title: Determination of diketopiperazines of Burkholderia cepacia CF-66 by gas chromatography-mass spectrometry.
abstract: 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.
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhong-shan Road, Dalian, 116023, China.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Wang
authors.forename: Chun-Shan
authors.initials: CS
authors.lastname: Quan
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Qi
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Sheng-Di
authors.initials: SD
authors.lastname: Fan
mesh_terms: D000935:Antifungal Agents / Q000032:analysis* / Q000494:pharmacology; D016956:Burkholderia cepacia / Q000737:chemistry*; D002176:Candida albicans / Q000187:drug effects; D054659:Diketopiperazines / Q000032:analysis* / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000935:Antifungal Agents; D054659:Diketopiperazines