Cholic acid
Cholic acid was a crystalline acidic substance secreted by the humanoid liver. This acid played an important role in digestion.

When Chief Engineer Geordi La Forge and Lieutenant Barclay were analyzing a corrosive organic solvent in a Jefferies tube, La Forge mentioned there were high levels of cholic acid enzymes which were dissolving a bulkhead and conduit. Upon completing a biospectral analysis, the solvent was later learned to be that of Lieutenant Worf's venom, as he was spraying it throughout the ship after becoming infected with Barclay's Protomorphosis Syndrome. ()

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Biochemical compounds