The SAR Table app is undergoing a number of enhancements to make it more suited for planning new compounds based on existing structure-activity relationships. A lot of this has to do with property prediction, model building and scaffold searching of public databases. One of the features slated for the next update is a bit more down to earth: presenting a indication of activities when selecting scaffolds or substituents for reuse.

The SAR Table app was originally designed as a data entry tool, to be used for preparing figures for manuscripts, or for re-entering figures previously published, in order to obtain the structure-activity data in a useful digital form. One of the key features used to make this process as painless and non-repetitive as possible is the value picker: by selecting the command bank icon, or simply double-tapping on an empty structure cell, brings up a list that shows the unique values for each of the current values for that field (be it scaffold or R-group substituent).

In the currently available version of the SAR Table app, the list just shows structures. In the next version, if you have any properties that have been configured to use a scheme, i.e. colour coded, then they will be shown on the right hand side, corresponding to the structure. If you look closely at the screenshot above, though, you will notice that these are not all just single colours: some of them correspond to a number of compounds (e.g. all those with R1=H). The gradation in shades reflects all of the constituents, and the composition is done by an algorithm that is not as simple as it may at first seem: properties can be ranges, so values such as “>10000 nM” or “< 1 uM” or “5.5 – 6.5” are all accounted for by smearing their possible activity values across the spectrum appropriately.

The plotting of colour-coded property spectra is a visual aid for hypothesising new compounds. If you’re looking to assemble known R-groups onto a scaffold in a way that’s likely to maximise the activity, it’s a visual clue as to which ones are already observed in the active or inactive compounds.

This particular improvement is simple but useful. Stay tuned for news on improvements that have a bit more heavy machinery backing them up.