After the first string search for a compound name you will get a list of names which correspond to that string. The search is done in all synonym names, but only the list of compound names (our definition of the correct, or main, name) is shown. Sometimes this list is quite long, so the possiblity is added to enter an additional search string. This argument searches within the displayed results, again both in the compound names as well as in the synonyms thereof. This process can be repeated endlessly.
It is also possible to enter an exclude string: the result is a list of compound names where this exclusion string does not appear in the name. Not in the compound name, and also not in any of the synonyms belonging to that compound.
An example of usage is the search for names with 'ethyl'. Enter the 'ethyl' string first, then enter 'methyl' as the exclude string to remove any *methyl* names.
The search within results option is also available for the search in literature references.
Additional search possiblities
When searching for 'alpha', 'beta', etc within names you may use the replacing strings 'alpha-', 'beta-', 'gamma-', 'delta-', 'epsilon-' or 'psi-'. Allways include the minus sign in your search string.