Comments on: The InChI Key Has Been Unveiled – and now there are 17.2 MILLION of them online

By: Antony Williams

Antony Williams — Wed, 12 Dec 2007 01:32:22 +0000

the only way to convert from an InChIKey to a molfile is via a lookup. The InChIString can be converted though.

it IS a one way generation

By: Henning Hermjakob

Henning Hermjakob — Tue, 11 Dec 2007 11:10:29 +0000

Is it possible to convert from an InChI key to a molfile?
I know there’s a method on http://www.chemspider.com/inchi.asmx which does that based on lookup of InChI keys in Chemspider. But I understand there is no direct algorithm to do this, as the InChI key generation is a one way transformation?

By: ChemSpider Blog » Blog Archive » Access to ChemSpider Web Services Starts - Initial Exposure of InChI Related Services

Fri, 14 Sep 2007 02:50:18 +0000

[...] about that soon). As part of this general direction and because of the recent interest in InChI (1,2) we decided to expose a series of web services built on a combination of OpenBabel and the InChI [...]

By: ChemSpider Blog » Blog Archive » Seth Godin’s Big Ideas, the InChiKey and Structure Searching the Web

Thu, 13 Sep 2007 15:45:30 +0000

[...] A few years ago at a meeting in Washington I sat in on probably the earliest public forum discussion on the potential of InChI. As a result of excellent teamwork between NIST and IUPAC, and doing rather than just talking they got it done. There was some negativity expressed during the initial meetings about InChI but it did not distract the team from producing the prototype versions, initial release and now the latest update with InChIKey support. [...]

By: Antony Williams

Antony Williams — Thu, 13 Sep 2007 04:16:31 +0000

The InChiKey has now been linked up to perform direct searched on Google… see http://www.chemspider.com/news/?p=76

By: Antony Williams

Antony Williams — Tue, 11 Sep 2007 02:52:12 +0000

We have now checked for clashes. We do not see ANY clashes at all – there are no two hash keys representing different structures. We DID find some non-deduplicated structures and these will be resolved shortly.

InChIKey is working as expected.

By: ChemSpider News » Blog Archive » InCHI keys Now Available on ChemSpider

Tue, 11 Sep 2007 02:33:39 +0000

[...] InChI Key has recently been released in a beta form (version 1.02) and is discussed in more detail over on the ChemSpider Blog. As of today these InChIs have been made searchable on the ChemSpider [...]

By: Joerg Kurt Wegner

Joerg Kurt Wegner — Mon, 10 Sep 2007 22:47:50 +0000

A brief answer about the hashing problem was given on the CCL list today (eh, yesterday)
http://www.ccl.net/cgi-bin/ccl/message-new?2007+09+10+001

The paper I had in mind was written already in 1994 by WDI, the multi-lingual cheminformatics guru
Article (ig94) Ihlenfeldt, W. D. & Gasteiger, J. Hash Codes for the Identification and Classification of Molecular Structure Elements J. Comp. Chem., 1994, 15, 793-813.

In general, any hashing identifier might run into collision problems, this is exactly a reason why they have to be designed. The purpose of hashing is a fast indexing and reducing the collitions, not necessarily to avoid them completely. In other words, creating globally optimal hashing identifiers is an optimization or statistics problem, which has to be solved by some smart computer scientists or mathematicians.

By: Antony Williams

Antony Williams — Mon, 10 Sep 2007 15:44:38 +0000

We have not yet checked for clashes but based on other experiences I doubt we will find them..and if we do it may be more indicative of lapses in our de-duplication procedures and therefore be very useful. We WILL do this work shortly and report back if we find any issues.

Joerg – can you comment more on the “statistical analysis”?

By: Egon Willighagen

Egon Willighagen — Mon, 10 Sep 2007 12:03:21 +0000

On the CCL list it is reported that the major open compound databases, like ZINC, PubChem, and no clashes have been found.