Chemical Composition and Future Perspectives of Essential Oil Obtained from a Wild Population of Stachys germanica L. Distributed in the Balkan Mountains in Bulgaria

Table 1

Volatile constituents of the EO of S. germanica L. from Bulgaria as a percentage of total EO.

No.	Compound	RI	RI lit. data	Formula	Class of compound	% of total EO
1	α-Pinene	957	944	C10H16	MH	0.55
2	Camphene	966	956	C10H16	MH	2.52
3	Benzaldehyde	972	968	C7H6O	O	0.17
4	β-Pinene	982	980	C10H16	MH	1.32
5	1-Octen-3-ol	987	986	C8H16O	O	0.16
6	Trans-β-Ocimene	1034	1038	C10H16	MH	0.17
7	Camphor	1144	1144	C10H16O	MO	52.96
8	Borneol	1159	1156	C10H18O	MO	0.59
9	Trans-Chrysanthenyl acetate	1224	1228	C12H18O	MO	2.66
10	Bornyl acetate	1277	1273	C12H20O2	MO	2.54
11	α-Copaene	1366	1372	C15H24	SH	0.43
12	β-Elemene	1379	1387	C15H24	SH	0.53
13	β-Caryophyllene	1403	1411	C15H24	SH	0.18
14	Octyl 2-methylbutanoate	1433	1436	C13H26O2	O	0.45
15	(E)-β-Farnesene	1457	1458	C15H24	SH	3.97
16	Germacrene-D	1471	1470	C15H24	SH	0.9
17	α-Muurolene	1490	1488	C15H24	SH	0.25
18	δ-Cadinene	1510	1509	C15H24	SH	0.42
19	Bornyl angelate	1550	1547	C15H24O2	MO	0.55
20	(E)-Nerolidol	1558	1561	C15H26O	SO	0.39
21	Spathulenol	1562	1582	C15H24O	SO	0.95
22	Caryophylene oxide	1564	1565	C15H24O	SO	0.23
23	α-Cadinol	1638	1639	C15H26O	SO	1.44
24	Geranyl-p-cymene	1898	No data	C20H30	O	10.49
	Terpene classes
	MH—monoterpene hydrocarbons					4.56
	MO—oxygenated monoterpenes					59.30
	SH—sesquiterpene hydrocarbons					6.68
	SO—oxygenated sesquiterpenes					3.01
	O—others					11.27
	Total identified					84.82

The relative percentage of peak area is shown as the mean of three independent measurements and the standard error of the mean has been removed and does not exceed 2%. A comparison was made between the RI obtained for each compound and the reference values from the literature data [40, 41].