Sedative effect on humans of inhalation of essential oil of linalool: Sensory evaluation and physiological measurements using optically active linalools

The sedative properties of linalool were examined using the optically active linalools, (R)-(-)-, (S)-(+)- and (RS)-(+/-)-forms. (R)-(-)-linalool with specific rotation of [alpha](D)= -15.1 degrees was isolated by repeated flash column chromatography from lavender oil, while (S)-(-)-linalool with [alpha](D)= +17.4 degrees and (RS)-(+/-)-linalool with [alpha](D)=0 degrees and content of (R)-form 50.9% and (S)form 49.1% were obtained from coriander oil and commercial linalool, respectively, by using the same method. The effect of (RS)-(+/-)-linalool in our experiments, which was quite similar to that of linalool, with much more favorable impressions accompanied by a tendency to a greater decrease of the beta wave after hearing environmental sound after, rather than before work, appeared to be identical to that observed for (R)-(-)-linalool. The feature was just the reverse in the case of (S)-(+)-linalool. (C) 1998 Elsevier Science B.V.