Two New Diarylheptanoids from the Rhizomes of Zingiber officinale

1306
Chinese Chemical Letters Vol. 15, No. 11, pp 1306-1308, 2004
http://www.imm.ac.cn/journal/ccl.html
Two New Diarylheptanoids from the Rhizomes of Zingiber officinale
Jian Ping MA, Xiao Ling JIN, Li YANG, Zhong Li LIU*

National Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000


Abstract: Two new diaryheptanoids, (5S)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-3-
heptanone (1) and (3S,5S)-3,5-diacetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane (2) were
isolated from the rhizomes of Zingiber officinale. Their structures were elucidated by spectral
methods.

Keywords: Zingiber officinale, diarylheptanoid, (5S)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxy-
phenyl)-3-heptanone, (3S,5S)-3,5-diacetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane.

Ginger, the rhizome of Zingiber officinale Roscoe (Zingiberaceae) is one of the most
popular spices and has been frequently used in Chinese traditional medicines both in fresh
and dried forms1. Numerous chemical investigations of this material have led to the
isolation and identification of a large number of biologically active compounds, such as
gingerols, shogaol and zingerone2. As a part of our ongoing program on finding
biologically active components from Chinese herbs3 we found two previously unknown
diarylheptanoids 1 and 2, besides 21 known gingerol-related constituents from the ethanol
extract of the rhizomes of Zingiber officinale. We report herein the structural elucidation of
these two new compounds.

O
OAc
OAc OAc
1
CH
7
3O
2'
2''
OCH3
OCH
3'
1'
CH3O
3
3
1''
5
3''
2
4
6
4'
4''
HO
1
OH
HO
2
OH




O
OAc
OAc OAc
CH3O
OCH3
CH3O
OCH3
AcO
OAc
3
HO
4
OH




* E-mail: liuzl@lzu.edu.cn

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Jian Ping MA et al.
1307
Table 1 1H (400 MHz) and 13C (100.5 MHz) NMR spectral data for 1 and 2a

Compound

1

2

Position
?C
?H
HMBC correlations
?C
?H
1
29.29
2.80
C-1/H-2, H-2’ 31.18
2.52, 2.54
2
45.15
2.69
C-2/H-1 36.66

1.84
3
206.86

C-3/H-1, H-2, H-4a,b
69.72
5.00
4
47.36
2.54, 2.70

38.55
1.76, 1.92
5
69.97
5.26
C-5/H-4a,b, H-6, H-7 69.72
5.00
6
36.01
1.86
C-6/H-4a,b, H-7 36.66
1.84
7
31.27
2.57
C-7/ H-5, H-6, H-2’’ 31.18
2.52, 2.54
3-OAc



170.75, 21.09
2.01
5-OAc
170.41, 21.04
2.00
C=O/H-5
170.75, 21.09
2.02
1?
132.77
C-1’/H-1,
H-5’
133.20

2?
111.10
6.66
C-2’/H-1, H-6’
110.85
6.67
3?
146.44
C-3’/H-2’, H-5’
146.33
4?
143.90

C-4’/H-2’, H-5’, H-6’
143.72
5?
114.34
6.82 C-5’/H-6’
114.20
6.62
6?
120.79
6.65
C-6’/H-1, H-2’ 120.79
6.81
3?-OMe 55.90
3.85
C-3’/OMe
55.81
3.87
1? 132.99

C-1’’/H-7, H-5’’ 133.20

2?
110.95
6.66
C-2’’/H-7, H-6’’
110.85
6.67
3?
146.44

C-3’’/H-2’’, H-5’’
146.33
4?
143.99

C-4’’/H-2’’, H-5’’, H-6’’
143.72
5?
114.34
6.82 C-5’’/H-6’’
114.20
6.81
6?
120.84
6.65
C-6’’/H-7, H-2’’ 120.79
6.62
3?-OMe 55.91
3.88
C-3’’/OMe
55.81
3.87
a.
Determined in CDCl3 with TMS as the internal standard.

Compound 1 was obtained as colorless oil, [?]25 +3.0 (c 0.60, CHCl
D
3). HR-ESI-MS
gave a molecular ion peak at m/z 434.2164, corresponding to the molecular formula of
C23H28O7 (cald. for M+NH4 434.2173). Its IR spectrum showed characteristic absorptions
for hydroxyl (3434 cm-1), carbonyl (1720 cm-1) and aromatic (3015, 1606 and 1516 cm-1)
functionalities. The 1H NMR signals at ? 6.81 (dd, 2H, J = 2.0, 8.0 Hz ), 6.66 (d, 2H, J =
2.0 Hz) and 6.63 (d, 2H, J = 8.0 Hz), as well as those at ? 3.85 (s, 3H) and 3.87 (s, 3H),
suggested the presence of two 1,3,4-trisubstituted phenyl groups bearing a methoxyl group
that was supported by the characteristic base peak at m/z 137 ([CH2C6H3(OH)(OMe)]+) for
the 4-hydroxy-3-methoxyphenyl moiety in curcumin derivatives2a. The 1H NMR signal
at ? 2.00 (3H, s) and the 13C NMR signals at ? 21.04 and 170.41 revealed the presence of
an acetyl group that was supported by the fragment ion peak at m/z 356 from the
deacetoxylation of the molecule. Comparison of its 1H and 13C NMR data with those of
hexahydrocurcumin2a-c suggested that 1 is the acetylated hexahydrocurcumin with the
acetoxyl group at C-5 that was confirmed by its gHMBC spectrum which shows clear
correlation of the acetyl carbonyl carbon (? 170.41) with H-5 (? 5.26). Total 1H and 13C
assignments together with the HMBC correlations are listed in Table 1. In order to
determine the stereochemistry of C-5, 1 was acetylated with acetic anhydride in pyridine to
produce 5,4?,4?-triacetoxylhexahydrocurcumin 3 as the unique product, which is identical

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1308 Two New Diarylheptanoids from the Rhizomes of Zingiber officinale
to the acetylation product of hexahydrocurcumin obtained under the same experimental
conditions. Since the configuration of hexahydrocurcumin was known to be 5S 2a-c,
compound 1 is assigned as (5S)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxy-phenyl)-
3-heptanone (5-acetyl-hexahydrocurcumin) which has not been reported previously.
Compound 2 was obtained as colorless oil, [?]26 + 7.0 (c 0.68, CHCl
D
3). HR-ESI-MS
gave a molecular ion peak at m/z 478.2431, corresponding to the molecular formula of
C25H32O8 (cald. for M+NH4 478.2435). The IR, UV and HR-ESI-MS spectra of 2 are
completely identical with those of the known compound (3R,5S)-3,5-diacetoxy-1,7-
bis(4-hydroxy-3-methoxyphenyl)heptane 42b which was also obtained from the ethanol
extract of the rhizomes of Zingiber officinale. However, different from 4, 2 was found to be
optical active. These facts suggested that 2 is a stereoisomer of 4. Comparison of the
13C NMR spectrum of 2 with that of 4 indicated that two signals of the two compounds are
apparently distinguishable although most signals of 2 and 4 are indistinguishable. They
are signals of C-3 and C-5 (? 69.72 and 70.64 for 2 and 3, respectively) and those of C-2
and C-6 (? 36.66 and 35.91 for 2 and 3, respectively. Deacetylation of 2 and 4 with
KOH/MeOH gave the corresponding 3,5-dihydroxyl derivatives 2a and 4a which were
identified as (3S,5S)- and (3R,5S)-3,5-dihydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)
heptanes, respectively, by comparing their 1H and 13C NMR spectral data and optical
rotations with those reported in the liturature2c. Therefore, compound 2 was assigned as
(3S,5S)-3,5-diacetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane which is a new com-
pound. Total 1H and 13C NMR assignments are listed in Table 1. Investigation of
antioxidation and anticancer activities of compounds 1, 2 and other diarylheptanoids
obtained from the rhizomes of Zingiber officinale is in progress in this laboratory.


Acknowledgments

We thank the National Natural Science Foundation of China (Grant Nos. 20172025 and 20332020)
for financial support.


References

1. X. S. HUANG, Chinese Condiment, 1997, (8), 2.
2. (a) S. I. Uehara, I. Yasuda, K. Akiyama, et al., Chem. Pharm. Bull., 1987, 35, 3298. (b) H.
Kikuzaki, J. Usuguchi, N. Nakatani, Chem. Pharm. Bull., 1991, 39, 120. (c) H. Kikuzaki, M.
Kobayashi, N. Nakatani, Phytochem., 1991, 30, 3647. (d) K. Endo, E. Kanno, Y. Oshima,
Phytochem., 1990, 29, 797. (e) H. Kikuzaki, S. M. Tsai, N. Nakatani, Phytochem., 1992, 31,
1783. (f) Z. Yu, H. Wu, J. Ding, Acta Botanica Yunnanica, 1998, 20, 113.
3. (a) J. Q. Dai, Y. P. Shi, L. Yang, Y. Li, Chin. Chem. Lett., 2002, 13, 143. (b) J. Q. Dai, Z. L.
Liu, L. Yang, Phytochem., 2002, 59, 537. (c) J. Q. Dai, Q. X. Zhu, C. Y. Zhao, L. Yang, Y. Li,
Phytochem., 2001, 58, 1305. (d) J. Dai, C. Zhao, Q. Zhang, et al., Phytochem., 2001, 58, 1107.
(e) H. Wang, L. Yang, X. Tian, Y. Z. Chen, Pharmazie, 2001, 56, 889. (f) J. Dai, C. Zhao, Y.
Wang, et al., J. Chem. Res. (S), 2001, 74. (g) J. Q. Dai, B. Zhou, Y. L. Wang, et al., Chin.
Chem. Lett., 2001, 12, 151.

Received 23 September, 2003

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