Comparative Studies on Phytochemical Constituents Andantimicrobial Activity on Three Onion Species

Abstract

L. Ibrahim,A. Abdulazeez,S. Ummisalma, A. Usman, S. U. Nagenu, U. Badeggi,  S. H.  Mohammed, A. I.  Muhammad  and F. B. Salahuu

Several studies have been carried out on the phytochemical constituents of onions, without recourse to the understanding that there are different species of onions (Allium cepa, Allium ascalanicum and Crinum ornatum). This study is designed to determine and compare the phytochemical constituents and antimicrobial activity of different species of onions. Phytochemical analysis was carried out on the different plant samples using wass distilled water, ethanol and chloroform as solvents. The results gotten show that flavonoid, saponin and steroids were present while tannin was present in the ethanol extract and absent in the rest extract. Glycosides were present in distilled and chloroform extracts, alkaloid was present in both distilled water and ethanol extracts but absent in the chloroform extract. Hydroxyl anthraquinone was absent in all three samples Phytochemical data for Crinum ornatum, indicated the absence of flavonoid, tannins and hydroxyl anthraquinone was absent in distilled water extract, for the ethanol extract flavonoid, tannins saponin, glycosides alkaloid were present while steroid and hydroxyl anthraquinones were absent. Flavonoid, saponin, glycosides steroid, and hydroxyl anthraquinones were absent in the chloroform extract while tannins and alkaloids were present. The information obtained for their phytochemical analysis indicated that onion bulbs have some medicinal valuece. The antimicrobial investigations show that the ethanol extracts of crinum ornatum, allium cepa and allium ascalonicumexhibited11.2, 8.9and 8.9mm which is consistent with a zone of high inhibition against the Staphylococcus aureus while the distilled water and chloroform extracts showed minimum inhibitory action. However, Efaecalis ethanol extracts of allium cepa, allium ascalanicum, and cranium ornatumdisplayedthe highest inhibitory action of 4.84.8and 8.2mm respectively for E. faecalis, compared to distilled water, ethanol. For E-colalsohighgh inhibitory zones exhibited ethanol extract of crinum ornatum (8.6 mm),  allium cepa (5.8mm) and allium ascalonicum (5.8mm) were also observed., compared to distilled water and chloroform extracts that exhibited inhibitory zones positioned at 18and 4.4 and 4.4 mm for crinum ornatum, allium cepa and allium ascalonicumrespectively. Other active inhibitory zones were also observed and they gave evidence that the different species of onions have certain .antimicrobia properties.