Next Article in Journal
Complexes of 3dn Metal Ions with Thiosemicarbazones: Synthesis and Antimicrobial Activity
Previous Article in Journal
Evaluation of the Antioxidant Properties of Litchi Fruit Phenolics in Relation to Pericarp Browning Prevention
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Chemical Composition and Antimicrobial Activity of the Essential Oil of Algerian Phlomis bovei De Noé subsp. bovei

1
Department of Pharmacy, Div. of Pharmacognosy, Chemistry of Natural Products, University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
2
Department of Biology, Faculty of Sciences, University Ferhat Abbas, Setif, Algeria
3
Department of Food Technology, Technological Educational Institution (T.E.I.) of Larissa, Terma Temponera str., Karditsa, Greece
*
Author to whom correspondence should be addressed.
Molecules 2007, 12(4), 772-781; https://doi.org/10.3390/12040772
Submission received: 27 February 2007 / Revised: 27 March 2007 / Accepted: 3 April 2007 / Published: 12 April 2007

Abstract

:
The chemical composition of essential oil obtained by steam distillation of dried aerial parts of Phlomis bovei De Noé subsp. bovei collected from Algeria, was analyzed by GC and GC/MS. Seventy five constituents (corresponding to 86.37% of the total weight) were identified. The main components were: germacrene D, β-caryophyllene, β-bournonene, thymol and hexahydrofarnesyl acetone. Furthermore, the antimicrobial activity of the oil was evaluated against six Gram (+/-) bacteria and three pathogenic fungi, using the agar dilution technique. It was found that the oil exhibited strong antimicrobial activity against most of the tested microorganisms.

Introduction

The plants of the genus Phlomis are native to Turkey, North Africa, Europe and Asia. Phlomis bovei De Noé, syn. Phlomis samia Desfontaines (Lamiaceae) is a rare Algerian endemic plant, commonly known as Kayat El Adjarah [1] in the Algerian dialect or variously named Farseouan, Tarseouan, Iniji, R’ilef and Azaref throughout the North of Africa [2]. It is one among the nine endemic plants recorded in the ‘Rapport National sur la Diversité Biologique’ [1]. P. bovei is a herbaceous perennial plant, which grows up to 0.8 m. and often develops a stout woody base. All parts are sticky, because of its dendroid stellate glandular hairs. Its basal leaves are green, heart-shaped, with scalloped margins, 6.5-25 x 4.5-20 cm and it has a petiole of between 4-18 cm in length. To date two subspecies have been recorded for P. bovei De Noé: P. bovei De Noé subsp. bovei and P. bovei De Noé subsp. maroccana Maire. The present study refers to the former, which to our knowledge has never been studied phytochemically before, whereas previous studies on the essentials oils of Phlomis species from around the Mediterranean have included: Phlomis fruticosa, P. cretica, P. samia, P. lanata, P. linearis, P. leucophracta, P. chimerae and P. grandiflora var. grandiflora.

Results and Discussion

The essential oil obtained by hydrodistillation of aerial parts of Phlomis bovei De Noé subsp. bovei was light yellow in color and possessed a distinct sharp odor. The yields were 0.22 % w/w. The analysis of the volatile constituents was carried out using two different GC-MS systems, equipped with two columns of different polarities (HP-5 and Aquawax, respectively). The chemical compositions are summarized in Table 1 and Table 2. The identified components represented 86.37% of all the components found in the oil samples. These percentages were based on normalization of peak areas without application of the response correction factor. The major components included: germacrene D (21.45%), thymol (8.43%), β-caryophyllene (7.05%) and hexahydrofarnesyl acetone (5.84%). We should also note the presence in the essential oil of a total 6.03 % of normal saturated hydrocarbons (see Table 2). Although most of the identified constituents occurred in both methods of analysis, it was also noted that some chemical constituents occurring in appreciable amounts in HP-5 were absent in Aquawax and viceversa. This was due to the differences between the GC-MS instruments, the two columns and the absence of reference retention indexes for the second column. Thus the identification of the components for the second column was based on their mass spectra and by comparison of their retention times with those of authentic samples.
Table 1. Main components of the essential oil from the aerial parts of P. bovei De Noé.
Table 1. Main components of the essential oil from the aerial parts of P. bovei De Noé.
Compounds*RI§% in Essent. oilMethod of identification
HP-5Aquawax
1.1-Octen-3-ol97715051.08a, b, d,
2.3-Octanol99313940.07a, b, d
3.n-Octanal100412890.08a, b, d
4.E,E-2,4-Heptadienal1012-0.03a, b, d
5.p-Cymene 102312700.04a, b, c, d
6.Limonene1024-0.05a, b, c,d
7.Phenylacetaldehyde1046-0.02a, b, d
8.γ-Terpinene105812460.06a, b, d
9.n-Octanol107115740.13a, b, d
10.Linalool110415700.43a, b, d
11.Nonanal1107-0.8a, b, d
12.Benzeneethanol111518960.06a, b, d
13.trans-2-Nonenal116015550.29a, b, d
14.Terpine-4-ol117515930.21a, b, d
15.α- Terpineol1187-0.24a, b, c, d
16.Caprylic acid [Octanoic acid]118920210.12a, b, d
17.Methyl salicylate119117490.05a, b, d
18.n-Decanal 1203-0.15a, b, d
19.β-Cyclocitral1215-0.04a, b, d
20.Thymol methyl ether1225-0.04a, b, d
21.Carvacrol methyl ether1230-0.04a, b, d
22.trans-2-Decenal126916300.32a, b, d
23.Thymol129620658.43a, b, d, c
24.Carvacrol1303-1.03a, b, d, c
25.trans,trans-2,4-Decadienal 132817830.15a, b, d
26.Thymol methyl ester1331-0.05a, b, d
27.α-Cubebene1342-0.17a, b, d
28.2-Undecenal1359-0.54a, b, d
29.α-Copaene136415230.73a, b, d
30.β-Bourbonene137615402.96a, b, d, c
31.trans-β-Damascenone138717890.68a, b, d
32.β-Elemene1389-1.42a, b, d
33.Dodecanal1399-0.31a, b, d
34.β-Caryophyllene141815867.05a, b, d, c
35.trans -β-Copaene1423-0.66a, b, d
36.β-Gurjunene1432-0.41a, b, d
37.α-Humulene144316461.45a, b, d
38.trans-β-Farnesene146216641.49a, b, d,
39.Germacrene D1475168921.45a, b, d, c
40.α-Selinene1499-0.83a, b, d,
41.α-Muurolene150317630.38a, b, d
42.Germacrene A1509-0.27a, b, d
43.β-Bisabolene151017131.08a, b, d
44.Butylated hydroxytoluene [Ional]151519050.88a, b, d
45.epi-Bicyclosesquiphellandrene151715820.03a, b, d
46.δ-Cadinene152517362.16a, b, d, c
47.Cadina-1(2),4-dien1532-0.34a, b, d
48.α- Cadinene1535-0.22a, b, d
49.α- Calacorene1540-0.16a, b, d
50.Nerolidol156120140.36a, b, c, d
51.Spathulenol157720370.79a, b, d
52.Caryophyllene Oxide158419472.41a, b, d, c
53.Copaen-4-Α-Ol1585-0.43a, b, d
54.nor-Copaenone1627-0.11a, b, d
55.Cadina-1,4-Dien-3-Ol1628-0.19a, b, d
56.epi-α-Muurolol1643-0.97a, b, d
57.α-Muurolol [Torreyol]1649-0.7a, b, d
58.Amylcinnamalaldehyde166220810.54a, b, d
59.α-Cadinol1664-2.38a, b, d
60.Eudesmadienol derivative1685-2.56a, b, d
61.Hexahydrofarnesyl acetone (6,10,14-Trimethyl-2-pentadecanone) 185120435.84a, b, d
62.Nonadecane190019000.19a, b, d
63.Farnesyl acetone B1925-0.24a, b, d
64.Hexadecanoic acid methyl ester1926-0.14a, b, d
65.Eicosane200020000.19a, b, d
66.Heneicosane210021000.21a, b, d
67.Docosane220022000.18a, b, d
68.Tricosane230023001.4a, b, d
69.Tetracosane240024000.27a, b, d
70.Pentacosane250025001.21a, b, d
71.Hexacosane260026000.06a, c, d
72.Heptacosane270027001.19a, c, d
73.Octacosane280028000.13a, c, d
74.Triacontane300030000.66a, c, d
75.Hentriacontane310031000.34a, c, d
Total:86.37
*Compounds listed in order of elution from a HP-5 MS column.
§Retention indices (KI) on HP-5 MS capillary column.
a= Retention time; b = Retention Index; c = Peak enrichment; d = mass spectra.
Table 2. Composition of P. bovei De Noé subsp. bovei essential oil by substance class.
Table 2. Composition of P. bovei De Noé subsp. bovei essential oil by substance class.
Compounds% in essential oil
Monoterpenes0.15
Sesquiterpenes43.26
Saturated 6.03
Hydrocarbons total :49.44
Alcohols18.38
Aldehydes3.27
Ketones, Ethers, Acids, Esters, Oxides12.28
Oxygenated compounds total:36.93
Total compounds:86.37
For the essential oil obtained from the leaves of P. fruticosa collected in Montenegro (Table 3) the main constituents were: β-caryophyllene (12.0%), (E)-methyl-isoeugenol (15.3%), α-asarone (10.9%), caryophyllene oxide (8.1%) and α-pinene (6.6%) [3]. The antimutagenic activity of the essential oil and of the crude extract was evaluated by the same research group [4]. Studies on the same plant, from the same region, have been conducted considering the antimicrobial and the antifungal activity of its essential oil, as well as its methanolic extract, with moderate results [5]. Traditionally the infusion of P. fruticosa leaves is used in Greece as a tonic drink, whereas in Italy the dried leaves are used as a poultice on wounds [6].
The flowers of P. fruticosa collected in Greece (Table 3) yielded an essential oil rich in germacrene D (17.8%), γ-bisabolene (12.6%), α-pinene (8.9%) and β-caryophyllene (8.7%) [7]. In another study on the essential oil from the aerial parts of P. fruticosa collected in central-East Peloponnesus, the main constituents were: germacrene D (21.4%), Z-γ-bisabolene (7.1%), α-pinene (12.6%) and β-caryophyllene (12.6%) and linalool (8.0%) [8]. In the same study, the volatile constituents of two other Greek Phlomis species - P. cretica and P. samia - were studied. For P. cretica the major compounds were: α-pinene (9.4%), limonene (7.1%), cis-β-ocimene (5.4%), linalool (7.5%), β-caryophyllene (17.3%) and germacrene D (20.1%). P. samia also exhibited large amounts of β-caryophyllene (5.8%), germacrene D (6.3%) and linalool (2.3%) but its major compound was (E)-β-farnesene (20.7%). The essential oils were tested against Gram (±) bacteria and fungi, showing moderate activity [8].
The main chemicals identified in the essential oil of the aerial parts of P. lanata, another Phlomis growing in Greece (Table 3) were: α-pinene (25.41%), limonene (15.67%), β-caryophyllene (8.76%), isocomene (4.91%) and γ-muurolene (4.53%). The essential oil of the plant was tested against Gram (±) bacteria and fungi. Like the previous study, it showed moderate antimicrobial activity, with the exception of E. coli and P.aeruginosa, towards which it exhibited stronger activity [9].
P. linearis Boiss. & Bal., growing in central East and Southeast Anatolia, an endemic Phlomis of Turkey, was characterized by the predominance of: β-caryophyllene (24.2%), germacrene D (22.3%) and caryophyllene oxide (9.2%) [10].
Table 3. Main components of the essential oils from different Mediterranean Phlomis species.
Table 3. Main components of the essential oils from different Mediterranean Phlomis species.
ComponentsPhlomis bovei De Noé subsp. boveiP.cretica [8]P.fruticosa [3] P.fruticosa [7] P.fruticosa [8] P.samia [8]P.linearis [10]P.lanata [9]P.leucophracta [11]P.cimereae [11]P.grandiflora var.grandiflora [11]
Hexahydro-Farnesyl Acetone5.84--------0.40-
Spathulenol0.790.100.50--3.70--0.30-0.40
α -Pinene -9.406.608.9012.600.80-25.4119.2011.002.40
Limonene 0.057.100.500.400.900.10-15.6711.005.502.70
cis-β-Ocimene-5.40--0.50--2.89-0.400.60
δ-Cadinene2.161.200.901.801.002.401.001.510.405.001.30
(E)-Methyl-Isoeugenol --15.30--------
γ-Bisabolene 1.08-1.4012.607.10----0.202.50
α-Asarone--10.90--------
Thymol8.43-0.20---0.50----
Germacrene D21.4520.102.3017.8021.406.3022.30-4.506.1045.40
β-Caryophyllene7.0517.3012.008.7012.605.8024.208.7620.2031.6022.80
γ-Muurolene ------0.404.53tr-tr
Linalool -7.500.600.708.002.300.600.78-4.700.60
E-β-Farnesene1.49- 0.6020.70--1.100.501.00
Caryophyllene Oxide2.410.608.101.900.803.209.202.861.704.800.40
Bicyclogermacrene------1.10-0.80-4.90
The essential oils of three other Turkish Phlomis species (Table 3) have also been studied previously [11]. The essential oil of P. leucophracta consisted mainly of β-caryophyllene (20.2%), α-pinene (19.2%) and limonene (11.0%), while in P. chimerae the principal compounds were β-caryophyllene (31.6%), α-pinene (11.0%), germacrene D (6.1%), limonene (5.5%) and linalool (4.7%), and in P. grandiflora var. grandiflora: germacrene D (45.4%), β-caryophyllene (22.8%) and bicyclogermacrene (4.9%) have been identified among the most abundant constituents [11]. The oils of P. bovei De Noé and of the other Mediterranean species: P. grandiflora var. grandiflora [11], P. cretica [8], P. fruticosa [3,7,8], P. samia [8], P. linearis [10], P. lanata [9], P. leucophracta [11] and P. cimereae [11], presented great amounts of the sesquiterpenoids germacrene D, E-β-farnesene and β-caryophyllene. In accordance to these results, in our study besides the presence of germacrene D (21.45%) and β-caryophyllene (7.05%), hexahydrofarnesyl acetone (5.84%) has been also identified among the most abundant compounds, which could be considered as the biosynthetic predecessor of the above referred sesquiterpenoids, from the well known mevalonic acid pathway [12].
The essential oil of Phlomis bovei De Noé subsp. bovei exhibited a wide profile of antimicrobial activity against most of the tested microorganisms, in comparison with the tested antibiotics and the standards β-caryophyllene and thymol (Table 4), while only K. pneumoniae appeared to be a microorganism displaying significant resistence. Considering the fact that β-caryophyllene possesses in general moderate antimicrobial activity, we conclude that the antimicrobial activity of the essential oil from P. bovei can be attributed, to a considerable degree, to the presence of germacrene D and thymol, which are well known to posses strong antimicrobial activity [13,14,15].
Table 4. Antimicrobial activities (MIC mg/mL) of the studied Phlomis essential oils and its main components.
Table 4. Antimicrobial activities (MIC mg/mL) of the studied Phlomis essential oils and its main components.
Species-Essential OilsS. aureusS. epidermidisP. aeruginosaE. cloacaeK. pneumoniaeE. coliC. albicansC. tropicalisC. glabrata
P. bovei0.98±0.0040.85±0.0071.00±0.0111.37±0.0184.75±0.0351.12±0.0181.35±0.0080.95±0.0150.89±0.013
β-Caryophyllene>20>20>20>20>20>20---
Thymol1.25±0.0101.38±0.0082.45±0.0222.00±0.0052.88±0.0271.70±0.0231.50±0.0131.34±0.0201.18±0.018
Itraconazole------1x10-30.1x10-31x10-3
5-Flucytocine------0.1x10-31x10-310x10-3
Amphotericin B------1x10-30.5x10-30.4x10-3
Netilmicin4x10-34x10-38.8x10-38x10-38x10-310x10-3---
Amoxicillin2x10-32x10-32.4x10-32.8x10-32.2x10-32x10-3---
Clavulanic acid0.5x10-30.5x10-31x10-31.6x10-31x10-31.2x10-3---
- = not active

Conclusions

Our GC and GC/MS study of the essential oil from Algerian Phlomis bovei De Noé led to the identification of 75 constituents (corresponding to 86.37% of the total weight) among which germacrene D, β-caryophyllene, β-bournonene, thymol, and hexahydrofarnesyl acetone were the main ones. The oil exhibited a broad spectrum of strong antimicrobial activities and it possessed a much better antimicrobial activity in comparison with all previously tested and assayed samples from Greek Phlomis species [8], showing that this plant oil could have a commercial potential as an antiseptic agent, however, further investigation should be carried out against new series of pathogenic microorganisms.

Experimental

Plant material and essential oil isolation

Aerial parts of Phlomis bovei De Noé were collected from the wild in July 2004 at ca. 1,550 m of altitude on Megriss Mountain (Eastern Algeria). The plants were authenticated by the staff of the Laboratory of Natural Resource Valorization by comparison with herbarium specimens. Voucher specimens are deposited in the Herbarium of the Institute of Biology, University of Setif, Algeria. The material was air-dried indoors prior to isolation of the essential oil. The dried aerial parts were subjected to hydro-distillation in 0.4 L of water in a Clevenger-type apparatus for 4 hrs, using a water-cooled oil receiver to reduce formation of potential artifacts due to overheating during the hydro-distillation process [16]. The essential oil was collected over water, dried over anhydrous sodium sulfate (Panreac Quimica S.A. Barcelona, Spain) and stored at 4o–6 oC until it was analyzed.

Essential oil analysis

The oil was analysed by GC on a Perkin-Elmer 8500 gas chromatograph equipped with a FID, fitted with a Supelcowax-10 fused silica capillary column (30 m x 0.32 mm; film thickness, 0.25 μm). The column temperature was programmed from 75 oC to 200 oC at a rate of 2.5 oC/min. The injector and detector temperatures were programmed at 230 oC and 300 oC, respectively. Helium was used as carrier gas at flow rate of 0.6 mL/min. The GC-MS analysis was carried out using two different GC-MS systems. The first was a Hewlett Packard 5973-6890 GC-MS operating on EI mode (equipped with a HP 5MS 30 m x 0.25 mm x 0.25 μm film thickness capillary column). Helium (1 mL/min) was used as carrier gas. Temperature program: initial temperature of the column was 60 °C (for 5 min), then raised to 280 oC at 3 °C/min, and held there for 30 min (total time: 93.33 min). The compounds were identified by comparison of their retention indexes (RI) [17], retention times (RT) and mass spectra with those of authentic samples and/or the NIST/NBS, NIST02, Wiley 575 libraries spectra and the literature [18]. The percentage composition of the essential oil is based on peak areas obtained without FID factor corrections. The second GC-MS system analysis was a Finnigan Trace GC Ultra system, operating on EI mode and equipped with AT™ Aquawax 30 m x 0.32 mm x 0.25 μm film thickness capillary column. Helium was used as the carrier gas, at a flow rate of 1.5 mL/min (constant flow) and a 1:10 split ratio. Temperature program: initial temperature of the column 60 °C (for 5 min), then raised to 235 oC at 3°C/min, and held there for 30 min (total time: 93.33 min). The MS parameters were as follows: source temperature, 200 °C; ionization energy, 70 eV; emission, 200 µA; mass range, 35-650 Da; scan time,1.25 s., scan rate (amu/s) 500.0; scans per second, 0.7974.

Antimicrobial activity

Antimicrobial activity of the essential oils against bacteria and fungi was determined by using the agar dilution technique. The microorganisms included two Gram-positive bacteria: Staphylococcus aureus (ATCC 25923) and Staphylococcus epidermidis (ATCC 12228); four Gram-negative bacteria: Escherichia coli (ATCC 25922), Enterobacter cloacae (ATCC 13047), Klebsiella pneumoniae (ATCC 13883) and Pseudomonas aeruginosa (ATCC 227853); and the pathogenic fungi Candida albicans (10231), C. tropicalis (13801) and C. glabrata (28838). Standard antibiotics (netilmicin and amoxicillin with clavulanic acid) were used as controls for the sensitivity of the tested bacteria and 5-flucytocine, amphotericin B and itraconazole were used as controls for the tested fungi. The technical details have been described previously [19]. Minimum inhibitory concentrations (MICs) were determined for oil samples and the standard pure compounds β-caryophyllene and thymol (Extrasynthese SAS, France), under identical conditions, for comparison purposes. Statistical analysis: data are expressed as means ± S.D.

References

  1. Quezel, P.; Santa, S. Nouvelle flore de l’Algérie et des régions désertiques méridionales; TII, CNRS: Paris, 1963; p. 812. [Google Scholar]
  2. Trabut, L. Répertoire des noms indigènes des plantes spontanées, cultivées et utilisées dans le Nord de l’Afrique. Collection du centenaire de l’Algérie; Imprimeries "La Typo-Litho" et Jules Carbonnel Réunies: Alger, 1935; p. 190. [Google Scholar]
  3. Sokovic, M.D.; Marin, P.D.; Janackovic, P.; Vajs, V.; Milosavljevic, S.; Dokovic, D.; Tesevic, V.; Petrovic, S. Composition of the essential oils of Phlomis fruticosa L. (Lamiaceae). J. Essent. Oil Res. 2002, 14, 167–168. [Google Scholar]
  4. Sokovic, M.D.; Marin, P.D.; Simic, D.; Knezevic-Vukcevic, J.; Vajs, V.; Petrovic, S. Antimutagenic activity of essential oil and crude extract of Phlomis fruticosa. Pharm. Biol. 2002, 40, 311–314. [Google Scholar] [CrossRef]
  5. Ristic, M.D.; Duletic-Lausevic, S.; Knezevic-Vukcevic, J.; Marin, P.D.; Simic, D.; Vukojevic, J.; Janackovic, P.; Vajs, V. Antimicrobial activity of essential oils and ethanol extract of Phlomis fruticosa L. (Lamiaceae). Phytother. Res. 2000, 14, 267–271. [Google Scholar]
  6. Tammaro, F.; Xepapadakis, G. Plants used in phytotherapy, cosmetics and dyeing in the Pramanda district (Epirus, northwest Greece). J Ethnopharmacol. 1986, 16, 167–74. [Google Scholar]
  7. Tsitsimi, E.; Loukis, A.; Verykokidou, E. Composition of the essential oil of the flowers of Phlomis fruticosa L. from Greece. J. Essent. Oil Res. 2000, 12, 355–356. [Google Scholar] [CrossRef]
  8. Aligiannis, N.; Kalpoutzakis, E.; Kyriakopoulou, I.; Mitaku, S.; Chinou, I.B. Essential oils of Phlomis species growing in Greece chemical composition and antimicrobial activity. Flav. Frag. J. 2004, 19, 320–324. [Google Scholar] [CrossRef]
  9. Couladis, M.; Tanimanidis, A.; Tzakou, O.; Chinou, I.B.; Harvala, C. Essential oil of Phlomis lanata growing in Greece: chemical composition and antimicrobial activity. Planta Med. 2000, 66, 670–672. [Google Scholar] [CrossRef] [PubMed]
  10. Demirci, B.; Dadandi, M.Y.; Paper, D.H.; Franz, G.; Baser, K.H. Chemical composition of the essential oil of Phlomis linearis Boiss. & Bal., and biological effects on the CAM-assay: a safety evaluation. Z. Naturforsch. C 2003, 58, 826–829. [Google Scholar]
  11. Celik, S.; Gokturk, R.S.; Flamini, G.; Cioni, P.L.; Morelli, I. Essential oils of Phlomis leucophracta, Ph. chimerae and Ph.grandiflora var. grandiflora from Turkey. Biochem. Syst. Ecol. 2005, 33, 617–623. [Google Scholar]
  12. Umlauf, D.; Zapp, J.; Becker, H.; Adam, K.P. Biosynthesis of the irregular monoterpene artemisia ketone, the sesquiterpene germacrene D and other isoprenoids in Tanacetum vulgare L. (Asteraceae). Phytochemistry 2004, 65, 2463–2470. [Google Scholar]
  13. Juteau, F.; Masotti, V.; Bessière, J.M.; Dherbomez, M.; Viano, J. Antibacterial and antioxidant activities of Artemisia annua essential oil. Fitoterapia 2002, 73, 532–535. [Google Scholar] [CrossRef] [PubMed]
  14. Ettayebi, K.; El Yamani, J.; Rossi-Hassani, B.D. Synergistic effects of nisin and thymol on antimicrobial activities in Listeria monocytogenes and Bacillus subtilis. FEMS Microbiol. Letts. 2000, 183, 191–195. [Google Scholar] [CrossRef]
  15. Olasupo, N.A.; Fitzgerald, D.J.; Gasson, M.J.; Narbad, A. Activity of natural antimicrobial compounds against Escherichia coli and Salmonella enterica serovar Typhimurium Lett. Appl. Microbiol. 2003, 37, 448–451. [Google Scholar] [CrossRef]
  16. British Pharmacopoeia 1993; Vol. I, International Ed. edHMSO: London, 1993.
  17. Massada, Y. Analysis of Essential Oil by Gas Chromatography and Spectrometry; John Wiley & Sons: New York, 1976. [Google Scholar]
  18. Adams, R.P. Identification of Essential Oil Components by Gas Chromatography/Mass Spectroscopy; Allured: Carol Stream, IL, USA, 2001. [Google Scholar]
  19. Ngassapa, O.; Runyoro, D.K.B.; Harvala, E.; Chinou, I.B. Composition and Antimicrobial Activity of the Essential Oils of two different populations of Lippia javanica growing in Tanzania. Flav. Frag. J. 2003, 18, 221–224. [Google Scholar] [CrossRef]
  • Sample availability: Samples of the essential oils are available from the authors.

Share and Cite

MDPI and ACS Style

Liolios, C.; Laouer, H.; Boulaacheb, N.; Gortzi, O.; Chinou, I. Chemical Composition and Antimicrobial Activity of the Essential Oil of Algerian Phlomis bovei De Noé subsp. bovei. Molecules 2007, 12, 772-781. https://doi.org/10.3390/12040772

AMA Style

Liolios C, Laouer H, Boulaacheb N, Gortzi O, Chinou I. Chemical Composition and Antimicrobial Activity of the Essential Oil of Algerian Phlomis bovei De Noé subsp. bovei. Molecules. 2007; 12(4):772-781. https://doi.org/10.3390/12040772

Chicago/Turabian Style

Liolios, Christos, Hocine Laouer, Nacira Boulaacheb, Olga Gortzi, and Ioanna Chinou. 2007. "Chemical Composition and Antimicrobial Activity of the Essential Oil of Algerian Phlomis bovei De Noé subsp. bovei" Molecules 12, no. 4: 772-781. https://doi.org/10.3390/12040772

Article Metrics

Back to TopTop