InChI (International Chemical Identifier)

This section provides a quick introduction of InChI (International Chemical Identifier).

InChI (International Chemical Identifier) - InChI is a text string that denotes a chemical substance, developed under the auspices of IUPAC (International Union of Pure and Applied Chemistry).

For a given molecule, the InChI string can be generated through a set of rules, which are not so easy to follow. So you should use some software tools to help you, like the free "InChI Software" provided at inchi-trust.org/downloads/.

Open Babel can also be used to generate the InChI string for any given molecule.

Here is a list of InChI strings of some molecules.

Common     InChI
Name       String
------     ------
Alcohol    1S/C2H6O/c1-2-3/h3H,2H2,1H3
Aspirin    1S/C9H8O4/c1-6(10)13-8-5-3-2-4-7(8)9(11)12/h2-5H,1H3,(H,11,12)
Caffeine   1S/C8H10N4O2/c1-10-4-9-6-5(10)7(13)12(3)8(14)11(6)2/h4H,1-3H3
Oxygen
Salt
Soda
Sugar
Water
...

You can use https://pubchem.ncbi.nlm.nih.gov to find the InChI string of a given molecule.

For more information, see the InChI Website at iupac.org/who-we-are/divisions/division-details/inchi/.

Table of Contents

 About This Book

 Introduction of Molecules

Molecule Names and Identifications

 Molecule Common Names

InChI (International Chemical Identifier)

 InChIKey - InChI Hash String

 IUPAC Nomenclature

 Canonical SMILES

 Molecule Mass and Weight

 Protein and Amino Acid

 Nucleobase, Nucleoside, Nucleotide, DNA and RNA

 Gene and Chromosome

 Protein Kinase (PK)

 DNA Sequencing

 Gene Mutation

 SDF (Structure Data File)

 PyMol Installation

 PyMol GUI and CLI

 PyMol Selections

 PyMol Editing Functions

 PyMol Measurement Functions

 PyMol Movie Functions

 PyMol Python Integration

 PyMol Object Functions

 ChEMBL Database - European Molecular Biology Laboratory

 PubChem Database - National Library of Medicine

 PDB (Protein Data Bank)

 INSDC (International Nucleotide Sequence Database Collaboration)

 HGNC (HUGO Gene Nomenclature Committee)

 Relocated Tutorials

 Resources and Tools

 Molecule Related Terminologies

 References

 Full Version in PDF/EPUB