although may fit some definition of alkaloids which are excluded from the group because. It can simply be done practically. Purines, pyridine, pyrazine, vitamins, antibiotics and amino sugar are all excluded.

 

CASSIA OCCIDENTALIS LINN.

The plant cassia occidentalis also commonly known as Negro coffee or coffee weed is a herb found in many countries including India, South America, and some parts of Africa. It belongs to the family Leguminosae. It’s habitat is likely meadows, pastures wastes places and it grow abundantly after rain. The leave are pinnately compounded with four to six (4 – 6) pars of smooth long-pointed ovate leaflet that has a sharp tip. Flowers occurs in leaf axils. Sepals are green and long. The petals are yellow and long. The stamens are of two different length. The pod is smooth and slender, slightly curved and dark brownish in colour. The seeds are dull and flattened on both ends. The seeds, leaves and other parts of the plants have been investigated and showed that it is highly medicinal. It has also been used for the treatment of inflammation, fever, liver disorder constipation, fungal infection, ulcers, respiratory infection and snake bite etc. The seeds when roasted are used as an alternative form of coffee tea.

1.3   AIMS OF THE STUDY

This project work is aim at analyzing the extract of alkaloids from the seed of Cassia occidentalis with different diodal reagents.

1.4   STATEMENT OF THE PROBLEM

herbal medicine is neglected because it lacks scientific analysis and most plant have medicinal effect on human being. Besides its chemical and inorganic constituent are not determined.

1.5   SIGNIFICANCE OF THE STUDY

The research work is important because it helps to know the alkaloid content of this medicinal plant (Cassia occidentalis seed). It will also help us to know if any of their constituent will be extracted and used in other sphere of human endeavour like the chemical industries, cosmetics, especially food and insecticidal industries.

1.6   SCOPE OF THE STUDY

For the purpose of the work, approximate analysis was carried out in the laboratory using solvent extraction process. Detection of the extract alkaloids was also carried out using diode reagent.

1.7   LIMITATION OF THE STUDY

The project work was only limited because of the high cost of spectroscopic instrument like UV, IR and NMR as these would have helped determining the structure analysis of the extracted alkaloids.