Mono- and dicyclic unsaturated triterpenoid hydrocarbons in ...

886 R. de Mesmay et al. / Organic Geochemistry 39 (2008) 879–893
relative intensity
%
100
50
0
%
100
50
0
%
100
50
0
43
57
69
86
A
relative intensity
O1
O4
O
H
113
109 123
O4 O5
O2 O3
40 60 80 100 120 140 160 180 200 220 240 m/z
43
55 71
83
95
100
113
O7
127
141
465) twice more intense than the similar ion in the spectrum
of e (35% instead of 16%), suggesting that more than
one ethyl group occurs in j. Unfortunately, GC-MS analysis
of the ozonolysis products did not allow identification of
the compound resulting from the cleavage of the right half
part of the molecule, likely due to coelution with triphenyl
+H
O6 O7 O8
18 20 22 24 26 time (min.)
B C
113
226
141
141
151 168 179 197
O
H
155
161
240
O
57
226
236
M +.
254
D E
184
225
207
197 240 M
250
+. -H2O 40 60 80 100 120 140 160 180 200 220 240 260 m/z
55
O10
H
O
+H
113
+H
113
O
184
155
225
O
+H 71
100
F G
43
69
40 60 80 100 120 140 160 180 200 220 240 260 m/z
85
95 141
123
113
151
169
267
198 226
253 M
282
+.
+H +H
+H
86
254 198
141 141 254
156
M +. -CH3 M +. -C2H5 O
+H
169
127
156
+H
86
+H
21
86
O
H
43
%
100
50
0
O9
43
55
55
71
83
O10
100
O11
O5
M +.
109
123
179
240
137 155168 189 207 225 250 268
113
40 60 80 100 120 140 160 180 200 220 240 260 280
43
83
127
95
109
H
O9
H
O
+H
156
155
141
167
M
253
184 212 240
+. M -CH3 250
+. -H2O M +.
268
40 60 80 100 120 140 160 180 200 220 240 260 m/z
43
55
71
72
84
95
113
109 127
O11
O
phosphine, the reagent used for the reduction of the polyozonides.
However, taken with these mass spectral data,
the strong structural relationship between the C34-C35 masokocenes
and the C 36 analogue allows us to assign compound
j as a C36 dicyclic botryococcene with two geminal
ethyls on carbon C-21.
O
113
240
113
O
155
155
225
156
+H
O
71
+H
100
+H
72
O
H
+H +H
240 184
141 127
+H
240
72
H
184
+H +H
+H
H
O
141 197
72
137
155
169
184
222
M
281
250
40 60 80 100 120 140 160 180 200 220 240 260 m/z
+. -CH3 296
M+.
Fig. 6. (A) Total ion chromatogram of ozonised hydrocarbon fraction from Lake Masoko sediment at 1856–1871 cm depth. (B-G) EI mass spectra of
compounds O4, O5, O7, O9, O10 and O11.
%
100
50
0
%
100
50
0
O
127
155
H
197
-H
141
O
84
43