[Comparison of chemical components of essential oils in needles of Pinus massoniana Lamb and Pinus elliottottii Engelm from Guangxi].

Essential oils were extracted by steam distillation from the needles of Pinus massoniana Lamb and Pinus elliottottii Engelm grown in Guangxi. Various factors such as pine needle dosage and extraction time which may influence the oil yield were investigated. The optimum conditions were found to be as follows: pine needle dosage 700 g, extraction time 5 h. The essential oil yields from the needles of Pinus massoniana Lamb and Pinus elliottottii Engelm were 0.45% and 0.19%, respectively. Moreover, the chemical compositions of the essential oils were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Sixty four components in the essential oil from needle of Pinus massoniana Lamb were separated and twenty of them (98.59%) were identified while seventy three components in the essential oil from needle of Pinus elliottottii Engelm were separated and twenty nine of them (94.23%) were identified. Generally, the compositions of the essential oils from needles of the two varieties were similar but the contents of some compounds differed greatly. Especially, the content of alpha-pinene in the essential oils from Pinus massoniana Lamb needles was 2.6 times as that from Pinus elliottottii Engelm needles, but the content of beta-pinene was less than the latter. Mono- and sesquiterpenes were the main composition of the essential oils from Pinus massoniana Lamb and Pinus elliottottii Engelm needles.