Pyrimidine Nucleosides, Benzoic Acid Derivative and Bipyridine from the Marine‐Derived Streptomyces sp. DS52

Fourteen new compounds were isolated from marine‐derived Streptomyces sp. DS52, including twelve pyrimidine nucleosides (1‐12), one benzoic acid derivative (13) and one dipyridine derivative (14). Additionally, twenty‐eight known compounds (15‐42) were identified. The structures of all compounds were elucidated through extensive analysis of NMR spectroscopic and HRESIMS data. ECD calculations were employed to investigate the configurations of compounds 1, 2 and 4‐13. Bioactivity evaluations of all of the compounds showed that compounds 6, 7, 9, 11, 15, 33‐38, 41, and 42 exhibited cytotoxicity against HCT‐116 human colon cancer cell lines and MDA‐MB‐231 human breast cancer cell lines, with IC50 values ranging from 0.73 ± 0.06 to 17.44 ± 0.53 μM and from 1.11 ± 0.06 to 18.51 ± 3.07 μM, respectively. Notably, compound 41 exhibited significant cytotoxicity against the HCT‐116 and MDA‐MB‐231 human cancer cell lines with IC50 values of 0.73 ± 0.06 and 1.11 ± 0.06 μM, respectively.