Study Of The Essential Oil Of Eucalyptus Citriodora Hooker Cultivated In Kenya
Abstract
The yield of essential oil from leaves of Eucalyptus
citriodora Hooker varied considerably but was always within
the range 2.2 to 8.3%. The physico-chemical properties of
the oil from leaves collected from different places and at
different times were as follows: d20 = 0.8623 to 0.8867;
n 20 ~20 D = 1.4515 to 1.4582; ~ D :::-1.0to + 4.0;
acid value 2.8 to 5.5; ester value 5.2 to 30.7 and ester
value after acetylation 290 to 330. The oil was soluble
in 1.5 to 4.0 volumes of 70% alcohol. The Principal
components identified in the leaf oil from Kenyan plants
were citronellal (65-88%), citronellol (2-25%) and
isopulegol (1:.5~19%). Other components isolated from leaf
oil were: C><. - pi.nerie, f3 -pinene, camphene, 0( - phellandrene,
B-phellandrene, limonene, p-cymene, citronellyl acetate,
geraniol, eugenol, carvone and 11 unidentified terpenoid
compounds. The oil components were identified by ir
spectroscopy, glc, tlc and other chemical methods.
Investigations performed indicate presence of 2 intraspecific
varieties of E. citriodora in Kenya differing from the
normal, "Type", only in the composition of leaf oil. The
variability of oil content and its composition depended on
individual trees, age of leaves and the collection time.
Other parts of the plant namely flower buds, flowers,
fruits, branchlets, pedicels and peduncles show much lower
oil content. The oil from these parts contained mainly
hydrocarbons with 0<- pinene as the main constituent
(23-86.6%) .
The leaf oil was found to increase bile secretion in
rats by 50% at a dosage of 50 mg/kg body weight. The
antispasmodic effect of the oil against acetylcholine and
histamine induced spasms in isolated rabbit ileum and
isolated guinea pig trachea was demonstrated. The
insecticidal action of the oil on termites was compared
with that of malathion. The oil was found to exhibit a weak
larvicidal action. The antimicrobial action of the oil
was also confirmed.
Citation
Masters of science (Pharmacognosy)Publisher
University of Nairobi