式根岛海绵宏基因组文库的抗菌吲哚三聚体

Antibacterial Indole Trimer from Metagenomic Library of Marine Sponge Discodermia calyx

构建了式根岛海绵的宏基因组文库,对其进行双层琼脂抗菌活性功能筛选,得到1株抗菌活性克隆pDC111.以抗菌活性为指导,对pDC111的化学成分进行分析和分离,得到化合物1,并通过1D NMR(1H NMR和13C NMR)及2D NMR(1H-1H COSY,HMQC和HMBC)结合HR-TOFMS数据,确定其结构为吲哚三聚体.抗菌活性实验结果表明,化合物1在10μg/paper(id=6 mm)时,对蜡状芽孢杆菌的抑菌圈达到12 mm.本文利用功能宏基因组方法,从蕴藏大量不可培养微生物的海绵中寻找到活性物,并具有通过分子生物学技术获得其功能基因的潜能.

Marine sponge Discodermia calyx harboring highly complex consortia is a rich and important source of biologically active compounds. Considering the chemical and biological diversity present in the sponge mi- crobial community, the metagenomic library of marine sponges should be an interesting resource to search for unique bioactive small molecules and the corresponding unknown functional genes. Therefore, we constructed the metagenomic library of a marine sponge, Discodermia calyx. Functional screening of this library afforded one antibacterial clone pDClll by two-layer top agar method. The antibacterial clone pDClll was cultured and the chemical constituent was analyzed and separated by bioassay-guided fractionation. Compound 1 was afforded and identified as indole trimer by its 1D NMR（1H NMR, 13C NMR）, 2D NMR（1H-1H COSY, HMQC, HMBC ） and HR-TOFMS data. Antibacterial test results showed that compound 1 exhibited anti- Bacillus cereus activity with inhibition zone of 12 mm at 10 μg/paper （i. d. 6 mm ）. This indicated that functional metagenomics could be used to search for active compounds from marine sponges consisting of large population of uncultured microbes. Furthermore, there are highly potentials that the functional genes of indole trimer 1 could be identified by further molecular biology techniques investigation.