. 2021 Apr 25;7(4):e06884. doi: 10.1016/j.heliyon.2021.e06884

Table 1.

Chemical composition of essential oil of Piper nigrum (PNEO).

No.	Component	Formula	RI	% of abundance	Identification
1.	Thujene	C₁₀H₁₆	902	2.76	MS, RI, RT
2.	α-pinene	C₁₀H₁₆	936	7.84	MS, RI, RT
3.	Camphene	C₁₀H₁₆	943	0.22	MS, RI, RT
4.	Sabinene	C₁₀H₁₆	967	22.86	MS, RI, RT
5.	β-pinene	C₁₀H₁₆	972	10.43	MS, RI, RT
6.	Myrecene	C₁₀H₁₆	992	1.68	MS, RI
7.	α-phellaldrene	C₁₀H₁₆	1003	1.12	MS, RI
8.	δ-3-carene	C₁₀H₁₆	1013	0.49	MS, RI
9.	α -Terpinene	C₁₀H₁₆	1018	0.11	MS, RI
10.	Limonene	C₁₀H₁₆	1030	25.34	MS, RI, RT
11.	β-Ocimene	C₁₀H₁₆	1037	0.15	MS, RI
12.	β-cymene	C₁₀H₁₄	1042	0.22	MS, RI
13.	γ – Terpinene	C₁₀H₁₆	1062	0.18	MS, RI
14.	Limonene oxide –cis	C₁₀H₁₆O	1135	0.12	MS, RI
15.	Terpinene-4-ol	C₁₀H₁₈O	1137	0.56	MS, RI
16.	Limonene oxide –trans	C₁₀H₁₆O	1139	0.11	MS, RI
17.	α-Terpineol	C₁₀H₁₈O	1186	0.18	MS, RI
18.	α-Cubebene	C₁₅H₂₄	1344	0.28	MS, RI
19.	α -Copaene	C₁₅H₂₄	1378	2.83	MS, RI
20.	α-Bergamotene	C₁₅H₂₄	1424	0.39	MS, RI
21.	β -Copaene	C₁₅H₂₄	1430	0.17	MS, RI
22.	Zingiberene	C₁₅H₂₄	1451	0.56	MS, RI
23.	Humulene	C₁₅H₂₄	1458	0.38	MS, RI
24	β-Farnesene	C₁₅H₂₄	1461	1.12	MS, RI
25.	Cubebol	C₁₅H₂₆O	1472	0.14	MS, RI
26.	Caryophyllene	C₁₅H₂₄	1484	13.38	MS, RI
27.	α-Guainene	C₁₅H₂₄	1490	0.32	MS, RI
28.	Germacrene-D	C₁₅H₂₄	1515	0.10	MS, RI
29.	Bisabolene	C₁₅H₂₄	1518	3.98	MS, RI
30.	Viridiflorol	C₁₅H₂₆O	1530	0.23	MS, RI
31.	Caryophyllene oxide	C₁₅H₂₄O	1576	0.14	MS, RI
32.	α -Cadinol	C₁₅H₂₆O	1580	0.15	MS, RI
33.	α-Bisbolol	C₁₅H₂₆O	1616	0.11	MS, RI
	Total identified			98.33
	Monoterpene hydrocarbons			73.40
	Oxygenated monoterpenes			0.97
	Sesquiterpene hydrocarbons			23.51
	Oxygenated sesquiterpenes			0.45

RI: Identification based on retention indices corresponding to of n-alkanes homologous series; RT: Identification based on retention time of compounds, MS: Identification based on comparison of mass spectra.