LAUSR

Abstract Semen Platycladi is a highly valued seed tonic from the Cupressaceae Platycladus orientalis (L.) Franco, which contains abundant essential oils exhibiting antioxidant, antimicrobial, sedative and hypnotic potency. The study was formulated to estimate the potential antioxidant, anticancer and antibacterial activities of its essential oils as well as its correlation with chemical constituents. The comparison of three isolation methods including steam distillation extraction, heating reflux extraction, and Soxhlet extraction of ethanol was carried out to isolate essential oils whose chemical composition were identified and evaluated by Gas Chromatography-Mass Spectrometer. It turned out that the yield of essential oils obtained through heating reflux extraction and Soxhlet extraction was almost 40 % higher than those extracted by steam distillation extraction in nearly one-quarter of a time used by the steam distillation extraction. A total of 76 compounds were identified, including ten alkanes, 14 alkenes, 13 alcohols, one aldehyde ketone, three ethers, one acid, 17 esters, five aromatic compounds, and 12 others. The essential oils extracted by steam distillation extraction were proved to have the best antioxidant and antimicrobial activity although with the lowest yield. Scanning electron microscopic observation displayed that the of S. aureus revealed serious disruption of cell membranes resulting in the loss of cell viability. Therefore, it’s vital to adopt a proper method to obtain the target ingredients recommended as nutraceuticals and/or phytomedicines.