Carbohydrate Chemistry

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					                                             Carbohydrate Chemistry

Synthetic Carbohydrate Chemistry: Glycoside synthesis, preparative studies of
antibiotic and cytostatic oligosaccharides, synthesis of complex saccharide conju-
gates, preparations of carbohydrate mimetics, photochemical transformation of car-
                                                                                          Prof. Dr. Joachim Thiem
bohydrate derivatives.

Preparative Chemoenzymatic Synthesis: Application of glycohydrolases and gly-
cosyltransferases for synthesis of oligo- saccharides, use of further enzyme systems
for preparative purposes.

Carbohydrates as Chemical Feedstock: Studies on the synthesis of polymers
(polyesters, -urethanes, -ethers, -amides) from saccharide building units, work in the
field of saccharide based surfactants.

         Recent Examples                      ously glycosylated natural products
Synthetic Carbohydrate Chemistry:             such as steroids and tocopherols. In
                                              further studies we also deal with combi-
In this area we are involved in a number      natorial glycosylations. Some other        Institut für Organische Chemie
of different projects. Some are con-          work centered on carbohydrate mimet-       Universität Hamburg
cerned with methodology studies in gly-       ics employing sigmatropic rearrange-       Martin-Luther-King-Platz 6,
cosylation, e.g. we are elaborating           ments of saccharide-derived allyl          20146 Hamburg
applications for the synthesis of vari-       ketene acetals (Fig. 1) [1].
                                                                                         E-Mail: thiem@chemie.uni-
                                                                                         Telefon: +49-(0)40-42838 4241
                                                                                         Telefax: +49-(0)40-42838 4325

                                                                                         Chemistry study and Dissertation in
                                                                                         Hamburg with Prof. Dr. H. Paulsen
                                                                                         (1972); Habilitation (1978) and Assis-
                                                                                         tant Prof. in Hamburg (till 1982);
                                                                                         Associate Prof. in Münster (1983-
                                                                                         1989); Full Prof. in Hamburg (since
                                                                                         1989); Sabbaticals and Visiting Pro-
                                                                                         fessorships: University of California,
                                                                                         Berkeley,CA, USA (1984/85), Victoria
                                                                                         University and IRL, Wellington, NZ
                                                                                         (1993); CERMAV, Grenoble, F (1995).
Figure.1: Carbohydrate mimetics employing sigmatropic rearrangements of saccharide-      Scripps Research Institute (TSRI), La
derived allyl ketene acetals [1].                                                        Jolla, CA, USA (2005/06).

                                                                                         Public Service:
                                                  Preparative Chemoenzymatic             German Representative in European
                                                            Synthesis                    Carbohydrate Organisation (since
                                                                                         1987) and International Carbohydrate
                                              Here we perform enzymatic synthesis        Organisation (since 1990); Member
                                              employing efficiently available enzymes    of Executive Board FEI (since 1989);
                                              of the carbohydrate metabolism. In con-    Confidential Docent of FCI (since
                                              trast to the analytical biochemical        1991); Member of Scientific Work-
                                              approach focus is rather on the prepar-    group of Industrial Research Comitee
                                              ative aspect. With much success hydro-     (since 1991). Speaker of Collabora-
                                              lases can be used for synthesis in the     tive Research Grant (SFB 470) „Gly-
                                              sense of transglycosylations [2]. Also     costructures in Biosystems - Synthe-
                                              glycosyltransferases could be employed     sis and Impact“ (since 1997); Dean
                                              most efficiently giving rise to complex    Department of Chemistry 04/2002 –
                                              heterooligosaccharides [3]. Recently       10/2005.
                                              the unusual trans-sialidase could be
                                              expressed in E.coli and used in the syn-   Auszeichnungen:
                                              thesis of a-2-3 sialylated oligosaccha-    Heyrovsky Medaille 2001 der Tsche-
                                              rides (Fig.2 [4].                          chischen Akademie der Wissen-

                                                     Chemiedozententagung 2006                                            49
           Carbohydrates as
          Chemical Feedstock

Formation of saccharide derived poly-
mers requires avoiding the typical pro-
tecting group chemistry known for car-
bohydrate derivatives. We have realized
the preparation of many polymers of
interest such as polyesters, polyureas,
polyurethane, polyamides and poly-
ethers. Recently, novel polyglycosilox-
anes with interesting properties could
be obtained by hydrosilylation of carbo-
hydrate precursors (Fig.3) [5].

 [1] S. Jürs, J. Thiem, Tetrahedron Asymm., 16,
     1631-1638 (2005).
 [2] L. Kröger, J. Thiem, J. Carbohydr. Chem.
     24, 717-722 (2005)
 [3 A. M. Scheppokat, H. Bretting, J. Thiem,
     Carbohydr. Res., 338, 2083-2090 (2003).
 [4] B. Neubacher, D. Schmidt, P. Ziegelmüller,
     J. Thiem, Org. Biomol. Chem. 3, 1551-        Figure 2: Use of recombinant trans-sialidase (T. cruzi) for a-2-3 sialylation of D-Gal-terminat-
     1556 (2005).
                                                  ed oligosaccharides [4].
 [5] D. Henkensmeier, B. C. Abele, A. Candus-
     sio, J. Thiem, Macromol. Chem. Phys., 205,
     1851-1857 (2004).

Figure 3: General reaction pattern; X is a carbohydrate moiety, Mn (PDMS-H2) = 592 g/mol [5].

Das umfassende Know-how über
die Herstellung und Verwendung
von Kunststoff-Additiven sowie die
Entwicklung neuer Additivsysteme
zeichnen uns als forschendes                        Additive
Unternehmen mit großem kreativen
Potential aus.
Kontinuierliche Investitionen in
Forschung und Entwicklung
sowie die Weiterbildung unserer
Mitarbeiter sorgen für unsere hohe
Baerlocher, einer der führenden,
globalen Entwickler und Hersteller
von Kunststoff Addititvsystemen
- we add character to plastics.

     50                                                  Chemiedozententagung 2006

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