- Novel acyl carbamates and acyl / diacyl ureas show in vitro efficacy against Toxoplasma gondii and Cryptosporidium parvum
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Toxoplasma gondii and Cryptosporidium parvum are protozoan parasites that are highly prevalent and opportunistically infect humans worldwide, but for which completely effective and safe medications are lacking. Herein, we synthesized a series of novel small molecules bearing the diacyl urea scaffold and related structures, and screened them for in vitro cytotoxicity and antiparasitic activity against T. gondii and C. parvum. We identified one compound (GMG-1-09), and four compounds (JS-1-09, JS-2-20, JS-2-35 and JS-2-49) with efficacy against C. parvum and T. gondii, respectively, at low micromolar concentrations and showed appreciable selectivity in human host cells. Among the four compounds with efficacy against T. gondii, JS-1-09 representing the diacyl urea scaffold was the most effective, with an anti-Toxoplasma IC50 concentration (1.21 μM) that was nearly 53-fold lower than its cytotoxicity IC50 concentration, indicating that this compound has a good selectivity index. The other three compounds (JS-2-20, JS-2-35 and JS-2-49) were structurally more divergent from JS-1-09 as they represent the acyl urea and acyl carbamate scaffold. This appeared to correlate with their anti-Toxoplasma activity, suggesting that these compounds’ potency can likely be enhanced by selective structural modifications. One compound, GMG-1-09 representing acyl carbamate scaffold, depicted in vitro efficacy against C. parvum with an IC50 concentration (32.24 μM) that was 14-fold lower than its cytotoxicity IC50 concentration in a human intestinal cell line. Together, our studies unveil a series of novel synthetic acyl/diacyl urea and acyl carbamate scaffold-based small molecule compounds with micromolar activity against T. gondii and C. parvum that can be explored further for the development of the much-needed novel anti-protozoal drugs.
- Grooms, Gregory M.,Hernandez, Anolan Garcia,Khan, Shahbaz M.,Li, Kun,Stec, Jozef,Witola, William H.
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- Convenient One-Pot Two-Step Synthesis of Symmetrical and Unsymmetrical Diacyl Ureas, Acyl Urea/Carbamate/Thiocarbamate Derivatives, and Related Compounds
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A wide range of chemicals such as amides, hydrazides, amines, alcohols, carbazate, and sulfonate were reacted with acyl isocyanates generated by the reaction of primary amides with oxalyl chloride to give symmetrical and unsymmetrical diacyl urea derivatives, acyl ureas/carbamates/thiocarbamates, and related compounds. This method provides means for convenient one-pot, two-step synthesis of compounds bearing urea, carbamate, and other functional groups from cheap and commercially available starting reagents. It is expected that the results presented in this report will expand the medicinal chemist’s toolbox.
- Hernandez, Anolan Garcia,Grooms, Gregory M.,El-Alfy, Abir T.,Stec, Jozef
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p. 2163 - 2176
(2017/05/05)
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- Decomposition of N′-benzoyl-N-nitrosoureas in aqueous media
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The decomposition of N′-benzoyl-N-methyl-N-nitrosourea (BMNU) in aqueous media over the 0-14 pH range has been studied. In basic and neutral media (6 a = 7.8) and subsequent decomposition of the conjugate base of the thus formed nitrosourea, via an intermediate benzoyl isocyanate. Support for this mechanism is provided by the presence of N,N′-dibenzoylurea in the final reaction mixtures, as the result of the trapping of benzoyl isocyanate with benzamide generated from hydrolysis of the former. The hydrolysis of BMNU takes place through three competitive pathways: spontaneous decomposition of the conjugate base of BMNU, and buffer-catalyzed and hydroxide ion catalyzed water addition to the carbonyl group of the deprotonated nitrosourea. N′-Benzoyl-N,N′-dimethyl-N-nitrosourea (BDMNU), a benzoyl nitrosourea lacking the acidic proton of BMNU, is hydrolyzed in basic media by attack of hydroxide ion on the carbonyl group of the urea. In acid media (0 pH 6), BMNU gives only deamination products, differing from the reported behavior of other N-nitroso compounds and of the isoster nitrosoguanidine, in which denitrosation is almost quantitative. The reaction is acid-catalyzed in the 0-2.5 pH range and pH-independent in the 3-5 pH range. The presence of general acid catalysis (a = 0.60), the absence of nucleophilic catalysis, and the thermodynamic activation parameters for the reaction support the mechanism proposed in the literature for the deamination of N-nitrosoureas in acidic media. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
- Faustino, Celia,Garcia-Rio, Luis,Leis, Jose Ramon,Norberto, Fatima
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p. 154 - 161
(2007/10/03)
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- Effect of addition of calix[n]arenes on photooxygenation of 4,5-diphenylimidazolones
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Rates of dye sensitized photo-oxygenation of 4,5-diphenylimidazolones increase markedly and addition of calix[n]arenes. the effect of addition of calix[6]arenes is more pronounced than that of calix[4]- and calix[8]arenes and it varies with the size of th
- Chawla, H. Mohindra,Pathak, Manisha
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- Spiro-fysed 2-alkoxy-2-amino-Δ3-1,3,4-oxadiazolines. Synthesis and thermolysis to corresponding aminooxycarbenes
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Δ3-1,3,4-Oxadiazolines spiro-fused at C2 to C2 to oxazolidines (12) or to C2 of tetrahydro-1,3-oxazines (13) were synthesized. The oxadiazolines undergo thermolysis in benzene at 90°C with first-order rate constants of (1.6-50) × 10-5 s-1. The dependence of these rate constants on the nature of the substituents present on the oxadiazoline ring is consistent with a mechanism involving a carbonyl ylide intermediate. Substituents on N of the oxazolidine or tetrahydro-1,3-oxazine moieties play a major role in determining the fragmentation pathways. Oxadiazolines with N-carbonyl groups (12c-j, 13d,e) afford essentially quantitative yields of the corresponding aminooxycarbenes, while other fragmentation reactions compete with carbene generation in the case of oxadiazolines with N-methyl (12b, 13c) or N-sulfonyl (12k) groups.
- Couture, Philippe,Warkentin, John
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p. 1264 - 1280
(2007/10/03)
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- Interaction of calix(n)arenes with urea, dibenzoylurea and 4,5-diphenylimidazolin-2-one
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Interaction of urea, dibenzoylurea and 4,5-diphenylimidazolin-2-one with calix(n)arenes has been investigated by ultraviolet, infrared and NMR spectroscopy.It appears that urea can get incorporated into the cavity of 5,11,17,23-tetra-p-tert-butyl-25,26,27
- Chawla, H. Mohindra,Hooda, Usha
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p. 715 - 720
(2007/10/02)
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- Incorporation of molecular nitrogen into organic compounds III. Reaction of titanium-nitrogen complexes with acid halides and acid anhydrides
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The titanium-nitrogen complex 1, prepared from TiCl3 or TiCl4 and Mg in THF under nitrogen reacts with acid chloride to give amide and/or imide.The cyclic imides were obtained by the reaction of titanium-isocyanate complex 3, , made from titanium-nitrogen complex 1 and carbon dioxide, and the corresponding cyclic acid anhydrides.Benzoxazone derivatives afforded the corresponding quinazoline derivatives in a similar procedure.These results indicate that molecular nitrogen was incorporated into organic compounds via titanium nitrogen complexes.
- Mori, Miwako,Uozumi, Yasuhiro,Shibasaki, Masakatsu
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p. 255 - 267
(2007/10/02)
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- Dye sensitized photooxygenation of imidazolin-2-ones
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Imidazolin-2-ones(13-18) on photooxygenation in the presence of methylene blue yielded the corresponding diacylureas as the only products isolated at room temperature. The rate of photooxygenation followed the order 16>17>18>13>14>15. The reaction was als
- Chawla, H. Mohindra,Pathak, Manisha
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p. 1331 - 1342
(2007/10/02)
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- Photoreactions of 4,5-diarylimidazoles: Singlet oxygenation and cyclodehydrogenation
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4,5-Diarylimidazoles (1) undergo singlet oxygenation and cleavage to give N,N'-diaroylureas (2) on irradiation in alcoholic solutions in the presence of methylene blue as sensitizer. 5-Methoxy-4,5-diphenylimidazolin-2-one (5) and 4,5-dimethoxy-4,5-diphenylimidazolidin-2-one (6) have been reported as the principal products in the dye-sensitized irradiation of 4,5-diphenylimidazole in methanol.The formation of diaroylureas appears to proceed through the intermediacy of the corresponding imidazolin-2-one.A mechanistic pathway for the photochemical dye-sensitized oxygenation of the imidazoles is suggested.The photochemical cyclodehydrogenation reaction of the stilbene system present in 4,5-diarylimidazoles has also been carried out.
- Purushothaman, E.,Pillai, V. N. Rajasekharan
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p. 290 - 293
(2007/10/02)
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- INCORPORATION OF MOLECULAR NITROGEN INTO AMIDES AND IMIDES BY USE OF TITANIUM-NITROGEN COMPLEXES
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Molecular nitrogen was incorporated into amides and imides by the reaction of titanium-nitrogen complex 1 prepared from TiCl3 and Mg under N2 in THF with acyl chlorides 3.The cyclic imides 10, 12, 14 and quinazoline 16 were obtained by the reaction of isocyanate complex 6 generated by fixation of CO2 into titanium complex 1 with the corresponding cyclic anhydrides 9, 11, 13 and benzoxazone 15.
- Mori,Miwako,Uozumi, Yasuhiro,Shibasaki, Masakatsu
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p. 6187 - 6190
(2007/10/02)
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- 15N, 13C, AND 1H NMR SPECTRA OF ACYLATED UREAS AND THIOUREAS
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A series of 1-acylated and 1,3-diacylated (acyl=acetyl or benzoyl) ureas and thioureas have been prepared and their proton-coupled and proton-decoupled 15N, 13C, and 1H NMR spectra have been measured.All the signals have been assigned.The 15N NMR chemical
- Jirman, Josef,Lycka, Antonin
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p. 2474 - 2481
(2007/10/02)
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