2246 J. Agric. Food Chem., Vol. 54, No. 6, 2006
Feger et al.
Table 3. (Continued)
compound
systematic name
Rt (HPLC)g
UVmax (nm)
MS (m/z)
structure (Figure 1)
identification
RI (GC DB-5)
5-isopentenyloxy-7-methoxycoumarin
(C2: 5 R4, 7 R2)
Rt, UV
RI, MS
21.6
2351
208, 249, 326
+
260 (7, M ), 193 (7), 192 (100), 164 (46), 163 (14), 149 (11),
135 (18), 69 (66), 41 (35)
224, 250, 269, 312
cnidilin
Rt, UV
22.2
5-isopentenyloxy-8-methoxypsoralen
decomp
[232 (100), 217 (49), 189 (4), 175 (4), 160 (5), 69 (41),
(P3: 5 R4, 8 R2)
41 (19)]
+
[hydrogenated: 306 (46, M ), 236 (60), 221 (25), 194 (100),
179 (16), 151 (8), 91 (7), 77 (6), 43 (15)]
202, 222, 252, 310
270 (1, M ), 255 (1), 203 (5), 202 (58), 174 (16), 145 (9),
isoimperatorin
5-isopentenyloxypsoralen
Rt, UV
RI, MS
22.6
2394
+
(P1: R4)
8-geranyloxypsoralen
(P2: R10
89 (18), 69 (100), 67 (11), 41 (82)
197, 218, 248, 300
338 (-, M ), 203 (30), 202 (100), 174 (20), 136 (21), 93 (13),
Rt, UV
RI, MS
28.6
2865
+
)
69 (15), 41 (10)
204, 322
[Claisen: 358 (16, M ), 289 (21), 275 (26), 259 (31), 236 (52),
6,7-dimethoxy-5-geranyloxycoumarina,b,f
(C4: 5 R10, 6 R2, 7 R2)
Rt, UV
MS
28.6
decomp
+
235 (100), 123 (61), 122 (40), 41 (42)]
+
[TMS-ether: 430 (10, M ), 374 (5), 361 (25), 347 (13),
307 (65), 331 (10), 277 (9), 123 (12), 73 (100),
41 (18)]
auraptenea,b,d
7-geranyloxycoumarin
28.6
2634
202, 322
+
RI, MS
298 (-, M ), 163 (63), 162 (73), 137 (23), 136 (35), 134 (39),
(C1: R10
5-geranyloxy-8-methoxypsoralen
(P3: 5 R10, 8 R2)
)
93 (34), 81 (44), 69 (100), 41 (36)
222, 249, 267, 310
[368 (-, M ), 233 (13), 232 (100), 217 (35),189 (4), 95 (11),
Rt, UV
RI, MS
29.3
decomp
+
81 (23), 69 (52), 41 (19)]
+
[hydrogenated: 376 (28, M ), 236 (100), 221 (19), 194 (76),
179 (9), 85 (7), 71 (8), 57 (12), 43 (16)]
196, 250, 307
438 (10, M ), 368 (15), 287 (25), 245 (8), 203 (30),
neral oxypeucedaninyl acetala,b
(diastereomer a) (Figure 3)
29.5
3377
+
RI, MS
202 (65), 201 (23), 95 (50), 69 (100), 41 (55)
196, 250, 307
438 (10, M ), 368 (15), 287 (25), 245 (8), 203 (30),
neral oxypeucedaninyl acetala,b
(diastereomer b) (Figure 3)
1H NMR, 13C NMR
RI, MS
29.5
3388
+
202 (65), 201 (23), 95 (50), 69 (100), 41 (55)
196, 250, 307
438 (3, M ), 368 (5), 315 (9), 287 (20), 245 (10), 203 (20),
geranial oxypeucedaninyl acetala,b
(diastereomer a) (Figure 3)
1H NMR, 13C NMR
RI, MS
29.5
3430
+
202 (40), 201 (18), 95 (20), 69 (100), 41 (45)
196, 250, 307
438 (3, M ), 368 (5), 315 (9), 287 (20), 245 (10), 203 (20),
geranial oxypeucedaninyl acetala,b
(diastereomer b) (Figure 3)
29.5
3448
+
RI, MS
Rt, UV
202 (40), 201 (18), 95 (20), 69 (100), 41 (45)
220, 250, 308
bergamottin
5-geranyloxypsoralen
29.8
decomp
+
[Claisen: 338 (18, M ), 269 (17), 255 (22), 227 (30), 215 (79),
(P1: R10
)
171 (34), 123 (63), 115 (42), 69 (75), 41 (100)]
207, 248, 322
328 (3, M ), 193 (38), 192 (88), 164 (19), 135 (11), 81 (35),
5-geranyloxy-7-methoxycoumarin
(C2: 5 R10, 7 R2)
Rt, UV
RI, MS
30.1
2862
+
69 (100), 41 (33)
a Trace constituent. b Previously unknown in lime. c Artifact or transformation product during CCC. d Typical grapefruit components. e Typical orange components. f Tentatively.
g Rt: HPLC retention time in minutes (conditions see HPLC with diode array detection).
omers a and b): (70 eV), m/z 69 (100%), 202 (65%), 41 (55%), 95
(50%), 55 (25%), 85 (25%), 287 (25%), 109 (20%), 135 (15%), 368
(15%), 438 (M+; 10%); 1H NMR (diastereomer b) (250 MHz, CDCl3)
δ 6.26 [d, 1 H, J ) 9.7 Hz, H-C(3)], 8.17 [d, 1H, J ) 9.7 Hz, H-C(4)],
7.16 [s, br, 1H, H-C(8)], 7.59 [d, 1H, J ) 2.5 Hz, H-C(1′)], 6.95 [d,
1H, J ) 2.5 Hz, H-C(2′)], 4.45-4.49 [m, 2H, H-C(1′′)], 4.09 (m,
br, 1H, J ) 5.0 Hz, H-C(2′′)], 1.41 [s, 3H, H-C(4′′)], 1.29 [s, 3H,
H-C(5′′)], 5.69 [d, 1H, J ) 7.5 Hz, H-C(1′′′)], 5.20 [m, br, 1H, J )
7.5 Hz, H-C(2′′′)], 2.14-2.20 [m, 2H, H-C(4′′′)], 2.14-2.20 [m, 2H,
H-C(5′′′)], 5.12 [m, br, H-C(6′′′)], 1.60 [s, 3H, H-C(8′′′)], 1.68 [s,
3H, H-C(9′′′)],1.76 [s, br, 3H, H-C(10′′′)], 13C NMR diastereomer b
(62.5 MHz, CDCl3) δ 161.1 [C-2], 112.9 [C-3], 139.2 [C-4], 107.0
[C-4a], 148.3 [C-5], 113.6 [C-6], 158.1 [C-7], 94.6 [C-8], 152.6 [C-8a],
145.1 [C-1′], 104.7 [C-2′], 72.0 [C-1′′], 81.9 [C-2′′], 79.2 [C-3′′], 22.9
[C-4′′], 25.9 [C-5′′], 98.2 [C-1′′′], 122.3 [C-2′′′], 145.5 [C-3′′′], 32.6
[C-4′′′], 26.9 [C-5′′′], 123.5 [C-6′′′], 132.3 [C-7′′′], 17.8 [C-8′′′], 25.7
[C-9′′′], 23.7 [C-10′′′].
distillation) was added to fraction 1 of the lime preseparation to
synthesize the geranial acetals of oxypeucedanin. The reaction mixture
was chromatographed via CCC for isolation purposes. Due to the
isomerization of geranial to neral under acidic conditions, the geranial
acetals also contained some neral acetals.
Geranial Oxypeucedaninyl Acetal: (diastereomer a, RI 3430 and b,
RI 3448): UVmax(diastereomer a), 196, 250, 307 nm; GC-MS
(diastereomers a and b): (70 eV), m/z 69 (100%), 41 (45%), 202 (40%),
55 (20%), 95 (20%), 287 (20%), 85 (15%), 109 (20%), 438 (M+; 3%);
1H NMR (diastereomer a) (250 MHz, CDCl3) δ 6.28 [d, 1 H, J ) 9.7
Hz, H-C(3)], 8.18 [dd, 1H, J ) 9.7 Hz, J ) 1.0 Hz, H-C(4)], 7.17
[s, br, 1H, H-C(8)], 7.59 [d, 1H, J ) 2.4 Hz, H-C(1′)], 6.96 [dd, 1H,
J ) 2.4 Hz, J ) 1.0 Hz, H-C(2′)], 4.45-4.50 [m, 2H, H-C(1′′)],
4.11 (m, br, 1H, J ) 5.0 Hz, H-C(2′′)], 1.42 [s, 3H, H-C(4′′)], 1.30
[s, 3H, H-C(5′′)], 5.74 [d, 1H, J ) 7.5 Hz, H-C(1′′′)], 5.21 [m, 1H,
J ) 7.5 Hz, J ) 1.3 Hz, H-C(2′′′)], 2.01-2.10 [m, 2H, H-C(4′′′)],
2.01-2.10 [m, 2H, H-C(5′′′)], 5.07 [m, br, H-C(6′′′)], 1.58 [s, 3H,
H-C(8′′′)], 1.66 [s, 3H, H-C(9′′′)],1.78 [d, 3H, J ) 1.3 Hz,
H-C(10′′′)], 13C NMR diastereomer a (62.5 MHz, CDCl3) δ 161.0
Synthesis of Geranial Oxypeucedaninyl Acetal (Figure 3). Analogous
to the neral acetal, geranial (91%, isolated from Litsea cubeba oil by