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A new depsidone from Usnea diffracta
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Chinese Chemical Letters 20 (2009) 187–189 www.elsevier.com/locate/cclet
A new depsidone from Usnea diffracta Huan Yang Qi, Yuan Peng Jin, Yan Ping Shi * Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China Received 7 July 2008
Abstract A new depsidone, diffractione A (1), as well as six known phenolic compounds (2–7) were isolated from Usnea diffracta. Their structures were elucidated by 1D and 2D NMR spectroscopy together with HRESIMS analysis. All components were obtained for the first time from U. diffracta. # 2008 Yan Ping Shi. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. Keywords: Depsidone; Usneaceae; Usnea diffracta; Lichen; Diffractione A
Usnea diffracta Vain, locally known as ‘‘Gao-Gua-Cao’’, is one of the most important folk medicine used by Yugu nationality in northern regions of Gansu Province, China. It possesses wide uses in the treatment of legs and loin’s injuries, bone fractures and women disease [1]. The chemical components of U. diffracta have not been fully disclosed to date. Previous phytochemical studies on this species resulted in the isolation of usnic acid and diffractaic acid, and both of them have been reported as analgesic and antipyretic components [2]. As a part of our systematic search for new bioactive lead molecules from Yugu nationality folk medicine, U. diffracta was selected for chemical and biological investigations because of the antifungal activity of the crude ethyl acetate extract (EAE) against Actinomyces viscosus ATCC 27044, Streptococcus mutans ATCC 25175, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 8739, Bacillus subtilis ATCC 9372 and Pseudomonas aeruginosa ATCC 9027, respectively. The MIC values of EAE were reported in Table 1. From the EAE of U. diffracta, we isolated one novel depsidone (1), along with six known phenolic compounds (2–7). All these compounds were a group of secondary metabolites more commonly found in lichens. Related to 1 and 2 are the lichen compounds norstictic acid and 80 -O-ethylnorstictic acid [3], but the substitution pattern of the right-hand ring of 1 and 2 were only appeared in fungi [4]. Diffractione A (1), white powder; mp 223 8C; ½a20 D 20 (c 1.0, DMSO). The molecular formula was determined as C20H16O9 on the basis of the [M+Na]+ at m/z 423.0681 (calcd. 423.0687) in its HRESIMS. The UV (MeOH) spectrum of 1 showed maximal absorption bands at 252, 288 and 310 nm. IR (KBr) y (cm1): 3361, 2956, 1764, 1659, 1568, 1441, 1291, 1248, 1142, 1094, 1067, 1016, 955, 888, 780, 594. The 1H NMR spectrum of 1 contained eight proton signals, including three methyl groups at dH 2.17 (s, 3H), 2.41 (s, 3H), and 1.03 (t, 3H, J = 9.2), and one ethoxyl group at dH 3.66 (m, 2H), 1.03 (t, 3H, J = 9.2), one aromatic proton at dH 6.83 (s, 1H), one oxymethine group at dH 6.75
* Corresponding author. E-mail addresses: [email protected], [email protected] (Y.P. Shi). 1001-8417/$ – see front matter # 2008 Yan Ping Shi. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. doi:10.1016/j.cclet.2008.10.032
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H.Y. Qi et al. / Chinese Chemical Letters 20 (2009) 187–189
Table 1 MIC values of EAE from U. diffracta. MIC (ppm) results species
EAE
Positive control Triclosan
Oral bacterium
Actinomyces viscosus ATCC 27044 Streptococcus mutans ATCC 25175
Normal bacterium
Staphylococcus aureus ATCC 6538 Escherichia coli ATCC 8739 Bacillus subtilis ATCC 9372 Pseudomonas aeruginosa ATCC 9027
Table 2 NMR data of compound 1 (1H, 400 MHz; No.
dC (DEPT)
1 2 3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 100 200
112.4 (C) 164.0 (C) 111.4 (C) 164.5 (C) 118.1 (CH) 153.4 (C) 160.9 (C) 22.2 (CH3) 193.1 (CH) 109.4 (C) 153.0 (C) 122.4 (C) 149.0 (C) 138.0 (C) 134.0 (C) 166.6 (C) 99.2 (CH) 10.4 (CH3) 64.5 (CH2) 15.1 (CH3)
13
39.1 78.1 625 625 312.5 1250
Penicillin G
3.9 7.8 – – – –
– – 125 62.5 125 >250
C 100 MHz; in DMSO-d6, TMS, d ppm). H-1H COSY
dH
1
6.83 (br s, 1H)
8
3, 4, 7, 8
2.41 (s, 3H) 10.41 (s, 3H)
5
1, 2, 5, 6, 7 3, 4, 5
6.75 2.17 3.66 1.03
90 80 200 100
10 , 30 , 40 , 50 , 70 , 100 10 , 20 , 30 , 40 , 50 , 60 80 , 200 100
(s, 1H) (s, 3H) (m, 2H) (t, 9.2, 3H)
HMBC (H ! C)
(s, 1H), and one CHO group at dH 10.41 (s, 1H). The 13C NMR spectrum combined with the DEPT experiment displayed 20 C-atoms as three Me, one CH2, two CH groups, 13 quaternary C-atoms, and one CHO. Comparing the data and features of 1D NMR spectrum with those of excelsione (2) isolated from the same fraction, revealed that they were very similar, except for one ethoxyl group, one oxymethine group and one CHO group in 1 instead of two CH2 at dH 4.55 (s, 2H), 5.63 (s, 2H), and dC 51.9, 67.2 in 2 [4]. Therefore, a structure based on the known excelsione (2) was inferred. The structure of 1 was also established on the basis of HMBC correlations (Table 2 and Fig. 1). The two methyl groups could be linked at C-6 and C-30 by correlation from H-8 to C-1, C-2, C-5, C-6, C-7 and H-90 to C-10 ,
Fig. 1. The structure and key HMBC correlations (H ! C) of 1.
H.Y. Qi et al. / Chinese Chemical Letters 20 (2009) 187–189
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C-20 , C-30 , C-40 , C-50 and C-60 . Correlations from H-9 to C-3, C-4 and C-5 established the position of the CHO group at C-3. Correlations from H-100 to C-80 and H-80 to C-30 , together with correlation of H-80 and H-90 in the 1H-1H COSY, could establish the attached position of ethoxyl group at C-80 . Accordingly, the structure of 1 was elucidated as shown in Fig. 1, named as diffractione A. The structures of the known compounds 2–7 were elucidated by comparison of their NMR data and those reported in the literature. They were identified as excelsione (2) [4], atranol (3) [5], orsellinic acid (4) [6], methyl orsellinate (5) [7], ethyl orsellinate (6) [8], and lecanorin (7) [9], respectively. Acknowledgments The work was supported by the National 863 Program of China (No. 2007AA09Z403), and National Key Technology Research and Development Program of China (No. 2007BAI37B05), and Natural Science Foundation of Gansu Province (No. 0710RJZA120). References [1] [2] [3] [4] [5] [6] [7] [8] [9]
L. Qi, D.S. Luo, Collection of Chinese Minorities Medicine, Inner Mongolia Science Press, Inner Mongolia, 2000, p. 1330. E. Okuyama, K. Umeyama, M. Yarnazaki, Y. Kinoshita, Y. Yamamoto, Planta Med. 61 (1995) 113. H.D. Sun, F.D. Niu, Z.W. Lin, D. Cao, B. Li, Acta Bot. Sin. 32 (1990) 783. G. Lang, A.L.J. Cole, J.W. Blunt, W.T. Robinson, M.H.G. Munro, J. Nat. Prod. 70 (2007) 310. X.J. Yang, M.L. Wen, Z. Zhao, J.Z. Li, X.A. Li, Nat. Prod. Res. Dev. 18 (2006) 76. G.E. Evans, J. Staunton, J. Chem. Soc., Perkin. Trans. I (1988) 755. C.M. Li, S.G. Wu, G.D. Tao, H.D. Sun, Acta Bot. Yunnanica 12 (1990) 457. H. Kijima, T. Ide, H. Otsuka, C. Ogimi, E. Hirata, A. Takushi, Y. Takeda, Phytochemistry 44 (1997) 1551. C. Qiu, Y. Ding, Chin. J. Chin. Mater. Med. 9 (2001) 608.
Chinese Chemical Letters 20 (2009) 187–189 www.elsevier.com/locate/cclet
A new depsidone from Usnea diffracta Huan Yang Qi, Yuan Peng Jin, Yan Ping Shi * Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China Received 7 July 2008
Abstract A new depsidone, diffractione A (1), as well as six known phenolic compounds (2–7) were isolated from Usnea diffracta. Their structures were elucidated by 1D and 2D NMR spectroscopy together with HRESIMS analysis. All components were obtained for the first time from U. diffracta. # 2008 Yan Ping Shi. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. Keywords: Depsidone; Usneaceae; Usnea diffracta; Lichen; Diffractione A
Usnea diffracta Vain, locally known as ‘‘Gao-Gua-Cao’’, is one of the most important folk medicine used by Yugu nationality in northern regions of Gansu Province, China. It possesses wide uses in the treatment of legs and loin’s injuries, bone fractures and women disease [1]. The chemical components of U. diffracta have not been fully disclosed to date. Previous phytochemical studies on this species resulted in the isolation of usnic acid and diffractaic acid, and both of them have been reported as analgesic and antipyretic components [2]. As a part of our systematic search for new bioactive lead molecules from Yugu nationality folk medicine, U. diffracta was selected for chemical and biological investigations because of the antifungal activity of the crude ethyl acetate extract (EAE) against Actinomyces viscosus ATCC 27044, Streptococcus mutans ATCC 25175, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 8739, Bacillus subtilis ATCC 9372 and Pseudomonas aeruginosa ATCC 9027, respectively. The MIC values of EAE were reported in Table 1. From the EAE of U. diffracta, we isolated one novel depsidone (1), along with six known phenolic compounds (2–7). All these compounds were a group of secondary metabolites more commonly found in lichens. Related to 1 and 2 are the lichen compounds norstictic acid and 80 -O-ethylnorstictic acid [3], but the substitution pattern of the right-hand ring of 1 and 2 were only appeared in fungi [4]. Diffractione A (1), white powder; mp 223 8C; ½a20 D 20 (c 1.0, DMSO). The molecular formula was determined as C20H16O9 on the basis of the [M+Na]+ at m/z 423.0681 (calcd. 423.0687) in its HRESIMS. The UV (MeOH) spectrum of 1 showed maximal absorption bands at 252, 288 and 310 nm. IR (KBr) y (cm1): 3361, 2956, 1764, 1659, 1568, 1441, 1291, 1248, 1142, 1094, 1067, 1016, 955, 888, 780, 594. The 1H NMR spectrum of 1 contained eight proton signals, including three methyl groups at dH 2.17 (s, 3H), 2.41 (s, 3H), and 1.03 (t, 3H, J = 9.2), and one ethoxyl group at dH 3.66 (m, 2H), 1.03 (t, 3H, J = 9.2), one aromatic proton at dH 6.83 (s, 1H), one oxymethine group at dH 6.75
* Corresponding author. E-mail addresses: [email protected], [email protected] (Y.P. Shi). 1001-8417/$ – see front matter # 2008 Yan Ping Shi. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. doi:10.1016/j.cclet.2008.10.032
188
H.Y. Qi et al. / Chinese Chemical Letters 20 (2009) 187–189
Table 1 MIC values of EAE from U. diffracta. MIC (ppm) results species
EAE
Positive control Triclosan
Oral bacterium
Actinomyces viscosus ATCC 27044 Streptococcus mutans ATCC 25175
Normal bacterium
Staphylococcus aureus ATCC 6538 Escherichia coli ATCC 8739 Bacillus subtilis ATCC 9372 Pseudomonas aeruginosa ATCC 9027
Table 2 NMR data of compound 1 (1H, 400 MHz; No.
dC (DEPT)
1 2 3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 100 200
112.4 (C) 164.0 (C) 111.4 (C) 164.5 (C) 118.1 (CH) 153.4 (C) 160.9 (C) 22.2 (CH3) 193.1 (CH) 109.4 (C) 153.0 (C) 122.4 (C) 149.0 (C) 138.0 (C) 134.0 (C) 166.6 (C) 99.2 (CH) 10.4 (CH3) 64.5 (CH2) 15.1 (CH3)
13
39.1 78.1 625 625 312.5 1250
Penicillin G
3.9 7.8 – – – –
– – 125 62.5 125 >250
C 100 MHz; in DMSO-d6, TMS, d ppm). H-1H COSY
dH
1
6.83 (br s, 1H)
8
3, 4, 7, 8
2.41 (s, 3H) 10.41 (s, 3H)
5
1, 2, 5, 6, 7 3, 4, 5
6.75 2.17 3.66 1.03
90 80 200 100
10 , 30 , 40 , 50 , 70 , 100 10 , 20 , 30 , 40 , 50 , 60 80 , 200 100
(s, 1H) (s, 3H) (m, 2H) (t, 9.2, 3H)
HMBC (H ! C)
(s, 1H), and one CHO group at dH 10.41 (s, 1H). The 13C NMR spectrum combined with the DEPT experiment displayed 20 C-atoms as three Me, one CH2, two CH groups, 13 quaternary C-atoms, and one CHO. Comparing the data and features of 1D NMR spectrum with those of excelsione (2) isolated from the same fraction, revealed that they were very similar, except for one ethoxyl group, one oxymethine group and one CHO group in 1 instead of two CH2 at dH 4.55 (s, 2H), 5.63 (s, 2H), and dC 51.9, 67.2 in 2 [4]. Therefore, a structure based on the known excelsione (2) was inferred. The structure of 1 was also established on the basis of HMBC correlations (Table 2 and Fig. 1). The two methyl groups could be linked at C-6 and C-30 by correlation from H-8 to C-1, C-2, C-5, C-6, C-7 and H-90 to C-10 ,
Fig. 1. The structure and key HMBC correlations (H ! C) of 1.
H.Y. Qi et al. / Chinese Chemical Letters 20 (2009) 187–189
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C-20 , C-30 , C-40 , C-50 and C-60 . Correlations from H-9 to C-3, C-4 and C-5 established the position of the CHO group at C-3. Correlations from H-100 to C-80 and H-80 to C-30 , together with correlation of H-80 and H-90 in the 1H-1H COSY, could establish the attached position of ethoxyl group at C-80 . Accordingly, the structure of 1 was elucidated as shown in Fig. 1, named as diffractione A. The structures of the known compounds 2–7 were elucidated by comparison of their NMR data and those reported in the literature. They were identified as excelsione (2) [4], atranol (3) [5], orsellinic acid (4) [6], methyl orsellinate (5) [7], ethyl orsellinate (6) [8], and lecanorin (7) [9], respectively. Acknowledgments The work was supported by the National 863 Program of China (No. 2007AA09Z403), and National Key Technology Research and Development Program of China (No. 2007BAI37B05), and Natural Science Foundation of Gansu Province (No. 0710RJZA120). References [1] [2] [3] [4] [5] [6] [7] [8] [9]
L. Qi, D.S. Luo, Collection of Chinese Minorities Medicine, Inner Mongolia Science Press, Inner Mongolia, 2000, p. 1330. E. Okuyama, K. Umeyama, M. Yarnazaki, Y. Kinoshita, Y. Yamamoto, Planta Med. 61 (1995) 113. H.D. Sun, F.D. Niu, Z.W. Lin, D. Cao, B. Li, Acta Bot. Sin. 32 (1990) 783. G. Lang, A.L.J. Cole, J.W. Blunt, W.T. Robinson, M.H.G. Munro, J. Nat. Prod. 70 (2007) 310. X.J. Yang, M.L. Wen, Z. Zhao, J.Z. Li, X.A. Li, Nat. Prod. Res. Dev. 18 (2006) 76. G.E. Evans, J. Staunton, J. Chem. Soc., Perkin. Trans. I (1988) 755. C.M. Li, S.G. Wu, G.D. Tao, H.D. Sun, Acta Bot. Yunnanica 12 (1990) 457. H. Kijima, T. Ide, H. Otsuka, C. Ogimi, E. Hirata, A. Takushi, Y. Takeda, Phytochemistry 44 (1997) 1551. C. Qiu, Y. Ding, Chin. J. Chin. Mater. Med. 9 (2001) 608.