Chirality codes and molecular structure.

Some time ago a structure-descriptor, named "chirality code", was put forward [J. Chem. Inf. Comput. Sci. 2001, 41, 369-375], aimed at distinguishing between enantiomers. The chirality code is a sequence of (typically 100) numbers, being equal to the value of a certain "chirality function" at equidistant points within a chosen interval. For molecules of moderate size the chirality function has thousands of peaks (maxima and minima), one for each quartet of atoms. Therefore it looks as if the chirality code cannot provide a faithful representation of the chirality function and thus a faithful representation of the molecular structure. We now show that functional groups present in the molecule result in clusters of near-lying and partially overlapping peaks, whose position in the chirality code is characteristic for the particular functional group. This enables a sound structural interpretation of the chirality code.