Natural Diterpene and Triterpene Quinone Methides: Structures, Synthesis, and Biological Potentials

Quinone Methides

Volumn , Issue , 2009, Pages 269-295

  Zhou, Qibing ^a  

^a VIRGINIA COMMONWEALTH UNIVERSITY   (United States)

Author keywords

Natural diterpene and triterpene quinone methides structures, synthesis, and biological potentials; Natural triterpene QMs; Terpene QMs and reactive oxygen species

Indexed keywords

EID: 84889342704     PISSN: None     EISSN: None     Source Type: Book    
DOI: 10.1002/9780470452882.ch8     Document Type: Chapter

References (114)

1. Gates, K. S. Covalent modification of DNA by natural products. In Comprehensive Natural Products Chemistry; Barton, D.; Nakanishi, K.; Meth-Cohn, O.; Kool, E. T., Eds.; Elsevier: New York, 1999; Vol. 7, pp 491-552.
2. Thompson, D. C.; Thompson, J. A.; Sugumaran, M.; Moldeus, P. Biological toxical consequences of quinone methide formation. Chem.-Biol. Interact. 1993, 86, 129-162.
3. Moore, H. W.; Czerniak, R. Naturally occurring quinones as potential bioreductive alkylating agents. Med. Res. Rev. 1981, 1, 249-280.
4. Grünanger, P.; Chinomethide. In Methoden der Organisch Chemie; Muller, E.; Bayer, O.,Eds.; Houben-Weyl: Stuttgart, 1979; Vol. VII/3b, pp 395-521.
5. Wagner, H. U.; Gompper, R. Quinone methides. In The Chemistry of Quinonoid Compound; Patai, S.,Ed.; John Wiley & Sons: New York, 1974; Vol. 1, pp 1145-1178.
6. Turner, A. B. Quinone methides. Quart. Rev. 1964, 18, 347-360.
7. Kupchan, S. M.; Karim, A.; Marcks, C. Taxodione and taxodone, two novel diterpenoid quinone methide tumor inhibitors from Toxodium distichum. J. Am. Chem. Soc. 1968, 90, 5923-5924.
8. Kupchan, S. M.; Karim, A.; Marcks, C. Tumor inhibitors. XLVIII. Taxodione and taxodone, two novel diterpenoid quinone methide tumor inhibitors from Toxodium distichum. J. Org. Chem. 1969, 34, 3912-3918.
9. Esquivel, B.; Flores, M.; Hernández-Ortega, S.; Toscano, R. A.; Ramamoorthy, T. P. Abietane and icetexane diterpenoids from the roots of Salvia aspera. Phytochemistry 1995, 39, 139-143.
10. Fraga, B. M.; Diaz, C. E.; Guadanó, A.; González-Coloma, A. Diterpenes from Salvia broussonetii transformed roots and their insecticidal activity. J. Agric. Food Chem. 2005, 53, 5200-5214.
11. Sabri, N. N.; Abou-Donia, A. A.; Assad, A. M.; Ghazy, N. M.; El-Lakany, A. M.; Tempesta, M. S.; Sanson, D. R. Abietane diterpene quinones from roots of Salvia verbenaca and S. lanigera. Planta Med. 1989, 55, 582.
12. Topcu, G.; Ulubelen, A. Abietane and rearranged abietane diterpenes from Salvia montbretii. J. Nat. Prod. 1996, 59, 734-737.
13. Simões, F.; Michavila, A.; Rodríguez, B.; García-Alvarez, M. C.; Hasan, M. A quinone methide diterpenoid from the root of Salvia moorcrafiana. Phytochemistry 1986, 25, 755-756.
14. Ikeshiro, Y.; Mase, I.; Tomita, Y. Abietane-type diterpene quinones from Salvia nipponica. Planta Med. 1991, 57, 588.
15. Ulubelen, A. New diterpenes from Salvia pachystachys. J. Nat. Prod. 1990, 53, 1597-1599.
16. Li, M.; Zhang, J.-S.; Ye, Y.-M.; Fang, J.-N. Constituents of the roots of Salvia prionitis. J. Nat. Prod. 2000, 63, 139-141.
17. Guerrero, I. C.; Andrés, L. S.; León, L. G.; Machin, R. P.; Padrón, J. M.; Luis, J. G.; Delgadillo, J. Abietane diterpenoids from Salvia pachyphylla and S. clevelandii with cytotoxic activity against human cancer cell lines. J. Nat. Prod. 2006, 69, 1803-1805.
18. Luis, J. G.; Grillo, T. A. New diterpenes from Salvia munzii: chemical and biogenetic aspects. Tetrahedron 1993, 49, 6277-6284.
19. Schaller, F.; Rahalison, L.; Islam, N.; Potterat, O.; Hostettmann, K.; Stoeckli-Evans, H.; Mavi, S. A new potent antifungal 'quinone methide' diterpene with a cassane skeleton from Bobgunnia madagascariensis. Helv. Chim. Acta 2000, 83, 407-413.
20. Schaller, F.; Wolfender, J.-L.; Hostettmann, K.; Mavi, S. New antifungal 'quinone methide' diterpenes from Bobgunnia madagascariensis and study of their interconversion by LC/NMR. Helv. Chim. Acta 2001, 84, 222-229.
21. El-Lakany,A.M. Chlorosmaridione: a novel chlorinated diterpene quinone methide from Rosematinus officinalis L. Nat. Prod. Sci. 2004, 10, 59-62.
22. Martín, J. D. Newditerpenoids extractives of Maytenus dispermus. Tetrahedron 1973, 29, 2553-2559.
23. Esquivel, B.; Sánchez, A. A.; Vergara, F.; Matus, W.; Hemandez-Ortega, S.; Ramírez-Apan, M. T. Abietane diterpenoids from the roots of some Mexican Salvia species (Labiatae): chemical diversity, phytogeographical significance, and cytotoxic activity. Chem. Divers. 2005, 2, 738-747.
24. Clarkson, C.; StæK, D.; Hansen, S. H.; Smith, P. J.; Jaroszewski, J. W. Identification of major and minor constitutes of Harpagophytum procumbens (devil's claw) using HPLC-SPE-NMR and HPLC-ESIMS/APCIMS. J. Nat. Prod. 2006, 69, 1280-1288.
25. Karanatsios, D.; Scarpa, J. S.; Eugster, C. H. Struktur von Fuerstion. Helv. Chim. Acta 1966, 49, 1151-1171.
26. Ulubelen, A.; Öksüz, S.; Kolak, U.; Bozok-Johansson, C.; C̃elik, C.; Voelter, W. Antibacterial diterpenes from the roots of Salvia viridis. Planta Med. 2000, 66, 458-462.
27. Ulubelen, A.;Öksüz, S.;Kolak, U.; Birman, H.;Voelter, W. Cardioactive terpenoids and a new rearranged diterpene from Salvia syriaca. Planta Med. 2000, 66, 627-629.
28. Achebach, H.;Waibel, R.; Nkunya, M. H. H.;Weenen, H. Antimalarial compounds from Hoslundia opposita. Phytochemistry 1992, 31, 3781-3784.
29. Rüedi, P.; Eugster, C. H. Struktur von Coleon E, einem neuen ditepenoiden Methylenchinon aus der Coleus barbatus-Gruppe (Labiatae). Helv. Chim. Acta 1972, 55, 1994-2014.
30. Rüedi, P. Neue Diterpene aus Blattdrüsen von Plectranthus barbatus (Labiatae) Die absolute Konfiguration der 2-Hydropropyl-Seitenkette in Coleon E. Helv. Chim. Acta 1986, 69, 972-984.
31. Rüedi, P.; Eugster, C. H. Struktur von Coleon F. Helv. Chim. Acta 1973, 56, 1129-1132.
32. Mei, S.-X.; Jiang, B.; Niu, X.-M.; Li, M.-L.; Yang, H.; Na, Z.; Lin, Z.-W.; Li, C.-M.; Sun, H.-D. Abietane diterpenoids from Coleus xanthanthus. J. Nat. Prod. 2002, 65, 633-637.
33. Marques, C. G.; Pedro, M.; Simões, M. F. A.; Nascimento, M. S. J.; Pinto, M. M. M.; Rodríguez, B. Effect of abietane diterpenes from Plectranthus grandidentatus on the growth of human cancer cell line. Planta Med. 2002, 68, 839-840.
34. Cerqueira, F.; Corderio-Da-Silva, A.; Gaspar-Marques, C.; Simões, F.; Pinto, M. M. M.; Nascimento, M. S. J. Effect of abietane diterpenes from Plectranthus grandidentatus on T- and B-lymphocyte proliferation. Bioorg. Med. Chem. 2004, 12, 217-223.
35. Gaspar-Marques, C.; Rijo, P.; Simões, M. F.; Duarte, M. A.; Rodriguez, B. Abietanes from Plectranthus grandidentatus and P. hereroensis against methicillin- and vancomycinresistant bacteria. Phytomedicine 2006, 13, 267-271.
36. Rüedi, P.; Eugster, C. H. 14-Hydroxytaxodion: Partialsynthesse und Reaktionen. Helv. Chim. Acta 1981, 64, 2219-2226.
37. Teixeira, A. P.; Batista, O. B.; Simões, M. F.; Nascimento, J.; Duarte, A.; de la Torre, M. C.; Rodríguez, B. Abietane diterpenoids from Plectranthus grandidentatus. Phytochemistry 1997, 44, 325-327.
38. Rüedi, P.; Eugster, C. H. Coleone C, D, I, I0 aus einer madeǧassischen Plectranthus sp. nov. Interkonversion von cis- und trans-A/B-6,7-Diketoditerpenen. Helv. Chim. Acta 1975, 58, 1899-1912.
39. Arihara, S.; Rüedi, P.; Eugster, C.H. Diterpenoide Drüsenfarbstoffe: Coleone S und Taus Plectranthus caninus Roth (Labiatae), ein neues Diosphenol/trans-A/B-6,7-Diketon-Paar aus der Abietanreihe. Helv. Chim. Acta 1977, 60, 1443-1447.
40. Chen, B.; Duan, H.; Takaishi, Y. Triterpene caffeoyl esters and diterpenes from Celastrus stephanotifolius. Phytochemistry 1999, 51, 683-687.
41. Hueso-Rodríguez, J. A.; Jimeno, M. L.; Rodríguez, B.; Savona, G.; Bruno, M. Abietane diterpenoids from roots of Salvia phlomoides. Phytochemistry 1983, 22, 2005-2009.
42. González, A. G.;Aguiar, Z. E.; Luis, J.G.; Ravelo,A.G.;Domínguez,X. Quinonemethide diterpenoids from the roots of Salvia texana. Phytochemistry 1988, 27, 1777-1781.
43. Tada, M.; Hara, T.; Hara, C.; Chiba, K. A quinone methide from Salvia officinalis. Phytochemistry 1997, 45, 1475-1477.
44. Hirose, Y.; Hasegawa, S.; Ozaki, N. Three new terpenoid quinone methides from the seed of Chamaecyparis obtusa. Tetrahedron Lett. 1983, 24, 1535-1538.
45. Su, W.-C.; Fang, J.-M.; Cheng, Y.-S. Hexacarbocyclic triterpenes from leaves of Cryptomeria japonica. Phytochemistry 1993, 34, 779-782.
46. Rüedi, P.; Uchida, M.; Eugster, C.H. PartialsynthesederGrandidone A,7-Epi-A,B,7-Epi-B, C, D und 7-Epi-D aus 14-Hydroxytaxodion. Helv. Chim. Acta 1981, 64, 2251-2256.
47. Uchida, M.; Miyase, T.; Yoshizaki, F.; Bieri, J. H.; Rüedi, P.; Eugster, C. H. 14-Hydroxytaxodion als Hauptditerpen in Plectranthus grandidentatus Gürke; Isolierung von sieben neuen dimeren Diteroenen aus P. grandidentatus, P. myrianthus Briq. und Coleus carnosus Hassk.; Strukuren der Grandidone A, 7-Epi-A, B, 7-Epi-B, C, D und 7-Epi-D. Helv. Chim. Acta 1981, 64, 2227-2250.
48. Rüedi P. Struktur und Partialsynthese von dimerem Coleon F. Helv. Chim. Acta 1988, 71, 1638-1641.
49. Mori, K.; Matsui, M. Diterpenoid total synthesis. XIII. Taxodione, a quinone methide tumor inhibitor. Tetrahedron 1970, 26, 3467-3473.
50. Mastumoto, T.; Tachibana, Y.; Uchida, J.; Fukui, K. The total synthesis of (+)-taxodione, a tumor inhibitor. Bull. Chem. Soc. Jpn. 1971, 44, 2766-2770.
51. Mastumoto, T.; Usui, S.; Morimoto, T. A. Convenient synthesis of (+)-taxodione, (+)- ferruginol, and (+)-sugiol. Bull. Chem. Soc. Jpn. 1977, 50, 1575-1579.
52. Snitman, D. L.; Himmelsbach, R. J.; Haltiwanger, R. C.;Watt, D. S. A synthesis of (+)- cryptojapanol and (+)-taxodione. Tetrahedron Lett. 1979, 2477-2480.
53. Johnson, W. S.; Shenvi, A. B.; Boots, S. G. An approach to taxodione involving biomimetic polyene cyclization methodology. Tetrahedron 1982, 38, 1397-1404.
54. Stevens, R.V.; Bisacchi, G. S. Benzocyclobutenones as synthons for the synthesis of C-11 oxygenated diterpenoids. Application to the total synthesis of (+)-taxodione. J. Org. Chem. 1982, 47, 2396-2399.
55. Burnell, R. H.; Jean, M.; Poirier, D. Synthesis of (+)-taxodione. Can. J. Chem. 1987, 65, 775-781.
56. Harring, S. R.; Livinghouse, T. Sulfenium ion promoted polyene cyclizations in natural product synthesis. An efficient biomimetic-like synthesis of (+)-nimbidiol. Tetrahedron Lett. 1989, 30, 1499-1502.
57. Engler, T. A.; Sampath, U.; Naganathan, S.; Velde, D. V.; Takusagawa, F.; Yohames, D. Anewgeneral synthetic approach to diterpenes: application to synthesis of (+)-taxodione and (+)-royleanone. J. Org. Chem. 1989, 54, 5712-5727.
58. Sánchez, A. J.; Konopelski, J. P. Phenol benzylic epoxide to quinone methide electron reorganization: synthesis of (+)-taxodone. J. Org. Chem. 1994, 59, 5445-5452.
59. Harring, S. R.; Livinghouse, T. Polyene cascade cyclizations mediated by BF3.CH3NO2. An unusual efficient method for the direct, stereospecific synthesis of polycyclic intermediates via cationic initiation at non-functionalized 3° alkenes. An application to the total synthesis of (+)-taxodione. Tetrahedron 1994, 50, 9229-9254.
60. Burnell, R. H.; Jean, M.; Marceau, S. Synthesis of maytenoquinone. Can. J. Chem. 1988, 66, 227-230.
61. Yang, Z.; Kitano, Y.; Chiba, K.; Shibata, N.; Kurokawa, H.; Doi, Y.; Arakawa, Y.; Tada, M. Synthesis of variously oxidized abietane diterpenes and their antibacterial activities against MRSA and VRE. Bioorg. Med. Chem. 2001, 9, 347-356.
62. Li, A.; She, X.; Zhang, J.; Wu, T.; Pan, X. Synthesis of C-7 oxidized abietane diterpenes from racemic ferruginyl methyl ether. Tetrahedron 2003, 59, 5737-5741.
63. Haslinger, E.; Michl, G. Synthesis of (+)-taxodione from (-)-abietic acid. Tetrahedron Lett. 1988, 29, 5751-5754.
64. Tada, M.; Nishiiri, S.; Yang, Z.; Imai, Y.; Tajima, S.; Okazaki, N.; Kitano, Y.; Chiba, K. Synthesis of (+)- and (-)-ferruginol via asymmetric cyclization of a polyene. J. Chem. Soc., Perkin Trans. 1 2000, 2657-2664.
65. Gunatilaka, A. A. L. Triterpenoid quinonemethide and related compound (celastroloids). In Progress in the Chemistry of Organic Natural Products; Hertz, W.; Kirby, G. W.; Moore, R. E.; Steglich,W.; Tamm, C., Eds.; Springer-Verlag: New York, 1996; Vol. 67, 1-123.
66. Brown, I. R. Heat shock proteins and protection of the nervous system. Ann. N.Y. Acad. Sci. 2007, 1113, 147-158.
67. Corson, T. W.; Crews, C. M. Molecular understanding and modern application of traditional medicines: triumphs and trial. Cell 2007, 130, 769-774.
68. Ravelo, A. G.; Estévez-Braun, A.; Chávez-Orellana, H.; Pérez-Sacau, E.; Mesa-Siverio, D. Recent studies on natural products as anticancer agent. Curr. Top. Med. Chem. 2004, 4, 241-265.
69. Nagase, M.; Oto, J.; Sugiyama, S.;Yube, K.; Takaishi,Y.; Sakato, N. Apoptosis induction in HL-60 cells and inhibition of topoisomerase II by triterpene celastrol. Biosci. Biotechnol. Biochem. 2003, 67, 1883-1887.
70. Wu, C.-C.; Chan, M.-L.; Chen, W.-Y.; Tsai, C.-Y.; Chang, F.-R.; Wu, Y.-C. Pristimerin induced caspase-dependent apoptosis in MDA-MB-231 cells via direct effects on mitochondria. Mol. Cancer Ther. 2005, 4, 1277-1285.
71. Abbas, S.; Bhoumik, A.; Dahl, R.;Vasile, S.; Krajewski, S.; Cosford, N. D. P.; Ronai, Z. A. Preclinical studies of celastrol and acetyl isogambogic acid in melanoma. Clin. Cancer Res. 2007, 13, 6769-6778.
72. Dirsch, V. M.; Kiemer, A. K.; Wagner, H.; Vollmar, A. M. The triterpenoid quinonemethide pristimerin inhibits induction of inducible nitric oxide synthase in murine macrophages. Eur. J. Pharm. 1997, 336, 211-217.
73. Huang, F.-C.; Chan,W.-K; Moriarty,K. J.; Zhang, D.-C.; Chang, M. N.; He,W.;Yu, K.-T.; Zilberstein, A. Novel cytokine release inhibitors. Part I: triterpenes. Bioorg. Med. Chem. Lett. 1998, 8, 1883-1886.
74. Lee, J.-H.; Koo, T. H.; Yoon, H.; Jung, H. S.; Jin, H. Z.; Lee, K.; Hong, Y.-S.; Lee, J. J. Inhibition of NF-kB activation through targeting IkB kinase by celastrol, a quinone methide triterpenoid. Biochem. Pharm. 2006, 72, 1311-1321.
75. Sethi, G.; Ahn, K. S.; Pandey, M. K.; Aggarwal, B. B. Celastrol, a novel triterpene potentiates TNF-induced apoptosis and suppresses invasion of tumor cells by inhibiting NF-kB-regulated gene products and TAK1-mediated NF-kBactivation. Blood 2007, 109, 2727-2735.
76. Pinnaa, G. F.; Fiorucci, M.; Reimund, J.-M.; Taquet, N.; Arondel, Y.; Muller, C. D. Celastrol inhibits pro-inflammatory cytokine secretion in Crohn's disease biopsies. Biochem. Biophys. Res. Commun. 2004, 322, 778-786.
77. Zhang, D.-H.; Marconi, A.; Xu, L.-M.; Yang, C.-X.; Sun, G.-W.; Feng, X.-L.; Ling, C.-Q.; Qin, W.-Z.; Uzan, G.; d'Alessio, P. Tripterine inhibits the expression of adhesion molecules in activated endothelial cells. J. Leukoc. Biol. 2006, 80, 309-319.
78. Li, H.; Zhang, Y.-Y.; Huang, X.-Y.; Sun, Y.-N.; Jia, Y.-F.; Li, D. Beneficial effect of tripterine on systemic lupus erythematosus induced by active chromatin in BALB/c Mice. Eur. J. Pharm. 2005, 512, 231-237.
79. Xu, X.; Zhong, J.;Wu, Z.; Fang, Y.; Xu, C. Effects of tripterine on mRNA expression of TGF-b1 and collagen IV expression in BW F1 mice. Cell Biochem. Funct. 2007, 25, 501-507.
80. Traynor, B. J.; Bruijn, L.; Conwit, R.; Beal, F.; O'Neill, G.; Fagan, S. C.; Cudkowicz, M. E. Neuroprotective agents for clinical trials in ALS. A systematic assessment. Neurology 2006, 67, 20-27.
81. Jung, H. W.; Chung, Y. S.; Kim, Y. S.; Park, Y.-K. Celastrol inhibits production of nitric oxide and proinflammatory cytokines through MAPK signal transduction and NF-kB in LPS-stimulated BV-2 microglial cells. Exp. Mol. Med. 2007, 39, 715-721.
82. Cleren, C.; Calingasan, N. Y.; Chen, J.; Beal, M. F. Celastrol protects against MPTP- and 3-nitropropionic acid-induced neurotoxicity. J. Neurochem. 2005, 94, 995-1004.
83. Westerheide, S. D.; Bosman, J. D.; Mbadugha, B. N. A.; Kawahara, T. L. A.; Matsumoto, G.; Kim, S.; Gu,W.; Devlin, J. P.; Silverman, R. B.; Morimoto, R. I. Celastrol as inducers of the heat shock response and cytoprotection. J. Biol. Chem. 2004, 279, 56053-56060.
84. Wang, J.; Gines, S.; MacDonald, M. E.; Gusella, J. F. Reversal of a full-length mutant huntingtin neuronal cell phenotype by chemical inhibitors of polyglutamine-mediated aggregation. BMC Neurosci. 2005, 6,(1)1-12.
85. Chow, A. M.; Brown, I. R. Induction of heat shock proteins in differentiated human and rodent neurons by celastrol. Cell Stress Chaperones 2007, 12, 237-244.
86. Zhang, Y.-Q.; Sarge, K. D. Celastrol inhibits polyglutamine aggregation and toxicity through induction of the heat shock response. J. Mol. Med. 2007, 85, 1421-1428.
87. Allison, A. C.; Cacabelos, R.; Lombardi, V. R. M.; Alveraz, X. A.; Vigo, C. Celastrol, a potent antioxidant and anti-inflammatory drug, as a possible treatment for Alzheimer's disease Prog. Neuro-Psychopharmacol. Biol. Psychiatry 2001, 25, 1341-1357.
88. Paris, D.; Patel, N.; Quadros, A.; Linan, M.; Bakshi, P.; Ait-Ghezala, G.; Mullan, M. Inhibition of Ab production by NF-kB inhibitors. Neurosci. Lett. 2007, 415, 11-16.
89. Powers, M. V.; Workman, P. Inhibitors of the heat shock response: biology and pharmacology. FEBS Lett. 2007, 581, 3758-3769.
90. Hieronymus, H.; Lamb, J.; Ross, K. N.; Peng, X. P.; Clement, C.; Rodina, A.; Nieto, M.; Du, J.; Stegmaier, K.; Raj, S. M.; Maloney, K. M.; Clardy, J.; Hahn, W. C.; Chiosis, G.; Golub, T. R. Gene expression signature-based chemical genomic prediction identifies a novel class of HSP90 pathway modulators. Cancer Cell 2006, 10, 321-330.
91. Yang, H.; Chen, D.; Cui, Q. C.; Yuan, X.; Dou, Q. P. Celatrol, a triterpene extracted from the Chinese ''thunder of god vine'' is a potent proteasome inhibitor and suppresses human prostate cancer growth in nude mice. Cancer Res. 2006, 66, 4758-4765.
92. Yang, H.; Landis-Piwowar,K. R.; Lu, D.;Yuan, P.; Li, L.; Reddy, G. P.-V.;Yuan, X.; Dou, Q. P. Pristemerin induces apoptosis by targeting the proteasome in prostate cancer cells. J. Cell. Biochem. 2008, 103, 234-244.
93. He, W.; Huang, F.-C.; Morytko, M.; Jariwala, N.; Yu, K.-T. Novel cytokine release inhibitors. Part II: steroids. Bioorg. Med. Chem. Lett. 1998, 8, 2825-2828.
94. He,W.; Huang, F.-C.; Gavai, A.; Chan,W. K.; Amato, G.;Yu, K.-T.; Zilberstein, A. Novel cytokine release inhibitors. Part III: truncated analogs of tripterine. Bioorg. Med. Chem. Lett. 1998, 8, 3659-3664.
95. Moujir, L.; Gutiérrez-Navarro, A. M.; González, A. G.; Ravelo, A. G.; Luis, J. G. The relationship between structure and antimicrobial activity in quinones from the Celastraceae. Biochem. Syst. Ecol. 1990, 18, 25-28.
96. González, A. G.; Alvarenga, N. L.; Ravelo, A. G.; Bazzocchi, I. L.; Ferro, E. A.; Navarro, A. G.; Moujir, L. M. Suctione, a new bioactive norquinonemethide triterpene from Maytenus suctiodes (Celastraceae). Bioorg. Med. Chem. 1996, 4, 815-820.
97. Sotanaphun, U.; Suttisri, R.; Lipipun, V.; Bavovada, R. Quinone-methide triterpenoids from Glyptopetalum sclerocarpum. Phytochemistry 1998, 49, 1749-1755.
98. Sotanaphun, U.; Lipipun, V.; Suttisri, R.; Bavovada, R. Antimicrobial activity and stability of tingenone derivatives. Planta Med. 1999, 65, 450-452.
99. Mean-Rejón, G. J.; Pérez-Espadas, A. R.; Moo-Puc, R. E.; Cedillo-Rivera, R.; Bazzocchi, I. L.; Jiménez-Diaz, I. A.; Quijano, L. Antigiardial activity of triterpenoids from root bark of Hippocratea excelsa. J. Nat. Prod. 2007, 70, 863-865.
100. Figueiredo, J. N.; Räz, B.; Séquin, U. Novel quinone methides from Salacia kraussii with in vitro antimalarial activity. J. Nat. Prod. 1998, 61, 718-723.
101. Thiem, D. A.; Sneden, A. T.; Khan, S. I.; Tekwani, B. L. Bionortriterpenes from Salacia madagascariensis. J. Nat. Prod. 2005, 68, 251-254.
102. Jeller, A. H.; Salva, D. H. S.; Lião, L. M.; Bolzani, V. S.; Burlan, M. Antioxidant phenolic and quinonemethide triterpenes from Cheiloclinium cognatum. Phytochemistry 2004, 65, 1977-1982.
103. Bai, J.-P.; Shi, Y.-L.; Fang, X.; Shi, Q.-X. Effects of demethylzeylasteral and celastrol on spermatogenic cell Ca2+ channels and progesterone-induced sperm acrosome reaction. Eur. J. Pharm. 2003, 464, 9-15.
104. Sun, H.; Liu, X.; Xiong, Q.; Shikano, S.; Li, M. Chronic inhibition of cardiac Kir2.1 and hERG potassium channel by celastrol with dual effects on both ion conductivity and protein trafficking. J. Biol. Chem. 2006, 281, 5877-5884.
105. Morikawa, T.; Kishi, A.; Pongpiriyadacha, Y.; Matsuda, H.; Yoshikawa, M. Structures of new friedelane-type triterpenes and eudesmane-type sesquiterpene and aldose reductase inhibitors from Salacia chinensis. J. Nat. Prod. 2003, 66, 1191-1196.
106. Murayama, T.; Eizuru, Y.; Yamada, R.; Sadanari, H.; Matsubara, K.; Rukung, G.; Tolo, F. M.; Mungai, G. M.; Kofi-Tsekpo, M. Anticytomegalovirus activity of pristimerin, a triterpenoid quinone methide isolated from Maytenus heterophylla (Eckl. & Zeyh.). Antiviral Chem. Chemother. 2007, 18, 133-139.
107. Avilla, J.; Teixidó , A.; Velásquez, C.; Alvarenga, N.; Ferro, E.; Canela, R. Insecticidal activity of Maytenus species (Celastraceae) nortriterpene quinone methide against codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae). J. Agric. Food Chem. 2000, 48, 88-92.
108. Corsino, J.; de Carvalho, P. R. F.; Kato, M. J.; Latorre, L. R.; Oliveira, O. M. M. F.; Araújo, A. R.; Bolzani,V. S.; Franc̃a, S. C.; Pereira, A. M. S.; Furlan, M. Biosynthesis of friedelane and quinonemethide triterpenoids is compartmentalized in Maytenus aquifolium and Salacia campestris. Phytochemistry 2000, 55, 741-748.
109. Oikawa, S.; Hirosawa, I.; Hirakawa, K.; Kawanishi, S. Site specificity and mechanism of oxidative DNA damage induced by carcinogenic catechol. Carcinogenesis 2001, 22, 1239-1245.
110. Schweigert, N.; Acero, J. L.; von Gunten, U.; Canonica, S.; Zehnder, A. J. B.; Eggen, R. I. L. DNA degradation by the mixture of copper and catechol is caused by DNA-copperhydroperoxo complexes probably DNA-Cu(I)OOH. Environ. Sci. Mol. Mutagen. 2000, 36, 5-12.
111. Flowers, L.; Ohnishi, T.; Penning, T. M.DNAstrand scission by polycylic hydrocarbon oquinone: role of reactive oxygen species, Cu(II)/(I) redox cycling, and o-semiquinone anion radicals. Biochemistry 1997, 36, 8640-8648.
112. Zhou, Q.; Zuniga, M. A. Quinone methides formations in the Cu2+-induced oxidation of a diterpenone catechol and concurrent damage on DNA. Chem. Res. Toxicol. 2005, 18, 382-388.
113. Zuniga, M. A.; Wehunt, M. P.; Zhou, Q. DNA oxidative damage by catechol analogs of terpene quinone methides in the presence of Cu(II) and/or NADH. Chem. Res. Toxicol. 2006, 19, 828-836.
114. Trott, A.; West, J. D.; Klaic, L.; Westerheide, S. D.; Silverman, R. B.; Morimoto, R. I.; Morano, K. A. Activation of heat shock and antioxidant responses by the natural product celastrol: transcriptional signatures of a thiol-targeted molecule. Mol. Biol. Cell 2008, 19, 1104-1112.