Helma Wennemers

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Helma Wennemers

Helma B. Wennemers (born June 24, 1969 in Offenbach am Main ) is a German organic chemist . She is Professor of Organic Chemistry at the Swiss Federal Institute of Technology in Zurich ( ETH Zurich ).

Career

Helma Wennemers studied chemistry at the University of Frankfurt and completed her diploma thesis with Gerhard Quinkert in 1993 . In 1996 she did her PhD with W. Clark Still at Columbia University in New York . Between 1996 and 1998 she did a postdoctoral stay at the University of Nagoya with Hisashi Yamamoto , before she became Bachem Assistant Professor in 1999 and Associate Professor at the University of Basel in 2003 . 2011 she became Professor of Organic Chemistry at the ETH Zurich .

research

Helma Wennemers' research focuses on bio-inspired chemistry with an emphasis on proline- rich peptides .

Tripeptidic catalyst of the type H-Pro-Pro-Xaa

Wennemers developed tripeptides of the sequence H-Pro-Pro-Xaa (Pro: proline , Xaa: any amine ) as organocatalysts for C – C bond formation based on an enamine mechanism. A high reactivity , stereo and chemoselectivity for aldol or conjugate addition reactions , by varying the absolute configuration of each amino acid and the functional group of the Xaa residue can be achieved. The modularity of the peptides enabled the synthesis of a catalyst that can catalyze conjugate addition reactions of aldehydes to nitroolefins with as little as 0.05 mol% tripeptide. This is the lowest catalyst loading of a secondary amine-catalyzed C — C bond formation.

Wennemer's research also focuses on other organocatalyzed transformations . Inspired by natural polyketide synthases that use malonic acid half thioesters (MAHTs, e.g. malonyl-CoA ) as thioester - enolate equivalents, she developed organocatalytic methods for stereoselective addition reactions of MAHTs (and protected variants of monothiomalonates, MTMs) to electrophiles using cinchonailes - Alkaloid catalysts. The use of fluorinated MAHTs and MTMs enabled the stereoselective introduction of fluorine substituents in fluoroacetate aldol reactions as well as addition reactions to imines and nitroolefins.

In the field of chemical biology , Wennemers uses larger proline- rich peptides such as collagen model peptides or oligoprolines for applications such as tumor targeting, cell penetration or targeted drug release . Wennemers used Cγ-functionalized proline derivatives to functionalize and stabilize short-chain collagen triple helices, the basic structural building block of collagen . Wennemers also introduced aminoproline and γ-azaproline as pH-sensitive probes to influence the conformal stability of the collagen triple helix at different pH values . In the field of cell-penetrating peptides , Wennemers showed that the preorganization of cationic charges along an oligoproline framework increases the cellular uptake of peptides in various cancer cells (e.g. HeLa ) compared to more flexible oligoarginines with an undefined charge distribution. These cell-penetrating peptides based on oligoproline show a defined localization in the cell nucleus and a high proteolytic stability as well as a low cytotoxicity .

  • Synthetic materials :

Wennemers uses peptides to create ordered mesoscopic materials and control their morphology . She developed tripeptides for the synthesis of monodisperse , water-soluble silver - palladium - platinum - and gold - nanoparticles . Wennemers recently reported peptide-stabilized platinum nanoparticles , which have a higher toxicity have against liver cancer cells (HepG2) as compared with other cancer cells and non-cancerous liver cells. In addition, Wennemers is investigating conjugates of oligoprolines and π-conjugated systems, which form structures with different morphologies (e.g. nanofibers, nanorods, nanosheets). With such a conjugate, she succeeded in creating the first extensive, triaxial supramolecular meshwork that is held together by the interplay of weak non- covalent interactions - an important contribution to the field of molecular tissue.

Awards

Helma Wennemers was awarded the Leonidas Zervas Prize of the European Peptide Society (2010), the Pedler Prize of the Royal Society of Chemistry (2016), the Inhoffen Medal (2017) and the Netherlands Scholar Award for Supramolecular Chemistry (2019).

Web links

Individual evidence

  1. ↑ H. Wennemers: In: Chem. Commun. Volume 47, 2011, pp. 12036-12041.
  2. ↑ P. Krattiger, R. Kovasy, JD Revell, S. Ivan, H. Wennemers: In: Org. Lett. Volume 7, 2005, pp. 1101-1103.
  3. ↑ M. Wiesner, JD Revell, H. Wennemers: In: Angew. Chem. Int. Ed. Volume 47, 2008, pp. 1871-1874.
  4. ↑ M. Wiesner, M. Neuburger, H. Wennemers: In: Chem. Eur. J. Volume 15, 2009, pp. 10103-10109.
  5. ↑ T. Schnitzer, H. Wennemers: In: J. Am. Chem. Soc. Volume 139, 2017, pp. 15356-15362.
  6. ↑ J. Saadi, H. Wennemers: In: Nature Chem. Volume 8, 2016, pp. 276-280.
  7. ↑ E. Cosimi, OD Engl, J. Saadi, M.-O. Ebert, H. Wennemers: In: Angew. Chem. Int. Ed. Volume 55, 2016, pp. 13127-13131.
  8. ↑ E. Cosimi, J. Saadi, H. Wennemers: In: Org. Lett. Volume 18, 2016, pp. 6014-6017.
  9. ↑ C. Kroll, R. Mansi, F. Braun, S. Dobitz, H. Maecke, H. Wennemers: In: J. Am. Chem. Soc. Volume 135, 2013, pp. 16793-16796.
  10. ↑ a b YA Nagel, PS Raschle, H. Wennemers: In: Angew. Chem. Int. Ed. Volume 56, 2017, pp. 122–126.
  11. ↑ C. Siebler, RS Erdmann, H. Wennemers: In: Angew. Chem. Int. Ed. Volume 53, 2014, pp. 10340-10344.
  12. ↑ MR Aronoff, J. Egli, M. Menichelli, H. Wennemers: In: Angew. Chem. Int. Ed. Volume 58, 2019, pp. 3143-3146.
  13. ↑ S. Corra, MS Shoshan, H. Wennemers: In: Curr. Opin., Chem. Biol. Volume 40, 2017, pp. 138-144.
  14. ↑ MS Shoshan, T. Vonderach, B. Hattendorf, H. Wennemers: In: Angew. Chem. Int. Ed. Volume 58, 2019, pp. 4901-4905.
  15. ↑ U. Lewandowska, W. Zajaczkowski, S. Corra, J. Tanabe, R. Borrmann, EM Benetti, S. Stappert, K. Watanabe, NAK Ochs, R. Schaeublin, C. Li, E. Yashima, W. Pisula , K. Müllen, H. Wennemers: In: Nat. Chem. Volume 9, 2017, pp. 1068-1072.
personal data
SURNAME Wennemers, Helma
ALTERNATIVE NAMES Wennemers, Helma B.
BRIEF DESCRIPTION German organic chemist
DATE OF BIRTH June 24, 1969
PLACE OF BIRTH Offenbach am Main