An investigation of CO2 extraction of marigold (Calendula officinalis L.)

Abstract

Essential oil content (0.05 %) of marigold (Calendula officinalis L.) was determined using the official steam distillation procedure. High-pressure CO 2 extraction of plant material under supercritial (100, 200 and 300 bar and 40°C) and subcritical (60, 90 and 120 bar and 15°C) conditions for 3 h was investigated. It was found that the increase in the pressure promoted an increase in the yield. The essential oil contents obtained from the investigated CO 2 extracts by steam distillation were significantly higher (1.52-2.70 times) and increased with pressure. Major constituents of the oil, identified using GC-MS and GC-FID, were a-cadinol (26.54 %), T-cadinol and T-muurolol (9.80 %), g-cadinene (2.99 %), hexadecanoic acid (2.95 %), and ledane (2.45 %). In addition, the essential oils of the CO 2 extracts contained d-cadinene (6.50-19.87 % under supercritical and 16.09-19.41 % under subcritical conditions), which was not found in the essential oil obtained from the plant by steam distillation. The extraction kinetics was investigated at 200 bar and 40°C. The total extract obtained after 10 h of extraction was 6.54 % and essential oil content in it, refering to plant material, was 0.209 %, which is 4.16 time more than the one determined by the standard steam distillation procedure.

Chemical Composition and Chemometric Analysis of Variation in Essential Oils of Calendula officinalis L. during Vegetation Stages

“…The identified compounds are listed in Table 1. GS-MS analysis showed that sesquiterpenes and their derivatives were the main compounds in marigold extracts, but not the only one, such as that found in the marigold from Brazil [6] and Serbia [7]. The total amount of sesquiterpene hydrocarbons and sesquiterpenols was in the range 51.6-68.5%.…”

“…The compounds were identified by comparison of their linear retention indices (LRI) relative to C 8 -C 24 n-alkanes obtained on a non-polar DB-5 column with those provided in the database [16] and by matching their mass spectra to the data in NIST 05 library and to the results reported elsewhere [6][7][8]10].…”

“…For example, d-cadinene (22.5%), a-cadinol (20.4%), epi-a-muurol (12.9%), c-cadinene (8.9%) and a-muurolene (5.6%) were predominant compounds in C. officinalis flowers grown in Brazil [6], while a-cadinol (26.5%), s-cadinol ? s-muurol (9.8%) and c-cadinene (3.0%), and a-thujene (26.9%), s-muurol (24.9%), d-cadinene (13.1%) and germacrene D (2.8%) were the major identified compounds of C. officinalis samples collected from Serbia [7] and South Africa [8], respectively. It is known that different chemotypes of plants exist due to the variations of plant secondary metabolites caused by effects of light, soil, temperature and weather conditions during plant life time.…”

“…The extraction method used for the sample preparation also has high impact. Different extraction techniques have been used for the extraction of essential oils from C. officinalis, such as steam distillation [6,7], headspace solid-phase microextraction (SPME) [6], headspace cold finger extraction [6], hydrodistillation [8,10], and supercritical CO 2 [7] and subcritical CO 2 [7] extractions. It is thought that headspace analysis is more reliable because this technique is solvent free and avoids the loss of volatiles, which occur during solvent removing in solvent extractions [11].…”

A Novel Eudesmane Glycosides Sesquiterpene from <i>Calendula</i> <i>officinalis</i> L.

“…Previous studies demonstrated therapeutic potentialities of Calendula officinalis L. such as anti-inflammatory activity [2][3][4][5], immunomodulatory [6][7], Hepatoprotective [8], wound-healing [9], antioxidant [10][11][12], antibacterial and antiparasitic activity [13][14][15][16]. The essential oil from C. officinalis has been also investigated [17][18][19][20][21][22].…”