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…
Vasco, A. V.; Ceballos, L. G.; Wessjohann, L. A.; Rivera, D. G.;Multicomponent functionalization of the octreotide peptide macrocyclic scaffoldEur. J. Org. Chem.2022e202200687(2022)DOI: 10.1002/ejoc.202200687
The replacement of the disulfide bridge by other types of side chain linkages has been a continuous endeavor in the development of cyclic peptide drugs with improved metabolic stability. Octreotide is a potent and selective somatostatin analog that has been used as an anticancer agent, in radiolabeled conjugates for the localization of tumors and as targeting moiety in peptide-drug conjugates. Here, we describe an onresin methodology based on a multicomponent macrocyclization that enables the substitution of the disulfide bond by a tertiary lactam bridge functionalized with a variety of exocyclic moieties, including lipids, fluorophores, and charged groups. Conformational analysis in comparison with octreotide provides key information on the type of functionalization permitting the conformational mimicry of the bioactive peptide.
Publikation
Ditfe, T.; Bette, E.; N. Sultani, H.; Otto, A.; Wessjohann, L. A.; Arnold, N.; Westermann, B.;Synthesis and biological evaluation of highly potent fungicidal deoxy‐hygrophoronesEur. J. Org. Chem.20213827-3836(2021)DOI: 10.1002/ejoc.202100729
Although stripped from hydroxyl-groups, deoxygenated
hygrophorones remain highly active against severe phytopathogens. The
synthesis to these natural product congeners is achieved in
rearrangement sequences, with an optimized deprotection strategy
avoiding retro-aldol reactions. The activities are comparable to
fungicides used in agriculture.
Based on naturally occurring hygrophorones, racemic di-
and mono-hydroxylated cyclopentenones bearing an aliphatic side chain
have been produced in short synthetic sequences starting from furfuryl
aldehyde. For the series of dihydroxylated trans-configured derivatives, an Achmatowicz-rearrangement and a Caddick-ring contraction were employed, and for the series of trans-configured
mono-hydroxylated derivatives a Piancatelli-rearrangement. All final
products showed good to excellent fungicidal activities against the
plant pathogens B. cinerea, S. tritici and P. infestans.
Bücher und Buchkapitel
Restrepo, S.; Samper, C.; di Palma, F.; Hodson, E.; Torres, M.; Reol, E. M.; Eddi, M.; Wessjohann, L.; Jaramillo, G. P.; et al., .;Colombia hacia una sociedad
del conocimiento. Reflexiones
y propuestas1-450(2020)ISBN:978-958-5135-12-3
Medicago truncatula, owing to its small diploid genome (∼500 Mbp), short life cycle, and high natural diversity makes it a good model plant and has opened the door of opportunities for scientists interested in studying legume biology. But over the years, challenges are also being faced for genetic manipulation of this plant. Many genetic manipulation protocols have been published involving Agrobacterium tumefaciens, a pathogen causing tumor disease in plants. These protocols apart from being difficult to achieve, are also time consuming. Nowadays, an easy, less time consuming and highly reproducible Agrobacterium rhizogenes based method is in use by many research groups. This method generates composite plants having transformed roots on a wild‐type shoot. Here, stable transformed lines that can be propagated over time are not achieved by this method, but for root‐development or root–microbe interaction studies this method has proven to be a useful tool for the community. In addition, transformed roots can be propagated by root organ cultures (ROCs), wherein transformed roots are propagated on sucrose containing media without any shoot part. Occasionally, even stable transgenic plants can be regenerated from transgenic roots. In this chapter, developments and improvements of various transformation protocols are discussed. The suitability of composite plants is highlighted by a study on mycorrhization of transformed and non‐transformed roots, which did not show differences in the mycorrhization rate and developmental stages of the arbuscular mycorrhizal (AM) fungus inside the roots as well as in transcript accumulation and metabolite levels of roots. Finally, applications of the A. rhizogenes based transformation method are discussed.