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Concomitant inhibition of multiple oncogenic pathways is a desirable goal in cancer therapy. To achieve such an outcome with a single molecule would simplify treatment regimes. Herein the core features of ruxolitinib (1), a marketed JAK1/2 inhibitor, have been merged with the HDAC inhibitor vorinostat (2), leading to new molecules that are bispecific targeted JAK/HDAC inhibitors. A preferred pyrazole substituted pyrrolopyrimidine, 24, inhibits JAK1 and HDACs 1, 2, 3, 6, and 10 with IC50 values of less than 20 nM, is <100 nM potent against JAK2 and HDAC11, and is selective for the JAK family against a panel of 97 kinases. Broad cellular antiproliferative potency of 24 is supported by demonstration of JAK-STAT and HDAC pathway blockade in hematological cell lines. Methyl analogue 45 has an even more selective profile. This study provides new leads for assessment of JAK and HDAC pathway dual inhibiton achieved with a single molecule.

High performance liquid chromatography (HPLC) has seen a spectacular development during the last few years due to its rapidity and its high resolving power [l-7]. Recently, HPLC has also been applied to include biological macromolecules such as polynucleotides, polysaccharides and proteins [3-71. This paper describes the first use of bioaffinity supports (in contrast to normally used 'non-biological' stationary phases) to the resolution of biological macromolecules in combination with the technique of HPLC, and for this novel technique we suggest the term: high performance liquid affinity chromatography, HPLAC. Examples are given of enzyme and isozyme separations using an immobilised general ligand, AMP, and of albumins employing an immobilised immunosorbent, anti-serum albumin.

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Anti-adhesion drugs may be an alternative to antibiotics to control infection of micro-organisms. The well-characterized interaction between cholera toxin and the cellular glycolipid GM1 makes it an attractive model for inhibition studies in general. In this report, we demonstrate a high-performance liquid affinity chromatography approach called weak affinity chromatography to evaluate cholera toxin inhibitors. The cholera toxin B-subunit was covalently coupled to porous silica and a (weak) affinity column was produced. The K D values of galactose and meta-nitrophenyl α-D-galactoside were determined with weak affinity chromatography to be 52 and 1 mM, respectively, which agree well with IC 50 values previously reported. To increase inhibition potency multivalent inhibitors have been developed and the interaction with multivalent glycopolypeptides was also evaluated. The affinity of these compounds was found to correlate with the galactoside content but K D values were not obtained because of the inhomogeneous response and slow off-rate from multivalent interactions. Despite the limitations in obtaining direct K D values of the multivalent galactopolypeptides, weak affinity chromatography represents an additional and valuable tool in the evaluation of monovalent as well as multivalent cholera toxin inhibitors. It offers multiple advantages, such as a low sample consumption, high reproducibility and short analysis time, which are often not observed in other methods of analysis.Keywords affinity constant; carbohydrate interactions; cholera toxin; high-performance liquid chromatography; receptor; ligand interactions; weak affinity chromatography Carbohydrate structures on mammalian epithelial cells are targeted by micro-organisms for specific attachment and initiation of infection or toxic effect. A specific inhibition of this initial interaction is an attractive strategy to control viral and bacterial infections (1). Anti-adhesion drugs could, for example, be of outmost importance in defeating cholera and traveller's diarrhea (2). The causative agents in these diseases are the toxins produced by Vibrio cholerae and Escherichia coli, respectively. The two toxins, cholera toxin (CT) and the heat-labile enterotoxin (LT), have a homology of about 80% and are essentially identical in binding and toxic effect, even though LT causes less severe symptoms than CT (3). They belong to the *Corresponding author: Maria Bergström, E-mail: maria.bergstrom@hik.se. NIH Public Access Author ManuscriptChem Biol Drug Des. Author manuscript; available in PMC 2010 January 1. Published in final edited form as:Chem Biol Drug Des. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript heterohexameric AB 5 bacterial toxins which all have an organization comprising a toxic Asubunit and an independent homopentamer of B-subunits, responsible for the specific recognition of glycosphingolipids on epithelial cells. The natural target in the case of CT and LT is the ganglioside GM1 (Galβ1-3GalNAcβ1-4[NeuAcα2-3]Galβ1-4Gl...