1 / 71

The Epothilones

The Epothilones. Brian Lucas October 16, 2003. Epothiwhat?. Epo xide, thi azo l e, ket one = epothilone. Epothilone A, R = H Epothilone B, R = CH 3. Overview . The epothilones are extremely cytotoxic agents with a similar mode of action to Taxol®

zaltana
Télécharger la présentation

The Epothilones

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Epothilones Brian Lucas October 16, 2003

  2. Epothiwhat? Epoxide, thiazole, ketone = epothilone Epothilone A, R = H Epothilone B, R = CH3

  3. Overview • The epothilones are extremely cytotoxic agents with a similar mode of action to Taxol® • Epo B is more active than Taxol (in vitro) • Comparatively simple in structure Taxol Epothilone B

  4. Overview • The epothilones are active against Taxol resistant cancer cell lines • The epothilone scaffold is easier to derivatize than Taxol • The epothilones are more water soluble than Taxol Taxol Epothilone B

  5. Outline • Discovery and Background • Mode of Action • Biosynthesis • Initial Synthetic Efforts • Selected Total Syntheses • Structure Activity Relationships (SAR) • In vivo Studies and Phase I/II Clinical Results

  6. Discovery • First isolated from the common soil bacteria Sorangium cellulosum as early as 1987 by Höfle and Reichenbach (GBF) • Exhibited a narrow antifungal spectrum (against Mucor hiemalis only) • Found to be too toxic for use as an antifungal Höfle, G. Bedorf, N.; Gerth, K.; Reichenbach, H. (GBF), DE-B 4138042, 1993, [Chem. Abstr.1993, 120, 52841] Nicolaou, K.C.; Roshangar, F.; Vourloumis, D., Angew. Chem. Int. Ed.1998, 37, 2014.

  7. Cytotoxicity • Bollag (Merck) discovered taxol-like cytotoxicity • Epo A and B were competitive inhibitors of taxol binding • IC50 values comparable (Epo A) or better (Epo B) than Taxol • Active against Pgp MDR (“Taxol refractory”) cells Bollag, D.M.; McQueney, P.A.; Zhu, J.; Hensens, O.; Koupal, L.; Leisch, J.; Goetz, M.; Lazarides, E.; Woods, C.M. Cancer Res.1995, 55, 2325.

  8. Comparison of IC50 Values [nM] The epothilones retain activity in taxol-resistant cancer cell lines Altmann, K.H. Mini-Reviews in Medicinal Chemistry2003, 3, 149. Altmann, K.H.; Wartmann, M.; O’Reilly, T. Biochim. Biophys. Acta2000, 1470, M79

  9. Mode of Action • Like Taxol, the epothilones are microtubule stabilizers • Both bind to β tubulin • Competitive binding suggests same binding site • Epo B efficacy against tubulin-mutated cell lines suggests different interactions Bollag, D.M.; McQueney, P.A.; Zhu, J.; Hensens, O.; Koupal, L.; Leisch, J.; Goetz, M.; Lazarides, E.; Woods, C.M. Cancer Res.1995, 55, 2325.

  10. Epothilone B / Taxol Mode I Carbon:Taxol, Epothilone B Nitrogen,Oxygen Giannakakou, P.; Gussio, R.; Nogales, E. Downing, K.H.; Zaharevitz, D.; Bollubuck, B.; Poy, G.; Sackett, D.; Nicolaou, K.C. Fojo, T. Proc. Natl. Acad. Sci. USA, 2000, 97, 2904

  11. Epothilone B / Taxol Mode II Carbon:Taxol, Epothilone B Nitrogen,Oxygen Giannakakou, P.; Gussio, R.; Nogales, E. Downing, K.H.; Zaharevitz, D.; Bollubuck, B.; Poy, G.; Sackett, D.; Nicolaou, K.C. Fojo, T. Proc. Natl. Acad. Sci. USA, 2000, 97, 2904

  12. Formation of Microtubules Nicolaou, K.C.; Roshangar, F.; Vourloumis, D., Angew. Chem. Int. Ed.1998, 37, 2014.

  13. Stabilized Microtubules BlockMitosis Nicolaou, K.C.; Roshangar, F.; Vourloumis, D., Angew. Chem. Int. Ed.1998, 37, 2014.

  14. Epothilone Biosynthesis

  15. Biosynthesis • Produced by the myxobacterium Sorangium cellulosum So Ce90 • ~20 mg/L 2:1 Epo A : Epo B • The So Ce90 genome sequenced: • Nine modules of polyketide synthase (PKS) • One nonribosomal peptide synthetase (NRPS) • Cytochrome P450 monooxygenase (epoxidation) Molnar, I.; Schupp, T.; Ono, M.; Zirkle, R.E.; Milnamow, M.; Nowak-Thompson, B.; Engel, N.; Toupet, C.; Stratmann, A.; Cyr, D.D.; Gorlach, J.; Mayo, J.M.; Hu, A.; Goff, S.; Schmid, J. Ligon, J.M. Chem. Biol.2000, 7, 97. Tang, L.; Shah, S.; Chung, L.; Carney, J.; Katz, L.; Kholsa, C.; Julien, B. Science2000, 287, 640

  16. Epothilone Gene Cluster Walsh, C.T.; O’Connor, S.E.; Schneider, T.L. J. Ind. Microbiol. Biotechnol.2003, 30, 448.

  17. Post Assembly Line Epoxidation Boddy, C.N.; Scheider, T.L.; Hotta, K.; Walsh, C.T.; Khosla, C. J. Am. Chem. Soc.2003, 125, 3428 Crystal Structure of Epo D and Epo B bound Cytochrome P450EpoK : Nagano, S.; Huiyang, L.; Shimizu, H.; Nishida, Ogura, H.; Ortiz de Montellan, P.R.; Poulos, T.L. JBC Papers in Press, 2003.

  18. Cloning and Heterologous Expression • The epothilone gene cluster has been expressed in Streptomyces coelicolor CH999. • Doubling time of 2h vs. 16h • Expression in Myxococcus xanthus • 1:10 Epo A: Epo B “Large Scale” • Reengineering of the biosynthetic pathway can lead to novel epothilones Tang, L.; Shah, S.; Chung, L.; Carney, J.; Katz, L.; Kholsa, C.; Julien, B. Science, 2000, 287, 640 Arslanian, R.L.; Parker, C.D.; Wang, P.K.; McIntire, J.R.; Lau, J.; Starks, C.; Licari, P.J. J. Nat. Prod.2002, 65, 570. O’Connor, S.E.; Walsh, C.T.; Liu, F. Angew. Chem. Int. Ed. 2003, 42, 3917.

  19. Initial Synthetic Efforts Höfle, G.; Bedorf, N.; Steinmetz, H.; Schomburg, D.; Gerth, K.; Reichenbach, H. Angew. Chem. Int. Ed.1996, 35, 1567.

  20. The Race is On EpoA Oct. 17, 1996 EpoA Nov. 25, 1996 EpoA Dec 28, 1996

  21. Retrosyntheses All chose a late-stage epoxidation Key issues: E / Z isomers, stereochemistry, epoxidation selectivity

  22. Danishefsky’s Macroaldolization Balog, A.; Meng, D.; Kamenecka, T.; Bertinato, P.; Su, D.-S., Sorensen, E.J.; Danishefsky, S.J. Angew. Chem. Int. Ed.1996, 35, 2801

  23. Nicolaou’s Macrolactonization Nicolaou, K.C.; Sarabia, F.; Ninkovic, S.; Yang, Z. Angew. Chem. Int. Ed.1997, 36, 525. Nicolaou, K.C.; Ninkovic, S.; Sarabia, F.; Vourloumis, D.; He, Y.; Vallberg, H.; Finlay, M.R.V.; Yang, Z. J.Am. Chem. Soc.1997, 119, 7974.

  24. Schinzer’s RCM Schinzer, D.; Limberg, A.; Bauer, A.; Bohm, O.M.; Cordes, M. Angew. Chem. Int. Ed.1997, 36, 523.

  25. Nicolaou’s RCM Yang, Z.; He, Y.; Vourlumis, D.; Vallberg, H.; Nicolaou, K.C. Angew. Chem. Int. Ed.1997, 36, 166. Nicolaou, K.C.; He., Y.; Vourloumis, D.; Vallberg, H.; Roschanger, F.; Sarabia, F.; Ninkovic, S.; Yang, Z.; Trujillo, J.I. J. Am. Chem. Soc. 1997, 119, 7960.

  26. Danishefsky’s RCM Meng, D.; Bertinato, P.; Balog, A.; Su, D.-S.; Kameneka, T.; Sorensen, E.J.; Danishefsky, S.J. J. Am. Chem. Soc.1997, 119, 10073 Meng, D.; Su, D.-S.; Balog, A.; Bertinato, P.; Sorensen, E.J.; Danishefsky, S.J.; Zheng, Y.H.; Chou, T.C.; He, L.; Horwitz, S.B. J. Am. Chem. Soc.1997, 119, 2733.

  27. Substituent Effects on RCM Meng, D.; Bertinato, P.; Balog, A.; Su, D.-S.; Kameneka, T.; Sorensen, E.J.; Danishefsky, S.J. J. Am. Chem. Soc.1997, 119, 10073 Meng, D.; Su, D.-S.; Balog, A.; Bertinato, P.; Sorensen, E.J.; Danishefsky, S.J.; Zheng, Y.H.; Chou, T.C.; He, L.; Horwitz, S.B. J. Am. Chem. Soc.1997, 119, 2733.

  28. Overall # of Steps / Yields

  29. Summary of Initial Synthesesof Epothilone A • Remarkably short period of time from Höfle’s crystal structure to first syntheses • Numerous synthetic challenges were identified: • Z:E selectivity about C12-C13 • RCM problematic • Epoxidation yields / selectivity moderate • Stereochemical outcome of aldol reactions highly dependent on substrate

  30. Selected Total Syntheses

  31. More Epothilone Syntheses • Epo B Danishefsky (1997) • Subsequent syntheses by Nicolaou, Schinzer, Grieco, Mulzer, White, Sinha- Lerner, Panek, Shibasaki, Carreira, Ley, Taylor

  32. Mulzer’s “Early Epoxide” Route Martin, H.J.; Drescher, M.; Mulzer, J. Angew. Chem. Int. Ed. 2000, 39, 581.

  33. Mulzer’s “Early Epoxide” Route Martin, H.J.; Drescher, M.; Mulzer, J. Angew. Chem. Int. Ed. 2000, 39, 581.

  34. Reductive DIBAL-H (neutral) L-Selectride (ionic) Zn (metallic) Oxidative OsO4 / NaIO4 NaOCl2 Basic TBAF DMAP LDA Enolates Electrophilic Acyl Chloride Epoxide Stability Martin, H.J.; Drescher, M.; Mulzer, J. Angew. Chem. Int. Ed. 2000, 39, 581.

  35. Ley’s Resin Route to Epo C Storer, R.I.; Takemoto, T.; Jackson, P.S.; Ley, S.V. Angew. Chem. Int. Ed.2003, 42, 2521.

  36. Ley - Fragment A Storer, R.I.; Takemoto, T.; Jackson, P.S.; Ley, S.V. Angew. Chem. Int. Ed.2003, 42, 2521.

  37. Ley – Fragment B Storer, R.I.; Takemoto, T.; Jackson, P.S.; Ley, S.V. Angew. Chem. Int. Ed.2003, 42, 2521.

  38. Ley – Fragment C Storer, R.I.; Takemoto, T.; Jackson, P.S.; Ley, S.V. Angew. Chem. Int. Ed.2003, 42, 2521.

  39. Ley - Convergence Storer, R.I.; Takemoto, T.; Jackson, P.S.; Ley, S.V. Angew. Chem. Int. Ed.2003, 42, 2521.

  40. Ley’s Resin Route • 29 total steps • 17 step longest linear sequence from commercially available materials • 1 column • Most complex natural product built by these techniques

  41. Danishefsky’s “Scalable” Synthesis Chappell, M.D.; Stachel, S.; Lee, C.B.; Danishefsky, S.J. Org. Lett.2000, 2, 1633. Lee, C.B.; Wu, Z.; Zhang, F.; Chappell, M.D.; Stachel, S.J.; Chou, T.-C.; Guan, Y.; Danishefsky, S.J., J. Am. Chem. Soc.2001, 123, 5249.

  42. Subunit A Chappell, M.D.; Stachel, S.; Lee, C.B.; Danishefsky, S.J. Org. Lett.2000, 2, 1633. Lee, C.B.; Wu, Z.; Zhang, F.; Chappell, M.D.; Stachel, S.J.; Chou, T.-C.; Guan, Y.; Danishefsky, S.J., J. Am. Chem. Soc.2001, 123, 5249.

  43. Subunit B Chappell, M.D.; Stachel, S.; Lee, C.B.; Danishefsky, S.J. Org. Lett.2000, 2, 1633. Lee, C.B.; Wu, Z.; Zhang, F.; Chappell, M.D.; Stachel, S.J.; Chou, T.-C.; Guan, Y.; Danishefsky, S.J., J. Am. Chem. Soc.2001, 123, 5249.

  44. Subunit C / BC coupling Chappell, M.D.; Stachel, S.; Lee, C.B.; Danishefsky, S.J. Org. Lett.2000, 2, 1633. Lee, C.B.; Wu, Z.; Zhang, F.; Chappell, M.D.; Stachel, S.J.; Chou, T.-C.; Guan, Y.; Danishefsky, S.J., J. Am. Chem. Soc.2001, 123, 5249.

  45. Final Convergence Chappell, M.D.; Stachel, S.; Lee, C.B.; Danishefsky, S.J. Org. Lett.2000, 2, 1633. Lee, C.B.; Wu, Z.; Zhang, F.; Chappell, M.D.; Stachel, S.J.; Chou, T.-C.; Guan, Y.; Danishefsky, S.J., J. Am. Chem. Soc.2001, 123, 5249.

  46. Completion of Epo D 23 – 25 total steps 16 (13) step longest linear sequence 6.2% (17%) overall yield Chappell, M.D.; Stachel, S.; Lee, C.B.; Danishefsky, S.J. Org. Lett.2000, 2, 1633. Lee, C.B.; Wu, Z.; Zhang, F.; Chappell, M.D.; Stachel, S.J.; Chou, T.-C.; Guan, Y.; Danishefsky, S.J., J. Am. Chem. Soc.2001, 123, 5249.

  47. Epothilone B in vivo

  48. Epothilone B in vivo (MSK) • Found to be toxic in non-tumor-bearing nude mouse models • 0.6 mg/kg/day x 4 given i.p. resulted in 8/8 deaths (days 5-7) MX-1 xeno graft Chou, T.C.; Zhang, X.-G.; Balog, A.; Shu, D.-S.; Meng, D.; Savin, K.A.; Bertino, J.R.; Danishefsky, S.J. Proc. Nat. Acad. Sci. USA 199895, 9642.

  49. Epothilone B in vivo (Novartis) • Significant tumor regression in Pgp MDR cells (HCT-15, KB-8511) • relatively narrow therapeutic window • t½≈ 40 min in mouse plasma • stability in human plasma is much greater Altmann, K.H., Wartmann, KM.; O’Reilly, T. Biochem. Biophys. Acta. 2000, 1470, M79

  50. Structure-Activity Relationships

More Related