FGROUP by class
Carbon Carbon skeleton Hydrocarbon ring N-heterocyclic O-heterocyclic S-heterocyclic Mixed-heterocyclic Oxygen Carbonyl (F330000) Carboxylate (F331000) Aldehyde (F332000) Keto (F333000) Ketene (F333900) Carboxylate Ester (F334000) Ester (F334000) Anhydride (F335000) Peroxy acid (F336000) Carboxylate peroxide (F336000) Nitrogen Sulfur Phosphorus Halogen Boron Magnesium Silicon Iron Cobalt Asenic Selenium Tin