J Nat Prod. 2021 Feb 18. doi: 10.1021/acs.jnatprod.0c01296. Online ahead of print.
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.