论文部分内容阅读
Autoinducer 2 (AI-2),an important bioactive by-product of the LuxS-catalyzed S-ribosylhomocysteine cleavage reaction in the activated-methyl-cycle,has been suggested to serve as a universal intra-and inter-species signaling molecule.The development of reliable and sensitive methods for quantitative determination of AI-2 is highly desired.However,the chemical properties of AI-2 cause difficulty in its quantitative analysis.Herein,we report a high performance liquid chromatography-tandem mass spectrometric method that enables reproducible and sensitive measurement of AI-2 concentrations in complex matrixes.4,5-Dimethylbenzene-1,2-diamine (DMBDM),an easy-to-obtain commercial reagent,was used for the derivatization treatment.The assay was linear in the concentration range of 1.0-1000 ng/mL (R2 =0.999) and had a lower limit of quantification of 0.58 ng/mL.The method exhibited several advantages,e.g.,high selectivity,wide linear response range,and good sensitivity.Furthermore,the effectiveness of the method was further validated through measuring AI-2 concentrations in the cell-free culture supematant from Escherichia coli wild type.