FGROUP by class
Carbon Carbon skeleton Hydrocarbon ring N-heterocyclic O-heterocyclic S-heterocyclic Mixed-heterocyclic Oxygen Nitrogen Carboxamide (F450000) Amide (F450000) Acyl amide (F451000) N-alkyl acyl amide (F451200) Linear n-alkyl acyl amide (F451210) Sulfur Phosphorus Halogen Boron Magnesium Silicon Iron Cobalt Asenic Selenium Tin