### 2.11. Where can I find examples of InChIs and InChIKeys? 

**+++UPD**

Nowadays InChIs and InChIKeys have become widespread and may be easily found on the Web using any Internet search engine.

As for the large annotated collections of InChI/Keys associated with structural and chemical information look at the following, to name but a few:

<u>Pubchem</u> 

http://pubchem.ncbi.nlm.nih.gov/

235 million substance records representing 96 million chemical compounds from 691 data sources, as of August, 2019 

<u>NCI/CADD Chemical Identifier Resolver</u>

http://cactus.nci.nih.gov/chemical/structure

Programmatic web interface to interconnect ~100 million structures and their NCI/CADD identifiers, ~100 million Standard InChIKey's, 68million chemical names, as of  August, 2019 (https://cactus.nci.nih.gov/chemical/structure_documentation).

<u>ChemSpider</u> 

http://www.chemspider.com/

75 million structures from 270 data sources, as of  August, 2019

<u>ChEBI</u> 

http://www.ebi.ac.uk/chebi/ 

55,998 biologically important small molecules, as of August, 2019 (rel. 178)

<u>NIST Chemistry WebBook</u>

http://webbook.nist.gov/

Thousands of small chemical compounds (mostly organic ) with associated reference data

For some important/difficult/interesting cases, see throughout this FAQ, especially in the Section 14 ‘InChI by Examples’.