Publications de Cyril Portmann

Balgacyclamides, Antiplasmodial Heterocyclic Peptides from Microcystis aeruguinosa EAWAG 251

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

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

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

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

Cyril Portmann, Karl Gademann

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

Cyril Portmann, Karl Gademann

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

Cyril Portmann, Karl Gademann

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

Biologically active secondary metabolites from cyanobacteria

Cyril Portmann

For millennia, nature was the only source of medicine for mankind. Even today natural products represent a large proportion of the drugs in use. In some areas, like cancer or infectious diseases, about 50 % of the compounds used are of natural origin. Cyan ...

EPFL2010

Occurrence of microcystin-producing cyanobacteria in Ugandan freshwater habitats

Cyril Portmann, Karl Gademann

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

New antiplasmodial natural products from cyanobacteria: linking their ecological role to their therapeutic potential

Cyril Portmann, Karl Gademann

Cyanobacteria (blue-green algae) produce many metabolites that are directed towards competing photoautotrophs. Such algicidal compounds might offer new approaches for the selective inhibition of the malaria parasite, Plasmodium falciparum, as this organism ...

2009

Directed Biosynthesis of Phytotoxic Alkaloids in the Cyanobacterium Nostoc 78-12A

Cyril Portmann, Karl Gademann, Cora Prestinari, Theresa Myers

Nostocarboline, a chlorinated and N-methylated carbolinium alkaloid, displays potent and selective inhibition of photoautotrophic organisms as well as the malaria parasite Plasmodium falciparum, while showing very low toxicity to bacterial and fungal patho ...

2009

Aerucyclamides A and B: Isolation and Synthesis of Toxic Ribosomal Heterocyclic Peptides from the Cyanobacterium Microcystis aeruginosa PCC 7806

Cyril Portmann, Karl Gademann

Two new modified hexacyclopeptides, aerucyclamides A and B, were isolated from the toxic freshwater cyanobacterium Microcystis aeruginosa PCC 7806. The constitution was assigned by spectroscopic methods, and the configuration determined by chemical degrada ...

2008