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RSC Advances
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DOI: 10.1039/C6RA08776K
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this paper for the structure of tomentodione A (1) has been discussions. Moreover, we are grateful to Prof. Geoffrey Cordell at
deposited in the Cambridge Crystallographic Data Centre, which can the University of Illinois for editing the English.
be
obtained
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of
charge
via
Notes and references
Preparation of intermediates 4 and 5. The synthesis of the key
intermediates 4 and 5 was conducted according to our recently
reported paper,13 and the copies of their NMR spectra could be
found in the supporting information.
1
J. Chen, L. A. Craven, Flora of China, Vol. 13, Beijing/St. Louis:
Science Press/Missouri Botanical Garden Press, 2007, p.
330
Editorial Board of
Vol. , State Administration of Traditional Chinese Medicine
of the People Republic of China. Zhonghua Bencao.
Shanghai Science and Technology Publishers: Shanghai,
China, 2000, p. 643 646.
W. H. Hui, M. M. Li, K. Luk, Phytochemistry 1975, 14
833 834.
W. H. Hui, M. M. Li, Phytochemistry 1976, 15, 1741
J. Xiong, Y. Huang, Y. Tang, M. You, J. F. Hu, Chinese J. Org.
Chem. 2013, 33, 1304 1308.
A. Hiranrat, W. Mahabusarakam, Tetrahedron 2008, 64
11193 11197.
A. Hiranrat, W. Chitbankluoi, W. Mahabusarakam, S.
Limsuwan, S. P. Voravuthikunchai, Nat. Prod. Res. 2012, 26
1904 1909.
A. Hiranrat, W. Mahabusarakam, A. R. Carroll, S. Duffy, V. M.
Avery, J. Org. Chem. 2012, 77, 680 683.
Y. Z. Liu, A. J. Hou, C. R. Ji, Y. J. Wu, Nat. Prod. Res. Develop.
1997, 10, 14 19.
10 N. H. Tung, Y. Ding, E. M. Choi, P. V. Kiem, C. V. Minh, Y. H.
Kim, Arch. Pharm. Res. 2009, 32, 515 520.
11 T. Chen, C. G. Yu, B. L. Yang, Chem. Nat. Comp. 2011, 47
524 526.
−331.
2
‘
Zhonghua Bencao’, Zhonghua Bencao,
5
Preparation of tomentodiones A (1) and B (2).
’s
Method 1: (‒)-β-Caryophyllene (1.0 g, 5.0 mmol) and the α,β-
unsaturated ketone 5 (238 mg, 0.95 mmol) were dissolved in dry
toluene (5.0 mL). After heating at 120 oC for 3 h under N2, the
reaction mixture was cooled to ambient temperature and purified
directly by flash column chromatography (silica gel; n-
hexane/EtOAc, from 100:1 to 10:1) to afford 1 (112 mg, 26%), as
well as a mixture of 2 and by-products (270 mg) as a colorless solid.
The mixture was further purified using a 10 cm C18 reversed-phase
column with 100% MeOH as eluent to give 2 (133 mg, 31%). Both
products were identical in all aspects to the natural isolates. 1:
−
3
,
−
4
5
−1743.
−
6
7
,
−
,
−
colorless crystals; mp. 81-82 oC; [α]20 +38 (c 0.1, MeOH); 2:
8
9
D
−
1
colorless oil; [α]20 +19 (c 0.2, MeOH). H- (500 MHz) and 13C- (125
D
MHz) NMR spectral data were identical to those of the natural
compounds;
−
−
Method 2: (‒)-β-Caryophyllene (1.0 g, 5.0 mmol) and the α,β-
unsaturated ketone 5 (250 mg, 1.0 mmol) were mixed neatly and
allowed to stand at ambient temperature for 24 h under nitrogen.
After the starting material disappeared (TLC analysis), the reaction
products were purified by flash column chromatography (n-
hexane/EtOAc, from 100:1 to 10:1) to yield 1 (127 mg, 28%), as well
as a mixture of 2 and by-products (300 mg) as a colorless solid. The
mixture was further purified using a 10 cm C18 reversed-phase
column with 100% MeOH as eluent to afford 2 (146 mg, 34%). The
products were identical in all aspects to the natural isolates.
,
−
12 H. X. Liu, H. B. Tan, S. X. Qiu, J. Asian Nat. Prod. Res. 2016,
doi: 10.108/10286020.2015.1121997.
13 H. X. Liu, W. M. Zhang, Z. F. Xu, Y. C. Chen, H. B. Tan, S. X.
Qiu, RSC Adv. 2016,
14 B. P. S. Khambay, D. G. Beddie, M. D. J. Simmonds,
Phytochemistry 2002, 59, 69 71.
15 F. Bohlmann, C. Zdero, Phytochemistry 1978, 17
1135 1153.
16 A. D. Becke, J. Chem. Phys. 1993, 98, 5648
17 C. Lee, W. Yang, R. G. Parr, Phys. Rev. B 1988, 37, 785
18 A. V. Marenich, C. J. Cramer, D. G. Truhlar, J. Phys. Chem. B
2009, 113, 6378 6396.
19 T. Bruhn, A. Schauml
SpecDis 1.53, University of Wuerzburg, Germany, 2012.
6, 25882-25886.
−
,
−
−
5652.
−
789.
Antibacterial activity assay. Compounds 1 and 2 were assayed
against two bacteria, Staphylococcus aureus (ATCC6538) and
Escherichia coli (ATCC8739), which were purchased from Guangdong
−
ö
ffel, Y. Hemberger, G. Bringmann,
Microbiology Culture Center (Guangzhou, China). Assays were 20 J. W. V. Klink, J. J. Brophy, N. B. Perry, R. T. Weavers, J. Nat.
Prod. 1999, 62, 487
21 a) H. M ller, M. Paul, D. Hartmann, V. Huch, D. Blaesius, A.
Koeberle, O. Werz, J. Jauch, Angew. Chem. Int. Ed. 2010, 49
2045 2049. b) M. Morkunas, L. Dube, F. G tz, E. M. Maier,
Tetrahedron 2013, 69, 8559 8563.
22 A. M. Drummond, R. D. Waigh, In Pandalai, S. G. Research
Signpost, India, 2000, p. 143 152.
23 L. He, C. F. Zhu, Y. Yuan, Z. F. Xu, S. X. Qiu, Phytochemistry
Lett. 2014, , 175 178.
−489.
performed by the published microdilution method for the
estimation of minimum inhibitory concentration (MIC) values to
evaluate the antimicrobial activity.22,23 Vancomycin was used as
positive control. Optical density values at 600 nm were recorded
using a UV-6000 spectrophotometer (METASH, Shanghai, China).
ü
,
−
ö
−
−
9
−
Acknowledgments
This research was funded by the National Science and
Technology Major Projects of China (2014ZX10005002-005) and the
National Natural Science Foundation of China (No. 30973635,
81373293, 81502949). We acknowledge support of computational
source from lab of computational chemistry and drug design in
Peking University Shenzhen Graduate School and Prof. O. Wiest
(University of Notre Dame, IN, USA) for help with MacroModel. We
also thank Dr. X.-L. Feng (Sun Yat-sen University) for the X-ray
diffraction analysis. and Dr. G.-Q. Li (Jinan University) for helpful
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
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