Derwent fragmentation code

Table 1 Summary of Subheadings in the Derwent Fragmentation Code...

In order to access the Derwent fragmentation code, and also to access Derwent documentation abstracts with detailed Markush and chemical summaries, it is necessary to be a Derwent subscriber. Derwent subscriptions are widespread among corporations in North America, Europe, and Japan. The Derwent fragmentation data is not available to academic institutions or other nonsubscribers at this time. 

Whatever the search software offered, however, the database was of utmost importance. The DARC system not only offered a means to search generic structures in the short term, it also offered a way to record all of the information about structures found in patents, through a new and flexible input system. This capability was of incredible import to Derwent we could build a database that would not only serve the users today, but in future could be of more utility as search software was further developed. As opposed to the fragmentation code, there should never be a question of time-ranging. Moreover, though we assume that Markush DARC is a system not only of today but of tomorrow, we are building a database that can be converted and adapted to other search systems that may be offered by other organisations. 

The WPIM file corresponds to Derwent World Patents Index (DWPI) online file, and therefore includes documents from all of the countries that Derwent normally covers. Indexing for WPIM began in 1987, and since 1987, Derwent has double indexed all chemical patents with both the fragmentation codes and WPIM indexing. Specific structures are indexed if they are not part of a Markush structure in the same patent document. Polymers are not indexed in detail in the WPIM database. Polypeptides of 10 or more amino acids are indexed in a separate non-Markush database and are not included in WPIM. All four online services that carry the DWPI also have the WPIM accession numbers. WPIM indexes patents from all countries in the Derwent database, but it is available to subscribers only. 

Manual Code Chemical Code Ring Index Number Derwent Compound Number Derwent Registry Number Plasdoc Key Serials Fragment Code... 

TOPER AG (the Topological Fragment Code Generator program for chemical structure access to the Derwent patents data base) (26). 

The PSIDOM chemical structure drawing interface is being used in two other products which facilitate searching of online chemical information. Both of these products have been commissioned from HDS by Derwent Publications Ltd and are aimed at searching text-based files which contain chemical fragment codes used as... 

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