Essential Oil from the Stems, Leaves and Flowers of Pluchea rosea Godfrey and Pluchea purpurascens (Sw.) DC.

Abstract

The chemical composition of the stem, leaf and flower oils from Pluchea rosea Godfrey and Pluchea purpurascens (Sw.) DC. were studied by GC and GC/MS. In P. rosea, 132 compounds were identified which constituted more than 87%, 92% and 89% of the oil composition in the stem, leaf and flower oils, respectively; while in P. purpurascens, 163 compounds were identified which constituted more than 89%, 95% and 95% of the oil composition in stems, leaves and flowers, respectively. The most prominent compounds in the oils from P. rosea were 2,5-dimethoxy-p-cymene (33.7% in stem oil) and selin-11-en-4α-ol (43.1% and 47.8% in leaf and flower oils, respectively); while in P. purpurascens, the major compounds were β-selinene (27.6%), selin-11-en-4α-ol (21.6%) and β-bourbonene (11.7%) in the stem oil; selin-11-en-4α-ol (24.6%), caryophyllene oxide (12.6%) and 2,5-dimethoxy-p-cymene (8.8%) in the leaf oil, and β-selinene (26.9%), β-caryophyllene (12.8%), α-cadinol (8.0%) and caryophyllene oxide (7.4%) in the flower oil.