Essential oil composition of Valeriana officinalis L. roots cultivated in Iran: Comparative analysis between supercritical CO2 extraction and hydrodistillation

The composition of essential oil extracted from Valeriana officinalis L. roots growing wild in Iran was studied by hydrodistillation and supercritical CO2 extraction. Forty-seven components representing 89.3% and 35 constituents varying from 86.1% to 95.1% of the oil obtained by hydrodistillation and supercritical CO2 were identified, respectively. The major components in the extracted oil from supercritical CO2 were isovaleric acid (18.7–41.8%), valerenic acid (8.2–11.8%), acetoxyvaleranone (5.6–9.6%), (Z)-valernyl acetate (4.5–6.5%), bornyl acetate (2.3–7.7%) and valerenol (3.7–5.2%), whereas by hydrodistillation were bornyl acetate (11.6%), valerenic acid (8.0%), (Z)-valernyl acetate (7.9%) and acetoxyvaleranone (7.6%). The analysis of the extracts was performed by capillary GC and GC/MS.