- Development and application of a high-throughput screening assay for identification of small molecule inhibitors of the P. falciparum reticulocyte binding-like homologue 5 protein
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The P. falciparum parasite, responsible for the disease in humans known as malaria, must invade erythrocytes to provide an environment for self-replication and survival. For invasion to occur, the parasite must engage several ligands on the host erythrocyte surface to enable adhesion, tight junction formation and entry. Critical interactions include binding of erythrocyte binding-like ligands and reticulocyte binding-like homologues (Rhs) to the surface of the host erythrocyte. The reticulocyte binding-like homologue 5 (Rh5) is the only member of this family that is essential for invasion and it binds to the basigin host receptor. The essential nature of Rh5 makes it an important vaccine target, however to date, Rh5 has not been targeted by small molecule intervention. Here, we describe the development of a high-throughput screening assay to identify small molecules which interfere with the Rh5-basigin interaction. To validate the utility of this assay we screened a known drug library and the Medicines for Malaria Box and demonstrated the reproducibility and robustness of the assay for high-throughput screening purposes. The screen of the known drug library identified the known leukotriene antagonist, pranlukast. We used pranlukast as a model inhibitor in a post screening evaluation cascade. We procured and synthesised analogues of pranlukast to assist in the hit confirmation process and show which structural moieties of pranlukast attenuate the Rh5 – basigin interaction. Evaluation of pranlukast analogues against P. falciparum in a viability assay and a schizont rupture assay show the parasite activity was not consistent with the biochemical inhibition of Rh5, questioning the developability of pranlukast as an antimalarial. The high-throughput assay developed from this work has the capacity to screen large collections of small molecules to discover inhibitors of P. falciparum Rh5 for future development of invasion inhibitory antimalarials.
- Sleebs, Brad E.,Jarman, Kate E.,Frolich, Sonja,Wong, Wilson,Healer, Julie,Dai, Weiwen,Lucet, Isabelle S.,Wilson, Danny W.,Cowman, Alan F.
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p. 188 - 200
(2020/11/05)
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- Selective Optimization of Pranlukast to Farnesoid X Receptor Modulators
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Selective optimization of side activities (SOSA) offers an alternative entry to early drug discovery and may provide rapid access to bioactive new chemical entities with desirable properties. SOSA aims to reverse a drug's side activities through structural modification and to design out the drug's original main action. We identified a moderate side activity for the cysteinyl leukotriene receptor 1 (CysLT1R) antagonist pranlukast on the farnesoid X receptor (FXR). Systematic structural modification of the drug allowed remarkable optimization of its partial FXR agonism to sub-nanonmolar potency. The resulting FXR modulators lack any activity on CysLT1R and are characterized by high selectivity, high metabolic stability, and low toxicity. With their favorable in vitro profile, these SOSA-derived FXR modulators constitute a new FXR ligand chemotype that appears suitable for further preclinical evaluation.
- Schierle, Simone,Schmidt, Jurema,Kaiser, Astrid,Merk, Daniel
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p. 2530 - 2545
(2018/11/25)
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- PROCESS FOR PRODUCING CHROMONE COMPOUND
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A process for producing a dicarboxylic acid compound represented by the formula (4): wherein R1 and R2 are the same or different and each represents lower alkyl and the wavy line indicates that this compound is the E- or Z-isomer or
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- Process of producing 2-cyano-4-oxo-4H-benzopyran compounds
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There is disclosed a process of producing a 2-cyano-4-oxo-4H-benzopyran compound of the general formula (2): STR1 wherein R1 and R2 are independently hydrogen, halogen, hydroxy, C1 -C5 alkyl, C1 -Csu
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