Groenhagen Ulrike, Leandrini De Oliveira Ana Ligia, Fielding Elisha, Moore Bradley S, Schulz Stefan
Institute of Organic Chemistry, Technische Universität Braunschweig, Hagenring 30, 38106, Braunschweig, Germany.
Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
Chembiochem. 2016 Oct 17;17(20):1978-1985. doi: 10.1002/cbic.201600388. Epub 2016 Sep 6.
Terrestrial bacteria, especially actinomycetes, are known to be prolific producers of volatile compounds. We show here that bacteria from ocean sediments can also release complex bouquets of volatiles. The actinomycete Salinispora tropica produces cyclohexenyl compounds not previously known in nature, such as methyl cyclohex-2-ene-1-carboxylate (9), methyl 2-(cyclohex-2-en-1-yl)acetate (10), methyl (E/Z)-2-(cyclohex-2-en-1-ylidene)acetate (11/12), and related alcohols 8 and 13. These compounds were identified by GC/MS and confirmed by synthesis. In addition, rare spiroacetals, aromatic compounds, short-chain acids and esters, alcohols, and various cyclic compounds were produced by the bacteria. The biosynthesis of the cyclohexenyl compounds is closely coupled to that of cyclohexenylalanine (4), a building block of salinosporamide A, a proteasome inhibitor produced by S. tropica. Analysis of S. tropica strains that harbor knockouts of the salinosporamide biosynthetic genes salX and salD, coupled with feeding experiments, revealed that 3-(cyclohex-2-en-1-yl)-2-oxopropanoic acid (60) and 3-(cyclohex-2-en-1-ylidene)-2-oxopropanoic acid (isomers 61 and 62) are important intermediates in the biosynthesis of salinosporamide A, 4, and 8-13.
已知陆生细菌，尤其是放线菌，是挥发性化合物的丰富生产者。我们在此表明，来自海洋沉积物的细菌也能释放出复杂的挥发性化合物组合。热带盐孢放线菌产生了自然界中以前未知的环己烯基化合物，如环己 - 2 - 烯 - 1 - 羧酸甲酯（9）、2 - （环己 - 2 - 烯 - 1 - 基）乙酸甲酯（10）、（E/Z）-2 - （环己 - 2 - 烯 - 1 - 亚基）乙酸甲酯（11/12）以及相关醇类8和13。这些化合物通过气相色谱/质谱联用仪（GC/MS）鉴定，并通过合成得到证实。此外，这些细菌还产生了罕见的螺缩醛、芳香族化合物、短链酸和酯、醇类以及各种环状化合物。环己烯基化合物的生物合成与环己烯基丙氨酸（4）的生物合成紧密相关，环己烯基丙氨酸是热带盐孢放线菌产生的蛋白酶体抑制剂盐孢霉素A的一个组成部分。对携带盐孢霉素生物合成基因salX和salD敲除的热带盐孢放线菌菌株进行分析，并结合饲喂实验，结果表明3 - （环己 - 2 - 烯 - 1 - 基）-2 - 氧代丙酸（60）和3 - （环己 - 2 - 烯 - 1 - 亚基）-2 - 氧代丙酸（异构体61和62）是盐孢霉素A、4以及8 - 13生物合成中的重要中间体。
