FGROUP by class
Carbon Carbon skeleton Hydrocarbon ring N-heterocyclic O-heterocyclic S-heterocyclic Mixed-heterocyclic Oxygen Nitrogen Sulfur Mercaptan (F510000) Thiol (F510000) Thioacid (F516000) Thioether (F521000) Sulfide (F521000) Disulfide (F522000) Trisulfide (F523000) Tetrasulfide (F524000) Sulfonium (F530000) Acyl thioester (F540000) Thioester (F540000) Thiocarbonyl (F550000) Sulfoxide (F561000) S-oxide (F561000) Sulfone (F562000) Sulfonyl (F562000) Sulfenate (F571000) Sulfite (F572000) Sulfonate (F573000) Sulfate (F574000) Thiosulfate (F575000) Sulfamate (F581000) Sulfenamide (F582000) Sulfonamide (F583000) Phosphorus Halogen Boron Magnesium Silicon Iron Cobalt Asenic Selenium Tin