TY - JOUR
T1 - Characterization of (E,E)-farnesol and its fatty acid esters from anal scent glands of nutria (Myocastor coypus) by gas chromatography-mass spectrometry and gas chromatography-infrared spectrometry
AU - Lee, Hyeunjoo
AU - Finckbeiner, Steven
AU - Yu, Jose S.
AU - Wiemer, David F.
AU - Eisner, Thomas
AU - Attygalle, Athula B.
PY - 2007/9/21
Y1 - 2007/9/21
N2 - Several volatile compounds, including terpenoids, fatty alcohols, fatty acids and some of their esters, were identified from solvent extracts prepared from anal scent glands of nutria (a.k.a. coypu), a serious rodent pest ravaging wetlands in the USA. The major terpenoid constituents were identified as (E,E)-farnesol and its esters by a comparison of their gas chromatographic retention times, and electron-ionization (EI) and chemical-ionization (CI) mass spectra with those of authentic compounds. EI mass spectra of the four farnesol isomers are very similar, however, the ChemStation (Agilent) and GC-MS Solution (Shimadzu) software algorithms were able to identify the natural compound as the (E,E)-isomer, when a high-quality mass spectral library was compiled from reference samples and used for searching. Similarly, the esters were identified as those of (E,E)-farnesol. In contrast to EI spectra, the CI spectra of the (E,E)- and (E,Z)-isomers are distinctly different from those of the (Z,E)- and (Z,Z)-isomers. The intensities (I) of the peaks for the m/z 137 and 121 ions in the CI spectra offer a way of determining the configuration of the C-2 double bond of farnesols (for 2E isomers I137 > I121, whereas for 2Z isomers I137 < I121). Moreover, the infrared spectrum of the (E,E)-isomer is distinctly different from those of the other three isomers in the 2962-2968 cm-1 and 2918-2922 cm-1 bands, which represent asymmetric CH3 and CH2 stretching vibrations, respectively. Finally, the GC retention indices of farnesol and farnesyl ester isomers determined from authentic samples were used to confirm all identifications.
AB - Several volatile compounds, including terpenoids, fatty alcohols, fatty acids and some of their esters, were identified from solvent extracts prepared from anal scent glands of nutria (a.k.a. coypu), a serious rodent pest ravaging wetlands in the USA. The major terpenoid constituents were identified as (E,E)-farnesol and its esters by a comparison of their gas chromatographic retention times, and electron-ionization (EI) and chemical-ionization (CI) mass spectra with those of authentic compounds. EI mass spectra of the four farnesol isomers are very similar, however, the ChemStation (Agilent) and GC-MS Solution (Shimadzu) software algorithms were able to identify the natural compound as the (E,E)-isomer, when a high-quality mass spectral library was compiled from reference samples and used for searching. Similarly, the esters were identified as those of (E,E)-farnesol. In contrast to EI spectra, the CI spectra of the (E,E)- and (E,Z)-isomers are distinctly different from those of the (Z,E)- and (Z,Z)-isomers. The intensities (I) of the peaks for the m/z 137 and 121 ions in the CI spectra offer a way of determining the configuration of the C-2 double bond of farnesols (for 2E isomers I137 > I121, whereas for 2Z isomers I137 < I121). Moreover, the infrared spectrum of the (E,E)-isomer is distinctly different from those of the other three isomers in the 2962-2968 cm-1 and 2918-2922 cm-1 bands, which represent asymmetric CH3 and CH2 stretching vibrations, respectively. Finally, the GC retention indices of farnesol and farnesyl ester isomers determined from authentic samples were used to confirm all identifications.
KW - CI mass spectra
KW - Coypu
KW - EI mass spectra
KW - Farnesol isomers
KW - Farnesyl ester isomers
KW - GC-MS
KW - Methanolysis
KW - Myocastor coypus
KW - Nutria anal scent gland
KW - Terpenoids
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U2 - 10.1016/j.chroma.2007.06.041
DO - 10.1016/j.chroma.2007.06.041
M3 - Article
C2 - 17709112
AN - SCOPUS:34548154710
SN - 0021-9673
VL - 1165
SP - 136
EP - 143
JO - Journal of Chromatography A
JF - Journal of Chromatography A
IS - 1-2
ER -