Structure–ambergris odour relationship investigation in a mixed series of decalin and non-decalin compounds: the electronic-topological approach

A series of 201 compounds with decalin- and non-decalin-type skeletons has been investigated by means of the electronic-topological method (ETM) regarding the possession of ambergris odour. A structural fragment of activity (FA2) has been identified, which is a refinement of an activity feature (FA1) obtained as a result of an earlier electronic-topological study of the structure–odour relationship in a series of decalin-type compounds. The FA2 fragment consists of an oxygen atom and five carbon atoms situated in both decalin and cyclohexane parts of the molecules and possesses well-defined three-dimensional (3D) topology and strictly defined electronic characteristics. The applicability of FA2 to compounds with mixed odours is discussed as well.