Chemical composition, enantiomeric analysis and anticholinesterase activity of Lepechinia betonicifolia essential oil from Ecuador

Figures & data

Figure 1. Chromatogram of the essential oil of L. betonicifolia from Ecuador.

Table 1. Chemical composition of the essential oil of L. betonicifolia in DB-5MS.

Rt^a	Compound	LRI^b	LRI^c	%	Σ
8.08	α-Thujene	924	924	0.35	0.12
8.39	α-Pinene	932	932	4.97	1.32
9.08	Camphene	948	946	0.30	0.04
10.08	Sabinene	971	969	27.98	2.94
10.30	β-Pinene	976	974	30.45	2.25
10.79	Myrcene	988	988	0.34	0.10
11.46	p-Mentha-1(7),8-diene	1003	1003	0.48	0.03
11.57	α-Phellandrene	1006	1002	0.28	0.31
11.68	delta-3-Carene	1008	1008	1.08	1.20
12.07	α-Terpinene	1016	1014	0.37	0.48
12.43	p-Cymene	1023	1020	0.36	0.39
12.66	Limonene	1028	1024	3.84	0.72
12.72	β-Phellandrene	1029	1025	4.79	2.16
12.83	1,8-Cineole	1032	1026	0.79	0.27
13.48	(E)-β-Ocimene	1045	1044	0.18	0.17
14.04	γ-Terpinene	1057	1054	0.22	0.19
14.66	p-Mentha-2,4,8 diene	1070	1085	0.38	0.52
15.34	Terpinolene	1084	1086	0.13	0.04
18.35	Camphor	1146	1141	0.20	0.06
19.07	Pinocarvone	1161	1160	0.47	0.53
19.96	Terpinen-4-ol	1179	1174	0.39	0.14
20.66	Myrtenal	1194	1195	0.73	0.80
28.84	α-Copaene	1374	1374	0.67	0.66
29.18	β-Bourbonene	1381	1387	0.19	0.23
30.70	(E)-Caryophyllene	1417	1417	4.44	0.91
31.15	β-Gurjunene	1427	1431	0.62	0.11
31.91	Aromadendrene	1445	1439	0.26	0.21
32.20	α-Humulen	1452	1452	0.85	0.44
32.37	allo-Aromadendrene	1456	1458	0.41	0.30
33.26	γ-Muurolene	1477	1478	2.84	2.68
33.71	γ-Curcumene	1488	1481	2.95	2.41
33.85	Bicyclogermacrene	1491	1500	0.50	0.36
34.16	Viridiflorene	1498	1496	2.11	1.94
34.56	γ-Cadinene	1508	1513	0.21	0.11
34.77	δ-Cadinene	1514	1522	0.43	0.18
36.34	β-Germacrene	1554	1559	0.25	0.14
37.27	Caryophyllene oxide	1577	1582	0.76	0.69
37.86	Guaiol	1592	1600	0.98	0.50
	Monoterpene hydrocarbons			76.51
	Oxygenated monoterpene			2.58
	Sesquiterpene hydrocarbons			16.71
	Oxygenated sesquiterpene			1.74
	Total amount of compounds			97.55

^aRt: Retention time; ^bLRI: calculated linear retention indices obtained on DB-5ms column using a series of n-alkanes (C9–C24) from [19]; ^cLRI: reference linear retention indices from [20]; %: relative percentage amount.

Table 2. Enantioselective analysis of L. betonicifolia essential oil.

LRI^a	Compound	Enantiomeric distribution %	(e.e)%^b
931	α-Thujene +	61.72	23.44
933	α-Thujene −	38.28
966	β- Pinene +	3.37	93.25
971	β- Pinene −	96.63
988	Sabinene +	93.56	87.13
1000	Sabinene −	6.44
1466	γ-Muurolene +	37.37	25.25
1473	γ-Muurolene −	62.63

^aLRI, Linear retention index calculated on the chiral capillary column diethyl tertbuthysilyl-β-cyclodextrin; ^benantiomeric excess.

Figure 2. AChE inhibitory response from the essential oil of L. betonicifolia expressed as IC₅₀, calculated from nonlinear regression curve data fitting analysis, n = 9.