Chemical composition and biological activity of the essential oils from native Australian Callitris species

Abstract

The chemical composition of the essential oil of the wood of the Australian native cypress Callitris endlicheri, C. intratropica and C. columellaris were determined by GCMS. The colour of the oils from C. endlicheri were yellow, yellow green and light green, whilst the distinct blue colour of the oil from C. intratropica was in keeping with its generic name ‘blue cypress oil’. The sesquiterpene alcohol guaiol (1) comprised >50% of the C. endlicheri oil. Significant differences were observed in components between the three accessions. In contrast, the oils of C. intratropica showed more subtle variations between collection sites with both oils being high in guaiol (17–21%) together with the sesquiterpene lactones dihydrocolumellarin (2), 12–20%, and columellarin (3), 2–6%. The green oil from C. columellaris was dominantly dihydrocolumellarin.