Preliminary study the effects of semiquinone radicals on bacteriostatic activity

Objective: To study hydroquinone producing semiquinone radicals in alkaline conditions and its antimicrobial effects on methicillin-resistant staphylococcus aureus(MRSA), methicillin sensitive staphylococcus aureus(MSSA) and escherichia coli(BL) 21. Methods: Electron spin resonance method was used in testing the semiquinone radicals. High performance liquid chromatography(HPLC) method was used in testing the reaction products of semiquinone radicals in alkaline cinditions. Punching method was used in each species of MRSA, MSSA and BL21 to determine the antimicrobial effects of hydroquinone in alkaline conditions, and the method of 96-well plates was used to determine its minimal inhibitoryconcentration(MIC). At the same time, the three bacteria growth curve were measured and compared to antimicrobial activity about hy droquinone in pH =7.5 and pH =6 condition. Results: The antimicrobial effects of the semiquinone radicals were stronger than those of hydroquinone and its i nal products in alkaline conditions. The values of MIC that hydroquinone alkaline solution inhibited MRSA, MSSA and BL21 were respectively 0.081, 0.081 and 0.649mg/m L, while the hydroquinone solution 0.325, 0.325 and 1.298mg/mL. Conclusion: Hydroquinone antimicrobial activity in alkaline conditions was stronger than that in neutral or acid conditions.