Occurrence and Sources of Triterpenoid Methyl Ethers and Acetates in Sediments of the Cross-River System, Southeast Nigeria

Table 1

Sediment samples, environmental characteristics, and triterpenoid markers in the extracts from the Cross-River estuary, Nigeria.

Zones			I				II			III			IV	V
Sample code			CR-1	CR-2	CR-3	CR-4	CR-5	CR-6	CR-7	CR-8	CR-9	CR-10	UCR 1–10, range (ave.)	GKR 1–11, range (ave.)
Location name			Oron beach				Oku Iboku beach			Itu beach			Upper Calabar River	Great Kwa River
Sample coordinates			4°43.961N; 8°21.327E	4°46.531N; 8°18.908E	4°49.927N; 8°15.501E	4°52.675N; 8°12.742E	4°56.879N; 8°09.334E	5°00.437N; 8°07.062E	5°04.318N; 8°06.250E	5°08.198N; 8°04.303E	5°12.726N; 8°03.491E	5°12.258N; 8°00.222E
Environmental characteristics			Nypa frutican with sparsely distributed Elaeis guineensis and Andropogoneae				Rizophoria with sparsely distributed Elaeis guineensis and Andropogoneae			Avicennia with sparsely distributed Elaeis guineensis and Andropogoneae
TOC (%)			4.03	3.64	4.35	4.56	4.20	4.38	2.77	1.27	2.66	4.26	na	na
EOM (mg/kg)			3000	3680	1920	2950	3710	4140	2650	1510	1140	1850	na	na
THC (mg/kg)			329	511	227	185	148	60	99	44	16	2	na	na
Compounds (mg/kg dw)	MW	Formula
Taraxer-14-en-3-one	424	C30H48O	1.9	2.63	9.6	1.34	3.8	1.1	1.05	0.3	0.39	1.36	0.3–12.8 (4.9)	0.15–21.4 (10.7)
Taraxer-14-en-3β-ol methyl ether	440	C31H52O	0.16	0.21	0.14	0.18	0.51	0.18	0.28	0.26	0.88	0.97	0.2–1.2 (0.4)	0.1–0.6 (0.25)
Germanicol methyl ether	440	C31H52O	0.05	0.11	0.07	0.06	0.17	nd	0.42	0.11	0.40	0.52	0.3–2.1 (0.7)	0.04–1.07 (0.29)
β-Amyrin methyl ether	440	C31H52O	0.12	0.17	0.04	0.06	0.04	0.08	0.32	0.18	0.22	0.36	nd	0.26–1.80 (0.44)
Fern-9(11)-en-3β-ol methyl ether	440	C31H52O	0.30	0.32	0.31	0.38	0.21	0.22	nd	0.12	0.38	0.94	0.4–2.2 (1.1)	0.01–2.35 (0.68)
α β-Amyrinyl acetates	468	C32H52O2	0.57	4.73	1.60	0.06	0.15	0.02	0.59	0.31	3.12	0.97	0.8–2.1 (0.9)	0.13–1.05 (0.23)
Lupeyl acetate	468	C32H52O2	0.19	1.31	nd	nd	nd	nd	nd	nd	3.05	nd	nd	nd
Germanicyl acetate	468	C32H52O2	0.11	0.86	0.05	nd	nd	nd	nd	nd	0.18	0.02	nd	nd
α β-Amyrinyl hexanoates	524	C36H60O2	nd	0.32	0.48	0.03	nd	nd	nd	nd	0.21	0.03	nd	nd
Lupeyl hexanoate	524	C36H60O2	nd	0.02	0.07	0.01	nd	nd	nd	nd	0.02	nd	nd	nd

Abbreviations: EOM: extractable organic matter; THC: total hydrocarbons; nd: not detected (minimum detection limit = 0.002 mg/kg); na: not analyzed.