FGROUP by class
Carbon Carbon skeleton Hydrocarbon ring N-heterocyclic Monocyclic 5-membered Aromatic Pyrrole (F221531) Pyrazole (F221532) Imidazole (F221533) Hydantoin (F221534) O-heterocyclic S-heterocyclic Mixed-heterocyclic Oxygen Nitrogen Sulfur Phosphorus Halogen Boron Magnesium Silicon Iron Cobalt Asenic Selenium Tin