Abstract
Present research work evaluates variation in volatile chemicals profile and
biological activities of essential oil (EO) obtained from the leaves of
eucalyptus (
Eucalyptus camaldulensis
Dehnh.) using
hydro-distillation (HD) and supercritical fluid extraction (SFE). The yield
(1.32%) of volatile oil by HD was higher than the yield (.52%) of the SFE method
(
P
< .05). The results of physical factors like density,
color, refractive index, and solubility of the EOs produced by both the methods
showed insignificant variations. Gas chromatography - mass spectrometry (GC-MS)
compositional analysis showed that eucalyptol (31.10% and 30.43%) and
α
-pinene (11.02% and 10.35%) were the main constituents
detected in SFE and HD extracted
Eucalyptus camaldulensis
EO,
respectively. Antioxidant activity-related parameters, such as reducing ability
and DPPH free radical scavenging capability exhibited by EO obtained via SFE
were noted to be better than hydro-distilled EO. Supercritical fluid extracted
and hydro-distilled essential oils demonstrated a considerable but variable
antimicrobial potential against selected bacterial and fungal strains.
Interestingly, oil extracted by SFE showed relatively higher hemolytic activity
and biofilm inhibition potential. The variation in biological activities of
tested EOs can be linked to the difference in the volatile bioactives
composition due to different isolation techniques. In conclusion, the EO
obtained from
Eucalyptus
leaves by the SFE method can be
explored as a potential antioxidant and antimicrobial agent in the functional
food and nutra-pharmaceutical sector.