An Automated Electrochemical Flow Platform to Accelerate Library Synthesis and Reaction Optimization.

Automated batch and flow setups are well-established for high throughput experimentation in both thermal chemistry and photochemistry. However, the development of automated electrochemical platforms is hindered by cell miniaturization challenges in batch and difficulties in designing effective single-pass flow systems. In order to address these issues, we have designed and implemented a new, slug-based automated electrochemical flow platform.

Synthesis of amide and sulfonamide substituted N-aryl 6-aminoquinoxalines as PFKFB3 inhibitors with improved physicochemical properties.

In oncology, the "Warburg effect" describes the elevated production of energy by glycolysis in cancer cells. The ubiquitous and hypoxia-induced 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) plays a noteworthy role in the regulation of glycolysis by producing fructose-2,6-biphosphate (F-2,6-BP), a potent activator of the glycolysis rate-limiting phosphofructokinase PFK-1. Series of amides and sulfonamides derivatives based on a N-aryl 6-aminoquinoxaline scaffold were synthesized and tested for their inhibition of PFKFB3 in vitro in a biochemical assay as well as in HCT116 cells.

Predicting Residence Time and Drug Unbinding Pathway through Scaled Molecular Dynamics.

Computational approaches currently assist medicinal chemistry through the entire drug discovery pipeline. However, while several computational tools and strategies are available to predict binding affinity, predicting the drug-target binding kinetics is still a matter of ongoing research. Here, we challenge scaled molecular dynamics simulations to assess the off-rates for a series of structurally diverse inhibitors of the heat shock protein 90 (Hsp90) covering 3 orders of magnitude in their experimental residence times.

Discovery and Structure-Activity Relationships of N-Aryl 6-Aminoquinoxalines as Potent PFKFB3 Kinase Inhibitors.

Energy and biomass production in cancer cells are largely supported by aerobic glycolysis in what is called the Warburg effect. The process is regulated by key enzymes, among which phosphofructokinase PFK-2 plays a significant role by producing fructose-2,6-biphosphate; the most potent activator of the glycolysis rate-limiting step performed by phosphofructokinase PFK-1. Herein, the synthesis, biological evaluation and structure-activity relationship of novel inhibitors of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), which is the ubiquitous and hypoxia-induced isoform of PFK-2, are reported.

Ligand Desolvation Steers On-Rate and Impacts Drug Residence Time of Heat Shock Protein 90 (Hsp90) Inhibitors.

Residence time and more recently the association rate constant k are increasingly acknowledged as important parameters for in vivo efficacy and safety of drugs. However, their broader consideration in drug development is limited by a lack of knowledge of how to optimize these parameters. In this study on a set of 176 heat shock protein 90 inhibitors, structure-kinetic relationships, X-ray crystallography, and molecular dynamics simulations were combined to retrieve a concrete scheme of how to rationally slow down on-rates.

A Non-Competitive Inhibitor of VCP/p97 and VPS4 Reveals Conserved Allosteric Circuits in Type I and II AAA ATPases.

AAA ATPases have pivotal functions in diverse cellular processes essential for survival and proliferation. Revealing strategies for chemical inhibition of this class of enzymes is therefore of great interest for the development of novel chemotherapies or chemical tools. Here, we characterize the compound MSC1094308 as a reversible, allosteric inhibitor of the type II AAA ATPase human ubiquitin-directed unfoldase (VCP)/p97 and the type I AAA ATPase VPS4B.

Cell survival and protein secretion associated with Golgi integrity in response to Golgi stress-inducing agents.

The Golgi apparatus is part of the secretory pathway and of central importance for modification, transport and sorting of proteins and lipids. ADP-ribosylation factors, whose activation can be blocked by brefeldin A (BFA), play a major role in functioning of the Golgi network and regulation of membrane traffic and are also involved in proliferation and migration of cancer cells. Due to high cytotoxicity and poor bioavailability, BFA has not passed the preclinical stage of drug development.

A novel strategy for ADME screening of prodrugs: combined use of serum and hepatocytes to integrate bioactivation and clearance, and predict exposure to both active and prodrug to the systemic circulation.

Common strategies to optimize prodrugs use either in vitro or rodent in vivo approaches, which do not consider elimination pathways that do not result in the generation of the desired product or might be misleading because of species differences, respectively. As a step forward, we have incorporated a novel application of hepatocytes into our prodrug optimization strategy to increase the bioavailability of a poorly soluble drug candidate by attaching a charged ester linker. The model involves the incubation of hepatocytes from multiple species in serum-containing medium to mimic formation as well as simultaneous metabolism of both prodrug and active drug.

Functional analysis of Hsp70 inhibitors.

The molecular chaperones of the Hsp70 family have been recognized as targets for anti-cancer therapy. Since several paralogs of Hsp70 proteins exist in cytosol, endoplasmic reticulum and mitochondria, we investigated which isoform needs to be down-regulated for reducing viability of cancer cells. For two recently identified small molecule inhibitors, VER-155008 and 2-phenylethynesulfonamide (PES), which are proposed to target different sites in Hsp70s, we analyzed the molecular mode of action in vitro.

Fragment-based discovery of hydroxy-indazole-carboxamides as novel small molecule inhibitors of Hsp90.

Inhibitors of the Hsp90 molecular chaperone are showing considerable promise as potential molecular therapeutic agents for the treatment of cancer. Here we describe the identification of novel small molecular weight inhibitors of Hsp90 using a fragment based approach. Fragments were selected by docking, tested in a biochemical assay and the confirmed hits were crystallized.