Bienta will be paricipating in the 18th European Symposium on Fluorine Chemistry, Kyiv, Ukraine, August 7th–12th, 2016.

N-arylsulfamoylbenzenesulfonyl fluorides as inhibitors of serine proteases

Petro Borysko,1 Maria Kliachyna,1  Sergey Zozulya,1,2 Oleksandr Vasylchenko,3 Andrey Bogolubsky,1 Yurii Moroz,2 Pavel Mykhailiuk,1,4 and Andrey Tolmachev1,2

1Enamine Ltd., 78 Chervonotkatska Street, Kyiv, 02094, Ukraine,

2ChemBioCenter, Kyiv National Taras Shevchenko University, 61 Chervonotkatska Street, Kyiv, 02094, Ukraine.

3Institute of Molecular Biology and Genetics National Academy of Sciences of Ukraine, 150, Zabolotnogo Street, Kyiv, 03680, Ukraine.

4Department of Chemistry, Kyiv National Taras Shevchenko University, 64 Volodymyrska Street, Kyiv, 01601, Ukraine.

Sulfonyl fluorides (SF) have been among popular covalent protein modifiers that can assess functionally important protein residues. Moderate reactivity of these sulfonyl halides allows them to selectively react only with strong nucleophiles; for example, serine or threonine residues of catalytic triads of serine or threonine proteases; and some SF are marketed as protease inhibitors (phenylmethanesulfonyl fluoride, PMSF, 4-(2-aminoethyl)benzenesulfonyl fluoride, AEFBS). Despite popularity, the marketed SF inhibitors have drawbacks associated with solubility, stability in aqueous solution and toxicity.

In a search for new motifs for the SF covalent protein modifiers, we decided to combine two functions in one molecule: sulfonamide and sulfonyl fluoride groups. These sulfamoylbenzenesulfonyl fluorides can be prepared by acylation of amines with non-equivalent bis-sulfonyl halides. We focus our research on the AEFBS analogues and selected three derivatives: 2-(chlorosulfonyl)benzenesulfonyl fluoride, 3-(chlorosulfonyl)benzenesulfonyl fluoride, and 4-(chlorosulfonyl)benzenesulfonyl fluoride. Then, we enumerated a library of the sulfonyl fluorides using our REAL approach based on experimental feasibility and availability of reagents. In silico docking of the library against bovine trypsin, a model protease, afforded 30 member set that was further synthesized. Binding studies utilizing protein thermal shift assay revealed more than 10 binders. Inhibition potency of these compounds was determined using a trypsin BAPNA assay that identified new trypsin inhibitors more potent than the known SFs.