TROPOLONES EXTRACTED FROM THE WOOD OF WESTERN RED CEDAR BY SUPERCRITICAL CARBON-DIOXIDE

Tropolones were efficiently extracted using a supercritical carbon dioxide extraction procedure from the wood of western red cedar (Thuja plicata D. Don). The yields and composition of the extractives obtained by hot water distillation were compared with those of the extractives by supercritical carbon dioxide obtained from the same source. The extractive yield with supercritical carbon dioxide was 7.8 fold higher than yield of extractives obtained by hot water distillation. The tropolones from the extractives obtained by supercritical carbon dioxide was about 8 times higher than that of the extractives obtained by hot water distillation. The most efficient condition for extracting tropolones from the wood of western red cedar was under 300 kgf/cm2 at 40-degrees-C for 180 min. Thujic acid, nezukone and beta-thujaplicin were presented in large amounts in the extractives obtained by supercritical carbon dioxide. Nearly ninety percent of the extractives obtained by the present method were composed of the above tropolones.