Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Seit Februar 2021 bietet Wolfgang Brandt, ehemaliger Leiter der Arbeitsgruppe Computerchemie am IPB, sein Citizen Science-Projekt zur Pilzbestimmung an. Dafür hat er in regelmäßigen Abständen öffentliche Vorträge zur Vielfalt…
An ancient reaction vessel: TobZ carbamoylates the antibiotic tobramycin to form nebramycin 5′. The YrdC‐like domain (blue) catalyzes the formation of the novel intermediate carbamoyladenylate, which is channeled through a common “reaction chamber” to the Kae1‐like domain (brown), site of carbamoyl transfer.
Publikation
Béres, T.; Gemrotová, M.; Tarkowski, P.; Ganzera, M.; Maier, V.; Friedecký, D.; Dessoy, M. A.; Wessjohann, L. A.; Spíchal, L.; Strnad, M.; Doležal, K.;Analysis of cytokinin nucleotides by capillary zone electrophoresis with diode array and mass spectrometric detection in a recombinant enzyme in vitro reactionAnal. Chim. Acta751176-181(2012)DOI: 10.1016/j.aca.2012.08.049
A capillary zone electrophoresis (CZE) method for separation of adenosine and N6-isopentenyladenosine (cytokinin) nucleotides was developed, optimized and validated. Aqueous solutions of several amino acids were evaluated as the background electrolyte constituents. Separation of six nucleotides in less than 20 min with high theoretical plate number (up to 400 000 for isopentenyladenosine triphosphate) was achieved using a 100 mM sarcosine/ammonia buffer at pH 10.0. The detection limits of the CZE-UV method are in the low micromolar range (0.69–1.27 μmol L−1). Good repeatability of migration times (within 1.3%), peak areas (within 1.8%) and linearity (R2 > 0.999) was achieved over the concentration range 5–1000 μmol L−1. The method was used to assay the activity of the recombinant Arabidopsis thaliana isopentenyltransferase 1 (AtIPT1). Baseline separation of isopentenylated nucleotides by CE–ESI-MS using a volatile buffer (30 mM ammonium formate; pH 10.0) was accomplished. The identities of the reaction products – isopentenyladenosine di- and triphosphate were confirmed by HPLC-QqTOF-MS. Dephosphorylation of ATP was observed as a parallel reaction.
Publikation
van Berkel, S. S.; Brauch, S.; Gabriel, L.; Henze, M.; Stark, S.; Vasilev, D.; Wessjohann, L. A.; Abbas, M.; Westermann, B.;Traceless Tosylhydrazone-Based Triazole Formation: A Metal-Free Alternative to Strain-Promoted Azide-Alkyne CycloadditionAngew. Chem. Int. Ed.515343-5346(2012)DOI: 10.1002/anie.201108850
Triple‐T trick! Traceless tosylhydrazone‐based triazole formation is readily achieved by reacting primary amines with functional α,α‐dichlorotosylhydrozones under ambient conditions. This fast and efficient alternative affords exclusively 1,4‐substituted triazole “click products” with complete retention of configuration. Primary amines, inherent to many natural products, can be modified in this way without protecting group manipulations.