Meehanines L-W, spermidine alkaloidal glycosides from Meehania urticifolia

Article abstract of DOI:10.1021/np900454r

Twelve new spermidine alkaloidal glycosides, meehanines L-W (1-12), were isolated from the whole plant Meehania urticifolia. The structures of these new compounds were elucidated on the basis of spectroscopic data analyses.

Full text of DOI:10.1021/np900454r

J. Nat. Prod. 2009, 72, 1937–1943
1937
Meehanines L-W, Spermidine Alkaloidal Glycosides from Meehania urticifolia
Toshihiro Murata,*,† Toshio Miyase,‡ and Fumihiko Yoshizaki†
Department of Pharmacognosy, Tohoku Pharmaceutical UniVersity, 4-1 Komatsushima 4-chome Aoba-ku, Sendai 981-8558, Japan, and School
of Pharmaceutical Sciences, UniVersity of Shizuoka, 52-1, Yada, Suruga-ku, Shizuoka 422-8526, Japan
ReceiVed July 27, 2009
Twelve new spermidine alkaloidal glycosides, meehanines L-W (1-12), were isolated from the whole plant Meehania
urticifolia. The structures of these new compounds were elucidated on the basis of spectroscopic data analyses.
Meehania urticifolia (Miq.) Makino belongs to the family
Lamiaceae. It is a popular wild plant due to its large violet flowers
that appear from April to May and is named “Rashomon-kazura”
in Japan. In our previous paper, 11 spermidine alkaloidal glycosides,
meehanines A-K, were reported from this plant.1 Various cyclic
spermidine alkaloids2,3 and their glucosides4 have been reported
from plants classified in the Celastraceae, Flacourtiaceae, Equi-
setaceae, Apocynaceae, Cannabaceae, Cruciferae, and Gyrostemo-
naceae. Recently, four alkaloidal glycosides similar to meehanines
were also reported from another Lamiaceae plant, Dracocephalum
tanguticum Maxim.5 The differences between meehanines and other
cyclic spermidine alkaloids are that meehanines are diglycosides,
have a C-8 hydroxy group or O-acetyl group, and possess a rich
diversity of acylated moieties. In this study, the alkaloids of M.
urticifolia were investigated, and 12 new cyclic spermidine gly-
cosides were isolated.
respectively. In the 1H-1H COSY spectrum, the oxymethine proton
at δH 5.19 (1H, overlapped, H-8) was correlated with the C-7
methylene protons (2H, δH 1.93, overlapped) and H2-9 (2H, δH 3.32,
br d, J ) 4.0 Hz). The C-7 methylene protons correlated with the
C-6 protons at δH 2.23 (1H, br dd, J ) 11.5 and 10.0 Hz) and 2.75
(1H, m). The chemical shift of H-8 (δH 5.19) and a carbonyl carbon
at δC 169.7 suggested the presence of an C-8 acyl group. However,
the methyl proton and carbon signals of an acetyl group were not
clearly discernible in pyridine-d5. 1H and 13C NMR spectra acquired
in methanol-d4 (Table 2) showed acetyl protons at δH 2.08 (3H, s)
and a carbon at δC 20.8. These data suggested the presence of an
N-CH2-CH2-CH(-O-Ac)-CH2-N moiety. An amide proton
at δH 9.69 (1H, br t, J ) 6.0 Hz, H-1), methylene protons at δH
3.36 (2H, overlapped, H2-11), 1.97 (1H, overlapped, H-12), 2.08
(1H, overlapped, H-12), 3.05 (1H, m, H-13), and 3.90 (1H, m,
1
H-13), and their H-1H COSY correlations showed the presence
of an N-(CH2)3-N spin system. The presence of a 13-membered
spermidine ring was established using the correlations observed in
the HMBC spectra. The CD spectrum of 1 showed negative Cotton
effects in the 210-230 nm region, suggesting the absolute
configuration of C-4 to be S.7 The optical rotation of 1 in MeOH
was negative, similar to those of meehanines A-K.1 Accordingly,
the absolute configuration of C-8 of compound 1 was assumed to
be R.
Results and Discussion
The methanol and acetone extracts of whole plants of M.
urticifolia were dissolved in H2O and partitioned with Et2O. Each
H2O layer was fractionated by multistep column chromatography,
and 12 cyclic spermidine alkaloidal glycosides, meehanines L-W
(1-12), were isolated as amorphous powders. Their molecular
formulas were determined on the basis of HRFABMS. The 1H and
13C NMR spectra of compounds 9, 11, and 12, measured in
pyridine-d5 at 30 °C, and of compounds 5-8, 10, and 12, which
were acquired in methanol-d4 at 30 °C, showed the presence of
two sets of closely spaced resonances (Tables 1 and 2) similar to
those of meehanines A-K, found in our previous study.1 However,
compounds 1-4, lacking a 10-N amide moiety, showed only one
set of resonances (Table 1). The observation of duplicated signals
for 5-12 may be attributed to cis-trans isomerism due to the partial
CdN double-bond character of the 10-N amide functional group.5,6
Meehanine L (1) showed an [M + H]+ at m/z 762.3449 in the
HRFABMS, which indicated the molecular formula C37H51N3O14.
Two anomeric carbons at δC 98.6 and 107.1 (Table 1) suggested
the presence of two monosaccharide moieties. Their corresponding
anomeric protons resonated at δH 6.20 (1H, br s) and 5.38 (1H, d,
J ) 7.5 Hz), respectively, which were also observed in the 1H-1H
COSY and HMQC spectra, showing the presence of a rhamnopy-
ranose and a glucopyranose unit. Sugar analyses showed the
presence of L-rhamnose and D-glucose units.8 The anomeric
R-configuration of the L-rhamnosyl residue was determined from
the 13C NMR chemical shifts of C-3 and C-5.9 Furthermore, the
D-glucosyl residue was determined to be ꢀ from the coupling
constant of the anomeric proton. The 1H NMR signals of Glc-6 at
δH 4.95 (1H, dd, J ) 11.5 and 4.5 Hz) and 5.19 (1H, br d, J )
11.5 Hz) were shifted downfield relative to that of the glucosyl
moiety of meehanine C. In the HMBC spectrum, they were long-
range coupled with a carbonyl carbon at δC 166.6 (C-1′′), revealing
that the C-6 hydroxy group of the glucosyl unit was acylated. The
aromatic protons at δH 8.07 (2H, br d, J ) 7.5 Hz, H-3′′ and H-7′′),
7.24 (2H, br t, J ) 7.5 Hz, H-4′′ and H-6′′), and 7.46 (1H, br t, J
) 7.5 Hz, H-5′′) showed a benzoate moiety, and the H-3′′ and H-7′′
signals were long-range coupled with the C-1′′ signal. In the HMBC
spectrum, the anomeric proton of the 6-benzoyl-ꢀ-D-glucosyl moiety
was long-range coupled with the carbon signal at δC 81.4 (Rha-2),
and the anomeric proton of R-L-rhamnose was long-range coupled
with the 1,4-disubstituted benzene ring carbon at δC 156.4 (C-4′).
Hence, the structure of 1 was formulated as shown in Figure 1.
For meehanine M (2), confirmation of the molecular formula of
C35H49N3O13 was achieved by HRFABMS, which was C2H2O less
1
In the H and 13C NMR spectra acquired in pyridine-d5 at 30 °C
(Table 1), 15 sp2 carbon signals and 22 sp3 carbon signals were
observed. Two methine, seven methylene, six aromatic, and two
carbonyl carbons and their corresponding proton signals were
considered to be components of an aglycone moiety. A set of
AA′BB′-type aromatic protons at δH 7.38 (2H, br d, J ) 8.5 Hz)
and 7.19 (2H, overlapped) and carbons at δC 134.7 (C-1′), 128.5
(C-2′ and C-6′), 117.2 (C-3′ and C-5′), and 156.4 (C-4′) suggested
the presence of a 1,4-disubstituted benzene ring. A methine proton
at δH 4.41 (1H, dd, J ) 11.5 and 3.5 Hz) and methylene protons at
δH 2.67 (1H, br dd, J ) 13.0 and 3.5 Hz) and 3.13 (1H, br dd, J
) 13.0 and 11.5 Hz) were ascribed to the C-4 and C-3 protons,
* To whom correspondence should be addressed. Tel and Fax: +81-22-
727-0220. E-mail: murata-t@tohoku-pharm.ac.jp.
† Tohoku Pharmaceutical University.
‡ University of Shizuoka.
than that of 1, indicating the absence of an acetyl group. The H
1
10.1021/np900454r CCC: $40.75  2009 American Chemical Society and American Society of Pharmacognosy
Published on Web 10/21/2009

1938 Journal of Natural Products, 2009, Vol. 72, No. 11
Murata et al.
Table 1. NMR Data (400 MHz, pyridine-d5) for Compounds 1-4, 9, 11, 12, and Meehanines C, G, and H
1
2
δH (J in Hz)
9.76, brt (6.0)
3
4
δH (J in Hz)
9.78, brt (6.5)
9
position
δH (J in Hz)
δC
δC
δH (J in Hz)
δC
δC δH (J in Hz)
δC
1
9.69, brt (6.0)
9.68, brt (5.5)
8.43, brt (6.0)
8.56, m
2
3
172.2
45.6
172.5
172.2
45.6
172.5
172.0b
46.7
2.67, brdd (13.0, 3.5)
3.13, brdd (13.0, 11.5)
4.41, dd (11.5, 3.5)
2.23, brdd (11.5, 10.0)
2.75, m
2.70, dd (13.0, 3.5)
3.10, dd (13.0, 12.0)
4.41, dd (12.0, 3.5)
2.24, dd (13.0, 10.0)
2.83, dd (13.0, 8.0)
45.9 2.67, dd (12.5, 3.5)
3.12, dd (12.5, 12.0)
60.6 4.42, dd (12.0, 3.5)
41.3 2.25, m
2.72, dd (12.5, 3.5)
3.12, dd (12.5, 11.5)
4.44, dd (11.5, 3.5)
2.26, dd (13.0, 10.0)
2.86, dd (13.0, 7.5)
45.9 2.76, m
4
6
60.8
41.7
60.8
41.7
60.6 4.42a
41.4 2.42, m
2.54, m
60.2b, 61.2
45.5b, 45.9b
2.77, ddd (12.5, 6.5, 2.0)
2.72a
7
8
9
1.93a
31.2
70.4c
51.8
1.89, m
2.02, m
4.25a
34.5 1.97a
31.2
70.4
51.8
1.86-2.10a
34.5 1.55-1.63a
32.6, 32.8
74.9, 81.3
49.7
5.19a
67.3 5.19, m
4.26a
67.3 5.39a
5.52, m
3.32, brd (4.0)
3.33a
3.42a
49.3 3.31, brd (4.0)
3.25, dd (12.5, 6.0)
3.41a
48.7 3.82, m
4.15a
4.68a
11
12
3.36a
49.6
26.6
3.39, m
49.5 3.36, m
26.5 1.86-2.13a
49.6
26.6
3.40a
2.00a
2.15a
3.19a
3.85, m
49.5 3.50-3.60a
26.5 1.76a
2.00-2.25a
39.0 3.30, m
3.43, m
43.8, 44.7
32.0
1.97a
1.99, m
2.08a
2.24, m
13
3.05, m
3.90, m
39.0
3.24, dd (12.5, 6.0)
3.85, m
39.0 3.03, m
3.89, m
39.4
36.6, 36.7
3.73, m
Ac CdO
169.7
20.3, br
134.7
128.5
117.2
156.4
117.2
128.5
98.6
169.7
20.8, br
134.9
128.5
117.2
156.5
117.2
128.5
98.7
169.1b, 171.1b
21.5
Ac CH3
1.80-1.84b
1.78-1.83b
134.9
2.02, s
135.5a
128.5 7.30a
117.2 7.30a
156.4
117.2 7.30a
128.5 7.30a
98.7 6.06, brs
81.4 4.71, m
72.5 4.64, m
74.1 4.35, m
70.5 4.15-4.35a
18.3 1.55, d (6.0)
1.56, d (6.0)
106.9
1′
2′
3′
4′
5′
6′
Rha-1
137.6b
128.3
117.4
155.9
117.4
128.3
100.4
72.3
7.38, brd (8.5)
7.19a
7.41, brd (8.5)
7.20a
128.5 7.43, brd (8.5)
117.1 7.24, brd (8.5)
156.3
7.47, brd (8.5)
7.26, brd (8.5)
7.19a
7.20a
117.1 7.24, brd (8.5)
128.5 7.43, brd (8.5)
98.6 6.15, d (1.5)
81.5 4.67, dd (3.5, 1.5)
72.4 4.59, dd (8.5, 3.5)
74.1 4.17a
7.26, brd (8.5)
7.47, brd (8.5)
6.16, brs
7.38, brd (8.5)
6.20, brs
7.41, brd (8.5)
6.20, brs
-2
4.71, dd (4.0, 1.5)
4.60, dd (8.5, 4.0)
4.21, dd (9.5, 8.5)
4.16a
81.4
4.69, dd (4.0, 2.0)
4.59, dd (9.0, 3.0)
4.20, dd (9.5, 9.0)
4.17a
81.3
4.68, dd (3.0. 1.5)
4.61, dd (8.5, 3.0)
4.20a
-3
72.5
72.5
72.8
-4
74.1
70.5c
74.1
74.0
-5
70.5 4.17a
70.5
4.18a
71.0
-6
1.44, d (5.5)
18.3
1.42, d (6.0)
18.3 1.45, d (5.5)
18.4
1.45, d (5.5)
18.8
Glc-1
-2
5.38, d (7.5)
4.15a
107.1
75.7
78.3
71.5
75.6
65.1
5.36a
107.1 5.32, d (7.5)
75.7 4.10, dd (7.5, 9.0)
78.3 4.19, dd (9.0, 9.0)
71.5 4.03a
106.9
75.7
78.3
71.5
75.6
64.3
5.33, d (7.5)
4.17a
4.11, dd (7.5, 9.0)
4.15-4.25a
75.6
-3
4.25, m
4.16a
4.25a
78.2
-4
4.16a
4.15-4.25a
74.1
-5
4.15a
4.16a
75.6 4.02a
4.04a
75.6
-6
4.95, dd (11.5, 4.5)
5.19, brd (11.5)
4.94, dd (11.5, 4.0)
5.19, brd (11.5)
65.1 4.74, dd (12.5, 5.0)
4.95, dd (12.5, 2.0)
166.6
4.75, dd (11.5, 5.5)
4.96, dd (11.5, 1.5)
64.3
4.49, dd (11.0, 2.0)
175.9b, 176.8b
37.2, 37.3
1′′
2′′
166.6
130.8
176.3
41.2
176.3
130.8 2.32, m
2.33, m
41.2 2.58, m
2.82, m
3′′
4′′
5′′
8.07, brd (7.5)
129.8
128.7
133.1
8.06, brd (7.5)
129.8 1.31, m
1.58, m
27.1
11.7
16.6
1.32, m
27.0 1.20-1.60a
1.90-2.05a
11.7 0.89, t (7.0)
0.95, t (7.0)
27.4, 27.8
12.7, 12.8
18.3, 18.6
1.58, m
7.24, brdd (7.5, 7.5)
7.46, dd (7.5, 7.5)
7.23, brdd (7.5, 7.5) 128.7 0.76, t (7.5)
0.76, t (7.5)
7.45, dd (7.5, 7.5) 133.1 1.01, d (7.0)
1.02, d (7.0)
16.6 1.12, d (6.5)
1.18, d (6.5)
6′′
7′′
7.24, brdd (7.5, 7.5)
8.07, brd (7.5)
128.7
129.8
7.23, brdd (7.5, 7.5) 128.7
8.06, brd (7.5) 129.8
1′′′
2′′′
3′′′
4′′′
5′′′
6′′′
7′′′
and 13C NMR spectra of 2 were similar to those of 1 except for the
N-CH2-CH2-CH(-OAc)-CH2-N moiety. The oxymethine pro-
ton at δH 4.25 (1H, overlapped, H-8) and carbon at δC 67.3 were
shifted upfield relative to those of 1. These data suggested that 2 is
the 8-de-O-acetyl analogue of 1, as shown.
an acyl group at 6-Glc of 3 was different from the benzoyl group
of 1. The 1H NMR data at δH 0.76 (3H, t, J ) 7.5 Hz, H3-4′′), 1.01
(3H, d, J ) 7.0 Hz, H3-5′′), 1.31 (1H, m, H-3′′), 1.58 (1H, m, H-3′′),
and 2.32 (1H, m, H-2′′) and the 13C NMR peaks at δC 11.7, 16.6,
27.1, 41.2, and 176.3 were assigned to a 2-(S)-methylbutyrate
moiety (see Experimental Section). Hence, the structure of 3 was
formulated as shown.
Meehanine N (3) had the molecular formula C35H55N3O14. The
1H and 13C NMR spectra of 3 were similar to those of 1. However,

Alkaloidal Glycosides from Meehania urticifolia
Journal of Natural Products, 2009, Vol. 72, No. 11 1939
Table 1. Continued
11
12
δH(J in Hz)
meehanine C
meehanine G
meehanine H
position δH (J in Hz)
δC
δC
δH(J in Hz)
δC
δH(J in Hz)
δC
δH(J in Hz)
δC
1
8.45, m
8.54, m
8.44, m
8.54, m
8.43, m
8.56, m
8.43, brt (6.0)
8.52, m
8.43, brt (6.0)
8.55, brdd (7.0, 4.0)
2
3
4
6
171.9, 172.0
47.1
171.6
171.6, 171.8
46.5, 46.8
171.6, 171.7
46.5, 46.8
61.1
171.6, 171.8
46.5, 46.8
61.0, 61.2
45.2, 45.7
2.74, m
4.27a
2.76, m
4.42, m
2.54a
46.5, 46.8 2.75, m
2.74, brt (5.5)
2.76, m
4.42, m
2.44, m
2.58, m
2.75a
61.4
61.6
45.4
4.39a
60.9, 61.1 4.38, m
a
2.43a
45.7
2.41, m
2.57a
45.3, 45.7 2.33-2.56
45.5
2.79a
2.67-2.78a
a
7
8
9
1.46-1.65a
32.7
1.45-1.80a
32.4
1.45-1.63
32.4, 32.5 1.49a
32.5
1.50-1.70a
32.4, 32.5
73.5, 74.7
49.5, 51.8
1.60a
73.6, 74.7 5.36, m
5.49, m
5.37a
74.5, 75.2 5.37, m
5.49, m
73.6, 74.8 5.38, m
5.52, brt (8.5)
49.7, 52.4 3.83, m
73.7, 74. 8 5.38, m
5.53, brt (8.5)
3.43a
5.49, brt (8.0)
3.83, m
52.6
3.78, m
4.61a
49.7, 51.8 3.76, m
4.64a
49.4, 52.4
4.64, m
4.67, m
3.83, brt (5.0)
4.67a
3.56a
4.08a
11
3.42-3.90a
43.6, 45.0 3.40-3.80a
43.4, 44.5 3.38-3.60a
43.5, 44.4 3.50a
43.4, 44.6
43.5, 44.4
4.14a
3.70a
4.17a
a
12
13
1.95-2.32a
30.1
2.00a
29.8
36.6
1.76a
29.7, 30.0 2.00
29.9, 30.9
36.3, 36.6
2.00a
2.19a
3.31, m
3.45a
3.73a
29.7
2.20, m
2.20a
36.3, 36.5 3.44a
3.70a
3.27, m
3.44a
3.66a
36.6, 36.8 3.40-3.80a
2.04-2.25a
36.3, 36.5
Ac CdO
170.8
170.4
170.6, 170.7
21.1, 21.3 1.96, s
2.02, s
170.5, 170.8
20.9, 21.3
170.6, 170.7
21.1, 21.3
Ac CH3
1.98, s
2.04, s
21.2, 21.6 1.94, s
2.02, s
20.9, 21.3 2.03, s
2.03, s
1′
2′
3′
4′
5′
6′
Rha-1
137.6
137.4
137.3, 173.4
137.4
128.0
117.0
156.0
117.0
128.0
98.6
137.4
128.0
117.0
156.1
117.0
128.0
98.7
7.22, brd (8.0)
7.16, brd (8.0)
128.2
117.2
156.3
117.2
128.2
98.8
7.29, brd (7.0)
7.27, brd (7.0)
128.0
117.0
156.1
117.0
128.0
98.7
7.24, brd (8.5)
128.0
116.9
156.0
116.9
128.0
98.6
7.22a
7.22a
7.28, brd (8.0)
7.30, brd (8.0)
7.17, brd (8.5)
7.16, brd (8.0)
7.22, brd (8.0)
6.16, brs
7.27, brd (7.0)
7.29, brd (7.0)
6.17, brs
7.17, brd (8.5)
7.24, brd (8.5)
6.16, d (1.0)
4.73, m
7.22a
7.22a
7.30, brd (8.0)
7.28, brd (8.0)
6.18, brs
6.24, brs
4.72, dd (3.5, 1.5)
4.62, dd (8.0, 3.5)
4.18a
-2
4.74, dd (3.5, 2.0)
4.61, dd (6.0, 3.5)
4.21-4.30a
4.20a
81.8
4.69, dd (3.5, 1.5)
4.62, m
4.19a
4.19a
81.4
81.5
81.5
4.68, dd (4.0, 2.0)
4.63, m
4.21a
4.21a
81.4
-3
72.9
72.5
4.61, m
72.6
72.5
72.5
-4
74.5
74.2
4.26a
74.2
74.2
74.1
-5
70.8
70.5
4.21a
70.6
4.22a
70.5
70.5
-6
1.49, d (5.5)
1.50 d (5.5)
5.40, d (8.0)
4.14, dd (8.0, 8.5)
4.21-4.30a
4.21a
18.7, 18.8 1.46, d (5.5)
18.4
1.48, d (6.0)
1.49, d (6.0)
5.39, d (8.0)
4.14, m
4.22-4.29a
4.22-4.29a
3.98, m
18.4
1.44, d (5.5)
1.45, d (5.5)
5.38, d (7.5)
4.16a
18.3
1.46, d (6.5)
1.47, d (6.5)
5.32, brd (7.5)
4.11, dd (8.5, 7.5)
4.20a
18.4
Glc-1
-2
107.5
76.2
78.7
71.6
79.1
5.32, d (7.5)
106.9
75.7
78.3
71.5
75.6
107.2
75.9
78.5
71.4
78.8
107.1
75.7
78.3
71.4
75.7
65.1
106.9
75.6
78.2
71.5
75.6
64.3
4.11, dd (7.5, 9.0)
4.21, dd (9.5, 9.0)
4.21, dd (9.5, 9.5)
4.04, m
-3
4.26, m
-4
4.18a
4.03a
-5
3.98, m
4.18a
4.04a
-6
4.39, dd (11.0, 5.0) 62.7
4.49, dd (11.0, 2.0)
4.76, dd (11.5, 5.0) 64.3
4.96, dd (11.5, 2.0)
173.2
4.38, dd (11.5, 4.0) 62.5
4.48 dd (11.5, 2.0)
4.97a
4.75, m
5.19, dd (11.5, 2.0)
4.96, brd (11.5)
1′′
2′′
172.6, 172.9
35.0
173.2, 173.4
26.1, 26.2
176.1
2.53, m
1.81, m
2.41, dd (15.5, 7.5) 26.1, 26.2
2.59, dd (15.5, 7.5)
2.41, dd (15.5, 7.5)
2.59, dd (15.5, 7.5)
1.21, t (7.5)
2.58, m
37.0, 37.7
2.83, m
3′′
4′′
5′′
19.4, 19.5 1.21, t (7.5)
1.24, t (7.5)
9.9, 10.1
9.9, 10.1
1.44a
27.1, 27.6
12.4, 12.5
18.0, 18.6
1.24, t (7.5)
1.47a
0.96, t (7.5)
0.98, t (7.5)
14.4, 14.5
0.89, t (7.5)
0.95, t (7.5)
1.12, d (7.0)
1.18, d (7.0)
6′′
7′′
1′′
2′′
3′′
176.3
166.6
130.8
129.8
176.3
41.2
27.1
2.33, m
41.2
27.1
2.33, m
1.31, m
8.07, dd (8.0, 1.0)
7.22a
1.32, m
1.57a
1.58, m
4′′
5′′
0.76, t (7.0)
11.7
16.6
128, 7
133.1
0.76, t (7.5)
0.77, t (7.5)
1.01, d (7.0)
1.02, d (7.0)
11.7
16.6
1.02, d (7.0)
7.41, m
6′′
7′′
7.22a
128.7
129.8
8.07, dd (8.0, 1.0)
a Unclear signal pattern due to overlapping. b Data were obtained from HMQC and HMBC spectra. c Assignments are interchangeable.
For meehanine O (4), confirmation of the molecular formula of
C33H53N3O13 was obtained from HRFABMS, which was C2H2O
less than that of 3, indicating the absence of an acetyl group. The
1H and 13C NMR spectra of the aglycone moiety of 4 were similar
to those of 2. These data suggested that 4 is the 8-de-O-acetyl
analogue of 3, as shown.
Meehanines P (5), Q (6), R (7), S (8), and T (9) had an (S)-(4-
hydroxyphenyl)-8-(R)-O-acetyl-10-N-[(S)-2-methylbutyl]amidated-

1940 Journal of Natural Products, 2009, Vol. 72, No. 11
Murata et al.

Alkaloidal Glycosides from Meehania urticifolia
Journal of Natural Products, 2009, Vol. 72, No. 11 1941
Figure 1. Structures of 1-12.
1,5,10-triazacyclotridecan-2-one cyclic spermidine alkaloidal skel-
eton as their common aglycone, which was the same as that of
meehanines A, C, H, J, and K in our previous report.1 The aglycone
meehanine C, indicating the absence of a glucosyl moiety. Hence,
the structures of 5-9 were formulated as shown in Figure 1.
Meehanines U (10) and V (11) had a 10-N-butylamidated cyclic
1
1
spermidine alkaloidal skeleton, which was suggested by H, 13C,
was yielded by acid hydrolysis of these compounds. The H and
13C NMR spectra of 5-8 measured in methanol-d4 were similar to
those of meehanine C1 except for the presence of a 6-acylated ꢀ-D-
glucosyl moiety. Compounds 5 and 6 had the molecular formula
C44H61N3O15 (see Experimental Section). Aromatic proton and
carbon signals suggested the presence of a cinnamoyl group; the
olefinic protons at δH 5.66 (1H, d, J ) 12.5 Hz, H-8′′′) and 6.78
(1H, d, J ) 12.5 Hz, H-7′′′) of 5 indicated a cis-cinnamoyl group.
The duplicated C-8′′′ and C-7′′′ olefinic protons [δH 6.25 (d, J )
16.0 Hz) and 6.26 (d, J ) 16.0 Hz), 7.54 (d, J ) 16.0 Hz), and
7.55 (d, J ) 16.0 Hz), respectively] of 6 showed a trans-cinnamoyl
group. For compound 7, confirmation of the molecular formula of
C41H65N3O15 was achieved by HRFABMS, which was C6H10O more
than that of meehanine C. A methyl carbon at δC 14.3 (C-6′′′),
four methylene carbons at δC 23.4 (C-5′′′), 32.4 (C-4′′′), 25.7 (C-
3′′′), and 34.9 (C-2′′′), and a carbonyl carbon at δC 175.2 (C-1′′′)
suggested the presence of a hexanoyl moiety. Methyl protons at
δH 0.86 (3H, t, J ) 7.0 Hz, H-6′′′), methylene protons at δH 1.22
(2H, m, H-5′′′), 1.15 (2H, m, H-4′′′), 1.44 (2H, m, H-3′′′), and 2.06
and 2D (1H-1H COSY, HMQC, HMBC) NMR spectra acquired
in methanol-d4 at 30 °C (Table 2) and in pyridine-d5 at 30 °C (Table
1), respectively. Compound 10 showed a protonated molecular peak
at m/z 798.4031 [M + H]+ in the HRFABMS, which indicated the
molecular formula C38H59N3O15. A methyl proton at δH 0.79 (3H,
t, J ) 7.5 Hz), two methylene signals [δH 1.42 (2H, m, H-3′′′) and
2.04 (2H, t, J ) 7.0 Hz, H-2′′′)], and carbons at δC 14.0, 19.4,
36.8, and 175.0 suggested the presence of a butanoyl groups on
the ꢀ-D-glucosyl moiety. Compound 11 had the molecular formula
1
C34H53N3O14. The H and 13C NMR spectra (Table 1) of 11 were
similar to those of meehanine C except for the presence of a 10-
N-butylamide moiety instead of a 10-N-(methyl)butylamide group
for meehanine C. Hence, the structures of 10 and 11 were
formulated as shown in Figure 1.
Meehanine W (12) showed a protonated molecular peak at m/z
798.4031 [M + H]+ in the HRFABMS, which indicated the
1
molecular formula C38H59N3O15. In the H and 13C NMR spectra
acquired in pyridine-d5 at 30 °C (Table 1), an aglycone moiety
and a sugar moiety of 12 were almost superimposable onto those
of meehanines G and H, respectively. The full assignments of the
1H and 13C NMR spectra of 12 in pyridine-d5 and methanol-d4
1
(2H, t, J ) 7.5 Hz, H-2′′′), and their H-1H COSY correlations
supported the presence of a CH3(CH2)4 spin system. The H-2′′′ and
H-Glc-6 (δH 4.12, dd, J ) 11.5, 6.5 Hz, and 4.47, dd, J ) 11.5,
2.0 Hz) signals were long-range coupled with the carbonyl carbon
at δC 175.2 (C-1′′′). Thus, compound 7 had a hexanoyl moiety at
Glc-6. For compound 8, confirmation of the molecular formula of
C38H59N3O15 was established by HRFABMS, which was C3H4O
more than that of meehanine C. A methyl carbon at δC 13.7 (C-
3′′′), a methylene carbon at δC 28.1 (C-2′′′), and a carbonyl carbon
at δC 175.8 (C-1′′′) suggested the presence of a propanoyl moiety
on Glc-6. For compound 9, the molecular formula C29H45N3O9 was
established by HRFABMS, which was C6H10O5 less than that of
1
(Tables 1 and 2) were established using H-1H COSY, HMQC,
and HMBC spectra, and its structure was formulated as shown in
Figure 1.
These 12 alkaloids are new members of the cyclic 13-membered
spermidine alkaloidal glycosides that were reported recently from
Lamiaceae plants.1,5 Most have various acyl groups on Glc-6 and
N-10. Compounds 1-4 are characterized by the absence of the
amide moiety at N-10. Unlike 1H and 13C NMR spectra of
meehanines A-K and compounds 5-12, those of these compounds

1942 Journal of Natural Products, 2009, Vol. 72, No. 11
Murata et al.
215 (-10 600), 201 (-41 600) nm; 1H and 13C NMR, Table 1;
HRFABMS m/z 720.3368 [M + H]+ (calcd for C35H50N3O13, 720.3345).
were free of duplicated signals due to absence of the cis-trans
isomerization of the 10-N amide bonds. Compounds 9 and 11 lack
an acyl group on Glc-6 or an acylated glucosyl moiety, which was
observed in meehanine C1 and dracotanosides C and D.5 Com-
pounds 5-8, 10, and 12 are acyl analogues of the spermidine
alkaloids from M. urticifolia.
Meehanine N (3): colorless, amorphous powder; [R]23 -23.9 (c
D
0.36, MeOH); CD (c 0.036, MeOH) λ(θ) 243 (3500), 225 (-17 400),
1
210 (-7300), 201 (-29 100) nm; H and 13C NMR, Tables 1 and 2;
HRFABMS m/z 742.3782 [M + H]+ (calcd for C35H56N3O14, 742.3764).
Meehanine O (4): colorless, amorphous powder; [R]21 -16.7 (c
D
Although M. urticifolia is not utilized for folk medicine and is
not blended in Kampo formulas in Japan, new findings concerning
the biological activities of these constituents are expected.
0.18, MeOH); CD (c 0.018, MeOH) λ(θ) 242 (8200), 224 (-8000),
207 (-700), 201 (-15 600) nm; 1H and 13C NMR, Tables 1;
HRFABMS m/z 700.3657 [M + H]+ (calcd for C33H54N3O13, 700.3658).
Meehanine P (5): colorless, amorphous powder; [R]20D 1.4 (c 0.14,
MeOH); CD (c 0.028, MeOH) λ(θ) 263 (8600), 224 (-24 600), 204
Experimental Section
1
(29 300) nm; H and 13C NMR, Table 2; HRFABMS m/z 872.4181
[M + H]+ (calcd for C44H62N3O15, 872.4183).
General Experimental Procedures. Optical rotations were measured
on a JASCO P-2300 polarimeter. CD spectra were recorded on a
JASCO J-700 spectropolarimeter. 1H NMR (400 MHz) and 13C NMR
(100 MHz) spectra were recorded on a JEOL JNM-AL400 spectrometer,
and chemical shifts are given as δ values with TMS as internal standard
at 30 °C. Inverse-detected heteronuclear correlations were measured
using HMQC (optimized for 1JC-H ) 145 Hz) and HMBC (optimized
Meehanine Q (6): colorless, amorphous powder; [R]20D 1.9 (c 0.21,
MeOH); CD (c 0.018, MeOH) λ(θ) 261 (7400), 225 (-24 300), 204
1
(32 900) nm; H and 13C NMR, Table 2; HRFABMS m/z 872.4203
[M + H]+ (calcd for C44H62N3O15, 872.4183).
Meehanine R (7): colorless, amorphous powder; [R]21D -2.2 (c 0.46,
MeOH); CD (c 0.048, MeOH) λ(θ) 245 (5600), 224 (-24 400), 202
n
1
(33 400) nm; H and 13C NMR, Table 2; HRFABMS m/z 840.4490
for JC-H ) 8 Hz) pulse sequences with a pulsed field gradient.
[M + H]+ (calcd for C41H66N3O15, 840.4496).
HRFABMS data were obtained on a JEOL JMS700 mass spectrometer,
using a m-nitrobenzyl alcohol or glycerol matrix. Preparative LPLC
and HPLC were performed on a Jasco 2089 instrument and detected
by UV at 210 nm.
Meehanine S (8): colorless, amorphous powder; [R]23D -6.7 (c 0.06,
MeOH); CD (c 0.012, MeOH) λ(θ) 252 (15 100), 224 (-8700), 205
1
(25 800) nm; H and 13C NMR, Table 2; HRFABMS m/z 798.4011
[M + H]+ (calcd for C38H60N3O15, 798.4026).
Plant Material. M. urticifolia (760 g) was collected in July 2007
and in September 2008 (670 g) in Sendai, Japan. The plant was
identified by Dr. Koji Yonekura, Tohoku University, Sendai, Japan. A
voucher specimen was deposited at the herbarium of Tohoku Pharma-
ceutical University under No. 20070727.
Meehanine T (9): colorless, amorphous powder; [R]23 -21.7 (c
D
0.12, MeOH); CD (c 0.012, MeOH) λ(θ) 241 (10 600), 224 (-6700),
205 (14 300) nm; 1H and 13C NMR, Table 1; HRFABMS m/z 580.3229
[M + H]+ (calcd for C29H46N3O9, 580.3236).
Extraction and Isolation. The dried and powdered whole plants
(760 g) of M. urticifolia were extracted with MeOH (12 L) at room
temperature for a month. The MeOH extract was concentrated at
reduced pressure, suspended in H2O (1.5 L), and partitioned with Et2O
(3 × 1.0 L). The H2O layer (98.52 g) was passed through a porous
polymer gel column (Mitsubishi Diaion HP-20, 70-180 mm) and eluted
with H2O; 10%, 45%, and 90% MeOH; and MeOH. The 90% MeOH
eluate (5.5 g) was chromatographed on a reversed-phase column using
ODS (Cosmosil 140C18-OPN, Nacalai Tesque, 150 g) and was eluted
with 20%, 30%, 40%, 50%, 60%, and 80% MeOH (fractions 1A-1F).
Fractions 1E and 1F (259.1 mg) were subjected to preparative HPLC
[columns, Tosoh, ODS-100 V, 20-250 mm; solvent, MeCN-H2O (40:
60), and Kanto Chemical, Mightysil RP-18 GP, 10 × 250 mm; solvent,
MeCN-H2O (30:70) and MeOH-H2O (55:45)] to yield compounds 5
(1.4 mg), 6 (2.0 mg), and 7 (5.2 mg).
Meehanine U (10): colorless, amorphous powder; [R]23 -10.0 (c
D
0.04, MeOH); CD (c 0.008, MeOH) λ(θ) 250 (22 700), 225 (-13 000),
205 (38 700) nm; 1H and 13C NMR, Table 2; HRFABMS m/z 798.4031
[M + H]+ (calcd for C38H60N3O15, 798.4026).
Meehanine V (11): colorless, amorphous powder; [R]23 -12.0 (c
D
0.20, MeOH); CD (c 0.020, MeOH) λ(θ) 253 (8000), 223 (-35 400),
203 (27 200) nm; 1H and 13C NMR, Table 1; HRFABMS m/z 728.3600
[M + H]+ (calcd for C34H54N3O14, 728.3607).
Meehanine W (12): colorless, amorphous powder; [R]22D -13.0 (c
0.23, MeOH); CD (c 0.021, MeOH) λ(θ) 249 (2800), 224 (-29 300),
1
204 (8300) nm; H and 13C NMR, Tables 1 and 2; HRFABMS m/z
798.4031 [M + H]+ (calcd for C38H60N3O15, 798.4026).
Acid Hydrolysis of 3 and 4 and Determination of the Configu-
ration of 2-Methylbutyric Acid. Compounds 3 (1 mg) and 4 (0.5 mg)
were separately dissolved in 7% HCl (1 mL) and stirred for 1 h at
60 °C. After cooling, the solution was extracted with CH2Cl2 (2 × 3
mL). From the CH2Cl2 layer, 2-methylbutyric acid was obtained. The
CH2Cl2 layers were washed with H2O and dried over 3 Å molecular
sieves. To the solutions, 1-hydroxybenzotriazole monohydrate, N,N′,-
dicyclohexylcarbodiimide, and (S)-1-(1-naphthyl)ethylamine were added
(10 mg each). After the mixtures had been stirred for 3 h at room
temperature, filtration and concentration gave residues that were
analyzed by HPLC with detection at 280 nm. Analytical HPLC was
performed on a Shiseido Capcell pak C18 column (4.6 × 250 mm) at
20 °C using MeCN-H2O (40:60) as the solvent. Peaks were detected
with a Tosoh UV8010 UV detector. (S)-2-Methyl-N-[(S)-1-(1-naphth-
yl)ethyl]butyramide (tR 33.0 min) was identified as the product resulting
from the 2-methylbutyryl moiety of 3 and 4 by comparing their retention
times with those of the authentic samples, (S)-2-methyl-N-[(S)-1-(1-
naphthyl)ethyl]butyramide (tR 33.0 min) and (R)-2-methyl-N-[(S)-1-
(1-naphthyl)ethyl]butyramide (tR 34.4 min).1,10,11
The dried and powdered whole plants (670 g) of M. urticifolia were
extracted with 80% acetone (2 × 12 L) at 56 °C. The extract was
concentrated at reduced pressure, suspended in H2O (1.0 L), and
partitioned with Et2O (3 × 1.0 L). The H2O layer (53.1 g) was passed
through a Diaion HP-20 column (eluted with H2O, 10% and 90%
MeOH, and MeOH). The 90% MeOH eluate (12.9 g) was chromato-
graphed on an ODS column and eluted with 20%, 30%, 40%, 50%,
and 80% MeOH (fractions 2A-2E). Fraction 2C (1.06 g) was subjected
to preparative LPLC [column, Yamazen, Ultra Pack ODS-SM-50C-
M, 37 × 100 mm; solvent, MeOH-0.2% TFA (35:65)] to give 10
fractions (3A-3J). Fractions 3B and 3C (44.2 mg) were subjected to
preparative HPLC [columns, Shiseido, Capcell-Pak Ph, 20 × 250 mm;
solvent, MeCN-0.2% TFA (15:85), and YMC, ODS-AM, 10 × 300
mm; solvent, MeCN-H2O (25:75 or 20:80)] to yield compounds 1
(15.2 mg), 2 (5.5 mg), 3 (4.0 mg), 8 (0.6 mg), 9 (1.0 mg), 10 (0.9 mg),
and 12 (2.9 mg). Fractions 2A and 2B (10.3 g) were dissolved in H2O,
which was passed through a Diaion HP-20 column (eluted with 5%,
20%, and 50% MeOH, and MeOH), and the 50% MeOH eluate was
subjected to preparative LPLC [solvent, MeOH-0.2% TFA (35:65)]
to give nine fractions (4A-4I). Fractions 4B and 4C (185.7 mg) were
subjected to preparative HPLC [columns, Cosmosil, AR-II, 20 × 250
mm; solvent, MeCN-0.2% TFA (15:85), and ODS-AM, solvent,
MeCN-H2O (22:78)] to yield compounds 4 (1.8 mg), 11 (1.3 mg),
and 12 (0.8 mg).
Acid Hydrolysis of Compounds 1-12. Compounds 1-12 (0.5 mg
each) were separately stirred for 1 h at 60 °C in 7% HCl (2 mL). After
cooling, the reaction mixtures of compounds 1-4 and 10-12 were passed
through an Amberlite IRA400 column, and the eluates were subjected to
preparative HPLC [column, YMC Pack, ODS-AM, 10 × 300 mm; solvent,
MeOH-H2O (10:90); detector, UV 210 nm] to yield a sugar fraction. The
reaction mixtures of compounds 5-9 were subjected to preparative HPLC
[column, Kanto Chemical, Mightysil RP-18 GP, 10 × 250 mm; solvent,
MeOH-H2O (20:80); detector, UV 210 nm] to yield the (S)-(4-hydrox-
yphenyl)-8-(R)-O-hydroxy-10-N-[(S)-2-methylbutyl]amidated-1,5,10-triaza-
cyclotridecan-2-one and sugar fractions.
Meehanine L (1): colorless, amorphous powder; [R]23 -26.4 (c
D
0.66, MeOH); CD (c 0.066, MeOH) λ(θ) 236 (4100), 223 (-14 900),
216 (-11 300), 201 (-36 400) nm; 1H and 13C NMR, Tables 1 and 2;
HRFABMS m/z 762.3449 [M + H]+ (calcd for C37H52N3O14, 762.3451).
Meehanine M (2): colorless, amorphous powder; [R]22 -25.8 (c
Sugar Identification. Sugar fractions from the hydrolysis of
compounds 1-12 were dissolved in pyridine (0.5 mL each) and stirred
D
0.48, MeOH); CD (c 0.053, MeOH) λ(θ) 236 (3300), 223 (-13 700),

Alkaloidal Glycosides from Meehania urticifolia
Journal of Natural Products, 2009, Vol. 72, No. 11 1943
References and Notes
with L-cysteine methyl ester (5 mg) before ꢁ-tolylisothiocyanate (20
µL) was added to the mixture using the same procedures as in our
previous report.1 The reaction mixtures were analyzed by HPLC and
detected at 250 nm. Analytical HPLC was performed on a Tosoh ODS-
100 V column (4.6 × 250 mm) at 25 °C using CH3CN-0.2% TFA in
H2O (30:70) as the solvent. Peaks were detected with a Tosoh UV8010
detector. D-Glucose (tR 12.0 min) and L-rhamnose (tR 19.8 min) were
identified as the sugar moieties of 1-12 and L-rhamnose in 9 by
comparing their retention times with those of authentic samples of
D-glucose (tR 12.0 min), L-glucose (tR 11.0 min), and L-rhamnose (tR
19.8 min).8
(1) Murata, T.; Miyase, T.; Warashina, T.; Yoshizaki, F. J. Nat. Prod.
2009, 72, 1049–1056.
(2) Guggisberg, A.; Hesse, M. In The Alkaloids; Cordell, G. A., Ed.;
Academic Press: San Diego, 1998; Vol. 50, Chapter 6, pp 221-243.
(3) Bienz, S.; Bisegger, P.; Guggisberg, A.; Hesse, M. Nat. Prod. Rep.
2005, 22, 647–658.
(4) Fu, X. P.; Wu, T.; Abdurahim, M.; Su, Z.; Hou, X. L.; Aisa, H. A.;
Wu, H. Phytochem. Lett. 2008, 1, 59–62.
(5) Wang, S. Q.; Ren, D. M.; Xiang, F.; Wang, X. N.; Zhu, C. J.; Yuan,
H. Q.; Sun, L. M.; Lv, B. B.; Sun, X. J.; Lou, H. X. J. Nat. Prod.
2009, 72, 1006–1010.
(6) Rasmussen, B.; Nkurunziza, A.; Witt, M.; Oketch-Rabah, H. A.;
Jaroszewski, J. W.; Staerk, D. J. Nat. Prod 2006, 69, 1300–1304.
(7) Schultz, K.; Kuehne, P.; Ha¨usermann, U. A.; Hesse, M. Chirality 1997,
9, 523–528.
(8) Tanaka, T.; Nakashima, T.; Ueda, T.; Tomii, K.; Kouno, I. Chem.
Pharm. Bull. 2007, 55, 899–901.
Acknowledgment. We thank Mr. S. Sato and Mr. T. Matsuki of
Tohoku Pharmaceutical University for assisting with the MS measure-
ments and Mr. H. Hayasaka and K. Ohba of the Department of
Experimental Station for Medicinal Plant Studies, Tohoku University,
for supplying the plant material.
(9) Kasai, R.; Okihara, M.; Asakawa, J.; Mizutani, K.; Tanaka, O.
Tetrahedron 1979, 35, 1427–1432.
(10) Bergot, B. J.; Anderson, R. J.; Schooley, D. A.; Henrick, C. A.
J. Chromatogr. 1978, 155, 97–105.
(11) Onuki, H.; Ito, K.; Kobayashi, Y.; Matsumori, N.; Tachibana, K. J.
Org. Chem. 1998, 63, 3660–3664.
Supporting Information Available: NMR spectra and tables of 1H,
13C, and HMBC data for compounds 1-12 and meehanines C, G, and
H. This material is available free of charge via the Internet at http://
pubs.acs.org.
NP900454R