Variation in Composition and Yield of Foliage Oil of Eucalyptus Polybractea

Abstract

Eucalyptus polybractea (blue mallee) is the essential oil rich species used in the commercial production of pharmaceutical-grade Eucalyptus oil in Australia. This species was grown at Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan during 2004-08 to investigate the quantity and quality of its foliage oil. The oils were extracted by hydro-distillation method, from the leaves of four year aged ten E. polybractea plants. The data showed a significant intra-species variation in their oil contents (29.3 to 41.8 mg g-1 fresh weight of leaves). Out of ten plants eight contained oil >30 mg g-1 fresh weight of leaves. The components of the extracted oils varied from 12-26 as detected by GC/FID on Carbowax 20 M packed glass column. Among all the oil components, 1, 8-cineole was the major compound (91.7–94.2 %), while the other identified compounds were -pinene (0–1.2 %), β-pinene (0.4–2.3 %), limonene (0.2–1.3 %), p-cymene (1.23–2.75 %), and terpinene-4-ol (0.6–0.92 %). The extracted oils from all the Eucalyptus polybractea plants contained high amount of 1, 8-cineole (>90 %), therefore, classified as species of high quality medicinal oil.