Substances found in many plants, containing the 4-hydroxycoumarin radical. They interfere with vitamin K and the blood clotting mechanism, are tightly protein-bound, inhibit mitochondrial and microsomal enzymes, and are used as oral anticoagulants.

A white crystalline compound prepared by condensation of benzaldehyde in potassium cyanide and used in organic syntheses. This should not be confused with benzoin gum from STYRAX.