Abstract Molecules, as defined by connectivity specified via the International Chemical Identifier (InChI), are precisely indexed by major web search engines so that Internet tools can be transparently used for unique structure searches.

Abstract Motivation: Chemical compounds like small signal molecules or other biological active chemical substances are an important entity class in life science publications and patents. Several representations and nomenclatures for chemicals like SMILES, InChI, IUPAC or trivial names exist. Only SMILES and InChI names allow a direct structure search, but in biomedical texts trivial names […]

Abstract Comparison of the quantitative structure—property relationships (QSPR) based on optimal descriptors calculated with the International Chemical Identifier (InChI) and QSPR based on optimal descriptors calculated with simplified molecular input line entry system has shown that the InChI-based optimal descriptors give more accurate prediction for the logarithm of octanol/water partition coefficient of platinum complexes.

Abstract An algorithm is introduced that enables a fast generation of all possible prototropic tautomers resulting from the mobile H atoms and associated heteroatoms as defined in the InChI code. The InChI-derived set of possible tautomers comprises (1,3)-shifts for open-chain molecules and (1,n)-shifts (with n being an odd number >3) for ring systems. In addition, our algorithm […]

Abstract A modified InChI (International Chemical Identifier) string scheme, yaInChI (yet another InChI), is suggested as a method for including the structural information of a given molecule, making it straightforward and more easily readable. The yaInChI theme is applicable for checking the structural identity with higher sensitivity and generating three-dimensional (3-D) structures from the one-dimensional […]

Abstract InChIKey is a 27-character compacted (hashed) version of InChI which is intended for Internet and database searching/indexing and is based on an SHA-256 hash of the InChI character string. The first block of InChIKey encodes molecular skeleton while the second block represents various kinds of isomerism (stereo, tautomeric, etc.). InChIKey is designed to be […]

Abstract The International Chemical Identifier (InChI) has had a dramatic impact on providing a means by which to deduplicate, validate and link together chemical compounds and related information across databases. Its influence has been especially valuable as the internet has exploded in terms of the amount of chemistry related information available online. This thematic issue […]

Abstract While chemical databases can be queried using the InChI string and InChIKey (IK) the latter was designed for open-web searching. It is becoming increasingly effective for this since more sources enhance crawling of their websites by the Googlebot and consequent IK indexing. Searchers who use Google as an adjunct to database access may be […]

Abstract UniChem is a low-maintenance, fast and freely available compound identifier mapping service, recently made available on the Internet. Until now, the criterion of molecular equivalence within UniChem has been on the basis of complete identity between Standard InChIs. However, a limitation of this approach is that stereoisomers, isotopes and salts of otherwise identical molecules […]

Abstract Background: There are many databases of small molecules focused on different aspects of research and its applications. Some tasks may require integration of information from various databases. However, determining which entries from different databases represent the same compound is not straightforward. Integration can be based, for example, on automatically generated cross-reference links between entries. […]

Abstract This paper documents the design, layout and algorithms of the IUPAC International Chemical Identifier, InChI.

Abstract The IUPAC International Chemical Identifier (InChI) is a non-proprietary, machine-readable chemical structure representation format enabling electronic searching, and interlinking and combining, of chemical information from different sources. It was developed from 2001 onwards at the U.S. National Institute of Standards and Technology under the auspices of IUPAC’s Chemical Identifier project. Since 2009, the InChI […]

Abstract Background The InChI algorithms are written in C++ and not available as Java library. Integration into software written in Java therefore requires a bridge between C and Java libraries, provided by the Java Native Interface (JNI) technology. Results We here describe how the InChI library is used in the Bioclipse workbench and the Chemistry […]

Abstract The HIV structural database (HIVSDB) is a comprehensive collection of the structures of HIV protease, both of unliganded enzyme and of its inhibitor complexes. It contains abstracts and crystallographic data such as inhibitor and protein coordinates for 248 data sets, of which only 141 are from the Protein Data Bank (PDB). Efficient annotation, indexing, […]

Abstract Optimal descriptors calculated with International Chemical Identifier (InChI) have been used to construct one-variable model of the solubility of fullerene C60 in organic solvents . Attempts to calculate the model for three splits into training and test sets gave stable results.

Capturing mixture composition: an open machine-readable format for representing mixed substances Alex M. Clark, Leah R. McEwen, Peter Gedeck & Barry A. Bunin Journal of Cheminformatics volume 11, Article number: 33 (2019) Abstract: We describe a file format that is designed to represent mixtures of compounds in a way that is fully machine readable. This […]

Toropov, A. A., Toropova, A. P., & Benfenati, E. (2010). QSAR-modeling of toxicity of organometallic compounds by means of the balance of correlations for InChI-based optimal descriptors. Molecular diversity, 14(1), 183-192. This paper present a use of InChI-based molecular descriptors to predict toxicity. Its abstract follows. “Quantitative structure–activity relationships (QSAR) for toxicity toward rats (pLD50) have been […]

The International Chemical Identifier (InChI) has been used to construct InChI-based optimal descriptors to model the  binding affinity for fullerene[C60]-based inhibitors of human immunodeficiency virus type 1 aspartic protease (HIV-1 PR). Statistical characteristics of the one-variable model obtained by the balance of correlations are as follows: n = 8, r2 = 0.9769, q2LOO = 0.9646, s = 0.099, F = 254 (subtraining set); n = 7, r2 = 0.7616, s = 0.681, F = 16 (calibration set); n = 5, r2 = 0.9724, s = 0.271, F = 106, Rm2 = 0.9495 (test set). Predictability of this approach […]

Optimal descriptors calculated with international chemical identifier have been used to construct one-variable model of the normal boiling points of acyclic carbonyl substances. Attempts to calculate the model for three splits into training and test sets gave stable results. Statistical quality of the model is n = 150, r 2 = 0.9825, s = 4.96 °C, F = 8,312 (training set) and n = 50, r 2 = 0.9791, s = 4.68 °C, F = […]

Summary: Metabolomic publications and databases use different database identifiers or even trivial names which disable queries across databases or between studies. The best way to annotate metabolites is by chemical structures, encoded by the International Chemical Identifier code (InChI) or InChIKey. We have implemented a web-based Chemical Translation Service that performs batch conversions of the most […]

A list of 270 structures of ordered co‐crystals of isomers, near isomers and molecules that are almost the same has been compiled. Searches for structures containing isomers could be automated by the use of IUPAC International Chemical Identifier (InChI™) strings but searches for co‐crystals of very similar molecules were more labor intensive. Compounds in which […]

The simplified molecular input-line entry system (SMILES) and IUPAC International Chemical Identifier (InChI) were examined as representations of the molecular structure for quantitative structure-activity relationships (QSAR), which can be used to predict the inhibitory activity of styrylquinoline derivatives against the human immunodeficiency virus type 1 (HIV-1). Optimal SMILES-based descriptors give a best model with n […]

Chemistry International, Volume 38, Issue 3-4, Pages 24–26 Abstract Progress in science has always been driven by data as a primary research output. This is especially true of the data-centric fields of molecular sciences. Scholarly journals in chemistry in the 19th century captured a (probably small) proportion of research data in printed journals, books, and compendia. […]

Galgonek and Vondrášek Journal of Cheminformatics 2014, 6:15 Abstract Background: There are many databases of small molecules focused on different aspects of research and its applications. Some tasks may require integration of information from various databases. However, determining which entries from different databases represent the same compound is not straightforward. Integration can be based, for […]

Chambers et al. Journal of Cheminformatics 2014, 6:43 Abstract UniChem is a low-maintenance, fast and freely available compound identifier mapping service, recently made available on the Internet. Until now, the criterion of molecular equivalence within UniChem has been on the basis of complete identity between Standard InChIs. However, a limitation of this approach is that […]

BURGESS, D. R., MANION, J. A. and HAYES, C. J. (2014), Data Formats for Elementary Gas Phase Kinetics, Part 1: Unique Representations of Species at the Molecular Level. Int. J. Chem. Kinet., 46: 640-650. doi:10.1002/kin.20875 Abstract Standardized electronic formats for data are needed to efficiently and transparently communicate the results of scientific studies. A format […]

Spjuth et al. Journal of Cheminformatics 2013, 5:14 Abstract Background: The InChI algorithms are written in C++ and not available as Java library. Integration into software written in Java therefore requires a bridge between C and Java libraries, provided by the Java Native Interface (JNI) technology. Results: We here describe how the InChI library is […]

Gu et al. Journal of Cheminformatics 2013, 5:51 Abstract Background: Cardiovascular disease (CVD) is the leading cause of death and associates with multiple risk factors. Herb medicines have been used to treat CVD long ago in china and several natural products or derivatives (e.g., aspirin and reserpine) are most common drugs all over the world. […]

This is a 2013 Journal of Cheminformatics article Abstract Since its public introduction in 2005 the IUPAC InChI chemical structure identifier standard has become the international, worldwide standard for defined chemical structures. This article will describe the extensive use and dissemination of the InChI and InChIKey structure representations by and for the world-wide chemistry community, […]

This is an article in Catalan that provides an introduction to chemical information and describes InChI along with other chemical identifiers. Its abstract reads: “Chemical information, once managed in books paradigmatically in Chemical Abstracts and several handbooks, has now migrated to Internet. Nowadays many large databases, both commercial and freely available, have much more information […]

This May 2018 open access Journal of Cheminformatics article by Guenter Grethe et al., describes the first official version (RInChI-V1.00) that was released in March of 2017 and is available for download at the InChI Trust (https://www.inchi-trust.org/wp/downloads/). RInChI provides a standard for the representation of chemical reactions . As different databases use different methods for […]