(-)-Vibsanin B, also known as (-)-Vibsanin B or Vibsanin B, is a diterpenoid natural product isolated from plants of the *Viburnum* genus, such as *Viburnum odoratissimum*. Its CAS number is 488-76-6. It is characterized by a complex 5/7/5-fused tricyclic ring system, which is a hallmark of the vibsane-type diterpenoids. This compound has garnered significant research interest primarily due to its potent and selective anti-cancer activities. Studies have shown that (-)-Vibsanin B exhibits strong inhibitory effects on the proliferation of various human cancer cell lines, including breast cancer (MCF-7), lung cancer (A549), and leukemia (HL-60) cells. Its mechanism of action is linked to the induction of apoptosis (programmed cell death) in cancer cells, often through the mitochondrial pathway and the activation of key enzymes like caspases. It is considered a promising lead compound for the development of novel anti-tumor agents. As a natural product lead, (-)-Vibsanin B is primarily used in pharmacological research and drug discovery. Its complex structure also makes it a target for total synthesis efforts in organic chemistry. It is typically supplied as a high-purity standard for biological screening and mechanistic studies.