Biological and phytchemical screening of guiera senegalensis leaves

Dissertant

Babakr, Raniya Sad Ahmad

Thesis advisor

Khalid, Hasan al-Subki
al-Imam, Yahya Muhammad Ahmad

University

Omdurman Islamic University

Faculty

Faculty of Pharmacy

Department

Department of Pharmacognosy

University Country

Sudan

Degree

Master

Degree Date

2010

English Abstract

The present study was carried to confirm or refute, on scientific basis, the folkloric uses of one selected Sudanese medicinal plant (Guiera senegalensis) in the therapy of abdominal pain via :- The chemical screening of petroleum ether, methanol and water extracts of Guiera senegalensis leaves (family : Combretaceae) which result in the presence of alkaloids, carotenoids, coumarins, flavonoids and volatile oils.

Flavonoids were found to be present in the petroleum ether extract as free aglycones and as glycosides in both of methanol and water extracts.

Volatile oils and higher fatty acids were found at low concentrations.

The methanol and water extracts revealed similarities in their constituents but there were variations in the detected amounts in each extract according to the metabolites solubility.

Hydrolysable tannins, anthocyanidin glycosides, reducing compounds, alkaloid salts and saponins as glycosides and as free aglycones were detected in both, but in rather high concentration in the methanol extract.

Tannins, polyuronides and saponins were found to be the major constituents of the aqueous extract.

All of the three extracts were devoid of steroid glycosides.

xi Assessment of the antimicrobial efficacy of the leaves of Guiera senegalensis against two standard gram positive bacteria (Bacillus subtilis, Staphylococcus aureus), two standard gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa) and two standard fungal organisms (Aspergillus niger, Candida albicans).

These resulted on that the methanol extract was found to be highly active against the two standard gram positive and gram negative bacteria and the two standard fungal organisms, followed by water extract.

The least antimicrobial activity was associated with chloroform extract which was just active against Bacillus subtilis.

The methanol extracts was subjected to fractionation by liquid- liquid extraction technique to three fractions (petroleum ether, ethyl acetate, water) and their antimicrobial activities were studied.

It was found that the ethyl acetate extract exhibit a significant antimicrobial activity against all the tested organisms and this led to further fractionations by the use of column chromatography.

Ten fractions of the column chromatography fractions were subjected to antimicrobial screening.

Fraction 14 was the most effective one so it was subjected to further fractionation by Preparative Thin Layer Chromatography PTLC and the antimicrobial activities of four fractions were studied.

Studying the effect of the aqueous extract on the isolated intestines of rabbit and guinea pig resulted in that the extract relaxed xii completely the rabbit duodenum and guinea pig ileum.

The relaxation of the duodenum was refractory to prior administration of both Tolazoline and Propranolol.

The extract did not affect the stimulant effect of Acetylcholine on guinea pig ileum.

Main Subjects

Botany

Topics

• Medicinal plants
• Botanical chemistry

No. of Pages

130

Table of Contents

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-364959