Oil Constituents of Artemisia nilagirica var. septentrionalis During Different Growth Phases at Subtropical Conditions of North Indian Plains

Journal of Essential Oil Research: JEOR, Jan/Feb 2007 by Haider, Flora, Naqvi, A A, Bagchi, G D

Abstract

Essential oils obtained from the aerial parts of Artemisia nilagirica (Clarke) Pamp. var. septentrionalis Pamp. harvested during different growth phases were analyzed by GC and GC/MS. The oil yield was highest (0.6%) during the flowering stage. During the vegetative, budding and fruiting stages camphor was the main constituent, while during the flowering stage, it was replaced by β-caryophyllene. Other important constituents of the oil were germacrene D, α-humulene and 1,8-cineole.

Key Word Index

Artemisia nilagirica var. septentrionalis, Asteraceae, essential oil composition, camphor, β-caryophyllene.

Plant Name

Artemisia nilagirica (Clarke) Pamp. var. septentrionalis Pamp. (Asteraceae) plants are found in western Himalayas at an altitude of 1500-2200 m (1).

Source

Live plants of A. nilagirica var. septentrionalis were, collected in May 2000 from Mussoorie, Uttaranchal, India (altitude 2205 m), and were first acclimatized under glass house conditions. In October 2001, on the onset of the winter season, plants were moved to experimental plots on a CIMAP research farm, Lucknow, Uttar Pradesh (altitude 120 m). A voucher specimen (No. 4912) of the plant has been deposited in the Herbarium of CIMAP, Lucknow.

Plant Parts

Aerial parts of the plants were collected during the vegetative (15th May, 2002), budding (15th September, 2002), flowering (1st October, 2002) and fruiting (30th October, 2002) stages.

Previous Work

Over 37 species of Artemisia are reported to occur in the temperate regions of India (1). Chemical analyses of oil of different Artemisia species have been done by many workers (2-15). An oil of A. nilagirica, collected during the flowering stage, from Chamoli, Garhwal Himalaya, has also been the subject of analysis (11). The oil yield was 0.2% on dry weight basis. The main constituents of the oil were camphor (9.7%), β-eudesmol (8.0%), 1,8-cineole (6.6%), borneol (5.3%), Artemisia alcohol (3.4%), camphene (2.6%), α-gurjunene (1.9%), p-cymene (1.6%), terpinen-4-ol (1.2%) and α-pinene (1.2%). However, analysis of oil of Artemisia nilagirica var. septentrionalis, has not been undertaken so far.

Present Work

Plants of A. ntiagirica var. septetronalis were domesticated in the subtropical conditions of Lucknow. Aerial parts of the plant were collected during vegetative, budding, flowering and fruiting stages. The fresh herbage (100 g) from each collection was separately hydrodistilled using a Clevenger-type apparatus for 5 h to obtain light yellow oil. The oil yield from the fresh aerial parts during vegetative, budding, flowering and fruiting stages were 0.2%, 0.4%, 0.6% and 0.5%, respectively.

GC analysis of the oil was performed using Perkin Elmer AUTO-XL GC, capillary column PE-5 (50 m x 0.32mm x 0.25 µm film thickness) with oven temperature programmed from 100°-280°C at 3°/min with initial hold of 2 min. Injector and detector temperatures were maintained at 220°C and 300°C, respectively. Hydrogen at 10 psi was used as a carrier gas split ratio of 1:50. The GC/MS analysis was carried out in El mode using Perkin Elmer Auto XL/ Turbo Mass instrument with the same column and analytical conditions. Helium at 10 psi was used as a carrier gas with split ratio of 1:20. Mass spectral data were identified using NIST and Wiley libraries and comparison with standard published data (12).

During the vegetative, budding, flowering and fruiting stages of A. nilagirica var. septentrionalis plants, 22, 20, 23 and 26 compounds were identified, which amounted to 80.8%, 84.7%, 81.3% and 89.9% of the oils, respectively. During the vegetative and budding stages, camphor was the main constituent, followed by β-caryophyllene and germacrene D. But during the flowering stage, β-caryophyllene was found to be the main constituent, followed by camphor and α-humulene. However, during the fruiting stage, camphor again was the main constituent followed by 1,8-cineole and β-caryophyllene. During the vegetative stage β-caryophyllene (13.0%), germacrene D (11.9%) andborneol (9.1%) was highest. During the flowering stage the other main components were β-caryophyllene (22.8%), α-humulene (9.8%) andcaryophyllene oxide (6.3%). However, during the fruiting stage, the main constituents were camphor (37.0%), 1,8-cineole (11.7%), β-caryophyllene (7.2%), limonene (6.7%) and camphene (6.2%). 3-Octanol that was not detected during the vegetative and budding stages was observed in the flowering and fruiting stages. On the otherhand, α-thujone and chrysanthenone, which were not observed in the earlier stages of the growth, were detected in the fruiting stage of the plant. The main constituents of A. nilagirica, collected from Chamoli, Garhwal Himalaya(11) were reported to be camphor (9.7%), followed by β-eudesmol (8.0%) and 1,8-cineole (6.6%). Artemsisia nilagirica var. septentrionalis, domesticated for the first time in the subtropical conditions of Lucknow, was also observed to be rich in camphor (16.7-37.0%), but its other major constituents were different: β-caryophyllene (7.2-22.6%), germacrene D (3.6-11.9%), α-humulene (2.4-9.8%) and borneol (2.8-9.1%). Occurrence of 3-octanol, α-terpinene, trans-sabinene hydrate, chrysathenone, β-elemene, α-humulene, germacrene D and caryophyllene oxide were the characteristic features of this domesticated variety, which were not reported in the naturally growing A. nilagirica plants (11).