Comparison of the Volatile Constituents of Elsholtzia fruiticosa Extracted by Hydrodistillation, Supercritical Fluid Extraction and Head Space Analysis

Abstract

Volatile constituents of Elsholtzia fruiticosa (D. Don) Rehder were studied by two different extraction techniques, supercritical fluid extraction (SFE) and hydrodistillation (HD), and the results were compared with head space analysis (HS). Thirty-five constituents were identified in both the SFE and HD oils and fourteen in the HS, accounting for 94.2%, 97.7% and 96.9% of the total identifications, respectively. A distinctive feature of the results was the very high content of non-terpenes (59.8%) in the HS, the high content of oxygenated monoterpenes (41.1%) in the HD oil and the high content of sesquiterpene hydrocarbons (21.8%) in the SFE oil. Monoterpene hydrocarbons were represented in HS (13.6%), HD (19.4%) and SFE (4.3%). In SFE sesquiterpene hydrocarbons formed 21.8% of the total, as compared to 6.6% in the HD and 1.1% in the HS Oxygenated sesquiterpenes represented 3.0% in SFE, 0.8% in HD and were absent in HS. Diterpenes were only present in the SFE oil (3.4%). Non-terpenes were represented by 24.5% in the SFE oil and 29.8% in the HD oil.

Comparison of Eucalyptus cinerea Essential Oils Produced by Hydrodistillation and Supercritical Carbon Dioxide Extraction

“…The yield of free volatiles (3.1%) produced by HD was about three times more than by SCE (1.1%), which is in agreement with our previous studies on Elsholtzia fruiticosa [24]. The lower extract yields in SCE is attributed to the fact that the moisture content in the fresh foliage acts as a barrier to the transfer of the analytes (volatile components) to the extraction fluid i.e.…”

“…The experimental set-up for SCE device/system was quite similar to those reported earlier [24]. The extraction vessel, filled with 1.5 kg fresh foliage, was initially pressurized with CO 2 up to the set pressure (140 bar) and temperature (60 O C) and kept for 1 h in a static condition.…”

Variation in the volatile oil composition of Eucalyptus citriodora produced by hydrodistillation and supercritical fluid extraction techniques

“…Similar observations were also noticed during the extraction of volatiles from E. cinerea (Mann, Babu, Guleria, & Singh, 2011) and Elsholtzia fruticosa (Saini et al, 2010) and the lower extract yields in SCE was attributed to the fact that the moisture content in the fresh foliage acts as a barrier in transfer of the analytes (volatile components) to the extracting fluid/solvent, i.e. CO 2 .…”

“…The essential oils and SCE extracts were analysed by GC and GC-MS under the experimental conditions quite similar to those reported earlier (Saini et al, 2010). Identification of constituents was carried out by comparing with MS data and from RRI values available in the literature (Adams, 1995) and from the National Institute of Standards and Technology (Stein, 1990) and our own library.…”

“…The extraction vessel filled with 1.5 kg fresh foliage was pressurised with CO 2 up to the set pressure (140 bar), temperature (60 C) and rest of the parameters in the SCE system set-up were maintained as mentioned in our earlier report (Saini et al, 2010). The essential oils and SCE extracts obtained from the above experiments were measured, dried over anhydrous sodium sulphate, filtered and stored at 0 C until analysis.…”