Seasonal Variation In Essential Oil Constituents of Japanese Spicebush

Japanese spicebush (Lindera obtusiloba Blume, family Lauraceae), a wild growing herb in Korea, Japan, and northeast China, has been used in traditional medicine (stems and bark), tea (young leaves), and food (leaves) in Korea.  The plant essential oil, extracted from leaves and stem, has a distinctive aroma, similar to ginger and the stem bark has been used as an insect repellant.  To determine the effect of collection season on constituency of the essential oil, the upper three leaves were collected three times (during the first week of June, August, and October) in the northern part of Gyeonggi-Do, South Korea, and extracted by simultaneous steam distillation/solvent method using Likens-Nickerson apparatus.  The extracted essential oil was analyzed using gas chromatography-mass spectrometry (Agilent 6890N, 5975MSD, U.S.A.).  Oil constituents were identified by comparison of the spectral data with that in the NIST mass spectral library, ver. 2.0 (NIST, U.S.A.).  The essential oil concentration was highest in August.  The concentration of major constituents in the oil showed little change, although α- and β-phellandrene, β-pinene, limonene, camphene, and caryophyllene oxide were slightly higher in October and caryophyllene was highest in August.