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) Hydroxamate (F451400) N-hydroxy n-alkyl amide (F451500) Lactam (F451600) Imide (F451700) Carbamoyl (F452000) Carbamic acid (F453000) Carbamate (F453000) Pseudourea (F454000) Urethane (F455000) Sulfur Phosphorus Halogen Boron Magnesium Silicon Iron Cobalt Asenic Selenium Tin