- Discovery of Novel Polycyclic Heterocyclic Derivatives from Evodiamine for the Potential Treatment of Triple-Negative Breast Cancer
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Evodiamine (Evo) is a quinazolinocarboline alkaloid found in Evodia rutaecarpa and exhibits moderate antiproliferative activity. Herein, we report using a scaffold-hopping approach to identify a series of novel polycyclic heterocyclic derivatives based on Evo as the topoisomerase I (Top1) inhibitor for the treatment of triple-negative breast cancer (TNBC), which is an aggressive subtype of breast cancer with limited treatment options. The most potent compound 7f inhibited cell growth in a human breast carcinoma cell line (MDA-MB-231) with an IC50 value of 0.36 μM. Further studies revealed that Top1 was the target of 7f, which directly induced irreversible Top1-DNA covalent complex formation or induced an oxidative DNA lesion through an indirect mechanism mediated by reactive oxygen species. More importantly, in vivo studies showed that 7f exhibited potent antitumor activity in a TNBC-patient-derived tumor xenograft model. These results suggest that compound 7f deserves further investigation as a promising candidate for the treatment of TNBC.
- Chen, Zhe-Sheng,Li, Dahong,Qiu, Yangyi,Wu, Liang,Xu, Jinyi,Xu, Shengtao,Yang, Dong-Hua,Yao, Hong,Zhou, Manzhen
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p. 17346 - 17365
(2021/12/09)
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- Silver(I)-Promoted ipso-Nitration of Carboxylic Acids by Nitronium Tetrafluoroborate
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A novel and efficient method for the regioselective nitration of a series of aliphatic and aromatic carboxylic acids to their corresponding nitro compounds using nitronium tetrafluoroborate and silver carbonate in dimethylacetamide has been described. This transformation is believed to proceed via the alkyl-silver or aryl-silver intermediate, which subsequently reacts with the nitronium ion to form nitro substances. Mild reaction conditions, tolerant of a broad range of functional groups, and formation of only the ipso-nitrated products are the key features of this methodology when compared to known methods for syntheses of nitroalkyls and nitroarenes.
- Natarajan, Palani,Chaudhary, Renu,Venugopalan, Paloth
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p. 10498 - 10504
(2015/11/18)
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- Alkylation of nitroarenes with Grignard reagents via oxidative nucleophilic substitution of hydrogen
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Alkylation of nitroarenes with Grignard reagents via oxidative nucleophilic substitution of hydrogen (ONSH) can be efficiently executed with potasium permanganate in liquid ammonia as an oxidative system for the σH adducts. The addition of RMgX to ArNO2 of stoichiometry 1:1 is accompanied with a redox process apparently of stoichiometry 2:1. Because of that, real stoichiometry of the reaction between nitroarenes and Grignard reagents is ca. 1:1.5.
- Ma?kosza, Mieczys?aw,Surowiec, Marek
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p. 167 - 171
(2007/10/03)
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- A novel safety-catch linker for the solid-phase synthesis of amides and esters
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(matrix presented) A new safety-catch linker for solid-phase organic synthesis is described. Synthesis and attachment of the linker to the solid phase was achieved via a simple and high-yielding strategy. The linker was exemplified by acylation to form unactivated amides, activation of the linker, and cleavage to release acyl moieties. Acids, amides, or esters were released under mild conditions and with exceptionally high purity. The reactivities of unactivated and activated amides are compared.
- Todd, Matthew H.,Oliver, Steven F.,Abell, Chris
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p. 1149 - 1151
(2008/02/09)
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- Method for preparing aromatic secondary amino compound
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Disclosed are (1) a method for preparing an aromatic secondary amino compound which comprises reacting an N-cyclohexylideneamino compound in the presence of a hydrogen moving catalyst and a hydrogen acceptor by the use of a sulfur-free polar solvent and/or a cocatalyst, and (2) a method for preparing an aromatic secondary amino compound which comprises reacting cyclohexanone or a nucleus-substituted cyclohexanone, an amine and a nitro compound corresponding to the amine in a sulfur-free polar solvent in the presence of a hydrogen moving catalyst, a cocatalyst being added or not added. In a further aspect, a method is provided for the preparation of aminodiphenylamine by reacting phenylenediamine and cyclohexanone in the presence of a hydrogen transfer catalyst in a sulfur-free polar solvent while using nitroaniline as a hydrogen acceptor.
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- The serotonin 5-HT4 receptor. 2. Structure-activity studies of the indole carbazimidamide class of agonists.
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A number of substituted indole carbazimidamides were prepared and evaluated as 5-HT4 receptor agonists by using the isolated field-stimulated guinea pig ileum preparation. Their selectivity for the 5-HT4 receptor was established by examining their affinity for other 5-HT receptors using radioligand-binding techniques. Several selective and highly potent full as well as partial agonists emerged from this study. For example, 1b,d were found to be the most potent, full 5-HT4 receptor agonist described so far (EC50 = 0.5 and 0.8 nM, respectively), being 6 and 4 times more potent than serotonin itself. On the other hand, 5b and 1h appeared as partial 5-HT4 receptor agonists in the nonstimulated guinea pig ileum preparation with potencies, evaluated against serotonin action, respectively similar (5b, Ki = 12 nM) to and 300-fold higher (1h, Ki = 0.04 nM) than serotonin.
- Buchheit,Gamse,Giger,Hoyer,Klein,Kloeppner,Pfannkuche,Mattes
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p. 2331 - 2338
(2007/10/02)
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- Process for the preparation of nitrophenyl alkyl ethers
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Nitrophenyl alkyl ethers can be advantageously prepared by reacting a nitrophenol with an alkyl halide in water as the reaction medium in such a manner that the nitrophenol is laid before with the water and the alkyl halide and a hydrogen halide-binding compound are then added simultaneously.
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- The synthesis of a novel series of substituted 2-phenyl-4H-3,1- benzoxazin-4-ones
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Following initial studies on a substituted 2-[3-methylphenyl]-4H-3,1- benzoxazin-4-one showing some cytotoxic activity, the synthesis of a novel series of 2-phenyl substituted 4H-3,1-benzoxazin-4-ones is reported herein.
- Pavlidis,Perry
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p. 533 - 548
(2007/10/02)
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- Correlation of Reaction Rates with a Substituent Constant Scale Derived from Calculated Electron Densities for a Computer Control Algorithm
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A new ? substituent scale based on electron density calculations by the AM1 quantum mechanical model has been established and used to correlate rates of O-methylation of substituted phenols, as part of a chemical artificial intelligence to control a fully automated apparatus for methyl iodide labeling.
- Cork, David G.,Hayashi, Nobuyoshi
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p. 1583 - 1585
(2007/10/02)
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- A Versatile and Efficient Construction of the 6H-Pyridocarbazole Ring System. Syntheses of the Antitumor Alkaloids Ellipticine, 9-Methoxyellipticine, and Olivacine and Their Analogues
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A general and efficient synthesis of the 6H-pyridocarbazole ring system is described, in which the key steps are (1) regioselective acylation of a 2-lithio-1-(phenylsulfonyl)indole (14) with 3,4-pyridinedicarboxylic acid anhydride (10), (2) cyclization of the deprotected keto acid 17 to keto lactam 19 with acetic anhydride, and (3) the addition of methyllithium to give, after reduction of the intermediate diol 23 with sodium borohydride, the target ring system.In this fashion, ellipticine (1a), 9-methoxyellipticine (1b), and 9-hydroxyellipticine (1c) were synthesized in excellent overall yields from indole.The use of Superhydride, in place of 1 equiv of methyllithium, provided a synthesis of olivacine (2), and the use of phthalic anhydride in the sequence allowed for the preparation of 6,11-dimethylbenzocarbazole (48).The overall yields of ellipticine (1a) (54percent) and 9-methoxyellipticine (1b) (47percent) in six steps from their respective indoles represent one of the most efficient syntheses of these antitumor alkaloids.
- Gribble, Gordon W.,Saulnier, Mark G.,Obaza-Nutaitis, Judy A.,Ketcha, Daniel M.
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p. 5891 - 5899
(2007/10/02)
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- Naturally Occurring Dibenzofurans. Part 5. Synthesis of Melacarpic Acid
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The total synthesis of the lichen dibenzofuran melacarpic acid (5) was achieved by intramolecular Ullman coupling of methyl 5-bromo-4-(2-bromo-5-methoxy-3-methylphenoxy)-6-heptyl-2-methoxybenzoate (48) or methyl 6-heptyl-5-iodo-4-(2-iodo-5-methoxy-3-methyl-4-nitrophenoxy)-2-methoxybenzoate (46) followed by appropriate transformations.
- Carvalho, Christopher F.,Sargent, Melvyn V.
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p. 1613 - 1620
(2007/10/02)
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- Nitration in Aqueous Nitric Acid: the Rate Profile and the Limiting Reaction Rates
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Rate coefficients for the nitration of a series of quaternary ammonium ions have been used to establish a rate profile for reaction in 63.7percent-100percent nitric acid at 25 deg C and to estimate the concentration of nitronium ions in the aqueous media.The kinetics of nitration of a series of reactive aromatic aromatic compounds (mainly phenolic ethers) in aqueous nitric acid have been analysed in terms of a first-order rate coefficient and the zeroth-order rate of formation of the nitronium ion.The first-order rate coefficients approach a limiting value as the reactivity of the aromatic substrate is increased and this value is as expected for the rate-limiting formation of an encounter pair (ArH*NO2+).The lifetime of nitronium ions in 60.4percent nitric acid (t1/2 ca. 5 x 10-8 s) has been calculated from the zeroth-order rate at 25 deg C and used to show that the formation of the encounter pair (ArH*NO2+) occurs by the diffusion together of the components, not by pre-association.The studies on the more reactive aromatic compounds were carried out in the presence of hydrazine since this was shown to prevent the nitrous-acid catalysed reactions previously observed.
- Draper, Mark R.,Ridd, John H. A.
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