Designing Anti-Tumor Drugs Using Natural and Synthetic Agents

1. 0 Designing Anti-Tumor Drugs Using Natural and Synthetic Agents Herman L. Holt, Jr. University of North Carolina, Asheville Asheville, NC 28804 ASHEVILLE

2. Medicinal Chemistry Folklore 0 • Medicinal chemistry is the science that deals with the discovery of therapeutic chemicals and their development into useful medicines • Medicinal chemistry has been practiced for thousands of years • The earliest written records of the African, Chinese, Indian, South American, and Mediterranean cultures and biblical languages describe the therapeutic effects of various plant concoctions • Man has search for cures by chewing on bark, roots, leaves and berries Dr. Milton Brown, University of Virginia

3. 0 ...Milton Brown, a native of Baltimore, MD, received his bachelor’s degree from Oakwood College in 1987, a Ph.D. in organic chemistry from the University of Alabama, and a M.D. from the University of Virginia, where he currently serves as an associate professor of Chemistry and principal investigator for various NIH funded research projects. He has published in numerous prestigious academic journals as well as receiving awards in research and teaching.

4. 0 A Father of Modern Medicinal Chemistry • Edward E. Smissman, University of Kansas • Smissman Award of the ACS Division of Medicinal Chemistry named in his honor

5. 0

6. 0 Tsung Ying (T.Y.) ShenUniversity of VirginiaProfessor Emeritus Famous for Synthesis and Discovery of the Mechanism of Action of: Indomethacin Sulindac Diflunisal Other anti-inflammatory-analgesic (NSAIDS) and immunoregulators More than 210 U.S. Patents and scientific publications

7. 0 • Medicinal Chemistry is defined as an interdisciplinary science situated at the interface of organic chemistry and life sciences (such as biochemistry, pharmacology, molecular biology, immunology, pharmacokinetics and toxicology) on one side and chemistry-based disciplines (such as physical chemistry, crystallography, spectroscopy and computer-based information technologies) on the other. Medicinal Chemistry Chemistry based disciplines Organic Chemistry Life Sciences

8. 0 • Terms more or less synonymous with medicinal chemistry • Pharmacochemistry • Molecular pharmacochemistry • Drug design • Selective toxicity

9. 0 Definition and Objectives • Medicinal chemistry relates to the design and production of compounds that can be used in medicine for the prevention, treatment or cure of human and animal diseases • Medicinal chemistry covers three critical steps: • A discovery step consisting of the identification and production of new active substances usually called lead compounds. Leads can originate from synthetic organic chemistry, from natural sources or from biotechnological processes. • An optimization step that deals mainly with the synthetic modification of the lead structure in order to improve potency, selectivity and lessen toxicity. Its characteristics are the establishment and analysis of structure-activity relationships (SAR). • A development step consisting of: • the optimization of the synthetic route for bulk production • modification of the pharmacokinetic and pharmaceutical properties of the active substance to render it suitable for clinical use. This may cover optimization of properties associated with: • Chemical formulation • Solubility • Elimination of unpleasant taste or irritation • Reduction of pain at site of injection

10. 0 Challenges for Medicinal Chemistry • Medicinal chemist must excel in organic synthesis and understanding modern approaches to structure-activity analysis. Medicinal chemist are involved in the design, synthesis, optimization and selection of new lead compounds • A survey of a range of company hiring representatives suggested these desired qualities: • Ability to fit a multidisciplinary team • Ability to search for novel molecules • Increased knowledge of how to synthesize molecules for focused biological testing • Understanding of the reasons for making compounds • Understanding drug design • Insight in SAR with insufficient data • Knowledge in collateral fields (pathophysiology, cell biology, genetics) • Familiarity with new techniques

11. 0 Designing Anti-Tumor Drugs Using Natural and Synthetic Agents Herman L. Holt, Jr. University of North Carolina, Asheville Asheville, NC 28804 ASHEVILLE

12. 0 TUBULIN • Taxoid Site • Vanca Alkaloid • Domain • Colchicine Site • Globular Protein

13. 0 MICROTUBULES • Tubulin Polymers

14. 0 MITOTIC SPINDLE • Composed of Microtubules and associated proteins • Needed for cellular division

15. 0 MICROTUBULES • Tubulin Polymers

16. 0 What is the MTT assay? •Cultured cancer cells are grown in the presence of potential drug for a specific time period (e.g. 72, 96 h) • The amount of viable cells remaining can be determined spectrophotometrically • Living cells convert the yellow water soluble-tetrazolium • salt into an insoluble purple formazan crystal • Crystal is dissolved in a suitable solvent (e.g. DMSO, • acid-IPA) and the absorbance at 570 nm is obtained • A dose response curve is plotted and the concentration • at 50% cell growth is obtained

17. 0 MTT = 3-(4’,5’-dimethylthiazol-2’-yl)-2,5-diphenyltetrazolium bromide

18. 0 CISPLATIN • Anti-cancer agent • Ovarian • Testicular • Lung • Breast

19. 0 CISPLATIN • Cleaves DNA

20. 0 TAXOL • Pacific Yew Tree • Anti-cancer agent • Ovarian • Testicular • Lung • Breast

21. 0 TAXOL • Stabilizes microtubules and prevents • disassembly and re-polymerization

22. 0 VANCOMYCIN • Tubulin polymerization inhibitor

23. COLCHICINE 0 • Meadow saffron or autumn Crocus • poisonous Copyright @ 1997 Alice B. Russell, James W. Hardin, Larry Grand

24. 0 COLCHICINE • Tubulin binder • Inhibits tubulin polymerization

25. 0 COMBRETASTATIN • Derived from the African bush willow tree, Combretum caffrum

26. 0 COMBRETASTATIN • Tubulin binder • Inhibits tubulin polymerization

27. 0

28. 0 • Combretastatin A-4 is the most developed and furthest along • in clinical studies among the vascular targeting agents.

29. 0

30. 0 http://www.oxigene.com/vascular/video1.asp

31. 0 HETEROCYCLE ANALOGS OF COMBRETASTATIN

32. 0 HETEROCYCLE ANALOGS OF COMBRETASTATIN Pati, Wicks, Holt, LeBlanc, Weisbruch, Forrest, Lee Heterocyclic Communications2005, in press. Maintain structural rigidity Increase water solubility

33. 0 COMBRETASTATIN AND TRIAZOLE SYNTHESIS

34. 0 COMBRETASTATIN AND TRIAZOLE SYNTHESIS

35. 0 AZIRIDINE ANALOGS OF COMBRETASTATINS

36. 0 AZIRIDINE TYPE ANALOGS OF COMBRETASTATINS

37. 0 MITOMYCINS • Anti-cancer agent • Bladder

38. 0 MITOMYCINS • DNA Alkylating Agent

39. 0 MITOMYCINS • SYNTHESIS IS CURRENTLY IN PROGRESS • RESEARCH PRESENTED AT: • ►Southeast Regional Meeting of the American • Chemical Society (joint meeting with Southwest region) • ► North Carolina Undergraduate Research Symposium • ► National Conference on Undergraduate Research • (Held at UNCA in celebration of its 20th Anniversary)

40. 0 REFERENCES http://en.wikipedia.org/wiki/Main_Page http://www.ces.ncsu.edu/depts/hort/consumer/poison/Colchau.htm Chemical and Engineering News2005, 83(5), several pages therein.

41. 0 MUCH APPRECIATION Jessica Maddox David Mabe Regan LeBlanc John Dickson Dr. Moses Lee Dr. Toni Brown Dr. Karen Buchmueller Lee Group UNC-Asheville Furman University NSF-REU NSF-MRPG