Isolation and Identification of Compounds from Bioactive Extracts ofTaraxacum officinaleWeber ex F. H. Wigg. (Dandelion) as a Potential Source of Antibacterial Agents

Abstract

Currently, the most effective treatment for recurrent urinary tract infections in women is antibiotics. However, the limitation for this treatment is the duration and dosage of antibiotics and the resistance that bacteria develop after a long period of administration. With the aim of identifying mainly novel natural agents with antibacterial activity, the present study was undertaken to investigate the biological and phytochemical properties of extracts from the leavesTaraxacum officinale.The structural identification of compounds present in hexane (Hex) and ethyl acetate (AcOEt) extracts was performed by mass spectrometry (GC-MS) spectroscopic techniques and nuclear magnetic resonance (NMR) with the major compounds corresponding to different sesquiterpene lactones (α-santonin, glabellin, arborescin, and estafiatin), monoterpene (9,10-dimethyltricycle [4.2.1.1 (2,5)]decane-9,10-diol), phytosterol (Stigmasta-5,22-dien-3β-ol acetate), terpenes (lupeol acetate, pregn-5-en-20-one-3β-acetyloxy-17-hydroxy, 2-hydroxy-4-methoxy benzaldehyde), and coumarin (benzofuranone 5,6,7,7-a-tetraaldehyde-4,4,7a-trimethyl). The results obtained show that the Hex extract was highly active againstStaphylococcus aureusshowing a MIC of 200 μg/mL and moderately active againstEscherichia coliandKlebsiella pneumoniaewith MIC values of 400 μg/mL and 800 μg/mL for the other Gram-negative strains tested withProteus mirabilisas uropathogensin vitro. Therefore, the effective dandelion extracts could be used in the development of future products with industrial application.