Streptomyces sp. FORM5 is a bacterium that is known to produce the antibiotic streptazolin and related compounds. We investigated the strain for the production of volatiles using the CLSA (closed-loop stripping analysis) method. Liquid and agar plate cultures revealed the formation of new 2-alkylpyridines (streptopyridines), structurally closely related to the already known 2-pentadienylpiperidines. The structures of the streptopyridines A to E were confirmed by total synthesis. The analysis of the liquid phase by solvent extraction or extraction with an Oasis adsorbent showed that streptazolin and 2-pentadienylpiperidine are the major compounds, while the streptopyridines are only minor components. In the gas phase, only the streptopyridines could be detected. Therefore, an orthogonal set of analysis is needed to assess the metabolic profile of bacteria, because volatile compounds are obviously overlooked by traditional analytical methods. The streptopyridines are strain specific volatiles that are accompanied by a broad range of headspace constituents that occur in many actinomycetes. Volatiles might be of ecological importance for the producing organism, and, as biosynthetic intermediates or shunt products, they can be useful as indicators of antibiotic production in a bacterium.
Streptomyces sp. FORM5 是一种已知能产生抗生素 streptazolin 及相关化合物的细菌。我们使用 CLSA(闭环蒸馏分析)方法研究了这株菌株的挥发性产物。液体和琼脂平板培养显示了新的 2-烷基吡啶(streptopyridines)的形成,这些化合物在结构上与已知的 2-戊二烯基哌啶密切相关。通过全合成确认了 streptopyridines A 到 E 的结构。通过溶剂萃取或使用 Oasis 吸附剂提取液相分析表明,streptazolin 和 2-戊二烯基哌啶是主要化合物,而 streptopyridines 只是次要成分。在气相中,只能检测到 streptopyridines。因此,需要一套正交分析方法来评估细菌的代谢谱,因为传统分析方法明显忽视了挥发性化合物。streptopyridines 是与菌株特异性相关的挥发性化合物,伴随着许多放线菌中出现的广泛的顶空成分。挥发性化合物可能对产生有生态重要性,同时,作为生物合成中间体或旁路产物,它们可用作细菌中抗生素产生的指标。