Two new chlorinated bis-indole alkaloids, dionemycin (1) and 6-OMe-7',7″-dichorochromopyrrolic acid (2), along with seven known analogs 3-9, were isolated from the deep-sea derived Streptomyces sp. SCSIO 11791. Their structures were elucidated by extensive HRESIMS, and 1D and 2D NMR data analysis. In vitro antibacterial and cytotoxic assays revealed that, compound 1, shows anti-staphylococcal activity with an MIC range of 1-2 μg/mL against six clinic strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated from human and pig. Additionally, compound 1 displayed cytotoxic activity against human cancer cell lines NCI-H460, MDA-MB-231, HCT-116, HepG2, and noncancerous MCF10A with an IC50 range of 3.1-11.2 μM. Analysis of the structure-activity relationship reveals that the chlorine atom at C-6″ could be pivotal for conferring their bioactivities, thus providing hints on chemical modifications on bis-indole alkaloid scaffold in drug design.

中文翻译：

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来自深海的链霉菌属物种的氯化双吲哚生物碱。SCSIO 11791具有抗菌和细胞毒性活性。

从深海链霉菌中分离出两种新的氯化双吲哚生物碱二酮霉素（1）和6-OMe-7'，7''-二氯色吡咯酸（2）以及七个已知的类似物3-9。SCSIO11791。通过广泛的HRESIMS以及1D和2D NMR数据分析阐明了它们的结构。体外抗菌和细胞毒性测定表明，化合物1对六种自人和猪分离出的耐甲氧西林金黄色葡萄球菌（MRSA）临床菌株具有抗葡萄球菌活性，MIC范围为1-2μg/ mL。此外，化合物1对人癌细胞株NCI-H460，MDA-MB-231，HCT-116，HepG2和非癌MCF10A表现出细胞毒活性，IC50范围为3.1-11.2μM。