Paul Peters (CAS) discussing CAS recent practice of indexing prophetic compounds from patents, included the following slide in his presentation on the forthcoming EPO Patent Information Conference in Biarritz, France (Nov. 3-5, 2009).

"The Hall of Shame: Top 5 patents with the most indexed exemplified prophetics

Patent number


Number of pages

Number of records

Number of prophetics


Sumitomo Chem.





Rohm and Haas





Sumitomo Chem.














"Most patents in pharma and agro contain less than 20 exemplified prophetic compounds."$File/cas_en.pdf (Slide 13) (Tuesday, 3 November 2009, 14.00 - 15.30 hrs)

Peter's example highlights several implications for chemical patent searching from CAS efforts to expand coverage of specific compounds from patents:

  1. Drafters of the featured above patent applications enumerated a fraction of possibly millions (as we well know) combinations which could cover Markush structures of a reasonable complexity. It is hard to say, which advantages, if any, a listing of hundred thousands compounds gives to patent owners in a infringement case, but it would give an extra headache for patent attorney, when compounds from such patents would be cited by a patent examiner in a novelty rejection (Note, that patent examiners do not like to search Markush databases)
  2. For industry patent searcher, such patents would represent the same challenge for report selection, as patents with broad Markush structures. It would open an opportunity to work with chemiformatics forks clarifying the answer how structure in question fit in a huge chemical space enumerated in such patents.
  3. An average chemical patent, on my experience, includes about a hundred of exemplified compounds for which preparation is written down; these compounds are already in the CAS Registry (notwithstanding the fact that some of them have been never made). When hundreds more compounds which are listed by name, images or in tables of possible substituents, would be added to the CAS Register, it would be possible to the a SciFinder user to identifier more patents which were previously more retrievable only by Markush search.
  4. As reliance on search using listed compounds (instead of Markush, or in addition to "automated" Markush searches) will grow, it would drive further use chemical mining tools in drug discovery (and not necessarily with CAS data).
  5. Two last observations represent treats for a job security for a chemical patent searcher. However, a comprehensive coverage of specific compounds in a searchable database open an opportunity for a patent searcher to search inside a patent (see also point 2) evaluating if a patent specification has enough supporting chemical examples, that the reference would be considered for patentability or freedom to operate evaluations. When such search [inside patent] procedures would be implemented into overall search process,& it empower a searcher comprehensively identify and analyze patents with thousands specific examples given insight into broad Markush structure which ordinarily would be disregarded.


Aleksandr Belinskiy

Patent Information Consultant


  1. The prophetic compound indexing policy at CAS has resulted in CAS having to create multiple records for one patent document due to the limitations of indexing space within one record.  Each one of the multiple records has the same abstract information and the bibliographic information seems to differ only by a portion of the application number.   CAS adds two characters to the application number information.  I recently had one patent number, with prophetic compounds indexed, that was indexed in 12 separate CAS records (to accomodate all the prothetic compound indexing.  Cost is a concern.  I would like the ability to reduce prophetic records to one record only. Is there a way to reduce the cost of having to display multiple CAS records for the same patent number indexed over multiple CAS records (due to prophetic issue, not family issue)?  

    Bob March


  2. This topic, at least the indexing of patents with prophetic substances, first arose in the early 90s.  Those readers who are also ACS and CINF mambers (at least of a certain age) may remember a symposium on the subject at the ACS meeting in Atlanta in the early 90s.  Kathy Shenton, then with Derwent, termed these "monster" patents as "Nasties" and stressed the strain it put on the indexing staff at Derwent.  Of course, some thought that it also diluted the relevance of retrieval and in fact the very validity of the approach was debated (shh, legal staffs may be watching ...).  Subsequent evolution of patent jargon yielded "prophetic patents" of which these Nasties are a very important subspecies.  After looking at a few, I've been calling them "Morrison and Boyd" patents becasue it seemed as though patentees were trying to cover all possible organic compounds (at least those covered or implied in the Organic text by Morrison and Boyd).

    Aleksandr's point 3 is also well taken.  Already, there are a myriad compositions cited, many with CASRN, that have never been prepared.  In the early days of the CAS Registry System, a number of polymers were claimed and the monomers indexed, although no preps were given and they were never indexed anywhere else (nor would they be).  I termed these "bottle on my shelf" compounds, as in "Nyah, nyah, I have it and you don't".  I always considered this practive patently unfair (pun intentional?).

  3. In response to customer requests, CAS patent coverage was enhanced to include exemplified prophetic substances and uses identified in English-language patents on December 12, 2007. Since then, CAS has expanded coverage to include patents in all languages from 9 of the major patent offices from January 2009-present. To date, CAS scientists have indexed an astonishing 9 million prophetic substances and uses.

    As noted in the comment from Bob March, certain patent documents with prophetic substances and uses are represented in our databases by more than one record. In fact, such multi-record patents are uncommon, with only 36 in nearly 7 million total patent records in CAplus (as of October 28, 2009). The purpose of splitting patent documents among several records is to account for the large number of prophetic substances and uses included in these rare patents. Extended substance indexing is included in separate records with matching bibliographic, abstract, and other information. A note in the abstract of each record indicates the number of records available for the patent document.

    For a more cost-effective display of multi-record patents, use the DUPLICATE REMOVE or FSORT commands on STN. Or, customize your patent family display using the new Patent Family Manager available in STN Express, Version 8.4. To determine the best option for your search needs, contact CAS Customer Care.