Antimicrobial activity and thiosulfinates profile of a formulation based on Allium cepa L. extract

• Published in: Open Chemistry Vol. 15; no. 1; pp. 175 - 181
• Main Authors: Orăşan, O., Oprean, R., Saplonţai-Pop, A., Filip, M., Carpa, R., Saroşi, C., Moldovan, M., Man, S.C.
• Format: Journal Article
• Language: English
• Published: De Gruyter Open 01.01.2017; De Gruyter
• Subjects: Allium cepa L; antimicrobial activity; HPLC-MS; natural extract; thiosulfinate compounds
• ISSN: 2391-5420; 2391-5420
• DOI: 10.1515/chem-2017-0021

Abstract Background Allium species extracts including Allium cepa L. contain sulfur compounds, known for their antiplatelet, antimicrobial, antineoplasic activities. Methodology Antibacterial activity of a formulation based on A . cepa extracts-liquid and lyophilized samples, has been demonstrated using two classes of bacteria: Gram-positive ( Staphylococcus aureus ) and Gram-negative ( Escherichia coli ) and three methods: discs soaked with liquid extract, the wells method in the culture medium, filled with the liquid extract and lyophilized formulation extracts transformed by the incorporation of ultrapure water. The second part of this study includes identification of thiosulfinates compounds from the studied samples by high performance liquid chromatography - mass spectrometry (HPLC-MS). Results The most important inhibition and the highest antibacterial effficiency were observed against Gram-positive bacteria, such as Staphylococcus aureus . The HPLC-MS thiosulfinates profile of the tested formulation extracts shows the presence of seven thiosulfinate compounds, MeS(O)S 1-propenyl ( E , Z ); n -PrS(O)S 1-propenyl-( E ); n -PrS(O)S 1-propenyl-( Z ); trans -zwiebelane; n -PrS(O)CHEtSS-1propenyl; 1-propenylS(O)CHEtSS1-propenyl, which may be responsible for antibacterial activity. Conclusion Testing antimicrobial effects using the three mentioned methods confirmed the antimicrobial activity of the tested samples based on A . cepa extracts, with a demonstrated content of seven thiosulfinate compounds.