Essential oil composition, total phenolic content, antioxidant and antibiofilm activities of four Origanum species from southeastern Turkey

Figures & data

Table 1. Collection sites, dates, voucher specimens, and yields of Origanum L. species studied.

	Local Name	Locality	Date	Voucher Specimen	Oil yield
O. hypericifolium	Delik Mercan	Denizli, Sandras Mountain, 1509 m, 37°07ʹ01ʺN 28°50ʹ10ʺE	16.09.2014	2528	1.54
O. sipyleum	Mor Mercan	Denizli, Servergazi, 884 m, 37°45ʹ42ʺN 28°58ʹ48ʺE	18.09.2014	2490	1.10
O. majorana	Beyaz Kekik	Antalya, Akseki, 1240 m, 37°01ʹ58ʺN 31°49ʹ55ʺE	14.08.2014	2541	1.86
O. onites	İzmir Kekiği	Denizli, Güzelpınar Village, 1170 m, 37°58ʹ58ʺN 29°12ʹ24ʺE	21.06.2014	2603	2.02

Table 2. Chemical composition (%) of essential oils of Origanum species growing in southeastern Turkey.

No	Compounds^a	RI (min)^b	O. hypericifolium	O. sipyleum	O. majorana	O. onites
1	α-thujene	930	1.68	-	1.57	1.22
2	α-pinene	937	1.46	11.03	0.81	1.09
3	camphene	952	1.12	-	0.32	0.83
4	sabinene	975	0.44	0.66	0.21	-
5	β-pinene	979	0.58	0.54	0.32	0.21
6	1-octen-3-ol	984	1.15	-	0.24	0.28
7	β-myrcene	992	1.47	1.60	2.22	2.00
8	α-phellandrene	1004	0.49	-	0.41	0.45
9	3-carene	1011	-	-	0.12	0.12
10	α-terpinene	1018	1.46	1.04	2.85	2.17
11	p-cymene	1025	33.08	13.21	6.38	5.57
12	β-phellandrene	1030	-	-	0.82	0.87
13	1,8-cineole	1035	-	-	0.53	-
14	trans-β-ocimene	1039	-	0.43	0.52	0.30
15	γ-terpinene	1060	14.92	9.61	11.63	6.43
16	α-terpinolene	1088	0.59	-	0.30	0.44
17	linalool	1099	0.35	-	38.38	14.35
18	camphor	1144	-	3.72	-	-
19	borneol	1166	4.06	-	0.88	2.87
20	terpinen-4-ol	1177	1.91	-	2.98	5.66
21	α-terpineol	1189	0.12		-	0.48
22	carvacrol methyl ether	1240	-	5.45	-	-
23	carvone	1245	-	-	-	-
24	thymol	1291	22.90	5.69	26.11	42.15
25	carvacrol	1299	5.28	13.14		8.47
26	trans-β-caryophyllene	1405	1.99	7.35	0.84	0.68
27	aromadendrene	1439	-	4.24	-	0.46
28	α-humulene	1454	0.18	-	-	-
28	germacrene D	1480	-	5.70	-	-
30	bicyclogermacrene	1495	0.20	5.90	0.31	-
31	β-bisabolene	1509	-	-	-	1.04
32	δ-cadiene	1513	0.16	-	-	-
33	caryophyllene oxide	1581	1.54	-	-	0.22
34	α-cadinol	1652	-	8.01	-	-

^aCompounds listed in order their elution.

^bRI: Retention index measured relative to n-alkanes on HP-5MS column. (-) = not detected.

Bold values indicate compounds present in highest amounts.

Figure 1. Total phenolic contents in the extracts of O. majorana, O. onites, O. hypericifolium, and O. sipyleum expressed in terms of gallic acid equivalent (mg of GAE/g of extract). results are presented as the mean from three independent experiments and expressed as relative mean ± standard deviation. Those with the same letter are not significantly different at the P < 0.05 level.

Figure 2. Flavonoid contents in the extracts of O. majorana, O. onites, O. hypericifolium, and O. sipyleum expressed in terms of rutin equivalent (mg of Ru/g of extract). results are presented as the mean from three independent experiments and expressed as relative mean ± standard deviation. Those with the same letter are not significantly different at the P < 0.05 level.

Table 3. DPPH scavenging activity of extracts from O. majorana, O. onites, O. hypericifolium, and O. sipyleum presented as IC₅₀ values.

Type of extract	Water	Methanol	Chloroform	Essential oil
Origanum majorana	18.02 ± 0.36	23.35 ± 0.25	16.03 ± 0.12	46.78 ± 0.33
Origanum onites	18.32 ± 0.22	24.12 ± 0.21	16.89 ± 0.15	46.94 ± 0.45
Origanum hypericifolium	44.89 ± 0.42	42.64 ± 0.35	24.40 ± 0.22	48.94 ± 0.51
Origanum sipyleum	41.88 ± 0.47	46.35 ± 0.48	36.85 ± 0.35	46.65 ± 0.49

Each value represents the mean ± SD (n = 3). IC₅₀ values were expressed as μg/ml.

Table 4. The biofilm inhibition effect of essential oils of Origanum species, expressed as percentage inhibition.

Essential oils	Concentration (mg/ml)			Bacteria
		S.a.1	S.a.2	E.f.1	M.l.	E.f.2	E.f.3	E.c.	S.t.	P.f.
O. onites	50	48.46	58.73	47.44	43.62	34.83	51.40	34.55	38.74	53.32
	25	38.97	37.39	33.58	32.14	22.90	29.25	27.54	32.90	31.16
	12.5	13.58	27.43	24.94	20.77	16.77	14.05	24.20	22.93	21.87
O. hypericifolium	50	37.69	62.29	41.57	87.40	32.41	68.19	41.40	49.00	68.68
	25	32.30	41.26	41.57	49.69	20.16	40.72	28.34	38.31	56.58
	12.5	19.23	40.14	20.25	38.28	10.00	26.22	17.35	32.05	44.28
O. majorana	50	32.69	62.19	40.93	92.24	67.11	75.37	37.11	68.34	66.25
	25	23.97	52.33	36.24	50.30	34.19	49.14	25.60	56.69	51.02
	12.5	16.02	26.93	22.17	31.68	24.74	32.19	21.00	47.47	48.25
O. sipyleum	50	30.89	57.31	48.82	52.45	41.55	56.50	66.13	85.71	74.89
	25	20.89	39.73	25.47	25.67	23.01	49.14	39.24	45.64	46.11
	12.5	16.53	23.47	15.45	12.55	18.09	19.93	28.16	25.58	32.45

S.a.1: S. aureus ATCC 33862, S.a.2: S. aureus ATCC 29213, E.f.1: E. faecalis M10, M.l.: M. luteus NRRL-B 1013, E.f.2: E. faecalis M18, E.f.3: E. faecalis ATCC 19433, E.c.: E. cloacea ATCC 28355, S.t.: S. tphymurium ATCC 14028, P.f.: P. fluorescens ATCC 55241.