Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhong-shan Road, Dalian, 116023, China.
Anal Bioanal Chem. 2010 Mar;396(5):1773-9. doi: 10.1007/s00216-009-3379-3. Epub 2010 Jan 9.
Bacteria communicate with each other by a process termed "quorum sensing" (QS), and diffusible, low-molecular-weight chemicals, called signal molecules, are used as the communication languages. In cell-free Burkholderia cepacia CF-66 culture supernatants, five compounds suspected of being signal molecules were identified. The gene (cepI) related with AHLs synthesis were not detected by polymerase chain reaction (PCR) using specific primers. Gas chromatography-mass spectrometry (GC-MS) revealed that these compounds were not AHLs but the diketopiperazines (DKPs) cyclo(Pro-Phe), cyclo(Pro-Tyr), cyclo(Ala-Val), cyclo(Pro-Leu), and cyclo(Pro-Val), all of which were both D and L-type. Four kinds of DKPs had been isolated from other gram-negative bacteria, but the other was a novel kind discovered in CF-66, and L-cyclo (Pro-Phe) was quantified by GC-MS. It was found that exogenous DKPs had a negative effect on the candidacidal activity of the culture supernatant extracts.
细菌通过一种称为“群体感应”（QS）的过程相互通信，并且可扩散的、低分子量的化学物质，称为信号分子，被用作通信语言。在无细胞伯克霍尔德氏菌 CF-66 培养上清液中，鉴定出了五种疑似信号分子的化合物。聚合酶链反应（PCR）使用特异性引物未检测到与 AHLs 合成相关的基因（cepI）。气相色谱-质谱联用（GC-MS）表明这些化合物不是 AHLs，而是二酮哌嗪（DKP）环（Pro-Phe）、环（Pro-Tyr）、环（Ala-Val）、环（Pro-Leu）和环（Pro-Val），它们都是 D 和 L 型。四种 DKP 已从其他革兰氏阴性菌中分离出来，但另一种是在 CF-66 中发现的新型 DKP，L-环（Pro-Phe）通过 GC-MS 进行定量。结果发现外源性 DKP 对培养上清液提取物的杀真菌活性有负面影响。
