Table of Contents  
Year : 2017  |  Volume : 16  |  Issue : 2  |  Page : 98-102

Microwave-assisted extraction as an alternative tool for extraction of Stachys aegyptiaca essential oil

1 Department of Phytochemistry, National Research Centre, Giza, Egypt
2 Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
3 Department of Medicinal and Aromatic Plants Researches, National Research Centre, Giza, Egypt

Date of Submission23-Feb-2017
Date of Acceptance03-Apr-2017
Date of Web Publication8-Sep-2017

Correspondence Address:
Mohamed-Elamir F Hegazy
Department of Phytochemistry, National Research Centre, 33 El-Bohouth St., Dokki, Giza - 12622
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/epj.epj_11_17

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Background and objectives
Stachys aegyptiaca Pers. (family Lamiaceae) is a perennial aromatic wild plant collected from Saint Catherine Protectorate, Sinai. The essential oil of S. aegyptiaca was obtained using two different techniques, conventional hydrodistillation (HD) and microwave-assisted extraction (MAE). The aim of the present study was to compare the effect of the two techniques on oil yield and oil composition. MAE offered reduction in the extraction time with better oil yield compared with HD.
Materials and methods
Two different techniques, conventional HD and MAE, were used for the extraction of essential oil from S. aegyptiaca. The chemical composition of the essential oil was analyzed using the gas chromatography–mass spectrometry technique.
Results and conclusion
Gas chromatography–mass spectrometry of the essential oils obtained revealed the presence of 48 and 30 components constituting 99.31 and 99.82% of the total composition of the oils obtained using; MAE and HD, respectively. Variations in the percentage yield and chemical composition were observed. The major component found in the extracted oils was α-pinene (24.65% HD and 41.14% MAE). MAE offered reduction in the extraction time (60 min vs. 3 h) with better oil yield (1.4% w/v) when compared with HD (0.9% w/v). MAE could be used as an alternative tool for the isolation of essential oils from their natural sources.

Keywords: hydrodistillation, microwave-assisted extraction, Stachys aegyptiaca

How to cite this article:
Shaheen AM, Saleh IA, El-Kashoury ESA, Tawfik WA, Omar EA, Hegazy MEF, Abdel-Sattar E. Microwave-assisted extraction as an alternative tool for extraction of Stachys aegyptiaca essential oil. Egypt Pharmaceut J 2017;16:98-102

How to cite this URL:
Shaheen AM, Saleh IA, El-Kashoury ESA, Tawfik WA, Omar EA, Hegazy MEF, Abdel-Sattar E. Microwave-assisted extraction as an alternative tool for extraction of Stachys aegyptiaca essential oil. Egypt Pharmaceut J [serial online] 2017 [cited 2023 Feb 5];16:98-102. Available from:

  Introduction Top

Genus Stachys is one of the largest genera of family Lamiaceae containing about 300 species and centered in the Mediterranean region and south western Asia [1]. Stachys spp., known as mountain tea, were used in folk medicine to treat several complaints. Teas prepared from the plants of this genus were used as sedative, diuretic, antispasmodic, and emmenagogue [2]. They were used in traditional medicine in the treatment of diarrhea, sore throat, internal bleeding, and weakness of the heart and liver [2]. The different species of the genus were also investigated for their antimicrobial [1],[3],[4], antioxidant [5],[6],[7], anxiolytic [8],[9],[10], and anti-inflammatory properties [11],[12],[13]. Phytochemical investigations of the genus Stachys revealed the presence of essential oils [14],[15],[16], terpenoids [17],[18],[19], flavonoids [20],[21],[22], phenylethanoid glycosides [23],[24],[25],[26], iridoids [27],[28], and saponins [29],[30],[31]. Halim et al. [14] studied the chemical constituents of essential oil. The results revealed the presence of 14 monoterpene hydrocarbons (75%), four oxygenated monoterpenes (1.16%), and seven sesquiterpene hydrocarbons (17%), and the dominant compound was α-pinene (54.46%).

Microwave extraction technology is considered as a greener method for medicinal and aromatic plant extraction when compared with the conventional extraction technique, as it offers shorter extraction time, great reduction in the power used, high extraction selectivity and increased production [32]. Conventional techniques run a severe risk for thermal degradation of most of the phytoconstituents with a high risk for increased pollution concerns. Microwave-assisted extraction (MAE) is a new concept for natural product extraction methodologies and is considered as a green sustainable innovative extraction technology that meets the challenges of the 21st century [33].

The objective of this research was to compare the potential of MAE for the extraction of essential oil from S. aegyptiaca with the conventional hydrodistillation (HD) method.

  Materials and methods Top

Plant material

Air-dried aerial parts of S. aegyptiaca Pers. were collected in May 2013 from Wadi Jibaal in Saint Catherine Protectorate. A voucher specimen (ID 213) has been deposited in the herbarium of National Research Centre. The collection was carried out under the permission of Saint Catherine Protectorate for scientific purposes. The plant was kindly authenticated by Dr Mona Marzouk, Associate Professor of Taxonomy, National Research Center, Cairo, Egypt.

Microwave-assisted extraction

MAE was carried out using a focused microwave apparatus (model MARS 240/50, no. 907511; CEM Corporation, Matthews, North Carolina, USA), frequency 2450 MHz operating at 2450 MHz with a maximum power of 1600 W. Hundred grams of the dried aerial parts was placed in a 5000 ml round bottomed flask that was connected to Clevenger-type apparatus outside of a microwave oven. The extraction was carried out in 800 W power for 60 min. Temperature was adjusted at 100°C. The essential oil was recovered and its volume was determined using a micropipette. The obtained yield was calculated as percentage (volume of recovered oil per weight of the sample). The obtained oil was dried using anhydrous sodium sulfate and saved in a refrigerator until analysis.

Hydrodistillation extraction

For comparison, HD extraction of the essential oil was carried out using 100 g of S. aegyptiaca. Extraction was carried out for 3 h using a Clevenger-type apparatus according to the Egyptian Pharmacopoeia procedures [34]. After HD extraction, the same post extraction procedures for MAE were applied to the recovered oil.

Investigation of the essential oil composition using gas chromatography–mass spectrometry

The gas chromatography–mass spectrometry (GC–MS) analysis of the essential oil samples was carried out using GC–MS instrument at the Department of Medicinal and Aromatic Plants Research, National Research Center, with the following specifications. A TRACE GC Ultra Gas Chromatographs (Thermo Scientific Corp., Waltham, MA, USA) coupled with a Thermo mass spectrometer detector (ISQ Single Quadrupole Mass Spectrometer) was used. The GC–MS system was equipped with a TraceGOLD™ TG-WaxMS, Waltham, MA USA; column (30 m×0.25 mm internal diameter, 0.25 µm film thickness). Analyses were carried out using helium as a carrier gas at a flow rate of 1.0 ml/min and a split ratio of 1 : 10 using the following temperature program: 40°C for 1 min; increasing at 4.0°C/min to 160°C and maintaining for 6 min, followed by increasing at 6°C/min to 210°C and maintaining for 1 min. The injector and detector were both maintained at 210°C. Oil samples were diluted with hexane (1 : 10, v/v) and 0.2 µl of the mixtures was injected. Mass spectra were obtained by means of electron ionization at 70 eV, using a spectral range of m/z 40–450. Most of the components were identified using mass spectra (authentic chemicals, Wiley spectral library collection, and NSIT library) as well as using comparison of their retention indices and mass spectra with those published [35].

  Results and discussion Top

The components identified in the essential oil extracted using HD and MAE techniques from the aerial parts of S. aegyptiaca and their relative percentages are given in [Table 1] in the order of their elution from the column.
Table 1: Identified components in Stachys aegyptiaca essential oil, extracted using hydrodistillation and microwave-assisted extraction and their relative percentages

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Forty-eight components were identified in microwave-extracted oil, representing 99.31% of the oil composition, whereas 30 components were identified in hydrodistilled oil, representing 99.82% of the oil composition. [Figure 1] shows the total ion chromatograms of S. aegyptiaca essential oils extracted using HD and MAE, respectively.
Figure 1: Total ion chromatograms of the essential oils obtained from the dried aerial part of Stachys aegyptiaca:(a) Hydrodistillation extraction and (b) microwave-assisted extraction

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The main components found in the oil were α-pinene (24.65 and 41.14%), trans-caryophyllene (14.65 and 8.63%), 6-epi-shyobunol (14.61 and 11.15%), α-cadinol (11.08 and 5.55%), δ-cadinene (5.75 and 2.39%), and (−)-spathulenol (5.41 and 4.32%) extracted by means of HD and MAE, respectively. Oxygenated sesquiterpenes and monoterpene hydrocarbons are the main classes of compounds of the extracted S. aegyptiaca essential oils, representing 37.91 and 49.56% of the oil composition using HD and MAE, respectively.

Although α-pinene has been similarly reported as a major component in the essential oil of the leaves [14], a qualitative and quantitative variation among other constituents is obvious.

Comparison of both methods revealed that α-terpineol (1.23%) extracted by means of HD was missing in microwave-extracted oil. However, some components were detected in MAE oil that were missing in HD: β-myrcene (0.35%), 3-carene (0.34%), α-terpinene (0.5%), o-cymene (0.22%), limonene (3.1%), γ-terpinene (0.27%), fenchone (0.09%), α-thujone (0.14%), β-thujone (0.12%), isopinocarveol (0.11%), cis-verbenol (0.05%), trans-verbenol (0.21%), terpinen-4-ol (0.12%), cis-p-mentha-1(7),8-dien-2-ol (0.13%), chrysanthenyl acetate (0.41%), carvacrol (1.31%), limonen-6-ol, pivalate (0.55%), ledene oxide-(II) (0.36%), and β-selinenol (0.3%).

MAE not only gives better yield (1.4 vs. 0.9%) but also shortens the extraction time when compared with HD (60 min vs. 3 h). The unique MAE mechanism, which provides non contact heat production and delivery to the extraction matrix, is able to heat up the intracellular contents of plant cells, which produces vapor and generates tremendous pressure on the plant cell wall, causing complete rupture of the cell wall, which causes complete and fast discharge of the active constituents from the ruptured cells to the surrounding extraction solvent [36]. The percentage of α-pinene in the oil obtained by means of MAE is much higher than that obtained by means of HD (41.14 vs. 24.65%). This gives an additional advantage to this method due to the biological activities (antibacterial, antiproliferative, anti-inflammatory, and antioxidant) reported for this compound [37],[38],[39]. These results are in agreement with those previously reported for a number of Stachys spp., which revealed the presence of α-pinene as the major constituent in their essential oils [15],[40],[41],[42],[43],[44].

  Conclusion Top

MAE, as an alternative green extraction method to conventional HD, showed better extraction yield (1.4 vs. 0.9%) and shorter extraction time (60 min vs. 3 h). α-Pinene was the dominant component extracted using both methods. In addition, the results revealed qualitative and quantitative variability in the composition of the oils obtained.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Jassbi AR, Miri R, Asadollahi M, Javanmardi N, Firuzi O. Cytotoxic, antioxidant and antimicrobial effects of nine species of woundwort (Stachys) plants. Pharm Biol 2014; 52:62–67.  Back to cited text no. 1
Venditti A, Bianco A, Nicoletti M, Quassinti L, Bramucci M, Lupidi G et al. Phytochemical analysis, biological evaluation and micromorphological study of Stachys alopecuros (L.) Benth. subsp. divulsa (Ten.) Grande endemic to central Apennines, Italy. Fitoterapia 2013; 90:94–103.  Back to cited text no. 2
Farjam MH, Khalili M, Rustayian A, Javidnia K, Izadi S. Biological activity of the n-butanolic extract of Stachys pilifera. Afr J Microbiol Res 2011; 5:5115–5119.  Back to cited text no. 3
Yildirim AB, Karakas FP, Turker AU. In vitro antibacterial and antitumor activities of some medicinal plant extracts, growing in Turkey. Asian Pac J Trop Med 2013; 6:616–624.  Back to cited text no. 4
Morteza-Semnani K, Saeedi M, Shahani S. Antioxidant activity of the methanolic extracts of some species of Phlomis and Stachys on sunflower oil. Afr J Biotechnol 2006; 5:2428–2432.  Back to cited text no. 5
Ebrahimabadi AH, Ebrahimabadi EH, Djafari-Bidgoli Z, Kashi FJ, Mazoochi A, Batooli H. Composition and antioxidant and antimicrobial activity of the essential oil and extracts of Stachys inflata Benth from Iran. Food Chem 2010; 119:452–458.  Back to cited text no. 6
Bilušić Vundać V, Brantner AH, Plazibat M. Content of polyphenolic constituents and antioxidant activity of some Stachys taxa. Food Chem 2007; 104:1277–1281.  Back to cited text no. 7
Rabbani M, Sajjadi S, Jalali A. Hydroalcohol extract and fractions of Stachys lavandulifolia vahl: effects on spontaneous motor activity and elevated plus‐maze behaviour. Phytother Res 2005; 19:854–858.  Back to cited text no. 8
Kumar D, Bhat ZA, Kumar V, Raja W, Shah M. Anti-anxiety activity of Stachys tibetica Vatke. Chin J Nat Med 2013; 11:240–244.  Back to cited text no. 9
Rabbani M, Sajjadi S, Zarei H. Anxiolytic effects of Stachys lavandulifolia Vahl on the elevated plus-maze model of anxiety in mice. J Ethnopharmacol 2003; 89:271–276.  Back to cited text no. 10
Sadeghi H, Zarezade V, Sadeghi H, Toori MA, Barmak MJ, Azizi A et al. Anti-inflammatory Activity of Stachys pilifera Benth. Iran Red Crescent Med J 2014; 16:1–8.  Back to cited text no. 11
Benmebarek A, Zerizer S, Laggoune S, Kabouche Z. Effect of Stachys mialhesi de Noé on the inflammation induced by hyperhomocysteinemia in Cardiovascular diseases. Der Pharmacia Lettre 2013; 5:212–223.  Back to cited text no. 12
Barreto RS, Quintans JS, Amarante RK, Nascimento TS, Amarante RS, Barreto AS et al. Evidence for the involvement of TNF-α and IL-1β in the antinociceptive and anti-inflammatory activity of Stachys lavandulifolia Vahl. (Lamiaceae) essential oil and (−)-α-bisabolol, its main compound, in mice. J Ethnopharmacol 2016; 191:9–18.  Back to cited text no. 13
Halim AF, Mashaly MM, Zaghloul AM, El-Fattah HA, De Pooter HL. Chemical constituents of the essential oils of Origanum Syriacum and Stachys aegyptiaca. Int J Pharmacognosy 1991; 29:183–187.  Back to cited text no. 14
Grujic-Jovanovic S, Ana DM, Ristic MS, Marin PD. Essential oil composition of Stachys anisochila. Chem Nat Comp 2011; 47:823–825.  Back to cited text no. 15
Karami A, Dehghan-Mashtani N. Composition of the essential oil of Stachys benthamiana Boiss. from the south of Iran. Nat Prod Res 2015; 29:1473–1476.  Back to cited text no. 16
Fazio C, Passannanti S, Paternostro MP, Arnold NA. Diterpenoids from Stachys mucronata. Planta Med 1994; 60:499.  Back to cited text no. 17
Paternostro MP, Maggio AM, Piozzi F, Servettaz O. Labdane diterpenes from Stachys plumosa. J Nat Prod 2000; 63:1166–1167.  Back to cited text no. 18
Mohamed AE-HH, Mohamed NS. A new trans-neo clerodane diterpene from Stachys aegyptiaca. Nat Prod Res 2014; 28:30–34.  Back to cited text no. 19
El-Ansari M, Abdalla M, Saleh N, Barron D, Le Quere J. Flavonoid constituents of Stachys aegyptiaca. Phytochemistry 1991; 30:1169–1173.  Back to cited text no. 20
El-Ansari MA, Nawwar MA, Saleh NA. Stachysetin, a diapigenin-7-glucoside-p, p′-dihydroxy-truxinate from Stachys aegyptiaca. Phytochemistry 1995; 40:1543–1548.  Back to cited text no. 21
Vundać V, Maleš Ž, Plazibat M, Golja P, Cetina-Čižmek B. HPTLC determination of flavonoids and phenolic acids in some Croatian Stachys taxa. J Planar Chromatogr 2005; 18:269–273.  Back to cited text no. 22
Ikeda T, Miyase T, Ueno A. Phenylethanoid glycosides from Stachys riederi. Nat Med 1994; 48:32–38.  Back to cited text no. 23
Nishimura H, Sasaki H, Inagaki N, Chin M, Mitsuhashi H. Nine phenethyl alcohol glycosides from Stachys sieboldii. Phytochemistry 1991; 30:965–969.  Back to cited text no. 24
Miyase T, Yamamoto R, Ueno A. Phenylethanoid glycosides from Stachys officinalis. Phytochemistry 1996; 43:475–479.  Back to cited text no. 25
Delazar A, Delnavazi MR, Nahar L, Moghadam SB, Mojarab M, Gupta A et al. Lavandulifolioside B: a new phenylethanoid glycoside from the aerial parts of Stachys lavandulifolia Vahl. Nat Prod Res 2011; 25:8–16.  Back to cited text no. 26
Munoz O, Pena RC, Montenegro G. Iridoids from Stachys grandidentata (Labiatae). Z Naturforsch C 2001; 56:902–903.  Back to cited text no. 27
Murata T, Endo Y, Miyase T, Yoshizaki F. Iridoid glycoside constituents of Stachys lanata. J Nat Prod 2008; 71:1768–1770.  Back to cited text no. 28
Cho HK, Kim CS, Suh WS, Kim KH, Lee KR. Two new triterpene saponins from the tubers of Stachys sieboldii. Heterocycles 2014; 89:2619–2626.  Back to cited text no. 29
Cho HK, Kim CS, Woo KW, Lee KR. A new triterpene saponin from the tubers of Stachys sieboldii. Bull Korean Chem Soc 2014; 35:1553–1555.  Back to cited text no. 30
Yamamato R, Miyase T, Ueno A. Stachysaaponins l-Vlll, New Oleanane-type Triterpene saponins from Stachys riederi. Chamisso Chem Pharm Bull 1994; 42:1291–1296.  Back to cited text no. 31
Cardoso-Ugarte GA, Juárez-Becerra GP, SosaMorales ME, López-Malo A. Microwave-assisted extraction of essential oils from herbs. J Microw Power Electromagn Energy 2013; 47:63–72.  Back to cited text no. 32
Chemat F, Rombaut N, Fabiano-Tixier A-S, Pierson JT, Bily A. Green extraction: from concepts to research, education, and economical opportunities, in Green Extraction of Natural Products: Theory and Practice. Chemat F, Strube J, editors. Weinheim: WILEY-VCH Verlag GmbH & Co. KGaA; 2015. p. 1–36.  Back to cited text no. 33
Central Administration and Pharmaceutical Affairs (CAPA). Egyptian Pharmacopoeia. 4th ed. Cairo, Egypt: CAPA, Ministry of Health and Population; 2005.  Back to cited text no. 34
Adams RP. Identification of essential oil components by gas chromatography/mass spectrometry. Illinois, USA: Allured Publishing Corporation; 2007.  Back to cited text no. 35
Zhang H-F, Yang X-H, Wang Y. Microwave assisted extraction of secondary metabolites from plants: current status and future directions. Trends Food Sci Technol 2011; 22:672–688.  Back to cited text no. 36
Silva ACRd, Lopes PM, Azevedo MMBd, Costa DCM, Alviano CS, Alviano DS. Biological activities of α-pinene and β-pinene enantiomers. Molecules 2012; 17:6305–6316.  Back to cited text no. 37
Kummer R, Estevão-Silva CF, Bastos RL, Rocha BA, Spironello RA, Yamada AN et al. Alpha-pinene reduces in vitro and in vivo leukocyte migration during acute inflammation. Int J App Res Nat Prod 2015; 8:12–17.  Back to cited text no. 38
Aydin E, Türkez H, Geyikoğlu F. Antioxidative, anticancer and genotoxic properties of α-pinene on N2a neuroblastoma cells. Biologia (Bratisl) 2013; 68:1004–1009.  Back to cited text no. 39
Aghaei Meibodi Z, Abroomand Azar P, Torabbeigi M, Saber Tehrani M. Composition of essential oil of flowers, leaves, stems and roots of Stachys inflata Benth. grown wild in Iran. Analyt Chem Lett 2015; 5:44–49.  Back to cited text no. 40
Mazinani SMH, Tajali AA, Gandomkar A, Roshandelpour A. Variability in chemical constituents of the essential oil of two species of Stachys genus from Iran. Int J Agriculture Crop Sci 2013; 5:2773–2776.  Back to cited text no. 41
Jamzad M, Akbari MT, Rustaiyan A, Masoudi S, Azad L. Chemical composition of essential oils of three Stachys species growing wild in Iran: Stachys asterocalyx Rech. f., Stachys obtusicrena Boiss. and Stachys multicaulis Benth. J Essent Oil Res 2009; 21:101–104.  Back to cited text no. 42
Khanavi M, Farahanikia B, Janbakhsh S, Sheibani S, Hoseini-Sajedi S, Salahi-Oliaee M et al. Comparison of the essential oil composition of Stachys trinervis Aitch. & Hemsl. and Stachys subaphylla Rech. F. J Essen Oil Bearing Plants 2008; 11:406–412.  Back to cited text no. 43
Norouzi‐Arasi H, Yavari I, Kia‐Rostami V, Jabbari R, Ghasvari‐Jahromi M. Volatile constituents of Stachys inflata Benth. from Iran. Flavour Frag J 2006; 21:262–264.  Back to cited text no. 44


  [Figure 1]

  [Table 1]

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