Institute of Organic Chemistry, Technical University of Braunschweig , Hagenring 30, 38106 Braunschweig, Germany.
J Nat Prod. 2012 Oct 26;75(10):1765-76. doi: 10.1021/np300468h. Epub 2012 Sep 20.
Volatile compounds released by 50 bacterial strains, 45 of them actinobacteria in addition to three chloroflexi and two myxobacteria, have been collected by use of a closed-loop stripping apparatus, and the obtained headspace extracts have been analyzed by GC-MS. Excluding terpenes that have recently been published elsewhere, 254 compounds from all kinds of compound classes have been identified. For unambiguous compound identification several reference compounds have been synthesized. Among the detected volatiles 12 new natural products have been found, in addition to mellein, which was released by Saccharopolyspora erythraea. The iterative PKS for this compound has recently been identified by in vitro experiments, but mellein production in S. erythraea has never been reported before. These examples demonstrate that headspace analysis is an important tool for the discovery of natural products that may be overlooked using conventional techniques. The method is also useful for feeding experiments with isotopically labeled precursors and was applied to investigate the biosynthesis of the unusual nitrogen compound 1-nitro-2-methylpropane, which arises from valine. Furthermore, several streptomycetes emitted compounds that were previously recognized as insect pheromones, thus questioning if bacterial symbionts are involved in insect communication.
使用闭路提取装置收集了 50 株细菌菌株（其中 45 株为放线菌，3 株为绿屈挠菌，2 株为黏细菌）释放的挥发性化合物，并通过 GC-MS 对获得的顶空提取物进行了分析。除了最近在其他地方发表的萜类化合物外，已经从各种化合物类别中鉴定出了 254 种化合物。为了明确化合物的鉴定，已经合成了几种参考化合物。在检测到的挥发物中，除了由红色糖多孢菌释放的 mellein 外，还发现了 12 种新的天然产物。这种化合物的迭代 PKS 最近已经通过体外实验确定，但之前从未报道过红色糖多孢菌产生 mellein。这些例子表明，顶空分析是发现可能被传统技术忽视的天然产物的重要工具。该方法还可用于使用同位素标记前体的喂养实验，并应用于研究来自缬氨酸的异常氮化合物 1-硝基-2-甲基丙烷的生物合成。此外，几种链霉菌释放的化合物以前被认为是昆虫信息素，因此质疑细菌共生体是否参与昆虫通讯。
