N-acyl homoserine lactones (AHL) are small signal molecules involved in the quorum sensing of many gram-negative bacteria, and play an important role in biofilm formation and pathogenesis. Present analytical methods for identification and quantification of AHL require time-consuming sample preparation steps and are hampered by the lack of appropriate standards. By aiming at a fast and straightforward method for AHL analytics, we investigated the applicability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Suitable MALDI matrices, including crystalline and ionic liquid matrices, were tested and the fragmentation of different AHL in collision-induced dissociation MS/MS was studied, providing information about characteristic marker fragments ions. Employing small-scale synthesis protocols, we established a versatile and cost-efficient procedure for fast generation of isotope-labeled AHL standards, which can be used without extensive purification and yielded accurate standard curves. Quantitative analysis was possible in the low pico-molar range, with lower limits of quantification reaching from 1 to 5 pmol for different AHL. The developed methodology was successfully applied in a quantitative MALDI MS analysis of low-volume culture supernatants of Pseudomonas aeruginosa.

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ñ酰基高丝氨酸内酯（AHL）是参与许多革兰氏阴性细菌群体感应的小信号分子，在生物膜形成和发病机理中起着重要作用。当前用于AHL鉴定和定量的分析方法需要耗时的样品制备步骤，并且由于缺乏适当的标准而受阻。通过针对AHL分析的快速，直接方法，我们研究了基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）的适用性。测试了合适的MALDI基质（包括晶体和离子液体基质），并研究了碰撞诱导解离MS / MS中不同AHL的裂解，从而提供了有关特征性标记碎片离子的信息。采用小规模的合成协议，我们建立了一种通用且具有成本效益的程序，可快速生成同位素标记的AHL标准品，而无需大量纯化即可使用，并能产生准确的标准曲线。可以在低皮摩尔范围内进行定量分析，对于不同的AHL，定量下限可达到1-5 pmol。所开发的方法已成功地用于定量的小批量培养上清液的MALDI MS分析。铜绿假单胞菌。

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