ANALYSIS CHEMICAL COMPOUNDS AND ANTIMICROBIAL ACTIVITY OF RED ONION (Allium cepa L.) BULB SKIN EXTRACT

摘要

Recently, drug resistance because of widespread abuse and uncontrol use of antibiotics has become an increasingly difficult problem, with the result that making the development of alternative antimicrobial very urgent handling. Aim of this study was to investigate chemical compounds and antimicrobial activity of outer layers (skin) of red onion bulbs from various extracts using different solvents according to their polarity. In this study, outer layers (skin) of onion (Allium cepa L.) bulbs extract by directly maceration method with methanol as solvent and stratified maceration method based on solvent polarity (hexane, ethyl acetate and methanol). Analysis of chemical compound of hexane, ethyl acetate and methanol extract carried by thin layer chromatography. Phytochemical screening carried out on outer layers of onion (Allium cepa L.) bulbs in simplicia powder. An antimicrobial activity using agar well diffusion method. The culture of microorganism used were Staphylococcus aureus ATCC 29737, Escherichia coli ATCC 10536 and Candida albicans ATCC 10231. Phytochemistry screening positive results of simplicia were showed against the class secondary metabolites of chemical compounds, namely alkaloids, flavonoids, glycosides, saponins, triterpenoids and tannins but not contained anthraquinone glycosides and cyanogenic glycosides. Analysis of chemical compounds of hexane, ethyl acetate and methanol extract produced different chemical compounds, namely triterpenoids and steroids (for hexane extract), polyphenols and alkaloids (for ethyl acetate extract), triterpenoids, polyphenols and alkaloids (for methanol extract). Data showed that extract from stratified maceration method using methanol provided the most extensive inhibitory diameter. Extract of directly maceration method using methanol and extract of stratified maceration method using ethyl acetate showed not so different antimicrobial activity, whereas for an extract from stratified maceration method using hexane was not provide antimicrobial activity at all.