FGROUP by class
Carbon Carbon skeleton Hydrocarbon ring N-heterocyclic Monocyclic 6-membered Saturated Piperidine (F221611) Dihydrocytosine (F221612) O-heterocyclic S-heterocyclic Mixed-heterocyclic Oxygen Nitrogen Sulfur Phosphorus Halogen Boron Magnesium Silicon Iron Cobalt Asenic Selenium Tin