Asperterpenoid A, a New Sesterterpenoid as an Inhibitor of <i>Mycobacterium tuberculosi</i>s Protein Tyrosine Phosphatase B from the Culture of <i>Aspergillus</i> sp. 16-5c

Asperterpenoid A (<b>1</b>), a novel sesterterpenoid with a new carbon skeleton, has been isolated from a mangrove endophytic fungus <i>Aspergillus</i> sp. 16-5c. Its structure was characterized by extensive spectroscopic methods, and the absolute configuration was determined by single crystal X-ray diffraction analysis. Asperterpenoid A (<b>1</b>) exhibited strong inhibitory activity against <i>Mycobacterium tuberculosis</i> protein tyrosine phosphatase B (<i>m</i>PTPB) with an IC₅₀ value of 2.2 μM