- The effect of MR1 ligand glyco-analogues on mucosal-associated invariant T (MAIT) cell activation
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Mucosal-associated invariant T (MAIT) cells are a subset of recently identified innate-like T lymphocytes that appear to play an important role in many pathologies ranging from viral and bacterial infection, to autoimmune disorders and cancer. MAIT cells are activated via the presentation of ligands by MR1 on antigen presenting cells to the MAIT T cell receptor (TCR), however few studies have explored the effects of systematic changes to the ligand structure on MR1 binding and MAIT cell activation. Herein, we report on the first study into the effects of changes to the sugar motif in the known MAIT cell agonists 7-hydroxy-6-methyl-8-d-ribityllumazine (RL-6-Me-7-OH) and 5-(2-oxopropylideneamino)-6-d-ribitylaminouracil (5-OP-RU). Tetramer staining of MAIT cells revealed that the absence of the 2′-hydroxy group on the sugar backbone of lumazines improved MR1-MAIT TCR binding, which could be rationalised using computational docking studies. Although none of the lumazines activated MAIT cells, all 5-OP-RU analogues showed significant MAIT cell activation, with several analogues exhibiting comparable activity to 5-OP-RU. Docking studies with the 5-OP-RU analogues revealed different interactions between the sugar backbone and MR1 and the MAIT TCR compared to those observed for the lumazines and confirmed the importance of the 2′-hydroxy group for ligand binding and activity. Taken together, this information will assist in the development of future potent agonists and antagonists of MAIT cells.
- Braganza, Chriselle D.,Shibata, Kensuke,Fujiwara, Aisa,Motozono, Chihiro,Sonoda, Koh-Hei,Yamasaki, Sho,Stocker, Bridget L.,Timmer, Mattie S. M.
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supporting information
p. 8992 - 9000
(2019/10/28)
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- Synthesis and biological evaluation of new carbohydrate-substituted indenoisoquinoline topoisomerase I inhibitors and improved syntheses of the experimental anticancer agents indotecan (LMP400) and indimitecan (LMP776)
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Carbohydrate moieties were strategically transported from the indolocarbazole topoisomerase I (Top1) inhibitor class to the indenoisoquinoline system in search of structurally novel and potent Top1 inhibitors. The syntheses and biological evaluation of 20 new indenoisoquinolines glycosylated with linear and cyclic sugar moieties are reported. Aromatic ring substitution with 2,3-dimethoxy-8,9-methylenedioxy or 3-nitro groups exerted strong effects on antiproliferative and Top1 inhibitory activities. While the length of the carbohydrate side chain clearly correlated with antiproliferative activity, the relationship between stereochemistry and biological activity was less clearly defined. Twelve of the new indenoisoquinolines exhibit Top1 inhibitory activity equal to or better than that of camptothecin. An advanced synthetic intermediate from this study was also used to efficiently prepare indotecan (LMP400) and indimitecan (LMP776), two anticancer agents currently under investigation in a Phase I clinical trial at the National Institutes of Health.
- Beck, Daniel E.,Agama, Keli,Marchand, Christophe,Chergui, Adel,Pommier, Yves,Cushman, Mark
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p. 1495 - 1512
(2014/03/21)
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- ALCOHOL-, DIOL-, AND CARBOHYDRATE-SUBSTITUTED INDENOISOQUINOLINES AS TOPOISOMERASE I INHIBITORS
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The invention described herein pertains to substituted indenoisoquinoline compounds as described herein, wherein RA, RD, W, X and Y are defined herein, pharmaceutical compositions and formulations comprising the indenoisoquinoline compounds, their synthesis, and methods for their use in the treatment and/or prevention of cancer.
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Page/Page column 46-47
(2012/12/13)
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- Alcohol-, diol-, and carbohydrate-substituted indenoisoquinolines as topoisomerase i inhibitors: Investigating the relationships involving stereochemistry, hydrogen bonding, and biological activity
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The DNA-relaxing enzyme topoisomerase I (Top1) can be inhibited by heterocyclic compounds such as indolocarbazoles and indenoisoquinolines. Carbohydrate and hydroxyl-containing side chains are essential for the biological activity of indolocarbazoles. The current study investigated how similar functionalities could be "translated" to the indenoisoquinoline system and how stereochemistry and hydrogen bonding affect biological activity. Herein is described the preparation and assay of indenoisoquinolines substituted with short-chain alcohols, diols, and carbohydrates. Several compounds (including those derived from sugars) display potent Top1 poisoning and antiproliferative activities. The Top1 poisoning activity of diol-substituted indenoisoquinolines is dependent upon stereochemistry. Although the effect is striking, molecular modeling and docking studies do not indicate any reason for the difference in activity due to similar calculated interactions between the ligand and Top1-DNA complex and ambiguity about the binding mode. A stereochemical dependence was also observed for carbohydrate-derived indenoisoquinolines. Although similar trends were observed in other classes of Top1 inhibitors, the exact nature of this effect has yet to be elucidated.
- Peterson, Katherine E.,Cinelli, Maris A.,Morrell, Andrew E.,Mehta, Akhil,Dexheimer, Thomas S.,Agama, Keli,Antony, Smitha,Pommier, Yves,Cushman, Mark
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p. 4937 - 4953
(2011/09/21)
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- Synthesis and Hydrolytic Lability of α-Phenoxyacetamides Containing Hydroxy Groups in the N-alkyl Residue
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Secondary and tertiary amides of 3,5-biscarbonyl>phenoxyacetic acid bearing hydroxy groups in positions β (β-OH) and γ (γ-OH) relative to the acetamide nitrogen atom have been synthesized.Such amides easily undergo cleavage of the acetamide bond in water at neutral pH.Hydrolysis rate constant for a series of such amides and protonation constants for the corresponding leaving amines were determined.No simple correlation between the two parameters could be found.A study of the dependence of these parameters on the structural features of the substrates, such as the presence of an N-methyl group and number of β-OH and γ-OH groups, was carried out.All these features lead to enhancement of the amide hydrolysis rate and a synergistic effect is operative when both N-methyl and β-OH groups are contained in the substrate.Presence of a methyl group increases the basicity of amines whereas β-OH and γ-OH groups have the opposite effect.Mechanistic speculations seem to indicate that the abnormal lability of the acetamide bond is due to protic-like catalysis by an intramolecular OH...N hydrogen bond.
- Anelli, Pier Lucio,Brocchetta, Marino,Canipari, Sonia,Losi, Pietro,Manfredi, Giuseppe,et al.
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p. 135 - 142
(2007/10/03)
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