Combination of microbiological, spectroscopic and molecular docking techniques to study the antibacterial mechanism of thymol against Staphylococcus aureus: membrane damage and genomic DNA binding
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- 作者：Lang-Hong Wang ; Zhi-Hong Zhang ; Xin-An Zeng…
- 关键词：Thymol ; Staphylococcus aureus ; Gas chromatography–mass spectrometry ; Membrane integrity ; Atomic force microscopy
- 刊名：Analytical and Bioanalytical Chemistry
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：409
- 期：6
- 页码：1615-1625
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Analytical Chemistry; Biochemistry, general; Laboratory Medicine; Characterization and Evaluation of Materials; Food Science; Monitoring/Environmental Analysis;
- 出版者：Springer Berlin Heidelberg
- ISSN：1618-2650
- 卷排序：409
文摘
Thymol (2-isopropyl-5-methylphenol) is a natural ingredient used as flavor or preservative agent in food products. The antibacterial mechanism of thymol against Gram-positive, Staphylococcus aureus was investigated in this work. A total of 15 membrane fatty acids were identified in S. aureus cells by gas chromatography–mass spectrometry. Exposure to thymol at low concentrations induced obvious alterations in membrane fatty acid composition, such as decreasing the proportion of branched 12-methyltetradecanoic acid and 14-methylhexadecanoic acid (from 22.4 and 17.3% to 7.9 and 10.3%, respectively). Membrane permeability assay and morphological image showed that thymol at higher concentrations disrupted S. aureus cell membrane integrity, which may decrease cell viability. Moreover, the interaction of thymol with genomic DNA was also investigated using multi-spectroscopic techniques, docking and atomic force microscopy. The results indicated that thymol bound to the minor groove of DNA with binding constant (Ka) value of (1.22 ± 0.14) × 104 M−1, and this binding interaction induced a mild destabilization in the DNA secondary structure, and made DNA molecules to be aggregated.