Relative Retention Times of Nematode Sterols

 
Sterols are important biomolecules within nematodes because sterols function as membrane components and serve as metabolic precursors to steroid hormones.  From the perspective of a nematode, sterols are nutritionally important because nematodes lack the ability to biosynthesize sterols, unlike plants or higher animals.  Therefore, nematodes possess a nutritional requirement for sterols, which parasitic nematodes must obtain from their animal or plant hosts.  This nutritional requirement can be exploited in the design of novel strategies for controlling agriculturally important plant-parasitic nematodes.

Consequently, a large part of David Chitwood’s research has focused on the biochemistry of sterols in nematodes.  A large number of structurally diverse sterols have been isolated by us from nematodes or their hosts or their diets; these sterols have been identified via gas chromatography and mass spectrometry.

As a courtesy to the scientific community, we present a table containing the gas chromatographic relative retention times of sterols isolated by us from nematodes or their hosts or diets.  This table is based upon a similar table in Lipids, volume 26, pages 619-627, 1991, "Metabolism of plant sterols by nematodes", by D. J. Chitwood and W. R. Lusby.  The U.S. Government has the right to retain a nonexclusive, royalty-free license in and to any copyright covering this paper.
 

Gas-Liquid Chromatographic Relative Retention Times (RRTs) of Sterols from Nematodes or Their Diets or Host Plants, Expressed Relative to Cholesterola
Sterol	DB-1	OV-17
1. Cholesta-5,7,9(11)-trienol	0.98	1.06
2. Cholest-8(14)-enol	0.99	1.02
3. Cholesterol	1.00	1.00
4. Cholestanol	1.02	1.02
5. Cholest-8(9)-enol	1.05	1.05
6. Cholesta-7,9(11)-dienol	1.05	1.16
7. Cholesta-5,7,9(11),24-tetraenol	1.07	1.28
8. Desmosterol	1.08	1.20
9. 7-Dehydrocholesterol	1.10	1.16
10. 24-Methylcholesta-5,22(E)-dienol	1.11	1.14
11. Cholest-24-enol	1.12	1.26
12. Lathosterol	1.12	1.19
13. 24-Methylcholest-22(E)-enol	1.14	1.17
14. Cholesta-8(9),24-dienol	1.15	1.28
15. Cholesta-5,7,9(11),22(E),24-pentaenol	1.16	1.48
16. Cholesta-5,22(E),24-trienol	1.17	1.43
17. Cholesta-5,7,24-trienol	1.21	1.42
18. Cholesta-7,24-dienol	1.23	1.44
19. 24-Methylcholesta-5,23-dienol	1.25	1.38
20. 24-Methylcholesta-5,7,9(11)-trienol	1.26	1.42
21. 24-Methylenecholesterol	1.26	1.37
22. Cholesta-5,7,22(E),24-tetraenol	1.29	1.68
23. 24-Methylenecholestanol	1.30	1.39
24. 24-Methylcholesterol	1.30	1.33
25. 24-Methylcholestanol	1.33	1.35
26. 24-Methylenecholesta-5,7-dienol	1.39	1.57
27. 24-Ethylcholesta-5,22(E)-dienol	1.40	1.45
28. 24-Methylcholesta-7,24(28)-dienol	1.41	1.63
29. 24-Methylcholesta-5,7-dienol	1.42	1.54
30. 24-Ethylcholest-22(E)-enol	1.43	1.47
31. 24-Methylcholest-7-enol	1.46	1.57
32. 24-Methylcholesta-5,24(25)-dienol	1.47	1.67
33. 24-Ethylcholesta-5,22(E),24(28)-trienol	1.50	1.60
34. 24-Ethylcholesta-5,23-dienol	1.53	1.67
35. 24-Ethylcholesta-7,22(E)-dienol	1.57	1.70
36. Fucosterol	1.59	1.76
37. 24-Ethylcholesterol	1.60	1.67
38. 24-Ethylcholestanol	1.63	1.69
39. Isofucosterol	1.66	1.85
40. Isofucostanol	1.69	1.88
41. 24-Ethylcholesta-5,24(25)-dienol	1.77	1.98
42. 24-Ethylcholesta-5,7-dienol	1.75	1.87
43. 24-Ethyllathosterol	1.81	1.96
44. 24-Ethylcholest-24(25)-enol	1.81	2.04
45. 24Z-Ethylidenelathosterol	1.89	2.20
46. 4a-Methylcholest-8(14)-enol	1.18  (1.15)b	1.15  (1.13)
47. 4a-Methylcholestanol	1.20  (1.17)	1.15  (1.13)
48. 4a-Methylcholesta-8(14),24-dienol	1.29  (1.26)	1.43  (1.39)
49. 4a-Methylcholest-7-enol	1.31  (1.27)	1.36  (1.33)
50. 4a-Methylcholesta-7,24-dienol	1.42  (1.38)	1.66  (1.61)
51. Obtusifoliol	1.52  (1.49)	1.56  (1.50)
52. 4a,24-Dimethylcholest-8(14)-enol	1.54  (1.49)	1.52  (1.48)
53. 4a,24-Dimethylcholestanol	1.58  (1.53)	1.52  (1.48)
54. 4a,24-Dimethylcholest-7-enol	1.69  (1.64)	1.80  (1.76)
55. 4a-Methyl-24-ethylcholest-22(E)-enol	1.71  (1.67)	1.66  (1.61)
56. 4a-Methyl-24-methylenelathosterol	1.75  (1.68)	1.86  (1.80)
57. 4a-Methyl-24-ethylcholestanol	2.10  (1.91)	1.87  (1.87)
58. 4a-Methylisofucostanol	2.07  (1.95)	2.11  (2.06)
59. 4a-Methyl-24(Z)-ethylidenelathosterol	2.26  (2.12)	2.52  (2.44)
60. Cycloartanol	1.71  (1.60)	1.67  (1.53)
61. Cycloeucalenol	1.74  (1.69)	1.88  (1.78)
62. Cycloartenol	1.86  (1.73)	2.05  (1.85)
63. 24-Methylenecycloartanol	2.14  (1.99)	2.28  (2.06)
a Gas-liquid chromatography (GLC) was performed on a temperature-programmed (90°C 1 min., 15°C/min. increase to 250°C) DB-1 fused silica capillary column (14 m x 0.25-mm i.d., 0.25-mm film) and on an isothermally operated packed glass column containing 2.0% OV-17 stationary phase.  Because of temperature program, cholesterol and 24-ethylcholesterol DB-1 RRTs were arbitrarily set at 1.00 and 1.60.  Remaining DB-1 retention times were logarithmically transformed with these two standards to obtain RRTs of the other compounds.  b Values in parentheses are RRTs of steryl acetates relative to cholesteryl acetate. Trivial and systematic names: cholesterol, cholest-5-en-3ß-ol; cholestanol, 5a-cholestan-3ß-ol; desmosterol, cholesta-5,24-dien-3ß-ol; lathosterol, 5a-cholest-7-en-3ß-ol; fucosterol, 24(E)-ethylidenecholest-5-en-3ß-ol; isofucosterol, 24(Z)-ethylidenecholest-5-en-3ß-ol; isofucostanol, 24(Z)-ethylidene-5a-cholestan-3ß-ol; obtusifoliol, 4a,14-dimethyl-24-methylene-5a-cholest-8-en-3ß-ol; cycloartanol, 4,4,14-trimethyl-9ß,19-cyclo-5a-cholestan-3ß-ol; cycloeucalenol, 4a,14-dimethyl-24-methylene-9ß,19-cyclo-5a-cholestan-3ß-ol; cycloartenol, 4,4,14-trimethyl-9ß,19-cyclo-5a-cholest-24-en-3ß-ol.  Mention of trade names or commercial products in this table is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.

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Mass spectra of sterols