*Article* **Genome Mining and Metabolic Profiling Reveal Cytotoxic Cyclodipeptides in** *Streptomyces hygrospinosus* **var. Beijingensis**

**Dashan Zhang, Junbo Wang, Yongjian Qiao, Baixin Lin, Zixin Deng, Lingxin Kong \* and Delin You \***

State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China

**\*** Correspondence: konglingxin7@sjtu.edu.cn (L.K.); dlyou@sjtu.edu.cn (D.Y.)

**Abstract:** Two new cyclodipeptide (CDP) derivatives (**1–2**) and another seven known cyclodipeptides (**3–9**) were isolated from *Streptomyces* 26D9-414 by the genome mining approach combined with genetic dereplication and the "one strain many compounds" (OSMAC) strategy. The structures of the new CDPs were established on the basis of 1D- and 2D-NMR and comparative electronic circular dichroism (ECD) spectra analysis. The biosynthetic gene clusters (BGCs) for these CDPs were identified through antiSMASH analysis. The relevance between this *cdp* cluster and the identified nine CDPs was established by genetic interruption manipulation. The newly discovered natural compound **2** displayed comparable cytotoxicity against MDA-MB-231 and SW480 with that of cisplatin, a widely used chemotherapeutic agent for the treatment of various cancers.

**Keywords:** genome mining; genetic dereplication; cyclodipeptide; OSMAC; cytotoxicity; *Streptomyces*
