Antibacterial <i>p</i>-Terphenyl with a Rare 2,2′-Bithiazole Substructure and Related Compounds Isolated from the Marine-Derived Actinomycete <i>Nocardiopsis</i> sp. HDN154086
Yimin Chang, Qian Che, Li Xing, Chuanteng Ma, Yaxin Han, Tianjiao Zhu, Blaine A. Pfeifer, Jixing Peng, Guojian Zhang, Dehai Li
Abstract
Assisted by MS/MS-based molecular networking and X-ray diffraction analysis, five new p-terphenyl derivatives, namely, nocarterphenyls D–H (1–5), were obtained and characterized from the cultures of the marine sediment-derived actinomycete Nocardiopsis sp. HDN154086. The skeleton of nocarterphenyl D (1) was defined to possess a rare 2,2′-bithiazole scaffold, naturally occurring for the first time, and nocarterphenyls E–H (2–5) are p-terphenylquinones with unusual thioether linked fatty acid methyl ester substitutions. Compound 1 showed promising activity against multiple bacteria with MIC values ranging from 1.5 to 6.2 μM, and 2 exhibited notable antibacterial activity against MRSA which surpassed the positive control ciprofloxacin.