Molecular shape descriptors.

This section reviews the molecular shape descriptors developed by Amoore, Allinger, Simon et al. and Testa and Purcell. The illustrative examples discussed refer to the odour similarity and cardiotoxic aglycones. One has stressed the methods based on the reference structure because, correctly formulated, these methods seem to offer promising perspectives to model the steric effects in biological systems. Finally, a short discussion of possible connections between steric and other substituent constants (relevant in the context of multicollinearity in QSAR) is included. [ABSTRACT FROM AUTHOR]