Publications by Karl Gademann | EPFL Graph Search

Genetically encoded betaxanthin-based small-molecular fluorescent reporter for mammalian cells

Karl Gademann, Simon Sieber, Leo Scheller

We designed and engineered a dye production cassette encoding a heterologous pathway, including human tyrosine hydroxylase and Amanita muscaria 4,5-DOPA dioxygenase, for the biosynthesis of the betaxanthin family of plant and fungal pigments in mammalian c ...

2020

Chemistry Europe Fellows Katharina M. Fromm and Karl Gademann

Karl Gademann

SWISS CHEMICAL SOC2020

Allelopathic Activity of the Iron Chelator Anachelin-A Molecular Hybrid with a Dual Mode of Action

Karl Gademann

One of the compounds suggested to be responsible for the cyanobacterial dominance over competing green algae is identified. Evidence is provided on the molecular, chemical level that the iron chelator anachelin from the cyanobacterium Anabaena cylindrica p ...

Wiley-V C H Verlag Gmbh2016

Functionally Optimized Neuritogenic Farinosone C Analogs: SAR-Study and Investigations on Their Mode of Action

Karl Gademann, Patrick Burch, Andrea Chicca

Several natural products derived from entomopathogenic fungi have been shown to initiate neuronal differentiation in the rat pheochromocytoma PC12 cell line. After the successful completion of the total synthesis program, the reduction of structural comple ...

Amer Chemical Soc2014

Balgacyclamides, Antiplasmodial Heterocyclic Peptides from Microcystis aeruguinosa EAWAG 251

Karl Gademann, Laeticia Da Silva, Simon Sieber, Cyril Portmann, Emilie Baudat

The isolation and structural characterization of three new heterocyclic and macrocyclic peptides, balgacyclamides A C, from Microcystis aeruginosa EAWAG 251 are reported. The constitutions were determined by 2D-NMR methods and mass spectrometry, and the co ...

Amer Chemical Soc2014

Telomerase Inhibitors from Cyanobacteria: Isolation and Synthesis of Sulfoquinovosyl Diacylglycerols from

Gerardo Turcatti, Damiano Banfi, Karl Gademann, Joachim Lingner, Laeticia Da Silva, Cyril Portmann, Emilie Baudat, Tom Woods

By using the Telospot assay, 27 different extracts of cyanobacteria were evaluated for telomerase inhibition. All extracts showed varying, but significant activity. We selected Microcystis aeruguinosa PCC 7806 to identify the active compound and a bioassay ...

Wiley-Blackwell2013

Bioinspired, releasable quorum sensing modulators

Adrien Keith Lawrence, Karl Gademann

We demonstrate the synthesis and immobilization of natural product hybrids featuring an acyl-homoserine lactone and a nitrodopamine onto biocompatible TiO2 surfaces through an operationally simple dip-and-rinse procedure. The resulting immobilized hybrids ...

Royal Society of Chemistry2013

Total Synthesis of Cyrneine A

Cindy Fellay, Karl Gademann

The tricyclic diterpene cyrneine A featuring a hexatrienal unit was prepared synthetically for the first time by a Heck reaction, a carbene ring expansion, and a reductive carbonylation. The structure of the natural product was assigned by X‐ray crystal an ...

Wiley-VCH Verlag GmbH2012

Antimalarial and antitubercular nostocarboline and eudistomin derivatives: synthesis, in vitro and in vivo biological evaluation

Simone Bonazzi, Luc Patiny, Rosario Scopelliti, Karl Gademann, Stewart Cole

The synthesis of nine nostocarboline derivatives with substitutions of the 2-methyl group by alkyl, aryl and functionalized residues, 10 symmetrical bis cationic dimers linking 6-Cl-norharmane through the 2-position and fifteen derivatives of the marine al ...

2010

Poly(ethylene glycol) Adlayers Immobilized to Metal Oxide Substrates Through Catechol Derivatives: Influence of Assembly Conditions on Formation and Stability

Karl Gademann

We have investigated Five different poly(ethylene glycol) (PEG, 5 kDa) catechol derivatives in terms of their spontaneous surface assembly from aqueous solution, adlayer stability, and resistance to nonspecific blood serum adsorption as a function of the t ...

2010

Anguinomycins and Derivatives: Total Syntheses, Modeling, and Biological Evaluation of the Inhibition of Nucleocytoplasmic Transport

Simone Bonazzi, Karl Gademann, Jean-Yves Wach, Ivo Zemp

The preparation of the polyketide natural products anguinomycin C and D is reported based on key steps such as Negishi stereoinversion cross coupling, Jacobsen Cr(III)-catalyzed Hetero Diels−Alder reaction, Evans B-mediated syn-aldol chemistry, and B-alkyl ...

2010

Multiple Toxin Production in the Cyanobacterium Microcystis: Isolation of the Toxic Protease Inhibitor Cyanopeptolin 1020

Karl Gademann, Cyril Portmann

The isolation and structure of cyanopeptolin 1020 (hexanoic acid-Glu-N[-O-Thr-Arg-Ahp-Phe-N-Me-Tyr-Val-]) from a Microcystis strain is reported. Very potent picomolar trypsin inhibition (IC50 = 670 pM) and low nanomolar values against human kallikrein (4.5 ...

2010

Surface Assembly of Catechol-Functionalized Poly(l-lysine)-graft-poly(ethylene glycol) Copolymer on Titanium Exploiting Combined Electrostatically Driven Self-Organization and Biomimetic Strong Adhesion

Karl Gademann, Cyril Portmann

Nonfouling coatings, based on surface-tethered, hydrophilic polymer chains, have widespread application in areas such as biosensing, medical devices, and biotechnology. Self-organization of polymers is a particularly attractive approach given its simplicit ...

American Chemical Society2010

Spatial isolation favours the divergence in microcystin net production by Microcystis in Ugandan freshwater lakes

Karl Gademann, Cyril Portmann

It is generally agreed that the hepatotoxic microcystins (MCs) are the most abundant toxins produced by cyanobacteria in freshwater. In various freshwater lakes in East Africa MC-producing Microcystis has been reported to dominate the phytoplankton, howeve ...

2010

The cytotoxic styryl lactone goniothalamin is an inhibitor of nucleocytoplasmic transport

Karl Gademann, Jean-Yves Wach

An in vivo nuclear export assay (immunostaining of Rio2 in HeLa cells) demonstrated that (R)-goniothalamin is an inhibitor of nucleocytoplasmic transport above 500 nM, which was rationalized also by molecular modeling. The cytotoxic styryl lactone natural ...

2010

A Synthetic Entry into the Taiwaniaquinoids Based on a Biogenetic Hypothesis: Total Synthesis of (-)-Taiwaniaquinone H

Rosario Scopelliti, Karl Gademann

(Chemical Equation Presented) Less carbon: Following a biogenetic proposal, the unusual 6-5-6 carbon skeleton of C19 taiwaniaquinoids was obtained by an intramolecular benzilic acid rearrangement from a C20 precur-sor. A protecting-group-free total synthes ...

2010

Design of a high-throughput device for screening surface modification protocols

Karl Gademann

The development of new high performance, ultra-thin organic coatings requires a strategy that has to consider a large number of surface treatment variables such as binding moieties, substrate, and adsorption conditions (e.g. temperature, solvent, concentra ...

2010

Synthetic Studies on the Sporolides: Exploration of the Enediyne Route

Massimo Binaghi, Simone Bonazzi, Cindy Fellay, Karl Gademann, Jean-Yves Wach

Synthetic studies towards the construction of the cyclopenta[a]indene fragment of the heptacyclic marine metabolite sporolide are reported based on a hypothetical biosynthesis. The key step of this biogenetic proposal includes a Bergman cyclization of an e ...

Georg Thieme Verlag2010

Connecting C-19 Norditerpenoids to C-20 Diterpenes: Total Syntheses of 6-Hydroxy-5,6-dehydrosugiol, 6-Hydroxysugiol, and Taiwaniaquinone H, and Formal Synthesis of Dichroanone

Rosario Scopelliti, Karl Gademann

Oxidation of the B-ring of abietane derivatives by Sharpless dihydroxylation gave the natural products 6-hydroxy-5,6-dehydrosugiol and 6-hydroxysugiol. Moreover, further oxidation gave a hydroxy dione derivative that provides a synthetic entry into the C-1 ...

2010

Occurrence of microcystin-producing cyanobacteria in Ugandan freshwater habitats

Karl Gademann, Cyril Portmann

Microcystins (MCs) are cyclic heptapeptides, which are the most abundant toxins produced by cyanobacteria in freshwater. The phytoplankton of many freshwater lakes in Eastern Africa is dominated by cyanobacteria. Less is known, however, on the occurrence o ...

2010