Researchers identified a new class of diketopiperazine alkaloids from the endophytic bacterium Kitasatospora sp. CPCC204717 by expressing a previously silent biosynthetic gene cluster in a heterologous host. The work revealed structurally novel natural products with antibiotic potential and expands the chemical space accessible from cryptic microbial pathways. Heterologous expression—transferring gene clusters into tractable microbial hosts to unlock silent biosynthetic routes—enabled structural elucidation and initial bioactivity profiling. The discovery illustrates how genome mining coupled with synthetic biology can accelerate natural‑product drug discovery where native producers are genetically intractable. What happened: scientists activated a cryptic gene cluster to produce new diketopiperazine alkaloids. Why it matters: the approach provides a replicable path to mine understudied microbes for antibiotic leads amid an urgent need for new antimicrobials.