Development of Continuous Flow Sonogashira Coupling of lead Anti-Cancer Small Molecule Inhibitors for Potential Treatment of Acute Myeloid Leukemia

As the technology for science develops, the research strategy in medicines and therapeutics also improves. In this paper, I will cover the process of Sonogashira cross-coupling and Amide Coupling reaction for an anticancer agent in both batch and flow chemistry. Continuous Flow Chemistry has advantages such as being more efficient, safer, and faster. This paper studies the synthesis of HSNO608, an anticancer lead compound for Acute Myeloid Leukemia (AML), which has a specific potent activity to FTL3 Kinase. Inhibition of FLT3 Kinase leads to inhibition of downstream pathways such as MPK and P13K pathways. In this two-step experiment, the Sonogashira cross-coupling reaction is a crucial step in the flow process. For the amidation reaction, it favored high retention time and low temperatures. For the Sonogashira cross-coupling reactions, different types of Palladium Catalyst and Copper Co-catalyst were screened. The best catalyst found was PdCl2(MeCN)2 with the ligand of [(t-Bu)3PH]BF4 giving us a yield of 88% with high loading (%10) of Copper and Pd catalyst. This condition was further optimized to reduce the catalyst loading to 1%. In conclusion, we were able to optimize and create methods to synthesize lead medicinal compounds. In the future, this approach could be applied to other anticancer targets and other medicinal chemical targets

Visualizing the Interface of Biotin and Fatty Acid Biosynthesis through SuFEx Probes

Site-specific covalent conjugation offers a powerful tool to identify and understand protein-protein interactions. In this study, we discover that sulfur fluoride exchange (SuFEx) warheads effectively crosslink the Escherichia coli acyl carrier protein (AcpP) with its partner BioF, a key pyridoxal 5′-phosphate (PLP)-dependent enzyme in the early steps of biotin biosynthesis by targeting a tyrosine residue proximal to the active site. We identify the site of crosslink by MS/MS analysis of the peptide originating from both partners. We further evaluate the BioF-AcpP interface through protein crystallography and mutational studies. Among the AcpP-interacting BioF surface residues, three critical arginine residues appear to be involved in AcpP recognition so that pimeloyl-AcpP can serve as the acyl donor for PLP-mediated catalysis. These findings validate an evolutionary gain-of-function for BioF, allowing the organism to build biotin directly from fatty acid biosynthesis through surface modifications selective for salt bridge formation with acidic AcpP residues.</p

Development of Human Carbonic Anhydrase II Heterobifunctional Degraders

Human carbonic anhydrase II (hCAII) is a metalloenzyme essential to critical physiological processes in the body. hCA inhibitors are used clinically for the treatment of indications ranging from glaucoma to epilepsy. Targeted protein degraders have emerged as a promising means of inducing the degradation of disease-implicated proteins by using the endogenous quality control mechanisms of a cell. Here, a series of heterobifunctional degrader candidates targeting hCAII were developed from a simple aryl sulfonamide fragment. Degrader candidates were functionalized to produce either cereblon E3 ubiquitin ligase (CRBN) recruiting proteolysis targeting chimeras (PROTACs) or adamantyl-based hydrophobic tags (HyTs). Screens in HEK293 cells identified two PROTAC small-molecule degraders of hCA. Optimization of linker length and composition yielded a degrader with sub-nanomolar potency and sustained depletion of hCAII over prolonged treatments. Mechanistic studies suggest that this optimized degrader depletes hCAII through the same mechanism as previously reported CRBN-recruiting heterobifunctional degraders

Atf1 Is a Target of the Mitogen-activated Protein Kinase Pmk1 and Regulates Cell Integrity in Fission Yeast

In fission yeast, knockout of the calcineurin gene resulted in hypersensitivity to Cl−, and the overexpression of pmp1+ encoding a dual-specificity phosphatase for Pmk1 mitogen-activated protein kinase (MAPK) or the knockout of the components of the Pmk1 pathway complemented the Cl− hypersensitivity of calcineurin deletion. Here, we showed that the overexpression of ptc1+ and ptc3+, both encoding type 2C protein phosphatase (PP2C), previously known to inactivate the Wis1–Spc1–Atf1 stress-activated MAPK signaling pathway, suppressed the Cl− hypersensitivity of calcineurin deletion. We also demonstrated that the mRNA levels of these two PP2Cs and pyp2+, another negative regulator of Spc1, are dependent on Pmk1. Notably, the deletion of Atf1, but not that of Spc1, displayed hypersensitivity to the cell wall-damaging agents and also suppressed the Cl− hypersensitivity of calcineurin deletion, both of which are characteristic phenotypes shared by the mutation of the components of the Pmk1 MAPK pathway. Moreover, micafungin treatment induced Pmk1 hyperactivation that resulted in Atf1 hyperphosphorylation. Together, our results suggest that PP2C is involved in a negative feedback loop of the Pmk1 signaling, and results also demonstrate that Atf1 is a key component of the cell integrity signaling downstream of Pmk1 MAPK