Fakultät für Chemie - Former
 
 
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Bielefeld University > Department of Chemistry > Organic Chemistry III > Team > Former

Personal data for Dr. Benedikt Sammet

  Dr. Benedikt Sammet
Dr. Benedikt Sammet
Scientific co-worker
Room: F2-264
Phone: 0521 106 2147
E-Mail:


Modified Cryptophycins


Cryptophycins are a class of macrocyclic depsipeptides. The first member of the family, cryptophycin-1, was isolated in 1990 from cyanobacteria. Several natural and synthetic compounds of this family proved to be extremely cytotoxic in biological screening studies. The bioactivity is based on their ability to interact with tubulin. Cryptophycin-1 and cryptophycin-52 display striking antiproliferative activities both in vitro and in vivo with 100- to 1000-fold increased potency compared to paclitaxel and vinblastine. Furthermore, they are remarkably cytotoxic against several multidrug resistant tumor cell lines and solid tumors.[1] Consequently, cryptophycin derivatives are considered as potential antitumor drugs. Cryptophycin-52 entered phase II clinical trials but failed due to its high neurotoxicity.[2]



As a consequence, my research focuses on the synthesis of structurally modified cryptophycins.
Recently, our research group published a short and efficient synthesis of a cryptophycin unit A building block[3] and we are now able to present an even shorter synthesis of a new unit A precursor via a modified Shi-epoxidation giving rise to a cis-epoxide in cryptophycin.[4] So far, such a stereochemistry within the unit A fragment had only been available by altering the stereochemistry of cryptophycin-1 on small scale.[5]



Literature


[1] S. Eißler, A. Stoncius, M. Nahrwold, N. Sewald, Synthesis2006, 22, 3747-3789.


[2] G. D’Agostino, J. D. Campo, B. Mellado, M. A. Izquierdo, T. Minarik, L. Cirri, L. Marini, J. L. Perez-Gracia, G. Scambia, Int. J. Gynecol. Cancer2006, 16, 71-76.


[3] S. Eißler, M. Nahrwold, B. Neumann, H.-G. Stammler, N. Sewald, Org. Lett., 2007, 9, 817-819.


[4] B. Sammet, H. Radzey, B. Neumann, H.-G. Stammler, N. Sewald, Synlett2009, 3, 417-420.


[5] S. Chaganty, T. Golakoti, C. Heltzel, R. E. Moore, W. Y. Yoshida, J. Nat. Prod.2004, 67, 1403.



Publications


A Two Step Synthesis of a Key Unit B Precursor of Cryptophycins by Asymmetric Hydrogenation
B. Sammet, M. Brax und N. Sewald, Beilstein J. Org. Chem.2011, 7, 243-245.


Approaches for the Synthesis of Functionalized Cryptophycins
B. Sammet, T. Bogner, M. Nahrwold, C. Weiss und N. Sewald, J. Org. Chem.2010, 75, 6953-6960.


4-Nitrophenyl Chloroformate: A Versatile Coupling Reagent (Review)
B. Sammet, Synlett2009, 18, 3050-3051.


Cryptophycin-39 Unit A Precursor Synthesis by a Tandem Shi Epoxidation and Lactonization Reaction of trans-Styryl Acetic Acid
B. Sammet, H. Radzey, B. Neumann, H.-G. Stammler, N. Sewald, Synlett2009, 3, 417-420.


A. Blum*, J. Böttcher*, B. Sammet*, T. Luksch, A. Heine, G. Klebe, W. Diederich, Bioorganic & Medicinal Chemistry2008, 16, 8574-8586.
*= equally contributing authors



Proceedings


Cryptophycins - Synthesis of Potent Functionalized New Antitumor Agents
B. Sammet und N. Sewald, Peptides 2010, European Peptide Society, 2010, ISBN 09715560-59.


Cryptophycins - Synthesis of Potent Functionalised New Antitumor Agents
B. Sammet und N. Sewald, J. Pept. Sci.2010, 16, S2, 123.


Modified Cryptophycins - New Cytotoxic Cyclodepsipeptides
N. Sewald, C. A. Mast, S. Eissler, M. Nahrwold, B. Sammet, T. Bogner und C. Weiss, J. Pept. Sci.2010, 16, S2, 34.


Modified Cryptophycins
B. Sammet, T. Bogner, C. Weiss, M. Nahrwold, S. Eissler und N. Sewald, Amino Acids2009, 37, (Suppl. 1), S42-S43.


Conference Abstracts


A. Heine, J. Boettcher, T. Ritschel, A. Blum, B. Sammet, S. Hoertner, P. Kohler, F. Diederich, W. E. Diederich, G. Klebe, Acta Cryst.2008, A64, C344-345.