S. Sugimoto et al. / Phytochemistry xxx (2014) xxx–xxx
3
Table 1
NMR spectroscopic data for compounds 1–3 (150 MHz for 13C, 600 MHz for 1H, methanol-d4), m: multiplet.
Position
Compound 1
Compound 2
Compound 3
13C
1H
13C
1H
13C
1H
1
2
3
4
5
6
7
144.1
127.9
129.4
128.6
129.4
127.9
76.3
–
137.1
138.1
131.3
129.3
127.0
130.6
70.7
–
–
155.3
128.6
128.9
132.9
116.6
132.5
16.8
–
7.45 (1H, dd, J = 1.4, 7.4 Hz)
7.28 (2H, t, J = 7.4 Hz)
7.22 (1H, m)
7.28 (2H, d, J = 7.4 Hz)
7.45 (1H, dd, J = 1.4, 7.4 Hz)
5.06 (1H, q, J = 6.6 Hz)
6.97 (1H, d, J = 2.0 Hz)
–
–
7.05 (1H, d, J = 8.0 Hz)
6.95 (1H, d, J = 2.0, 8.0 Hz)
2.24 (3H, s)
7.16 (1H, dd, J = 1.6, 7.3 Hz)
7.18 (1H, dd, J = 1.6, 7.3 Hz)
7.13 (1H, dd, J = 1.6, 7.3 Hz)
7.40 (1H, d, J = 7.3 Hz)
4.64 (1H, d, J = 11.6 Hz)
4.95 (1H, d, J = 11.6 Hz)
2.37 (3H, s)
8
24.7
1.47 (3H, d, J = 6.6 Hz)
19.4
20.9
2.25 (3H, s)
Glc 10
20
101.3
75.15
78.09
71.57
77.1
69.6
–
4.10 (1H, d, J = 7.4 Hz)
103.7
75.4
78.31
71.9
77.5
70.2
–
4.35 (1H, d, J = 7.9 Hz)
3.24 (1H, m)
3.36 (1H, m)
103.1
75.5
78.2
71.7
77.6
70.0
–
4.86 (1H, d, J = 7.6 Hz)
3.28 (1H, dd, J = 7.4, 8.5 Hz)
3.40 (1H, dd, J = 8.5, 8.9 Hz)
3.37 (1H, dd, J = 8.9, 9.0 Hz)
3.31 (1H, ddd, J = 2.0, 5.5, 9.0 Hz)
3.82 (1H, dd, J = 5.5, 11.7 Hz)
4.17 (1H, dd, J = 2.0, 11.7 Hz)
3.23 (1H, dd, J = 7.6, 8.0 Hz)
3.35 (1H, dd, J = 8.0, 8.9 Hz)
3.44 (1H, dd, J = 8.9, 9.2 Hz)
3.64 (1H, ddd, J = 1.9, 6.0, 9.2 Hz)
3.83 (1H, dd, J = 5.9, 11.6 Hz)
4.17 (1H, dd, J = 1.9, 11.6 Hz)
30
40
3.27 (1H, m)
50
3.46 (1H, ddd, J = 2.0, 5.9, 9.0 Hz)
3.81 (1H, dd, J = 5.9, 11.6 Hz)
4.18 (1H, dd, J = 2.0, 11.6 Hz)
60
Glc 100
200
104.9
75.21
78.13
71.64
77.8
4.46 (1H, d, J = 7.8 Hz)
3.29 (1H, dd, J = 7.8, 9.2 Hz)
3.32 (1H, m)
3.33 (1H, dd, J = 8.8, 9.8 Hz)
3.25 (1H, ddd, J = 1.5, 5.5, 9.8 Hz)
3.70 (1H, dd, J = 5.5, 11.8 Hz)
3.90 (1H, dd, J = 1.5, 11.8 Hz)
105.2
75.4
78.33
71.9
78.4
63.1
4.41 (1H, d, J = 7.9 Hz)
3.24 (1H, m)
3.34 (1H, m)
3.33 (1H, m)
3.26 (1H, m)
104.9
75.3
78.4
71.9
78.2
63.0
4.39 (1H, d, J = 7.7 Hz)
3.49 (1H, dd, J = 7.7, 8.3 Hz)
3.48 (1H, dd, J = 8.3, 8.6 Hz)
3.30 (1H, dd, J = 8.6, 9.0 Hz)
3.21 (1H, ddd, J = 2.3, 5.8, 9.0 Hz)
3.67 (1H, dd, J = 5.8, 12.0 Hz)
3.87 (1H, dd, J = 2.3, 12.0 Hz)
300
400
500
600
62.8
3.67 (1H, dd, J = 5.6, 11.9 Hz)
3.88 (1H, dd, J = 2.0, 11.9 Hz)
Table 2
NMR spectroscopicdata for compounds 4 and 5 (150 MHz for 13C, 600 MHz for 1H, a: pyridine-d5, b: methanol-d4, c: DMSO-d6), m: multiplet.
Position
Compound 4a
Compound 5b
Position
Compound 4c
13C
1H
13C
1H
13C
1H
1
–
–
–
–
1
–
–
2
3
4
5
148.7
122.9
135.8
68.9
84.1
62.5
–
149.9
123.7
135.8
69.6
84.1
63.0
–
2
3
4
5
147.7
121.9
135.0
66.5
82.5
62.1
–
6.47 (1H, dd, J = 1.4, 10.8 Hz)
6.41 (1H, dd, J = 3.3, 10.8 Hz)
5.05 (1H, ddd, J = 1.4, 3.3, 6.8 Hz)
5.74 (1H, d, J = 6.8 Hz)
3.91 (3H, s)
6.24 (1H, dd, J = 1.8, 10.8 Hz)
6.13 (1H, dd, J = 3.1, 10.8 Hz)
4.53 (1H, ddd, J = 1.8, 3.1, 7.4 Hz)
5.12 (1H, d, J = 7.4 Hz)
3.94 (3H, s)
6.26 (1H, dd, J = 1.5, 10.7 Hz)
6.18 (1H, dd, J = 3.7, 10.7 Hz)
4.44 (1H, ddd, J = 1.5, 3.7, 5.0, 6.5 Hz)
5.10 (1H, d, J = 6.5 Hz)
3.91 (3H, s)
6
6
2-OMe
2-OMe
5-OH
5.68 (1H, d, J = 5.0 Hz)
Glc 10
20
105.6
75.4
78.4
71.2
79.0
62.5
5.32 (1H, d, J = 7.9 Hz)
105.1
75.1
77.7
71.4
77.8
69.7
4.58 (1H, d, J = 7.8 Hz)
3.27 (1H, dd, J = 7.8, 8.9 Hz)
3.34–3.42 (1H, m)
Glc 10
20
103.7
73.6
76.3
69.6
77.1
60.8
4.49 (1H, d, J = 7.8 Hz)
4.05 (1H, dd, J = 8.2, 8.6 Hz)
4.22 (1H, dd, J = 8.9, 9.1 Hz)
4.27 (1H, dd, J = 9.1, 9.2 Hz)
3.95 (1H, ddd, J = 2.3, 5.0, 9.2 Hz)
4.38 (1H, dd, J = 5.0, 11.9 Hz)
4.51 (1H, dd, J = 2.3, 11.9 Hz)
3.04 (1H, ddd, J = 4.4, 7.8, 8.6 Hz)
3.21 (1H, ddd, J = 4.8, 8.6, 8.9 Hz)
3.13 (1H, ddd, J = 5.2, 8.9, 9.2 Hz)
3.18 (1H, ddd, J = 1.7, 5.5, 9.2 Hz)
3.52 (1H, br dd, J = 5.5, 11.5 Hz)
3.71 (1H, ddd, J = 1.7, 5.3, 11.5 Hz)
30
30
40
3.33 (1H, m)
40
50
3.54 (1H, ddd, J = 1.9, 6.2, 9.7 Hz)
3.87 (1H, dd, J = 6.2, 12.1 Hz)
4.14 (1H, dd, J = 1.9, 12.1 Hz)
50
60
60
Glc 100
200
104.8
75.4
77.8
71.7
78.0
62.8
4.63 (1H, d, J = 7.7 Hz)
3.22 (1H, dd, J = 7.7, 9.2 Hz)
3.34–3.42 (1H, m)
3.33 (1H, m)
3.34–3.42 (1H, m)
20-OH
30-OH
40-OH
60-OH
5.22 (1H, d, J = 4.4 Hz)
5.06 (1H, d, J = 4.8 Hz)
5.00 (1H, d, J = 5.2 Hz)
4.47 (1H, d, J = 5.3 Hz)
300
400
500
600
3.70 (1H, dd, J = 5.7, 11.9 Hz)
3.90 (1H, dd, J = 2.2, 11.9 Hz)
clarified by the HMBC experiment, which showed long-range cor-
relations between H3-7 and C-2, 3, and 4, H3-8 and C-3, 4 and 5,
and H-5 and C-1, 3. Consequently, the structure of 3 was deter-
mined to be 3,4-dimethylphenol b-gentiobioside.
Compound 4 was isolated as a major compound with colorless
crystals. The IR spectrum of 4 showed absorption bands at 3308,
1648, and 1028 cmꢀ1 ascribable to hydroxy, double bond, and
ether functional groups, respectively. The molecular formula, C12-
H19O8NS, of 4 was determined by positive-ion HR-ESI-MS mea-
surement (m/z 360.0726 [M+Na]+, calcd 360.0724). In the UV
on HPLC with an optical rotation detector. The 13C NMR (DMSO-d6)
spectrum displayed six signals attributable to one b-glucopyrano-
syl moiety, and the remaining six signals consisted of those of
one methoxy group (dC 62.5), two oxygenated methines (dC 68.9
and 84.1), one double bond (dC 122.9 and 135.8), and one fairly
deshielded carbon (dC 148.7) (Table 2). Structural elucidation of
the partial structural units was performed based on the 1H–1H
COSY spectrum. The positions of the substitutions were deter-
mined mainly based on HMBC correlations between the methoxy
protons and C-2, H-4 and C-2, H-5 and C-3, H-6 and C-2 and C-10,
and OH-5 and C-4, 5 and 6. The lonely and fairly deshielded sp2 car-
bon may be connected with a nitrogen atom to form an imine func-
tional group and thus a sulfur atom must be involved in the ring
spectrum of 4, absorption maxima were observed at 308 (log
1.51) and 249 (log 1.42) nm. Compound 4 was hydrolyzed with
1 M HCl to afford a sugar moiety, which was identified as -glucose
e
e
D
Please cite this article in press as: Sugimoto, S., et al. Structure elucidation of secondary metabolites isolated from the leaves of Ixora undulate and their