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Alatinone, an anthraquinone from Cassia alata
003 l--9422/93 $6.00 + 0.00 ci> 1993 Pcrgamon Press Ltd
Phytochemzstry. Vol 32, No 6, pp 1616 1617, 1993 Printed III Great Britain
ALATINONE, AN ANTHRAQUINONE
FROM CASSIA ALATA
HEMLATA and SURAJ B. KALIDHAR Department of Chemistry and Biochemistry, Haryana Agricultural University, Hisar 125004, India (Received in revised form 2 October 1992)
Key Word Index-Cassia
alata; Leguminosae;
anthraquinone;
alatinone.
Abstract-Stems of Cassia alata have been shown to contain 1,5,7-trihydroxy-3-methylanthraquinone (alatinone). This is a hitherto unreported compound. The other compounds isolated were dalbergin, 2,6-dimethoxybenzoquinone, santal, luteolin, B-sitosterol and /?-sitosteryl-/?-D-glucoside.
INTRODUCTION There are several reports on the chemical components of Cassia alata. [l-4]. There is, however, no report of the components of its stems. We have, therefore, undertaken the chemical investigation of this part of the plant. RESULTS AND
DISCUSSION
Compound 1 (molecular formula C,,H,,O,) appeared to be an anthraquinone from its colour reaction with methanolic NaOH and also with magnesium acetate. The ‘H NMR spectrum in CDCIJ + DMSO-d, revealed the presence of a methyl group at 62.43, typical of a b-methyl. Two broad singlets at 67.07 and 7.60 are attributable to H-2 and H-4 of an anthraquinone having OH-l and Me-3. Two metu-coupled doublets (J = 2.5 Hz) were observed at 66.63 and 7.30. These may be attributed either to H-5 and H-7 or to H-6 and H-8 of the resorcinol ring. The UV spectrum showed a shift from j”$p” 437 nm to j.$‘H+NaoH 497 nm indicative of a l,S-dihydroxyanthraquinone [S, 63. The IR spectrum showed a single carbonyl peak at 1622 cm-’ (chelated GO) and this again supports 1,5-dihydroxylation. Thus compound 1 has been identified as 1,5,7-trihydroxy-3-methylanthraquinone. A survey of the literature reveals that this is the first report of the isolation of this compound. The other compounds isolated from this plant included dalbergin [7], 2,6-dimethoxybenzoquinone [S], 5,3’,4’-trihydroxy7-methoxyisoflavone [9], luteolin [lo], &sitosterol [l l] and P-sitosteryl-/?-D-glucoside [ll]. Compounds Z-4 are 0
OH
reported from the Cassia genus for the first time. Moreover, this is the first report of the isolation of an isoflavone from this genus. EXPERIMENTAL
‘H NMR: 90 MHz, CDCl, plus DMSO-d, with TMS as int. standard. Plant material. The stems of C. aiata were procured from Landscape. HAU, Hisar. Extraction and isolation. Chopped stems of C. alata (3 kg) were successively extracted with hot CsH, and hot EtOH. The combined extracts were coned. dried, mixed with silica gel and subjected to silica gel (6&120 mesh) CC. Alatinone (1) (10 mg) was obtained using C,H, as eluent. Al&none (1). Crystallized from C,H, as orange needles, mp 266” (found: C, 66.3; H, 3.5. C,SH,,OS requires: C, 66.6; H, 3.7%). IR vkfi cm- ‘: 3610. 2895, 1622, 1475, 1400, 1360, 1325, 1290, 1258, 1202, 1155, 1090,900, 860, 850 750, 715. UV A”,&‘”nm: 222, 253, 289, 302, 437; ;:~$tNaoH n&: 250, 310, 330, 497; ‘HNMR (90 MHz, CDCl,+DMSO-d,): 67.60 (br s, lH, H-4), 67.30 (d, ./ =2.5 Hz, lH, H-8), 67.07 (br s, lH, H-2), 66.63 (d, J =2.5 Hz, lH, H-6), 62.43 (s, 3H, Me-3); MS m/z (rel. int.): 270 [M] + (lOO), 269 (1.5), 255 (1.2), 253 (1.9X 243 (l.O), 242 (9.8), 241 (6.1), 225 (1.3), 214 (3.8), 213 (6.1), 200 (1.3), 197 (1.8), 196 (1.6), 185 (2.7), 168 (2.7). Acknowledgements-We thank Dr V. K. Paliwal, HAU, Hisar, for UV spectral data; Mr Avtar Singh, P. U., Chandigarh for ‘H NMR data and Mr S. R. Dubey, L. S. Office, HAU, for supplying the plant material. REFERENCES
Me OH
1. Fuzellier,
0
M. C., Mortier,
Ann. Pharm.
F. and Lectard,
2. Rai, P. P. (1978) Curr. Sci. 47, 271. 3. Smith, R. M. and Ali, S. (1979) N.Z.J.
1
1616
P. (1982)
Fr. 40, 357. Sci. 22, 123.
Short Reports 4. Tiwari, R. D. and Yadava, 0. P. (1971) Planta Med. 19, 299. 5. Thomson, R. H. (1971) Naturally Occurring Quinones, p. 41. Academic Press, London. 6. Thomson, R. H. (1987) Naturally Occurring Quinones III: Recent Advances. Chapman & Hall, London. 7. Chatterjee, A., Ganguly, D. and Sen, R. (1976) Tetruhedron 32, 2407.
1617
8. Pearl, I. A. and Darling, S. F. (1968) Phytochemistry 7, 1851. 9. McCormick, S., Robson, K. and Bohm, B. (1985) Phytochemistry 24, 1614. 10. Kalidhar, S. B. and Sharma, P. (1985) J. Indian Chem. Sco. 62, 261.
11. Kalidhar, S. B., Parthasarathy, M. R. and Sharma, P. (1982) Phytochemistry 21, 796.
Phytochemzstry. Vol 32, No 6, pp 1616 1617, 1993 Printed III Great Britain
ALATINONE, AN ANTHRAQUINONE
FROM CASSIA ALATA
HEMLATA and SURAJ B. KALIDHAR Department of Chemistry and Biochemistry, Haryana Agricultural University, Hisar 125004, India (Received in revised form 2 October 1992)
Key Word Index-Cassia
alata; Leguminosae;
anthraquinone;
alatinone.
Abstract-Stems of Cassia alata have been shown to contain 1,5,7-trihydroxy-3-methylanthraquinone (alatinone). This is a hitherto unreported compound. The other compounds isolated were dalbergin, 2,6-dimethoxybenzoquinone, santal, luteolin, B-sitosterol and /?-sitosteryl-/?-D-glucoside.
INTRODUCTION There are several reports on the chemical components of Cassia alata. [l-4]. There is, however, no report of the components of its stems. We have, therefore, undertaken the chemical investigation of this part of the plant. RESULTS AND
DISCUSSION
Compound 1 (molecular formula C,,H,,O,) appeared to be an anthraquinone from its colour reaction with methanolic NaOH and also with magnesium acetate. The ‘H NMR spectrum in CDCIJ + DMSO-d, revealed the presence of a methyl group at 62.43, typical of a b-methyl. Two broad singlets at 67.07 and 7.60 are attributable to H-2 and H-4 of an anthraquinone having OH-l and Me-3. Two metu-coupled doublets (J = 2.5 Hz) were observed at 66.63 and 7.30. These may be attributed either to H-5 and H-7 or to H-6 and H-8 of the resorcinol ring. The UV spectrum showed a shift from j”$p” 437 nm to j.$‘H+NaoH 497 nm indicative of a l,S-dihydroxyanthraquinone [S, 63. The IR spectrum showed a single carbonyl peak at 1622 cm-’ (chelated GO) and this again supports 1,5-dihydroxylation. Thus compound 1 has been identified as 1,5,7-trihydroxy-3-methylanthraquinone. A survey of the literature reveals that this is the first report of the isolation of this compound. The other compounds isolated from this plant included dalbergin [7], 2,6-dimethoxybenzoquinone [S], 5,3’,4’-trihydroxy7-methoxyisoflavone [9], luteolin [lo], &sitosterol [l l] and P-sitosteryl-/?-D-glucoside [ll]. Compounds Z-4 are 0
OH
reported from the Cassia genus for the first time. Moreover, this is the first report of the isolation of an isoflavone from this genus. EXPERIMENTAL
‘H NMR: 90 MHz, CDCl, plus DMSO-d, with TMS as int. standard. Plant material. The stems of C. aiata were procured from Landscape. HAU, Hisar. Extraction and isolation. Chopped stems of C. alata (3 kg) were successively extracted with hot CsH, and hot EtOH. The combined extracts were coned. dried, mixed with silica gel and subjected to silica gel (6&120 mesh) CC. Alatinone (1) (10 mg) was obtained using C,H, as eluent. Al&none (1). Crystallized from C,H, as orange needles, mp 266” (found: C, 66.3; H, 3.5. C,SH,,OS requires: C, 66.6; H, 3.7%). IR vkfi cm- ‘: 3610. 2895, 1622, 1475, 1400, 1360, 1325, 1290, 1258, 1202, 1155, 1090,900, 860, 850 750, 715. UV A”,&‘”nm: 222, 253, 289, 302, 437; ;:~$tNaoH n&: 250, 310, 330, 497; ‘HNMR (90 MHz, CDCl,+DMSO-d,): 67.60 (br s, lH, H-4), 67.30 (d, ./ =2.5 Hz, lH, H-8), 67.07 (br s, lH, H-2), 66.63 (d, J =2.5 Hz, lH, H-6), 62.43 (s, 3H, Me-3); MS m/z (rel. int.): 270 [M] + (lOO), 269 (1.5), 255 (1.2), 253 (1.9X 243 (l.O), 242 (9.8), 241 (6.1), 225 (1.3), 214 (3.8), 213 (6.1), 200 (1.3), 197 (1.8), 196 (1.6), 185 (2.7), 168 (2.7). Acknowledgements-We thank Dr V. K. Paliwal, HAU, Hisar, for UV spectral data; Mr Avtar Singh, P. U., Chandigarh for ‘H NMR data and Mr S. R. Dubey, L. S. Office, HAU, for supplying the plant material. REFERENCES
Me OH
1. Fuzellier,
0
M. C., Mortier,
Ann. Pharm.
F. and Lectard,
2. Rai, P. P. (1978) Curr. Sci. 47, 271. 3. Smith, R. M. and Ali, S. (1979) N.Z.J.
1
1616
P. (1982)
Fr. 40, 357. Sci. 22, 123.
Short Reports 4. Tiwari, R. D. and Yadava, 0. P. (1971) Planta Med. 19, 299. 5. Thomson, R. H. (1971) Naturally Occurring Quinones, p. 41. Academic Press, London. 6. Thomson, R. H. (1987) Naturally Occurring Quinones III: Recent Advances. Chapman & Hall, London. 7. Chatterjee, A., Ganguly, D. and Sen, R. (1976) Tetruhedron 32, 2407.
1617
8. Pearl, I. A. and Darling, S. F. (1968) Phytochemistry 7, 1851. 9. McCormick, S., Robson, K. and Bohm, B. (1985) Phytochemistry 24, 1614. 10. Kalidhar, S. B. and Sharma, P. (1985) J. Indian Chem. Sco. 62, 261.
11. Kalidhar, S. B., Parthasarathy, M. R. and Sharma, P. (1982) Phytochemistry 21, 796.