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

Abstract The sedative properties of linalool were examined using the optically active linalools, (R)-(−)-, (S)-(+)- and (RS)-(±)-forms. (R)-(−)-linalool with specific rotation of [α]D= −15.1° was isolated by repeated flash column chromatography from lavender oil, while (S)-(−)-linalool with [α]D= +17.4° and (RS)-(±)-linalool with [α]D=0° 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.