Progress in the studies on tryptanthrin, an alkaloid of history

Archives of Pharmacal Research

Volumn 36, Issue 5, 2013, Pages 517-535

  Jahng, Yurngdong ^a  

^a Yeungnam University   (South Korea)

Author keywords

Alkaloid; Indoloquinazolinone; Tryptanthrin

Indexed keywords

ALKALOID DERIVATIVE; CANDIDIN; METHYLISATOID; OPHIUROIDINE; PHAITANTHRIN A; PHAITANTHRIN B; PHAITANTHRIN C; PHAITANTHRIN D; PHAITANTHRIN E; TRYPTANTHRIN; UNCLASSIFIED DRUG;

ANTIBACTERIAL ACTIVITY; ANTIFUNGAL ACTIVITY; ANTIINFLAMMATORY ACTIVITY; ANTIMALARIAL ACTIVITY; ANTINEOPLASTIC ACTIVITY; BIOLOGICAL ACTIVITY; CHEMICAL REACTION; CYTOTOXICITY; DRUG METABOLISM; DRUG SYNTHESIS; HUMAN; NONHUMAN; REVIEW; STRUCTURE ACTIVITY RELATION;

ANIMALS; CRYSTALLOGRAPHY, X-RAY; DRUG DISCOVERY; HUMANS; MOLECULAR STRUCTURE; QUINAZOLINES; STRUCTURE-ACTIVITY RELATIONSHIP;

EID: 84878260771     PISSN: 02536269     EISSN: 19763786     Source Type: Journal    
DOI: 10.1007/s12272-013-0091-9     Document Type: Review

References (130)

1. Akazome, M.; T. Kondo, and Y. Watanabe. 1993. Transition-metal complex-catalyzed reductive N-heterocyclization: Synthesis of 4(3H)-quinazolinone derivatives from N-(2-nitrobenzoyl)amides. Journal of Organic Chemistry 58: 310-312.
2. Azizian, J.; M.R. Mohammadizadeh, S. Zomorodbakhsh, A.A. Mohammadi, and A.R. Karimi. 2007. Microwave-assisted one-pot synthesis of some dicyanomethylene derivatives of indenoquinoxaline and tryptanthrin under solvent free conditions. ARKIVOC xv: 24-30.
3. Baeyer, A. 1878. Synthese des Indigoblaus. Chemische Berichte 11: 1296-1297.
4. Baeyer, A. 1879. Über die Einwirkung des Fünffachchlorphosphors auf Isatin und auf verwandte Substanzen. Chemische Berichte 12: 456-461.
5. Baeyer, A.; and S. Oekonomides. 1882. Über das Isatin. Chemische Berichte 15: 2093-2102.
6. Baiocchi, L.; M. Giannangeli, V. Rossi, V. Ambrogi, G. Grandolini, and L. Perioli. 1993. Synthesis and antimicrobial activity of some new indolo[2,1-b]quinazolin-6(12H)ones. Farmaco 48: 487-501.
7. Baker, J.T.; and C.C. Duke. 1972. Reactions of α-chloroisatin (2-Chloroindoleninone) with methanethiol and 1,2-ethanedithiol. Tetrahedron Letters 13: 307-308.
8. Baker, W.R.; and L.A.; Mitscher. 1995. Preparation of indolo[2,1-b]quinazoline-6,12-dione tuberculostatics. U.S. Patent 5,441,955.
9. Bandekar, P.P.; K.A. Roopnarine, V.J. Parekh, T.R. Mitchell, M.J. Novak, and R.R. Sinden. 2010. Antimicrobial activity of tryptanthrins in Escherichia coli. Journal of Medicinal Chemistry 53: 3558-3565.
10. Batanero, B.; and F. Barba. 2006. Electrosynthesis of tryptanthrin. Tetrahedron Letters 47: 8201-8203.
11. Begley, W.J.; and J. Grimshaw. 1975. Condensation between 2-chloro-3H-indol-3-one and phenols. Journal of Chemical Society, Perkin Transactions 1: 1840-1845.
12. Bergman, J.; B. Egestad, and J.O. Lindström 1977. The structure of some indolic constituents in Couroupita guaianesis Abul. Tetrahedron Letters 18: 2625-2626.
13. Bergman, J.; J.-O. Lindstöm, and U. Tilstam. 1985. The structure and properties of some indolic constituents in Couroupita guaianesis Abul. Tetrahedron 41: 2879-2881.
14. Bergman, J.; and U. Tilstam. 1985. Structure determination of candidine, A violet indolic constituents from culture solutions of Couroupita guaianesis Abul. Tetrahedron 41: 2883-2884.
15. Bhattacharjee, A.K.; D.J. Skanchy, B. Jennings, T.H. Hudson, J.J. Brendle, and K. Werbovetz. 2002. Analysis of stereoelectronic properties, mechanism of action and pharmacophore of synthetic indolo[2,1-b]quinazolin-6,12- dione derivatives in relation to antileishmanial activity using quantum chemical, cyclic voltammetry and 3-D-QSAR CATALYST procedures. Bioorganic and Medicinal Chemistry 10: 1979-1989.
16. Bhattacharjee, A.K.; M.G. Hartell, D.A. Nichols, R.P. Hicks, B. Stanton, J.E. van Hamont, and W.K. Milhous. 2004. Structure-activity relationship study of antimalarial indolo[2,1-b]quinazoline-6,12-diones (tryptanthrins). Three dimensional pharmacophore modeling and identification of new antimalarial candidates. European Journal of Medicinal Chemistry 39: 59-67.
17. Bird, C.W. 1963. The structure of methylisatoid. Tetrahedron 19: 901-904.
18. Bloxam, W.P. 1915. Our present knowledge of the chemistry of indigo. Journal of Chemical Society, Perkin Transactions 974-987.
19. Bond, C.C.; and M. Hooper. 1969. Isatogens. part VI. Synthesis of isatogens via tolan (diphenylacetylene) intermediate. Journal of Chemical Society C 2453-2460.
20. Bowman, W.R.; M.R.J. Elsegood, T. Stein, and G.W. Weaver. 2007. Radical reactions with 3H-quinazolin-4-ones: synthesis of deoxyvasicinone, mackinazolinone, luotonin A, rutaecarpine and tryptanthrin. Organic and Biomolecular Chemistry 5: 103-113.
21. Brufani, M.; W. Fedeli, F. Mazza, A. Gerhardt, and W. Keller-Schierlein. 1971. The structure of tryptanthrin. Experimentia 27: 1249-1250.
22. Butler, K.; M.W. Partridge, and J.A. Waite (1960) Cyclic amides. XIV. Derivatives of 7H-5,6a,12-triazabenzo[a]anthracene. Journal of Chemical Society 4970-4976.
23. Camargo, L.T.F.M.; M.M. Sena, and A.J.A. Camargo. 2009. A quantum chemical and chemometrical study of indolo[2,1-b]quinazoline and their analougues with cytotoxic activity against breast cancer cells. SAR and QSAR in Environmental Research 20: 537-549.
24. Chan, H.-L.; H.-Y. Yip, N.-K. Mak, and K.-N. Leung. 2009. Modulatory effects and action mechansims of tryptanthrin on murine myeloid leukemia cells. Cellular and Molecular Immunology 6: 335-342.
25. Cornforth, J.; P.B. Hitchcock, and P. Rozos. 1996. Isatin chlorides: a phantom reactions of 2-(2,2-dichloro-2, 3-dihydro-3-oxoindol-1-yl)-3H-indol-3- one. Journal of Chemical Society, Perkin Transactions 1: 2787-2792.
26. Cornforth, J.W. 1976. Structure of isamic acid and methylistoid. Journal of Chemical Society, Perkin Transactions 1: 2004-2009.
27. Costes, N.; H. Le Deit, S. Michel, F. Tillequin, M. Koch, B. Pfeiffer, P. Renard, S. Leonce, N. Guilbaud, L. Kraus-Berthier, A. Pierre, and Gh Atassi. 2000. Synthesis and cytotoxic and antitumor activity of benzo[b]pyrano[3,2-h] acridin-7-one analogues of acronycine. Journal of Medicinal Chemistry 43: 2395-2402.
28. Cox, E.G.; T.H. Goodwin, and A.I. Wagstaff. 1936. The structure of isatin. Proceedings of the Royal Society 157: 399-411.
29. Danz, H.; S. Stoyanova, P. Wippich, A. Brattstrom, and M. Hamburger. 2001. Identification and isolation of the cyclooxygenase-2 inhibitory principles in Isatis tinctoria. Planta Medica 67: 411-416.
30. Danz, H.; D. Baumann, and M. Hamburger. 2002a. Quantitative determination of the dual COX-2/5-LOX inhibitor tryptanthrin in Isatis tinctoria by ESI-LC-MS. Planta Medica 68: 152-157.
31. Danz, H.; S. Stoyanova, O.A.R. Thomet, H.-U. Simon, G. Dannhardt, H. Ulbrich, and M. Hamburger. 2002b. Inhibitory activity of tryptanthrin on prostaglandin and leukotriene synthesis. Planta Medica 68: 875-880.
32. Dorn, A.; S.R. Vippagunta, H. Matile, A. Bubendorf, J.L. Vennerstrom, and R.G. Ridley. 1998. A comparison and analysis of several ways to promote haematin (Haem) polymerisation and an assessment of its initiation in vitro. Biochemical Pharmacology 55: 737-747.
33. Eguchi, S.; H. Takeuchi, and Y. Matsushita. 1992. Short-step synthesis of rutaecarpine and tryptanthrin via intramolecular Aza-Wittig reaction. Heterocycles 33: 153-156.
34. Fedeli, W.; and F. Mazza. 1974. Crystal structure of tryptanthrin (indolo[2,1-b]quinazoline-6,12-dione). Journal of Chemical Society, Perkin Transactions 2: 1621-1623.
35. Fiedler, H.-P. 1974. Diss. Tübingen.
36. Fiedler, E.; H.-P. Fiedler, A. Gerhard, W. Keller-Schierlein, W.A. Koenig, and H. Zähner. 1976. Stoffwechselprodukte von Mikroorganismen. 156. Syntheses und Biosynthesese of substituierter Tryptanthrine. Archives of Mikrobiologie 107: 249-256.
37. Friedländer, P.; and N. Roschdestwensky. 1915. Über ein Oxydationspdukt des Indigblaus. Chemische Berichte 48: 1841-1847.
38. Gassman, P.G.; B.W. Cue Jr, and T.-Y. Luh. 1977. A general method for the synthesis of isatins. Journal of Organic Chemistry 42: 1344-1348.
39. Geckeler, K.; and J. Metz. 1979. A simple synrthesis of 1,2,3-benzotriazin-4(3H)-one. Archiv der Pharmazie 312: 842-844.
40. German Patent belongs to Farbwerke vonmals Meister, Lucius and Bruning 1913. Oxidation product. DE 276,808.
41. George, V.; A.S. Koshy, O.V. Singh, M.N.S. Nayar, and P. Pushpangadan. 1996. Tryptanthrin from Wrightia tinctoria. Fitoterapia 67: 553-554.
42. Gilman, R.E.; M.J. Novak, J.C. Baum, and J.A. Olson. 2008. Scanning tunneling microscopy of 8-fluoroindolo[2,1-b]quinazoline-6,12-dione (8-fluorotryptanthrin) at the graphite-solution interface: fully resolved molecular orbitals. Journal of Physical Chemistry C 112: 14545-14548.
43. Grandolini, G.; V. Ambrogi, L. Perioli, M. Giannangeli, L. Jovicevic, and V. Rossi. 1997. Synthesis and antimicrobial activity of some new derivatives of 6,12-dihydroindolo[2,1-b]quinazolin-6,12-dione. Farmaco 52: 679-683.
44. Hamburger, M. and H. Danz 2000. Indoloquinazolinones for inhibiting NF-κB and antiinflammatory applications. PCT Appl. WO 0061159.
45. Hamburger, M. 2002. Isatis tinctoria: From the rediscovery of an ancient medicinal plant towards a novel anti-inflammatory phytopharmaceutical. Phytochemistry Reviews 1: 333-344.
46. Hantzsch, A. 1921. Über die wirklichen und angeblichen Isomerien in der Isatin-Reihe. Chemische Berichte 54: 1221-1257.
47. Hantzsch, A. 1925. Über Isatoid und sogen. Isatol. Chemische Berichte 58: 685-692.
48. Hashimoto, T.; H. Aga, H. Chaen, S. Fukuda, and M. Kurimoto. 1999. Isolation and identification of anti-Helicobacter pylori compounds from Polygonum tinctorium Lour. The Journal of Natural Medicines (Tokyo) 53: 27-31.
49. Heller, G.; and W. Benade. 1907. Über die Farbenerscheinung der alkalischen Isatinlösung. Chemische Berichte 40: 1291-1300.
50. Heller, G. 1919. Neue Isomerien in der Isatinreihe. III. Chemische Berichte 52: 437-446.
51. Heller, G.; and W. Benade. 1922. Über die Natur der Isatoide. Chemische Berichte 55: 1006-1014.
52. Heller, G.; and R. Barthel. 1936. Zur Kenntnis des Indigos: cis-indigo. Chemische Berichte 69B: 563-565.
53. Hicks, R.P.; D.A. Nichols, C.A. DiTusa, D.J. Sullivan, M.G. Hartell, B.W. Koser, and A.K. Bhattacharjee. 2005. Evaluation of 4-azaindolo[2,1-b] quinazoline-6,12-diones' interaction with hemin and hemozoin: A spectroscopic, X-ray crystallographic and molecular modeling study Internet Electron. Journal of Molecular Design 4: 751-764.
54. Hill, A.J.; and H.R. Henze. 1924. Condensation reactions of cyclic ketones. I. The action of isatin and isatin alph chloride upon certain hydantoins. Journal of the American Chemical Society 46: 2806-2810.
55. Honda, G.; and M. Tabata. 1979. Isolation of antifungal principle tryptanthrin, from Strobilanthes cusia O. Kuntze Planta Medica 36: 85-86.
56. Honda, G.; M. Tabeta, and M. Tsuda. 1979. The microbial specificity of tryptanthrin. Planta Medica 37: 172-174.
57. Honda, G.; V. Tosirisuk, and M. Tabata. 1980. Isolation of an antidermatophytic, tryptanthrin, from indigo plants. Polygonum tinctorium and Isatis tinctoria. Planta Medica 38: 275-276.
58. Hong, Y.H.; W.J. Lee, S.H. Lee, J.K. Son, H.-L. Kim, M. Nam, Y. Kwon, and Y. Jahng. 2010. Synthesis and biological properties of benzo-annulated rutaecarpines. Biological and Pharmaceutical Bulletin 33: 1704-1709.
59. Hosoe, T.; K. Nozawa, N. Kawahara, K. Fukushima, K. Nishimura, M. Miyaji, and K. Kawai. 1999. Isolation of a new potent cytotoxic pigment along with indigotin from the pathogenic Basicdiomycetous fungus Schzophyllum commune. Mycopathologia 146: 9-12.
60. Hosoe, T.; K. Nozawa, N. Kawahara, K. Fukushima, K. Nishimura, M. Miyaji, and K. Kawai. 2000. Isolation of a new potent cytotoxic pigment along with indigotin from the pathogenic basidiomycetous fungus Schizophyllum commune. Mycopathologia 146: 9-12.
61. Ishihara, T.; K. Kohno, S. Ushio, K. Iwaki, M. Ikeda, and M. Kurimoto. 2000. Tryptanthrin inhibits nitric oxide and prosataglandin E2 synthesized by murine macrophases. European Journal of Pharmacology 407: 197-204.
62. Jahng, Y. 2012. Unpublished results.
63. Jao, C.-W.; W.-C. Lin, Y.-T. Wu, and P.-L. Wu. 2008. Isolation, structure elucidation, and synthesis of cytotoxic tryptanthrin analogues from Phaius mishmensis. Journal of Natural Products 71: 1275-1279.
64. Jahng, K.C.; S.I. Kim, D.H. Kim, C.S. Seo, J.-K. Son, S.H. Lee, E.-S. Lee, and Y. Jahng. 2008. One-pot synthesis of simple alkaloids: 2,3-Polymethylene-4(3H)-quinazolinones, luotonin A, tryptanthrin, and rutaecarpine. Chemical and Pharmaceutical Bulletin 56: 607-609.
65. 1H n. m. r. spectra of indolo[2,1-b]quinazoline-6,12-dione, tryptanthrin, and its 2- and 8-chloro-derivatives. Chemical Research (S) 186.
66. Kametani, T.; C.V. Loc, T. Higa, M. Koizmi, and K.J. Fukumoto. 1977. Iminoketene cycloaddition. 2. Total syntheses of arborine, glycosminine, and rutecarpine by condensation of iminoketene with amides. Journal of the American Chemical 99: 2306-2309.
67. 2-Lasers. Tetrahedron Letters 33: 3007-3008.
68. Kataoka, M.; K. Hirata, T. Kunikata, S. Ushio, K. Iwaki, K. Ohashi, M. Ikeda, and M. Kurimoto. 2001. Antibacterial action of tryptanthrin and kaempferol, isolated from the indigo plant (Polygunum tinctotium Lour.) against Helicobacter pylori-induced mongolian gerbils. Journal of Gastroenterology 36: 5-9.
69. Katritzky, A.R.; W.Q. Fan, A.E. Koziol, and G.J. Palenik. 1989. 2-Chloro-3H-indol-3-one and its reactions with nucleophiles. Journal of Heterocyclic Chemistry 26: 821-828.
70. Kikumoto, R.; and T. Kobayashi. 1966. The reactions of oxindoles and isatin with nitrobenzyl chlorides: Formation of 2′-hydroxy-spiro[2H- indole-2,3′-3′H-indole]. Tetrahedron 22: 3337-3343.
71. Kimoto, T.; K. Hino, S. Koya-Miyata, Y. Yamamoto, M. Takeuchi, Y. Nishizaki, M.J. Micallef, S. Ushio, K. Iwaki, M. Ikeda, and M. Kurimoto. 2001. Cell differentiation and apoptosis of monocyclic and promyelocytic leukemia cells (U-937 and HL-60) by tryptanthrin. Pathology International 51: 315-325.
72. King, R. A. 2009. Biotransformations in drug metabolism. In Drug metabolism handbook, concepts and applications. ed Nassar, A. F.; Hollenber, P. F.; and J. Scatina, 17-40. New York: Wiley.
73. Koya-Miyata, S.; T. Kimoto, M.J. Micallef, K. Hino, M. Taniguchi, S. Ushio, K. Iwaki, M. Ikeda, and M. Kurimoto. 2001. Prevention of azoxymethane-induced intestinal tumors by a cute ethyl acetate-extract and tryptanthrin extracted from Polygonum tinctorium lour. Anticancer Research 21: 3295-3300.
74. Kumar, A.; V. Deepak, and P. Kumar. 2011. β-Cyclodextrin catalyzed synthesis of tryptanthrin in water. Green Chemistry 13: 51-54.
75. Laatsch, H. and H. Ludwig-Köhn 1986. Isolierung des indigoiden Pigmentes Candidin aus Urin und Hämofiltrat von Urämikern. Liebigs Annalen der Chemie 1847-1857.
76. Lee, E.S.; J.G. Park, and Y. Jahng. 2003. A facile synthesis of simple alkaloids - Synthesis of 2,3-polymethylene-4(3H)-quinazolinones and related alkaloids. Tetrahedron Letters 44: 1883-1886.
77. Lee, S.K.; G.H. Kim, D.H. Kim, D.H. Kim, Y. Jahng, and T.C. Jeong. 2007. Biological and Pharmaceutical Bulletin 30: 1991-1995.
78. Li, Q.; J. Jin, M. Chong, and Z. Song. 1983. Studies on the antifungal constituent of Qing Dai (Isatis indigotica). Zhongcaoyao 14: 440-441.
79. Li, Q. 1987. The chemical constituents of Qing-Dai. Zhiwu Xuebao 29: 67-72.
80. Li, B.; W. Chen, S. Zheng, G. Yang, and C. Qiao. 2000. Two new alkaloids isolated from tetraploid Banlangen. Acta Pharmaceutica Sinica B 35: 508-510.
81. Liang, J.L.; J.-E. Eom, Y. Kwon, and Y. Jahng. 2012. Synthesis of benzo-annulated tryptanthrins and their biological properties. Bioorganic and Medicinal Chemistry 20: 4962-4967.
82. Liu, J.; C. Wang, Z. Liu 2008. Method for preparation of tryptanthrin derivatives and its application for preparation of indoleamine 2,3-dioxygenase inhibitor. Chin. Pat CN101177428.
83. Liu, Y.; F. Ouyang, H. Yu, L. Li, N. Wang, and X. Yao. 2009. Chemical constituents in the leaves of Baphicaanthus cusia. Chinese Journal of Medicinal Chemistry 19: 273-275.
84. Lygin, A.V.; and A. de Meijere. 2009. ortho-Lithiophenyl isocyanide: A versatile precursor for 3H-quinazolin-4-ones and 3H-quinazolin-4-thiones. Organic Letters 11: 389-392.
85. Machemer, H. 1930. Die Autoxydation der Metalkomplexe des Indigos. Chemische Berichte 63B: 1341-1347.
86. Mason, J.J.; T. Janosik, J. Bergman. 2009. A new approach to methoxyisatins leading to the total synthesis of ophiuroidine and other hydroxytryptanthrins. Synthesis 3642-3648.
87. Matsui, M.; M. Morita, K. Shibata, and Y. Takase. 1982. Ozonolysis of indigo. Nippon Kagaku Kaishi 7: 1268-1269.
88. Mitscher, L.A.; W.-C. Wong, T. DeMeulenaere, J. Sulko, and S. Crake. 1981. Antimicrobial agents from plants. New synthesis and bioactivity of tryptanthrin (indolo[2,1-b]quinazoline-6,12-dione) and its derivatives. Heterocycles 15: 1017-1021.
89. Mitscher, L.A.; and W.R. Baker. 1998a. Tuberculosis: A search for novel therapy starting with natural products. Medicinal Research Reviews 18: 363-374.
90. Mitscher, L.A.; and W.P. Baker. 1998b. A search for novel chemotherapy against tuberculosis amongst natural products. Pure and Applied Chemistry 70: 365-371.
91. Moskovkina, T.V. 1997. New synthesis of 6,12-dihydro-6,12-dioxoindolo[2, 1-b]quinazoline (tryptanthrine, couropitine A). Russian Journal of Organic Chemistry 33: 125-126.
92. Moskovkina, T.V.; A.I. Kalinovskii, and V.V. Makhan'kov. 2012. Synthesis of tryptanthrin (couroupitine) derivatives by reaction of substituted isatins with phosphoryl chloride. Russian Journal of Organic Chemistry 48: 123-126.
93. Motoki, T.; Y. Takami, Y. Yagi, A. Tai, I. Yamamoto, and E. Gohda. 2005. Inhibition of hepatocyte growth factor induction in human dermal fibroblasts by tryptanthrin. Biological and Pharmaceutical Bulletin 28: 260-266.
94. Murakami, T.; A. Kishi, T. Sakurama, H. Matsuda, and M. Yoshikawa. 2001. Chemical constituents of two oriental orchids, Calanthe discolor and C. liukiuensis: Precursor indole glycoside of tryptanthrin and indirubin. Heterocycles 54: 957-966.
95. Muruganandam, A.V.; and S.K. Bhattacharya. 2000. Indole and flavonoid constituents of Wrightia tinctoria, W. tomentosa and W. coccinea. Indian Journal of Chemistry - Section B 39B: 125-131.
96. Nugent, W.A.; and J.M. Mayer. 1988. Metal-Ligand Multiple Bonds. New York: Wiley-Science.
97. Oberthür, C.; R. Jaeggi, and M. Hamburger. 2005. HPLC based activity profiling for 5-lipoxygenase inhibitory activity in Isatis tinctoria leaf extracts. Fitoterapia 76: 324-332.
98. Okunade, A.L.; and M.P.F. Elvin-Lewis. 2009. Novel Therapeutic Agents from Plants, 405-452. Enfield: Science Publishers.
99. O'Neill, C. 1892. Chemistry News 65: 124.
100. Overthür, C.; B. Hoffmann, and M. Hamburger. 2002. Synthesis of d-tryptanthrin. Pharmazie 57: 586-587.
101. Perkin, A.G. 1906. An oxidation product of indigotin. Proceedings of the Chemical Society London 22: 198-199.
102. Pitzer, K.K.; Scovill, J.P.; Kyle, D.E.; and L. Gerena 2003. Antimalarial and antiproliferative pharmacophore models, novel trytptanthrin compounds having increased solubility, and methods of making and using thereof. U.S. Patent, 6,531,487.
103. Potewar, T.M.; S.A. Ingale, and K.V. Srinivasan. 2008. Synthesis of tryptanthrin and deoxyvasicinone by a regioselective lithiation-intramolecular electrophilic reaction approach. ARKIVOC 14: 100-108.
104. Rasmussen, L.E.L.; T.D. Lee, D. Daves Jr, and M. Schmidt. 1993. Female-to-male sex pheromones of low volatility in the Asian elephant, Elephas maximus. Journal of Chemical Ecology 19: 2115-2128.
105. Sandmeyer, T. 1919. Isonitrosoacetanilides and their condensation to isatins. Helvetica Chimica Acta 2: 234-242.
106. Schindler, W.; and H. Zähner. 1971. Stoffwechselprodukte von Mikroorganismen - 91. Mittelung: Tryptanthrin, ein von Tryptophan abzuleittendes Antibioticum aus Candida lipolitica. Archive der Mikrobiolologie 79: 187-203.
107. Schrenk, D.; D. Riebniger, M. Till, S. Vetter, and H.F. Fiedlerf. 1997. Tryptanthrins: A novel class of agonists of the aryl hydrocarbon receptor. Biochemical Pharmacology 54: 165-171.
108. Scovill, J.; E. Blank, M. Konnick, E. Nenortas, and T. Shapiro. 2002. Antitrypanosomal activities of tryptanthrins. Antimicrobial Agents and Chemotherapy 46: 882-883.
109. Seifert, K.; and W. Unger. 1994. Insecticidal and fungicidal compounds from Isatis tinctoria. Zeit Naturforsch C 49: 44-48.
110. Sen, A. K.; Mahato, S. B.; and Dutta, N. L.; Couroupitine A 1974. A new alkaloid from Courouita guianensis. Tetrahedron Letters 15: 609-610.
111. Sharma, V.M.; P. Prasanna, K.V. Seshu, B. Renuka, C.V. Rao, G.S. Kumar, C.P. Narasimhulu, P.A. Babu, R.C. Puranik, D. Subramanyam, A. Venkateswarlu, S. Rajagopal, K.B. Kumar, C.S. Rao, N.V. Mamidi, D.S. Deevi, R. Ajaykumar, and R. Rajagopalan. 2002. Novel indolo[2,1-b]quinazoline analogues as cytostatic agents: synthesis, biological evaluation and structure-activity relationship. Bioorganic and Medicinal Chemistry Letters 12: 2303-2307.
112. Siedel, P. 1822. BASF, Ludwigshafen 1938, in which a preparation of tryptanthrin had been described as early as 1822 by Dumas, Journ. Pharm. VIII, 377 (1822), author could not find the original paper.
113. Son, J.K.; J.G. Park, and Y. Jahng. 2003. A simple synthesis of tryptanthrin. Heterocyclic Communication 9: 621-623.
114. Staskun, B.; and H.F.S. Wolfe. 1992. New approach to the indolo[2, 1-b]quinazoline ring system by cyclization of 3-(o-chlorophenyl)-2-methyl-4(3H)- quinazolinone and its m-isomer. Synthesis of the antibiotic tryptanthrin. African Journal of Chemistry 45: 5-7.
115. Sugai, A. and S. Saito 1997. Preparation of tryptanthrin derivatives and electrophotographic photoreceptors containing them. Jpn. Kokai Tokyo Koho JP 09040672.
116. Sugai, A.; S. Matsumoto, N. Akiba, Y. Watanabe, H. Kawaguchi 1997. Tryptanthrin derivatives suitable for electron transporting agents and highly sensitive electronic photographic photoconductors using the same. Jpn. Kokai Tokyo Koho JP 09095621.
117. Tucker, A.M. and P. Grundt 2012. The chemistry of tryptanthrin and its derivatives. ARKIVOC (i): 546-569.
118. Utkina, N.K.; and V.A. Denisenko. 2007. Ophiuroidine, the first indolo[2,1-b]quinazoline alkaloid from the Caribbean brittle star Ophiocoma riisei. Tetrahedron Letters 48: 4445-4447.
119. Valiante, N. 2004. Use of tryptanthrin compounds for immune potentiation. PCT Int. Appl. WO 2004064759.
120. von Sommaruga, E. 1879. Über die Moleculargröfse des Indigos. Justus Libigs Annalen der Chemie 195: 302-313.
121. Wang, C.; L. Jianli, and S. Xiaoli. 2007. Progress in the synthesis of natural product tryptanthrin and its derivatives. Chemistry Online 70: 89-95.
122. Witt, A.; and J. Bergman. 2003. Recent developments in the field of quinazoline chemistry. Current Organic Chemistry 7: 659-677.
123. Wu, X.Y.; Y.H. Liu, W.Y. Sheng, J. Sun, and G.W. Qin. 1997. Chemical constituents of Isatis indigotica. Planta Medica 63: 55-57.
124. Xu, F.; H. Matsuda, H. Hata, K. Sugawara, S. Nakamura, and M. Yoshikawa. 2009. Structure of new flavonoids and benzofuran-type stilbene and degranulation inhibitors of rat basophillic leukemia cells from the Brazilian herbal medicine Cissus sucyoides. Chemical and Pharmaceutical Bulletin 57: 1089-1095.
125. Yoshikawa, M.; T. Murakami, A. Kishi, T. Sakurama, H. Matsuda, M. Nomura, H. Matsuda, and M. Kubo. 1998. Novel indole S, O-bisdesmoside, calanthoside, the precursor glycoside of tryptanthrin, indirubin, and isatin, with increasing skin blood flow promotic effects, from two Calanthe species (Orchidaceae). Chemical and Pharmaceutical Bulletin 46: 886-888.
126. Yu, S.T.; T.M. Chen, S.Y. Tseng, and Y.H. Chen. 2007. Tryptanthrin inhibits MDR1 and reverse doxorubicin resistance in breast cancer cells. Biochemical and Biophysical Research Communications 358: 79-84.
127. 2-terminal kinase-mediated apoptosis. Anti-Cancer Drugs 20: 382-388.
128. Yu, S.-T.; J.-W. Chern, T.-M. Chen, Y.-F. Chiu, H.-T. Chen, and Y.-H. Chen. 2010. Cytotoxicity and reversal of multindrug resistance by tryptanthrin-derived indoloquinazolines. Acta Pharmaceutica Sinica B 31: 259-264.
129. Zeide, O.A.; and G.V. Chelintsev. 1937. The action of chloropyridine on anthranilic acid. Journal of General Chemistry 7: 2318-2323.
130. Zou, J.; and L. Huang. 1985. Minor constituents of Qing Dai, a traditional Chinese medicine. I. Isolation, structure determination and synthesis of tryptanthrin and qingdainone. Acta pharmaceutica Sinica B 20: 45-51.