Isolation of Tritonicysteinolic Acid From a Marine Bacterium and Its Evaluation as a PGAM5 Inhibitor

The new sulfolipid‐like natural product tritonicysteinolic acid (TTC) was isolated from an extract of the marine bacterium Tritonibacter and exhibited inhibitory activity against PGAM5, a protein phosphatase that localizes in the inner mitochondrial membrane. The full stereochemistry of TTC was elucidated through total synthesis, thereby enabling the synthesis of various derivatives. Structure‐activity relationship (SAR) studies were conducted, which revealed that the derivatives exhibited higher inhibitory activity against PGAM5 phosphatase relative to the parent natural product.