Efficient Extraction Methods and Analy sis of Essential Oil from Softwood Leaves

For the effecient extraction methods of essential oil, pretreatment of leaves, ratios of water and leaves, extraction time, and collection season from the Chamaecyparis obtusa and Chamaecyparis pisifera leaves were studied. The chemical composition of essential oil was analyzed by GC-MS. The yield of essential oil from ground leaves was higher than that of chopped leaves. The yield of essential oil was not affected much by mixing ratios of water and leaves. The yield of essential oil reached maximum after 5 hours. The content of essential oil of C. obtusa leaves collected during winter was 4.5%, whereas the content of essential oil of C. pisifera collected during fall was 5.3%. The composition of essential oils extracted form C. obtusa and C. pisifera was different. The major constituents in the essential oil of C. obtusa were monoterpene as limonene, terpinene-4-ol, γ-selinene, and α-cedrene, and those of C. pisifera was monoterpens as α-pinene, myrcene, limonene, bornyl acetate, β- caryophyllene, longifolene, and β-cedrene.