Chemical Formula

Searches for small molecules defined in the Chemical Component Dictionary using their molecular formula.

The input for the search may be

  • A normal chemical formula, in which case only chemical components with the exact formula will be matched. The order that the elements are provided is not important and if the input formula does not include hydrogens, these will be ignored during the search. For example: the input "O1 C12 N4" will match a chemical component with formula "C12 H28 N4 O".

  • A chemical formula expressions that can contain ranges, wildcards, "0" for none and the wildcard element X. In more detail:

    Range expressions definitions

    • C10-15 : must have 10 to 15 Carbons

    • C4 : must have exactly 4 Carbons

    • C* : must have any number of carbons

    • C0 : must not have (have 0 carbons)

    • X10-12 : must have 10-12 other elements (not specified in the expression)

    • X5 : must have exactly 5 atoms of other elements (not specified in the expression excluding hydrogens)

    • X0 : must not have any other elements (not specified in the expression excluding hydrogens)

    • X* : this is implied if X is not specified in the expression (can have anything else)

    • H10-20 : must have 10-20 hydrogen atoms



Examples


  • O1 C12 N4 : will match a chemical component with formula "C12 H28 N4 O"

  • O1 C12 N4 : will not match a chemical component with formula "C12 H28 N4 O P"

  • O1 C12 N4 H28 : will match a chemical component with formula "C12 H28 N4 O"

  • O C3 N H2 : will not match a chemical component with formula "O C3 N"

  • C10-12 N4 O : must have 10 to 12 Carbons, exactly 4 Nitrogens, exactly 1 Oxygen and anything else

  • C* N0 : must have Carbon, not any nitrogens but can have anything else

  • C10-12 X3-5 : must have 10 to 12 Carbons and 3-5 non-carbon atoms (excluding hydrogens)

  • C10-12 N3-4 X0 : must have 10 to 12 Carbons 3-4 nitrogens and nothing else except hydrogens

  • C* N* O* X0 : anything that has Carbons, Nitrogens, Oxygens but nothing else apart from hydrogens

  • C10-12 H20-30 : must have 10 to 12 carbons, 20 to 30 hydrogens and anything else