E. citriodora oil is obtained by steam distillation of leaves and terminal
branches of E. citriodora Hook (lemon-scented gum). It is an almost
colorless, pale yellow, or greenish-yellow liquid with a citronellal-like odor.
d2020 0.860–0.870; n20D 1.4500–1.4560; α20D ?1 ° to +3 °; content of carbonyl compounds calculated as citronellal: min. 70%; content of citronellal by GC: min. 75%.
In addition to the main component, rac-citronellal, the oil contains citronellol
and isopulegol (5–10% each).
Young E. citriodora trees that are grown exclusively for essential oil production
are cut back to a height of 1–1.50m and develop into shrubs.The leaves
can be harvested throughout the year; more than 200 kg of oil can be obtained per hectare.
Worldwide production of E. citriodora oil amounts to ~1000 t/yr.Themain
producers are China and Brazil. Smaller quantities come from India, Vietnam,
and Paraguay. In Brazil, the oil is a by-product of commercial forestry; E. citriodora
wood serves as an energy source for steel production. E. citriodora oil
is a starting material for the manufacture of citronellal and products derived
from it. It is also used in perfumery for the same purposes as citronellal.