Table 1. Compounds identified from Plectranthus amboinicus leaf volatiles harvested at 8.00 AM using HS-SPME-GC-MS analysis.

No	RTa (min)	Compounds	RIb	Relative contentc (%)
1	8.304	β-Thujene	924	0.432 ± 0.048
2	10.081	1-Octen-3-ol	983	1.140 ± 0.054
3	10.279	β-Myrcene	990	1.372 ± 0.147
4	10.653	α-Phellandrene	1002	0.458 ± 0.030
5	11.043	α-Terpinene	1015	2.508 ± 0.212
6	11.434	ρ-Cymene	1027	8.208 ± 0.445
7	12.069	β-Ocimene	1048	0.149 ± 0.015
8	12.512	γ-Terpinene	1063	10.475 ± 0.465
9	13.229	Terpinolene	1086	0.161 ± 0.003
10	13.683	Linalool	1101	0.163 ± 0.020
11	15.665	Isoborneol	1169	0.131 ± 0.012
12	15.951	(-)-Terpinen-4-ol	1178	0.821 ± 0.026
13	16.370	α-Terpineol	1193	0.021 ± 0.010
14	18.032	Thymoquinone	1252	2.296 ± 0.753
15	19.343	Thymol	1294	0.331 ± 0.013
16	20.171	Carvacrol	1326	19.583 ± 1.937
17	21.144	Eugenol	1363	0.042 ± 0.004
18	22.794	Caryophyllene	1430	19.211 ± 2.355
19	23.213	α-Bergamotene	1447	19.529 ± 1.255
20	23.347	(+)-Epi-β-Santalene	1453	0.201 ± 0.014
21	23.627	Humulene	1464	5.636 ± 0.623
22	24.181	(E)-β-Famesene	1486	1.014 ± 0.056
23	24.385	(-)-Zingiberene	1501	0.181 ± 0.068
24	24.548	α-Muurolene	1508	0.478 ± 0.077
25	24.758	β-Bisabolene	1517	2.195 ± 0.079
26	25.108	β-Sesquiphellandrene	1532	1.080 ± 0.039
27	26.034	(±)-trans-Nerolidol	1571	0.033 ± 0.008
28	26.384	Thymohydroquinone	1586	0.213 ± 0.056
29	26.576	Caryophyllene oxide	1594	1.419 ± 0.123
30	27.148	Humulene epoxide II	1615	0.190 ± 0.022
31	28.797	α-Bisabolol	1688	0.039 ± 0.010

^a Retention time (RT) in min

^b van den Dool and Kratz retention index calculated for HP-5MS column

^c Relative peak area expressed as percentage of the peak area of corresponding compound over the total peak areas of all identified volatiles.