Y. Shikishima et al. / Phytochemistry 56 (2001) 377±381
381
10), 6.68 (2H, d, J=8.3 Hz, H-7, 9), 5.38 (1H, br s, H-1
of rham), 4.68 (1H, d, J=10.6 Hz, H-6 of glc), 4.40 (1H,
dd, J=5.8, 10.6 Hz, H-6 of glc), 4.38 (1H, d, J=7.7 Hz,
H-1 of glc), 4.25 (1H, m, H-5 of rham), 4.12 (1H, br s,
H-2 of rham), 3.95 (1H, m, H-3 of rham), 3.89 (6H, s,
OCH3), 3.72 (1H, m, H-2), 3.56 (1H, m, H-4 of rham),
3.46±3.17 (4H, m, H-2±5 of glc), 2.65 (2H, m, H-4), 1.84
(1H, m, H-3), 1.72 (1H, m, H-3), 1.19 (6H, d, J=6.2 Hz,
H-1, H-1 of rham); 13C NMR spectral data: Table 1.
6 h. After cooling, the reaction mixture was diluted with
water (30 ml) and extracted with EtOAc (30 ml). The
organic layer were combined and concentrated in vacuo.
The residue was puri®ed by GPC (MeOH) to give com-
1
pound 2a (4 mg), identi®ed by H NMR, 13C NMR,
TLC and [ꢀ]D comparison to (+)-rhododendrol (Das et
al., 1993). Compounds 3±6 were identi®ed by the same
method.
3.4.5. Maximol A (9)
Brown amorphous powder, [ꢀ]2D5 16.3ꢀ (c 0.75,
References
Das, B., Padma Rao, S., Srinivas, K.V.N.S., Yadav, J.S., 1993.
Stereospeci®c synthesis and absolute con®guration of (+)-rho-
dodendrol. Phytochemistry 33, 1529±1530.
KBr
max
MeOH); IR ꢃ
cm 1: 3377, 1601, 1488, 1237, 1152,
MeOH
max
997; UV l
nm (log"): 310 (4.6), 211 (4.8); HR-
FABMS m/z:455.1420 [M+H]+, calcd. for C28H23O6,
455.1485; 13C NMR spectral data (CD3OD) ꢁ:132.3 (C-
1), 128.7 (C-2, 6), 116.3 (C-3, 5), 158.7 (C-4), 94.9 (C-7),
58.7 (C-8), 145.3 (C-9), 107.7 (C-10, 14), 159.9 (C-11,
13), 102.5 (C-12), 132.8 (C-10), 124.1 (C-20), 132.4 (C-30),
161.0 (C-40), 110.3 (C-50), 128.7 (C-60), 129.4 (C-70),
127.4 (C-80), 141.1 (C-90), 105.8 (C-100, 140), 159.6
(C-110, 130), 102.7 (C-140); 1H NMR spectral data:
Table 2.
Fujita, T., Hatamoto, H., Takato, S., 1990. Production of rhododen-
drol glycosides with Acer nikoense. CA 113, 189794.
Ikemoto, T., Nakatsugawa, H., 1998. Melanin inhibitor and skin-
lightening cosmetics. CA 129, 153002.
Kashiwada, Y., Nonaka, G., Nishioka, I., 1986. Tannins and related
compounds. XLVII. Rhubarb. (6). Isolation and characterization of
new p-hydroxyphenylbutanones, stilbenes and gallic acid glucosides.
Chem. Pharm. Bull. 34, 3237±3243.
Kurihara, H., Kawabata, J., Ichikawa, S., Mizutani, J., 1990. ( )-"-
Viniferin and related oligostilbenes from Carex pumila Thunb.
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xystilbenes in vitro: production of a grapevine phytoalexin mimic. J.
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3.4.6. Maximol B (10)
Brown amorphous powder, [ꢀ]2D5+99.4ꢀ (c 0.34,
KBr
max
MeOH); IR ꢃ
cm 1: 3371, 1631, 1469, 1286, 1144,
Nonaka, G., Minami, M., Nishioka, I., 1977. Studies on rhubarb
(Rhei rhizoma). III. Stilbene glycosides. Chem. Pharm. Bull. 25,
2300±2305.
MeOH
max
1047; UV l
nm (log"): 298 (4.5), 205 (4.9); HR-
FABMS m/z:453.1309 [M-H] , calcd. for C28H21O6,
453.1338; 13C NMR spectral data (CD3OD) ꢁ:132.8 (C-
1), 128.6 (C-2, 6), 116.3 (C-3, 5), 158.7 (C-4), 94.7 (C-7),
58.7 (C-8), 145.1 (C-9), 107.7 (C-10, 14), 159.8 (C-11,
13), 102.5 (C-12), 131.7 (C-10), 127.3 (C-20), 131.4 (C-30),
160.3 (C-40), 109.8 (C-50), 130.7 (C-60), 131.0 (C-70),
129.7 (C-80), 140.9 (C-90), 108.4 (C-100, 140), 159.2 (C-
Okabe, H., Matsuo, K., Nishioka, I., 1973. Studies on rhubarb (Rhei
rhizoma). II. Anthraquinone glycosides. Chem. Pharm. Bull. 21,
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Oshio, H., Imai, S., Fujioka, S., Sugawara, T., Miyamoto, M., Tsukui,
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stituents, sennosides E and F. Chem. Pharm. Bull. 22, 823±831.
Pan, H., Lundgren, L.N., 1994. Rhododendrol glycosides and phenyl
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110, 130), 102.4 (C-140); H NMR spectral data: Table 2.
1
Satake, T., Saiki, Y., Hori, K., Coskun, M., Tanker, M., 1990.
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3.5. Hydrolysis of compounds 2±6
Tsuboi, M., Minami, M., Nonaka, G., Nishioka, I., 1977. Studies on
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A solution of 2 (10 mg) in MeOH (10 ml) was treated
with 10% HCl (10 ml), and the mixture was re¯uxed for