Antibacterial activity of essential oils from Eucalyptus and of selected components against multidrug-resistant bacterial pathogens

Figures & data

Table 1.  Composition of the essential oil of fruits from Eucalyptus globulus and from Eucalyptus leaves.

No	Constituents	RI (DB-5)	Relative abundance (%)
			EGF^§	EGL	ECL	ERL
1	α-Thujene	903	—	—	0.46	—
2	α-Pinene	925	1.53	4.74	0.38	3.68
3	Sabinene	968	—	—	0.58	1.40
4	β-Pinene	970	—	0.88	0.91	—
5	β-Myrcene	989	—	0.88	0.15	—
6	α-Phellandrene	1002	2.61	1.40	—	—
7	p-Cymene	1024	0.49	—	—	—
8	Limonene	1027	—	—	0.5	—
9	1,8-Cineole	1030	14.55	86.51	—	82.66
10	γ-Terpinene	1057	0.18	2.57	0.25	Tr
11	p-Menth-3,8-diene	1069	—	—	0.13	—
12	Terpinolene	1085	—	0.77	0.1	Tr
13	τ-Terpinene	1087	0.18	—	—	—
14	Isoterpinolene	1098	0.27	—	—	—
15	Linalool	1111	0.12	Tr	—	Tr
16	Citronellal	1160	—	Tr	90.07	—
17	Isopulegol	1177	—	Tr	tr	—
18	Carvenone	1164	0.07	—	—	—
19	Borneol	1166	0.41	0.09	—	—
20	Terpinen-4-ol	1176	1.87	0.69	—	1.53
21	α-Terpineol	1189	0.85	0.50	—	7.03
22	Sabinol	1199	1.14	—	—	—
23	Citronellol	1227	—	0.16	4.32	Tr
24	p-Ment-1(7)-en-2-one	1231	0.62	—	—	—
25	Piperiton	1249	0.31	Tr	—	Tr
26	Geraniol	1252	Tr	—	—	—
27	Thymol	1302	Tr	—	—	—
28	Exo-2-hydroxycineole acetate	1338	0.14	—	—	—
29	α-Terpinyl acetate	1348	1.27	—	—	Tr
30	Citronellyl acetate	1351	—	—	Tr	—
31	Geranyl acetate	1373	0.20	—	—	—
32	Isoledene	1378	0.81	—	—	—
33	Tricyclo(6.3.0.0(2.4))undec-8-ene-3,3,7,11-tetramethyl	1396	0.18	—	—	—
34	α-Gurjunene	1412	5.10	0.11	—	—
35	β-Caryophyllene	1418	—	—	1.46	—
36	Aromadendrene	1446	31.17	0.41	—	Tr
37	α-Caryophyllene	1452	—	—	Tr	0.04
38	allo-aromadendrene	1466	3.68	0.16	—	Tr
39	γ-Gurjunen	1476	0.70	—	—	—
40	α-Selinene	1490	0.84	—	—	—
41	Longifolene	1493	1.75	—	—	—
42	Ledene	1504	7.13	Tr	—	—
43	γ-Cadinene	1518	0.24	—	—	—
44	Dehydroaromadendrene	1526	0.75	—	—	—
45	δ-Cadinene	1543	0.64	—	Tr	0.55
46	α-Calacorene	1555	0.16	—	—	—
47	Epiglobulol	1566	5.17	Tr	—	—
48	Spathulenol	1567	—	Tr	—	Tr
49	Caryophyllen oxide	1572	—	—	—	—
50	Palustrol	1581	0.22	—	—	—
51	Viridiflorol	1593	0.24	Tr	—	Tr
52	Globulol	1595	10.69	Tr	—	Tr
53	τ-Eudesmol	1600	1.24	—	—	—
54	Guaiol	1607	0.79	—	—	—
55	β-Eudesmol	1611	0.31	—	—	—
56	Cubenol	1616	0.11	—	—	—
57	Sesquiterpene alcohol	1627	0.55	—	—	—
58	τ-Cadinol	1631	0.17	—	—	—
59	α-Eudesmol	1657	0.18	—	—	—
	Monoterpene hydrocarbons		4.77	11.24	3.46	5.10
	Oxygenated monoterpenes		21.58	87.96	94.41	91.26
	Sesquiterpene hydrocarbons		52.15	0.68	1.49	0.62
	Oxygenated sesquiterpenes		19.67	0.01	0.01	0.04
	Total identified		98.17	99.89	99.37	97.02

Relative abundance of the components are given as % (total peak area = 100%).

^§Previously reported (Mulyaningsih et al., 2010b).

Tr: trace amount, less than 0.05%; —: not detected.

EGF, E. globulus fruits; EGL, E. globulus leaves; ECL, E. citriodora leaves; ERL, E. radiata leaves; RI, retention index.

Table 2.  The antimicrobial activity of the essential oils of Eucalyptus against multidrug-resistant bacteria.

Microorganisms	ECL		ERL		EGL		EGF^§
	MIC	MBC	MIC	MBC	MIC	MBC	MIC	MBC
Gram-positive
MRSA
MRSA NCTC 10442*	2	4	4	>4	4	>4	0.25	0.06
USA300	2	4	>4	NT	>4	NT	0.5	1
1678/98	4	>4	>4	NT	>4	NT	0.125	0.5
635/93	2	4	>4	NT	4	>4	0.25	0.25
2387/00	2	4	4	>4	4	>4	0.12	0.12
1000/93	1	2	4	>4	2	4	0.12	0.25
BL7127/98	4	>4	>4	NT	4	>4	0.5	0.5
MR131/98	4	>4	>4	NT	>4	NT	0.5	0.5
MR134/93	>4	NT	>4	NT	4	>4	0.5	2
MR1150/93	>4	NT	>4	NT	>4	NT	1	2
VRE
VRE E. faecalis ATCC 51299*	>4	NT	>4	NT	>4	NT	1	2
VR902291	>4	NT	>4	NT	>4	NT	0.5	0.5
VR902316	>4	NT	>4	NT	>4	NT	0.5	0.5
VR902247	>4	NT	>4	NT	>4	NT	1	2
VR902267	>4	NT	>4	NT	>4	NT	1	2
Gram-negative
Escherichia coli*	>4	NT	>4	NT	>4	NT	8	NA
Pseudomonas aeruginosa*	>4	NT	>4	NT	>4	NT	>8	NT
Klebsiella pneumonia*	>4	NT	>4	NT	>4	NT	>8	NT
Acinetobacter baumannii*	2	2	1	1	2	2	1	1

^§Previously reported (Mulyaningsih et al., 2010b).

*Reference strain.

Concentrations are given in mg/ml; NT: not tested.

EGF, Eucalyptus globulus fruits; EGL, E. globulus leaves; ECL, E. citriodora leaves; ERL, E. radiata leaves; MRSA, methicillin-resistant Staphylococcus aureus; VRE, vancomycin-resistant enterococci; MIC, minimal inhibitory concentration; MBC, minimal bactericidal concentration.

Table 3.  The antimicrobial activity of the major components of the Eucalyptus oils against multidrug-resistant bacteria.

Microorganisms	Aromadendrene^$		1,8-Cineole^$		Citronellal		Citronellol
	MIC	MBC	MIC	MBC	MIC	MBC	MIC	MBC
Gram-positive
MRSA
MRSA NCTC 10442*	0.5	0.5	>8	NT	2	2	1	2
USA300	1	4	>8	NT	8	>8	2	2
1678/98	0.25	0.5	>8	NT	1–2	2	0.125	0.125
635/93	0.25	0.25	>8	NT	>8	>8	8	8
2387/00	0.25	0.5	>8	NT	8	8–>8	2	4
1000/93	0.25	0.25	>8	NT	>8	>8	4	4
BL7127/98	1	1	>8	NT	8	>8	1–2	4
MR131/98	0.5	1	>8	NT	0.5–1	1–2	0.125	0.5
MR134/93	1	4	>8	NT	8	>8	4	8
MR1150/93	1	2	>8	NT	8	>8	4	8
VRE
VRE E. faecalis ATCC 51299*	1	2	>8	NT	>8	>8	2	4
VR902291	1	2	>8	NT	8–>8	>8	8	4
VR902316	1	2	>8	NT	>8	>8	8	8
VR902247	1	4	>8	NT	>8	>8	8	8
VR902267	1	4	>8	NT	8–>8	>8	8	8
Gram-negative
Escherichia coli	>8	NT	>8	NT	>8	>8	4	8
Pseudomonas aeruginosa	>8	NT	>8	NT	>8	>8	>8	>8
Klebsiella pneumonia	>8	NT	>8	NT	>8	>8	>8	>8
Acinetobacter baumannii	2	2	8	8	2–4	4	0.125–0.25	0.25–0.5

^§Previously reported (Mulyaningsih et al., 2010b).

*Reference strain.

Concentrations are given in mg/ml; NT: not tested.

EGF, Eucalyptus globulus fruits; EGL, E. globulus leaves; ECL, E. citriodora leaves; ERL, E. radiata leaves; MRSA, methicillin-resistant Staphylococcus aureus; VRE, vancomycin-resistant enterococci; MIC, minimal inhibitory concentration; MBC, minimal bactericidal concentration.

Mulyaningsih S, Sporer F, Zimmermann S, Reichling J, Wink M. (2010b). Synergistic properties of the terpenoids aromadendrene and 1,8-cineole from the essential oil of Eucalyptus globulus against antibiotic-susceptible and antibiotic-resistant pathogens. Phytomedicine, 17, 1061–1066.

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