Stefan Tasler

N-substituted 2′-(aminoaryl)benzothiazoles as kinase inhibitors: Hit identification and scaffold hopping

Starting with a hit from vHTS attained by a docking procedure of virtual compounds into ATP pockets of different kinases applying the 4SCan technology, variations of the adenine mimic resulted in the identification of promising scaffolds, giving rise to in vitro IC(50) values in the nanomolar range on different kinases down to 63nM.

Substituted 2-arylbenzothiazoles as kinase inhibitors: Hit-to-lead optimization

Based on an (aminoaryl)benzothiazole quinazoline hit structure for kinase inhibition, a systematic optimization program resulted in a lead structure allowing for inhibitory activities in cellular phosphorylation assays in the low nanomolar range.

Inhibitors of potassium channels KV1.3 and IK-1 as immunosuppressants.

New structural classes of K(V)1.3 and IK-1 ion channel blockers have been identified based on a virtual high throughput screening approach using a homology model of KcsA. These compounds display inhibitory effects on T-cell and/or keratinocyte proliferation and immunosuppressant activity within a DTH animal model.

Preparation of Nickel-on-Charcoal (Ni/C): An Improved Protocol

A modified preparation of the inexpen- sive, heterogeneous precatalyst Ni(II)/C, has been developed which (1) reduces the number of solvent distillations; (2) generates no organic waste; (3) leads to complete impregnation of the Ni(II) salts in- vested; and (4) extends the number of sources of charcoal which can be used to make the catalyst. Several carbon-carbon, as well as carbon-nitrogen and carbon-hydrogen bond-forming reactions have been run which compare Ni/C prepared via this new protocol with those formed using the original proto- col. The results from each are virtually identical.

Thienopyrimidines as β3-adrenoceptor agonists: Hit-to-lead optimization

Resulting from a vHTS based on a pharmacophore alignment on known β3-adrenoceptor ligands, an aryloxypropanolamine scaffold comprising a thienopyrimidine moiety was further optimized as a human β3-AR agonist, yielding a lead compound with an excellent cellular activity of EC(50)=20 pM, selectivity over hβ1- and hβ2-adrenoceptors and a promising safety profile.

An aryloxypropanolamine hβ3-adrenoceptor agonist as bladder smooth muscle relaxant

The relaxant effect of an aryloxypropanolamine β3-adrenoceptor agonist on carbachol pre-contracted human detrusor muscle strips was evaluated and compared with literature results from reference compounds of similar mode of action, including mirabegron. A significant relaxation was observed for rac-4-{2-hydroxy-3-[1-(5-phenylthieno[2,3-d]pyrimidin-4-yl)piperidin-4-ylamino]propoxy}-2-(hydroxymethyl)phenol which was similar to that exerted by mirabegron. In order to allow for a thorough discussion of results in comparison to reference compounds, their affinity, selectivity and efficacy as hβ3-AR agonists have been evaluated and discussed thoroughly. A ranking of hβ3-AR agonists by relative efficacy resulted in the closest analogy to the order of relaxation potential, with only the relaxant effect of mirabegron not reflecting its excellent relative efficacy as such.

A vHTS approach for the identification of β-adrenoceptor ligands

Using a vHTS based on a pharmacophore alignment on known beta3-adrenoceptor ligands, a set of intriguing beta-adrenoceptor ligands was identified, optimization of which resulted in a selective and potent human beta2-AR antagonist.