anchor.diff:  
   Form fields:
   
  -
   * structure_format, Can be 'smiles' or 'sdf'. See http://www.emetabolomics.org/magma/help for information on the different formats
   * structures, structures as string
   * structures_file, structures as file
  
positive.code: 
  ### Retrieve list of molecules [GET]
  
  + Response 200 (application/json)
  
          {
  
negative.code:     * assigned, use null type filter
      * score, use numeric type filter, can only be used when `scanid` url parameter is set.
      * deltappm, use numeric type filter
      * reactionsequence, use reaction type filter
      * metid, molecule id,  use numeric type filter
      * probability, use numeric type filter
      * molformula, use string type filter
  