PHYTOCHEMICAL AND ANTIMICROBIAL STUDIES OF THE STEMBARK EXTRACT OF ERYTHROPHLEUM AFRICANUM (Welw. ex Benth) Harms
PHYTOCHEMICAL AND ANTIMICROBIAL STUDIES OF THE STEMBARK EXTRACT OF ERYTHROPHLEUM AFRICANUM (Welw. ex Benth) Harms
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Date
2015-04
Authors
ALHAJI, Shehu Ahmad
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Abstract
The Stembark of the Erythrophleum africanum plant (Welw. ex Benth) collected from Niger State, Nigeria was air-dried, pulverized and exhaustively extracted by maceration using ethanol. The phytochemical screening of the extract revealed the presence of secondary metabolites which include cardiac glycosides, flavonoids, terpenoids, saponins, alkaloids and steroids. The antimicrobial sensitivity test showed that the extract was sensitive to these organisms (with zone of inhibition indicated): S. aureus (25 mm), S. faecalis (27 mm), E. cloacae (29 mm), P. mirabilis (22 mm) and C. stellatoidea (24 mm) while E. coli, P. aeruginosa and C. albicans were resistant. The minimum inhibitory concentration (MIC) results revealed that the extract inhibited the growth of five (5) out of eight (8) tested organisms at 5 mg/ml for S. aureus, S. faecalis, E. cloacae, P. mirabilis and C. stellatoidea. P. aeruginosa, E. coli, C. ulcerans and C. albicans are not inhibited even at 20 mg/ml. The minimum bactericidal/fungicidal concentration (MBC/MFC) of the extract was 20 mg/ml against S. aureus and P. mirabilis, and 10 mg/ml for S. faecalis, E. cloacae and C. stellatoidea, while P. aeruginosa, E. coli, C. ulcerans and C. albicans proved to be resistant. The crude ethanol extract was dissolved in distilled water and then partitioned with petroleum ether, ethyl acetate, chloroform and n-butanol respectively. Preparative TLC on the n-butanol fraction developed with ethyl acetate/methanol (7:3 v/v) led to the isolation of the compound coded, NA. The isolated compound NA was screened for antimicrobial properties with the zone of inhibition found to be higher than that of crude ethanol extract. For the isolated compound NA, the zone of inhibition are S. aureus (26 mm), S. faecalis (29 mm), E. cloacae (30 mm), P. mirabilis (26 mm), and C. stellatoidea (29 mm). The minimum inhibitory concentration of the isolated compound NA against S. aureus and P. mirabilis was observed at 5 mg/ml and for S. faecalis, E. cloacae and C. stellatoidea at 2.5 mg/ml while P.
aeruginosa, E. coli, C. ulcerans and C. albicans are not inhibited even at 20 mg/ml. The minimum bactericidal/fungicidal concentration of the isolate NA against S. aureus, P. mirabilis, and C. stellatoidea was observed at 10 mg/ml while S. faecalis and E. cloacae was observed at 5 mg/ml, and the organisms showed moderate to very heavy colony growth at 2.5 to 1.25 mg/ml. The isolated compound NA was subjected to NMR analysis i.e 1HNMR, 13CNMR, DEPT, COSY, NOESY, HMBC and HSQC from which the structure of the isolated compound NA was elucidated and found to be ipolamiide which was confirmed from spectra data reported in the literature.
Description
A DISSERTATION SUBMITTED TO THE SCHOOL OF POST GRADUATE STUDIES, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF A MASTER OF SCIENCE DEGREE IN ORGANIC CHEMISTRY DEPARTMENT OF CHEMISTRY, FACULTY OF SCIENCE AHMADU BELLO UNIVERSITY, ZARIA NIGERIA.
Keywords
PHYTOCHEMICAL,, ANTIMICROBIAL STUDIES,, STEMBARK EXTRACT,, ERYTHROPHLEUM AFRICANUM,, (Welw. ex Benth),, Harms.