EPOXY ALCOHOL FROM OAT SEED PEROXYGENASE
555
TABLE 1
Diagnostic 1H NMR Chemical Shifts and Coupling Constants of Methyl
9,10-Epoxy-13- hydroxy-11(E)-octadenoate (4b)a
Number
Chemical shift (δ)
of protons
Appearance
Assignment
Coupling constant (Hz)
2.98
3.33
4.02
5.49
5.91
1H
1H
1H
1H
1H
dt
dd
dt
dd
dd
H-9
J8–9 = 6.1, J9–10 = 4.3
H-10
H-13
H-11
H-12
J9–10 = 4.3, J10–11 = 7.5
J12–13 = 5.3, J13–14 = 10.8
J10–11 = 7.9, J11–12 = 15.5
J11–12 = 15.6, J12–13 = 6.1
aNMR, nuclear magnetic resonance; for structure of 4b see Scheme 1.
The decoupled 13C NMR (C4D8O2, 400 MHz) spectrum of
the epoxy alcohol showed important signals at δ 51.4
(OCH3), 56.7 (C-9), 58.8 (C-10), 72.1 (C-13), 125.1 (C-11),
141.4 (C-12), and 174.0 [C(O)OCH3]. Because there are only
two signals for the epoxide carbons, two signals for the dou-
ble-bond carbons, and one signal for the alcoholic carbon, the
epoxy alcohol consists of one structural isomer.
utility of this procedure for the synthesis of highly oxy-
genated lipids with potential for use in industrial products.
ACKNOWLEDGMENTS
The authors thank Carroll F. Fox for technical assistance and Janine N.
Brouillette for NMR spectra.
Important signals from the 1H NMR (C4D8O2, 400 MHz)
spectrum of the epoxy alcohol are shown in Table 1. The cou-
pling constant J9–10 was 4.3 Hz, demonstrating that the con-
figuration of the epoxide is cis: J = 4.3 Hz for cis and 2.1–2.4
Hz for trans (10). The coupling constant J11–12 was 15.5–15.6
Hz, demonstrating that the double bond is in the trans config-
uration: J = 5–14 Hz for cis protons and 12–18 Hz for trans
protons (11). From all the above data, it was concluded that
the structure of the epoxy alcohol 4b is methyl cis-9,10-
epoxy-13(S)-hydroxy-11(E)-octadecenoate.
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in H2O/HCl as described previously (12). After formation of
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[Received October 9, 1998; accepted February 23, 1999]
JAOCS, Vol. 76, no. 5 (1999)