Free Web-Based Proton NMR Prediction and Assignment with NMRDB

May 20, 2008

NMR Prediction software can be a useful tool in spectral assignment and unknown identification. Until recently, the only available software consisted of rather expensive desktop-based packages. But a new Web service called looks ready to change that.

About is actually three services in one: NMR Resurrector; NMR Assigner; and NMR Predictor.

NMR Resurector is a remarkable tool that re-creates a proton NMR plot from tabulated peak frequencies. Output is available in PDF, and PNG image format.

NMR Assigner enables the interactive correlation of the atoms of a molecule with the peaks in a spectrum. Output is available in ACS format ready for inclusion in manuscripts, or as a text table.

NMR Predictor generates a complete proton NMR spectrum from an arbitrary chemical structure provided as a molfile or drawn with a structure editor. An interactive display (similar in concept to one discussed here recently) highlights both the atom giving rise to a signal and the signal itself in response to hovering with the mouse. Output is available in both PDF and PNG image format.

With each of nmrdb's services, a precompiled set of data can be used as a way to become familiar with what the service can do. a Web Service

Although useful as a standalone tool, NMR Resurector could be even more powerful when used as a Web service in combination with other Web applications. As a hint of the kinds of things that might be possible, nmrdb is capable of creating a predicted spectrum through a special URL into which a SMILES string is embedded. For example, click on the structure of cholesterol below (or use this link):

ChemSpider has added this capability to its compound summary pages under the link "NMR".

Conclusions is a very well thought-out service that could be of immediate benefit to chemists and developers alike. It also demonstrates that creating databases is but one way to chemically enable the Web.