- Toward fullerene-based X-ray contrast agents: Design and synthesis of non-ionic, highly-iodinated derivatives of C60
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An X-ray contrast agent precursor based on C60 has been designed, synthesized, and characterized. The compound is the monoadduct of a malonodiamide containing six iodine atoms and eight acetal-protected alcohols with multiple hindered rotations
- Wharton, Tim,Wilson, Lon J
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- Highly-iodinated fullerene as a contrast agent for X-ray imaging
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The first fullerene-based X-ray contrast agent (CA) has been designed, synthesized, and characterized. The new CA is an externally functionalized derivative of C60 that is conceptually based on contemporary X-ray CA, all of which use iodine as the X-ray attenuating vehicle and are based on the 2,4,6-triiodinated-benzene-ring substructure. Using a modified Bingel-type reaction, a single addend containing 6 iodine atoms and 8 protected hydroxyl groups was appended to C60 followed by the addition of 4 more addends each containing 4 protected hydroxyl groups. Final deprotection afforded the highly water-soluble (>460 mg/mL), non-ionic, highly-iodinated (24% I) fullerene for application as an X-ray contrast agent.
- Wharton, Tim,Wilson, Lon J.
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- Ammonium Chloride-Promoted Rapid Synthesis of Monosubstituted Ureas under Microwave Irradiation
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Monosubstituted ureas are important scaffolds in organic chemistry. They appear in various biologically active compounds and serve as versatile precursors in synthesis. Monosubstituted ureas were originally prepared using toxic and hazardous phosgene equivalents. Modern methods include transamidation of urea and nucleophilic addition to cyanate salts, both of which suffer from a narrow substrate scope due to the need for a strong acid and prolonged reaction times. We hereby report that ammonium chloride can promote the reaction between amines and potassium cyanate to generate monosubstituted ureas in water. This method proceeds rapidly under microwave irradiation and tolerates a broad range of functional groups. Unlike previous strategies, it is compatible with other nucleophiles, acid-labile moieties, and most of the common protecting groups. The products precipitate out of solution, allowing facile isolation without column chromatography.
- Lan, Chunling Blue,Auclair, Karine
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p. 5135 - 5146
(2021/10/19)
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- Toward the development of chemoprevention agents (III): Synthesis and anti-inflammatory activities of a new class of 5-glycylamino-2-substituted-phenyl-1,3-dioxacycloalkanes
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A new series of 5-glycylamino-2-substituted-phenyl-1,3-dioxacycloalkanes were designed and synthesized. The anti-inflammatory activities of these compounds were tested using the xylene-induced mouse ear edema model. Sixteen of these new compounds exhibited comparable or better anti-inflammatory activities than aspirin suggesting that they can be further developed as potential anti-inflammatory drug leads. In addition, treatment with these anti-inflammatory agents did not prolong tail bleeding time in mice. The structure/activity relationships were also analyzed among these compounds. Considering their good efficacy and safety profiles, some 5-glycylamino-2-substituted-phenyl-1,3-dioxacycloalkanes are worthy to be explored further in assessing the possible link between anti-inflammation and cancer prevention.
- Bi, Lanrong,Zhao, Ming,Gu, Keli,Wang, Chao,Ju, Jingfang,Peng, Shiqi
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p. 1764 - 1774
(2008/09/20)
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- Toward the development of chemoprevention agents. Part II: Chemo-enzymatic synthesis and anti-inflammatory activities of a new class of 5-amino-2-substitutedphenyl-1,3-dioxacycloalkanes
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A new series of optically pure 5-amino-2-substitutedphenyl-1,3-dioxacycloalkanes were designed and synthesized via a chemo-enzymatic combined method to develop new chemoprevention agents. Twenty-four of newly synthesized compounds significantly inhibited xylene-induced rat ear edema and exhibited comparable or better anti-inflammatory activities than the reference drug aspirin. Treatment of these anti-inflammatory agents did not prolong the tail bleeding time in rat. In addition, 5-amino-2-substitutedphenyl-1,3-dioxacycloalkanes exhibited good membrane permeability based on in vitro Caco-2 cell monolayer permeability assay. Furthermore, some preliminary structure-activity relationships were further analyzed among these compounds. Taken together, 5-amino-2-substitutedphenyl-1,3-dioxacycloalkanes may represent a new class of anti-inflammatory drugs with safer pharmacological profile.
- Gu, Keli,Bi, Lanrong,Zhao, Ming,Wang, Chao,Ju, Jingfang,Peng, Shiqi
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p. 6273 - 6290
(2008/04/05)
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- Synthesis and CB1 receptor activities of dimethylheptyl derivatives of 2-arachidonoyl glycerol (2-AG) and 2-arachidonyl glyceryl ether (2-AGE)
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Results from a factor analysis and activity studies of commercially available endocannabinoid-type compounds set the starting point for the current study where dimethylheptyl (DMH) analogues of two endocannabinoids, 2-arachidonoyl glycerol (2-AG) and 2-ar
- Parkkari, Teija,Salo, Outi M.H.,Huttunen, Kristiina M.,Savinainen, Juha R.,Laitinen, Jarmo T.,Poso, Antti,Nevalainen, Tapio,Jaervinen, Tomi
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p. 2850 - 2858
(2007/10/03)
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- Conformational Analysis of 5-Substituted 1,3-Dioxanes. 7. Effect of Lithium Bromide Addition
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The position of equilibria, established by means of BF3, between diastereomeric cis- and trans-5- substituted-2-phenyl-1,3-dioxanes, in solvents THF and CHCl3, and in the presence of 0, 1, and 10 equiv of LiBr has been determined. The observed ΔG° values show that the addition of salt to the reaction medium influences the position of equilibrium. Lithium bromide effects on the conformational behavior are discussed in terms of lithium ion complexation events that lead to increased stability of the axial isomers when the substituent at C(5) is CO2H, CO2CH3, CONHCH3, and CH2- OH. By contrast, disruption of the intramolecular hydrogen bond present in the axial 5-acetamido derivative (cis-9 substituent equal to NHCOCH3) modifies the preference for the axial conformation in salt-free 9 to a net dominance of the equatorial isomer in the presence of LiBr. Interpretation of the experimental observations was based on models that are apparently supported by semiempirical AM1 calculations. The results derived from the present study contribute to our understanding of the processes involved in molecular recognition and may model salt effects in physiological events.
- Juaristi, Eusebio,Díaz, Francisco,Cuéllar, Geiser,Jiménez-Vázquez, Hugo A.
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p. 4029 - 4035
(2007/10/03)
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