Floral fragrance chemistry in the early flowering shrub Daphne mezereum

The floral fragrance of the shrub Daphne mezereum in central Sweden was collected by means of the head-space technique and investigated by GC-MS and multi-dimensional GC. (S)-(+)-Linalool was the main constituent (95%) of the flower fragrance and its enantiomeric purity exceeded 99% in the samples. The (2S, 5S)- and (2R, 5S)-furanoid and the (3R, 6S)- and (3S, 6S)-pyranoid linalool oxide isomers constituted 2-5% of the fragrance. The elution order of these compounds on a permethylated beta-cyclodextrin column is reported. A fragrance sample of D. mezereum as well as (S)-(+)-linalool attracted males of the vernal solitary bee species Colletes cunicalarius and Andrena cinerea. A racemic mixture of the two enantiomeric pairs of known furanoid linalool oxides was only weakly attractive to the bees. The role of the fragrance in the pollination specialization of the plant is discussed.