Study of the Interference between Plectranthus Species Essential Oils from Brazil and Aminoglycosides

Table 1

Chemical composition (%) of the leaf oils of P. amboinicus, P. ornatus, and P. barbatus.

Components	IR^a	IR^b	Composition (%)
			P. amboinicus	P. ornatus	P. barbatus
α-pinene	941	939	0.8	0.7	0.3
sabinene	972	975	—	1.2	0.6
β-pinene	981	979	1.2	2.2	—
β-myrcene	987	991	—	—	1.8
p-cymene	1022	1025	10.3	—	—
cis-β-ocimene	1032	1037	1.3	2.2	1.9
trans-β-ocimene	1046	1050	—	0.9	1.2
γ-terpinene	1064	1060	5.9	—	—
Terpinen-4-ol	1173	1177	0.9	2.5	—
Thymol methyl ether	1235	1235	1.6	—	—
Thymol	1288	1290	1.3	16.6	15.3
Carvacrol	1296	1299	67.9	13.9	12.1
Eugenol	1365	1359	—	22.9	25.1
α-copaene	1375	1377	—	2.4	8.9
β-cubebene	1385	1388	—	1.2	3.7
β-caryophyllene	1422	1419	2.8	18.2	10.7
(E)-α-bergamotene	1430	1435	1.4	—	0.5
α-humulene	1451	1455	0.7	0.8	1.6
Aromadendrene	1458	1460	1.2	—	—
β-bisabolene	1509	1506	—	—	—
δ-cadinene	1519	1523	—	—	1.4
trans-nerolidol	1558	1563	—	0.8	0.2
Caryophyllene oxide	1582	1583	—	0.3	2.4
epi-α-cadinol	1638	1640	—	—	0.6
Total identified			97.3	86.4	88.3

 ^aRelative retention indices experimental: n-alkanes were used as reference points in the calculation of relative retention indices. ^bRelative retention indices (the literature values).