InChI converter features

InChI reading

This tool uses a conversion library called OASA which is distributed as part of the BKchem chemical editor. BKchem provides the same functions for converting InChIs as this online tool with addition of many more exporting and editing capabilities.

The current implementation of InChI conversion is experimental and has some limitations. Details are given below.

Features that are supported:

• Reading of the connectivity
• Localization of movable hydrogens
• Fixed hydrogens
• Generation of atom coordinates
• Charges, both in the q and p form

Features that are not supported:

• multi-component formulas (such as C6H6.H2O)
• stereochemistry
• isotopes

Some statistics

The library used for InChI conversion was tested on more than 120 000 compounds from the NCI database. From these about 5% were multicomponent compounds that are not supported. From the rest 98.7% of compounds were successfully converted to Molfile and the InChI regenerated from this file matched the starting InChI. In about 0.3% of the cases the starting and resulting InChIs did not match. In the rest of the cases (~0.9%) the program was not able to create a valid chemical structure from the input.

InChI generation

For InChI generation the official InChI software is used behind the scenes with OASA as a frontend. When the input is a Molfile, the file is used directly, otherwise the input is converted into a Molfile inside OASA and then submitted to the InChI program.