Abstract:
Variations in the yield and composition of the essential oils from Calendula officinalis
L. cultivated in Alice (Eastern Cape) are reported. Essential oils were obtained by hydrodistillation
using the Clevenger apparatus and analysis was performed by GC-MS.
The yield in essential oil revealed a maximum at the full-flowering stage (0.97%) and a
minimum during the pre-flowering stage (0.13%). The composition showed different patterns
at different phases of the vegetative cycle. Sesquiterpenes (α-cadinene, α-cadinol,
T-muurolol, and epi-bicyclosesquiphellandrene) and monoterpenes (limonene, 1,8-
cineole, and trans-β-ocimene) showed highest correlations with the age of the plant. An
interesting stage is the post-flowering period, the essential oil being rich in α-cadinene, α-
cadinol, T-muurolol, limonene, 1,8-cineole, with p-cymene presenting lower levels.
The oils were extracted by hydrodistillation from fresh leaves, dry leaves, and fresh
flowers yielding 0.06 %, 0.03 %, and 0.09 %, respectively. The analysis of oils by GCMS
revealed a total of 30, 21, and 24 compounds from the fresh leaves, dry leaves, and
the flowers, respectively, representing 91.7, 89.8, and 87.5% of the total oil composition.
Sesquiterpenoids dominated in the fresh leaves (59.5 %) and flowers (26 %), while the
monoterpenes dominated in the dry leaves (70.3 %). T-Muurolol (40.9 %) predominated
in the fresh leaf oil, α-thujene (19.2 %) and δ-cadinene (11.8 %) were present in high
quantities. In contrast, 1,8-cineole (29.4%), γ-terpenene (11.6 %), δ-cadinene (9.0 %), β-
pinene (6.9 %), and α-thujene (6.3 %) were the major components in the dry leaf oil,
while in the fresh flower oil, α-thujene (15.9 %), δ-cadinene (13.1 %) and γ-cadinene
(10.9 %) were the major components. The significance of the effect of drying and age on
essential oil composition is discussed.
