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New on STN

October 2019

Third 2019 update to Emtree(TM) now available on STN(R)

October 2019

New CAS FORMULATIONS TM Database Launched on STNext

April 2019

New legal status codes for US patent applications and granted patents in INPADOC

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EPOPIC 2019 - EPO Patent Information Conference, 29.-30. Oct, Bukarest
IP-Service World, 25.-26. Nov, Munich

STN User Meetings

Hamburg, 23.10.2019
Milano, 23.10.2019
London, 05.11.2019

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 Summary Sheet


Producer: Chemical Abstracts Service (CAS), USA
File Size:More than 499,630 records (08/2018)
File Type:Markush structure
Content:Markush structures in patents

The CAS Markush Search Service database contains the Markush structure records for patents cited in the CA file. Because a typical Markush structure represents more than 250 hypothesized substances, the database offers more than 70 million opportunities to retrieve relevant patents. Sources include patents from 33 national patent offices, EPO, and WIPO. Structures are searchable and displayable. Bibliographic information, patent family information, cited references for records added to the database from 1999 to the present,  abstracts, and indepth substance and subject indexing of the original CA file record are displayable. A learning file, LMARPAT, is available.


Chemical Abstracts Service
2540 Olentangy River Road
P. O. Box 3012
Columbus, Ohio 43210-0012
Phone:  (+1) 614-447-3600
Fax: (+1) 614-447-3798
Email: help(at)cas(dot)org
Copyright Holder

Usage Terms

The CAS Information Use Policies which apply to your use of the MARPAT File on STN are explained in detail.

Contents of CAS Information Use Policies

Part 1:
I. Introduction
II. Definitions

Part 2:
III. Authorized Use of CAS Information

Part 3:
IV. Unauthorized Use of CAS Information
V. Special Permission
VI. Further Information

Further details on the STN Information Keep & Share Program.