- 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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- Bent-core mesogens with an aromatic unit at the terminal position
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Bent-core liquid crystals with a naphthalene central unit and an aromatic ring at the terminal position of molecular tails were synthesised with the aim of enhancing nanosegregation. It was found that the length of the spacer between the rigid core and the terminal aromatic moiety had a profound influence on the liquid crystal polymorphism. The homologues with short spacers exhibited nematic and columnar phases, whereas the homologue with long spacers exhibited a tilted lamellar phase with a liquid-like in-plane order, indicating an unusual morphology of the densely packed toroidal objects. The morphology can be changed to twisted ribbons by small additives adsorbed on the membrane surface. This is the first example of twisted ribbons constructed by a lamellar system with no long-range in-plane order.
- Bajzíková, Kvetoslava,Svoboda, Ji?í,Novotná, Vladimíra,Pociecha, Damian,Gorecka, Ewa
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supporting information
p. 4672 - 4679
(2017/07/10)
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- IMIDAZOPYRIDINE COMPOUND
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The present invention provides an imidazopyridine compound represented by formula (I), wherein R1 and R2 each independently represent a C1-6 alkyl group et al; R3 and R4 each independently represent a hydrogen atom, a methyl et al; Ar1 is a divalent substituent representing a monocyclic or bicyclic, 3- to 8-membered aromatic or aliphatic heterocyclic group et al; Ar2 represents an aromatic carbocyclic group, or an aromatic heterocyclic group; W represents -(CH2)m et al, and m indicates an integer of from 0 to 10. This compound acts as a melanin concentrating hormone receptor antagonist, and is useful as treating agents for obesity.
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Page/Page column 51
(2008/06/13)
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- New potent antagonists of leukotrienes C4 and D4. 1. Synthesis and structure-activity relationships
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(p-Amylcinnamoyl)anthranilic acid (3a) had moderate antagonist activities against LTD4-induced smooth muscle contraction on guinea pig ileum and LTC4-induced bronchoconstriction in anesthetized guinea pigs. Modifications were made in the hydrophobic part (cinnamoyl moiety) and the hydrophilic part (anthranilate moiety) of 3a. A series of 8-(benzoylamino)-2-tetrazol-5-yl-1,4-benzodioxans and 8-(benzoylamino)-2-tetrazol-5-yl-4-oxo-4H-1-benzopyrans were revealed to be potent antagonists of leukotrienes C4 and D4. Among both series, ONO-RS-347 (18k) and ONO-RS411 (19h) were the most potent and orally active antagonists, respectively. Structure-activity relationships are discussed.
- Nakai,Konno,Kosuge,Sakuyama,Toda,Arai,Obata,Katsube,Miyamoto,Okegawa,Kawasaki
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