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Trying to squeeze sense out of chemical data

Archive for the ‘inchi’ tag

rinchi – An R package to generate InChI’s and InChI Keys

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While trying to update rcdk on CRAN it was pointed out to me that usage of the library resulted in modifications to the users home directory. Specifically, this occurred when generating InChI‘s. The CDK makes use of jni-inchi, which in turn depends on JNATI which enables Java code to work with native libraries in a platform independent fashion. As part of this, it creates $HOME/.jnati – which is a no-no for CRAN packages. To resolve this, the latest version of rcdklibs excludes the InChI module and its dependencies. Hopefully rcdk and rcdklibs will now pass CRAN QC.

To access InChI functionality in R you can use the rinchi package which is hosted on Github. Since it will modify the users home directory, it cannot be hosted on CRAN. However, it’s easy enough to install

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library(devtools)
install_github("cdkr", "rajarshi", subdir="rinchi")

Importantly, if all you need is to go from SMILES to InChI, there is no need to install rcdk as well. So the following works

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inchi <- get.inchi('CCC')
inchik <- get.inchi.key('CCC')

But if you do have a molecule object obtained via rcdk, you can also pass that in to get an InChI or InChI key representation.

Written by Rajarshi Guha

August 30th, 2014 at 6:23 pm

Posted in cheminformatics,software

Tagged with , , , , ,

Accessing Chemistry on the Web Using Firefox

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With the profusion of chemical information on the web – in the form of chemical names, images of structures, specific codes (InChI etc), it’s sometimes very useful to be able to seamlessly retrieve some extra information while browsing a page that contains such entities. The usual way is to copy the InChI/SMILES/CAS/name string and paste into Pubchem, Chemspider and so on.

However, a much smoother way is now available via a Firefox extension, called NCATSFind, developed by my colleague. It’s a one click install and once installed, automatically identifies a variety of chemical id codes (CAS number, InChI, UNII) and when such entities are identified uses a variety of backend services to provide context. In addition, it has a cool feature that lets you select an image and generate a structure (using OSRA in the background).

Check out his blog post for more details.

Written by Rajarshi Guha

July 23rd, 2014 at 1:35 pm