- Improving the metabolic stability of antifungal compounds based on a scaffold hopping strategy: Design, synthesis, and structure-activity relationship studies of dihydrooxazole derivatives
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L-amino alcohol derivatives exhibited high antifungal activity, but the metabolic stability of human liver microsomes in vitro was poor, and the half-life of optimal compound 5 was less than 5 min. To improve the metabolic properties of the compounds, the scaffold hopping strategy was adopted and a series of antifungal compounds with a dihydrooxazole scaffold was designed and synthesized. Compounds A33-A38 substituted with 4-phenyl group on dihydrooxazole ring exhibited excellent antifungal activities against C. albicans, C. tropicalis and C. krusei, with MIC values in the range of 0.03–0.25 μg/mL. In addition, the metabolic stability of compounds A33 and A34 in human liver microsomes in vitro was improved significantly, with the half-life greater than 145 min and the half-life of 59.1 min, respectively. Moreover, pharmacokinetic studies in SD rats showed that A33 exhibited favourable pharmacokinetic properties, with a bioavailability of 77.69%, and half-life (intravenous administration) of 9.35 h, indicating that A33 is worthy of further study.
- Cheng, Maosheng,Su, Xin,Sun, Nannan,Sun, Yin,Tian, Linfeng,Yin, Wenbo,Zhang, Chu,Zhao, Dongmei,Zhao, Liyu,Zhao, Shizhen,Zheng, Yang
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- DNA as a bioligand supported on magnetite for grafting palladium nanoparticles for cross-coupling reaction
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The utilization of deoxyribonucleic acid (DNA) in nanotechnology is a promising area of research wherein the distinct properties of DNA are exploited for the design and development of new materials and applications. The biodegradability and natural profusion of DNA makes it highly suitable for use in various fields. In this report, we have treated DNA as a bioligand, supported on functionalized magnetite for the grafting of palladium (Pd) nanoparticles to make Pd-DNA bio-nanocatalyst. The Pd-DNA was subjected to Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Brunauer–Emmett–Teller, energy dispersive X-ray spectroscopy, vibrating sample magnetometry, X-ray photoelectron spectroscopy, and inductively coupled plasma optical emission spectrometry analysis. The prepared Pd-DNA was found to be highly efficient in catalyzing Suzuki–Miyaura cross-coupling reaction with excellent yields when compared with commercially available palladium-based catalysts. Also, the Pd-DNA could be easily recovered from the reaction mass using an external magnet and recycled up to six times without substantial loss of activity. Furthermore, Felbinac, a non-inflammatory drug, was synthesized in quantitative yields using the Pd-DNA bio-nanocatalyst.
- Kandathil, Vishal,Kempasiddaiah, Manjunatha,Nataraj, Sanna Kotrappanavar,Patil, Siddappa A.,Somappa, Sasidhar Balappa
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- Design, synthesis, and structure-activity relationship studies of L-amino alcohol derivatives as broad-spectrum antifungal agents
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To discover broad spectrum antifungal agents, two strategies were applied, and a novel class of L-amino alcohol derivatives were designed and synthesized. 3-F substituted compounds 14i, 14n, 14s and 14v exhibited excellent antifungal activities with broad antifungal spectra against C. albicans and C. tropicalis, with MIC values in the range of 0.03–0.06 μg/mL, and against A. fumigatus and C. neoformans, with MIC values in the range of 1–2 μg/mL. Notably, Compounds 14i, 14n, 14s and 14v also displayed moderate activities against fluconazole-resistance strains 17# and CaR that were isolated from AIDS patients. Moreover, only compounds in the S-configuration showed antifungal activity. Preliminary mechanistic studies showed that the potent antifungal activity of compound 14v stemmed from inhibition of C. albicans CYP51. Compounds 14n and 14v were almost nontoxic to mammalian A549 cells, and their stability in human plasma was excellent.
- Zhao, Liyu,Tian, Linfeng,Sun, Nannan,Sun, Yin,Chen, Yixuan,Wang, Xinran,Zhao, Shizhen,Su, Xin,Zhao, Dongmei,Cheng, Maosheng
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p. 374 - 385
(2019/06/05)
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- Combating fluconazole-resistant fungi with novel β-azole-phenylacetone derivatives
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A series of β-azole-phenylacetone derivatives with novel structures were designed and synthesized to combat the increasing incidence of susceptible fungal infections and drug-resistant fungal infections. The antifungal activity of the synthesized compounds was assessed against five susceptible strains and five fluconazole-resistant strains. Antifungal activity tests showed that most of the compounds exhibited excellent antifungal activities against five pathogenic strains with MIC values in the range of 0.03–1 μg/mL. Compounds with R1 = 3-F substituted and 15o and 15ae exhibited moderate antifungal activities against fluconazole-resistant strains 17# and CaR with MIC values in the range of 1–8 μg/mL. Compounds with R1 = H or 2-F (such as 15a, 15o, 15p) displayed moderate to good antifungal activity against fluconazole-resistant strains 632, 901 and 904 with MIC values in the range of 0.125–4 μg/mL. Notably, 15o and 15ae exhibited antifungal activity against five susceptible strains and five fluconazole-resistant strains. Preliminary mechanistic studies showed that the potent antifungal activity of compound 15ae stemmed from inhibition of C. albicans CYP51. Compounds 15o, 15z and 15ae were nearly nontoxic to mammalian A549 cells.
- Zhao, Liyu,Sun, Nannan,Tian, Linfeng,Sun, Yin,Chen, Yixuan,Wang, Xinran,Zhao, Shizhen,Su, Xin,Zhao, Dongmei,Cheng, Maosheng
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- Discovery of biphenyl imidazole derivatives as potent antifungal agents: Design, synthesis, and structure-activity relationship studies
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Fungal infections have became a serious medical problem due to their high incidence and mortality. We describe the discovery and structure-activity relationships studies (SARs) of a series of novel biphenyl imidazole derivatives with excellent antifungal
- Zhao, Dongmei,Zhao, Shizhen,Zhao, Liyu,Zhang, Xiangqian,Wei, Peng,Liu, Chunchi,Hao, Chenzhou,Sun, Bin,Su, Xin,Cheng, Maosheng
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p. 750 - 758
(2016/12/28)
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- A convenient chemical-microbial method for developing fluorinated pharmaceuticals
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A significant proportion of pharmaceuticals are fluorinated and selecting the site of fluorine incorporation can be an important beneficial part a drug development process. Here we describe initial experiments aimed at the development of a general method of selecting optimum sites on pro-drug molecules for fluorination, so that metabolic stability may be improved. Several model biphenyl derivatives were transformed by the fungus Cunninghamella elegans and the bacterium Streptomyces griseus, both of which contain cytochromes P450 that mimic oxidation processes in vivo, so that the site of oxidation could be determined. Subsequently, fluorinated biphenyl derivatives were synthesised using appropriate Suzuki-Miyaura coupling reactions, positioning the fluorine atom at the pre-determined site of microbial oxidation; the fluorinated biphenyl derivatives were incubated with the microorganisms and the degree of oxidation assessed. Biphenyl-4-carboxylic acid was transformed completely to 4′-hydroxybiphenyl-4-carboxylic acid by C. elegans but, in contrast, the 4′-fluoro-analogue remained untransformed exemplifying the microbial oxidation-chemical fluorination concept. 2′-Fluoro- and 3′-fluoro-biphenyl-4-carboxylic acid were also transformed, but more slowly than the non-fluorinated biphenyl carboxylic acid derivative. Thus, it is possible to design compounds in an iterative fashion with a longer metabolic half-life by identifying the sites that are most easily oxidised by in vitro methods and subsequent fluorination without recourse to extensive animal studies.
- Bright, Tara V.,Dalton, Fay,Elder, Victoria L.,Murphy, Cormac D.,O'Connor, Neil K.,Sandford, Graham
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supporting information
p. 1135 - 1142
(2013/03/28)
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- Amine Compounds
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There is provided a compound exhibiting an activity of suppressing immune response with reduced adverse drug reactions, which compound is useful in the chemotherapy for preventing or treating, for example, a wide range of various autoimmune diseases including systemic erythematodes, chronic rheumatoid arthritis, Type I diabetes, inflammatory bowel disease, biliary cirrhosis, uveitis, multiple sclerosis or other disorders, or chronic inflammatory diseases, or cancers, lymphoma or leukemia, or resistance to organ or tissue transplantation or rejection against transplantation. Novel amine compounds having an S1P1/Edg1 receptor agonist effect, possible stereoisomers or racemic bodies of the compounds, or pharmacologically acceptable salts, hydrates or solvates of the compound, the stereoisomers or the racemic bodies, or prodrugs of the compounds, the stereoisomers, the racemic bodies, the salts, the hydrates or the solvates, are provided.
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Page/Page column 160
(2008/12/08)
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- INDANE DERIVATES AS MUSCARINIC RECEPTOR AGONISTS
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The present invention relates to compounds of Formula I: I which are agonists of the M-1 muscarinic receptor.
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- MUSCARINIC AGONISTS
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The present invention relates to compounds of Formula (I): which are agonists of the M-1 muscarinic receptor.
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- MUSCARINIC AGONISTS
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The present invention relates to compounds of Formula (I): which are agonists of the M-1 muscarinic receptor.
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- Diflunisal Analogues Stabilize the Native State of Transthyretin. Potent Inhibition of Amyloidogenesis
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Analogues of diflunisal, an FDA-approved nonsteroidal antiinflammatory drug (NSAID), were synthesized and evaluated as inhibitors of transthyretin (TTR) aggregation, including amyloid fibril formation. High inhibitory activity was observed for 26 of the compounds. Of those, eight exhibited excellent binding selectivity for TTR in human plasma (binding stoichiometry > 0.50, with a theoretical maximum of 2.0 inhibitors bound per TTR tetramer). Biophysical studies reveal that these eight inhibitors dramatically slow tetramer dissociation (the rate-determining step of amyloidogenesis) over a duration of 168 h. This appears to be achieved through ground-state stabilization, which raises the kinetic barrier for tetramer dissociation. Kinetic stabilization of WT TTR by these eight inhibitors is further substantiated by the decreasing rate of amyloid fibril formation as a function of increasing inhibitor concentration (pH 4.4). X-ray cocrystal structures of the TTR·182 and TTR·202 complexes reveal that 18 and 20 bind in opposite orientations in the TTR binding site. Moving the fluorines from the meta positions in 18 to the ortho positions in 20 reverses the binding orientation, allowing the hydrophilic aromatic ring of 20 to orient in the outer binding pocket where the carboxylate engages in favorable electrostatic interactions with the ε-ammonium groups of Lys 15 and 15′. The hydrophilic aryl ring of 18 occupies the inner binding pocket, with the carboxylate positioned to hydrogen bond to the serine 117 and 117′ residues. Diflunisal itself appears to occupy both orientations based on the electron density in the TTR·12 structure. Structure-activity relationships reveal that para-carboxylate substitution on the hydrophilic ring and dihalogen substitution on the hydrophobic ring afford the most active TTR amyloid inhibitors.
- Adamski-Werner, Sara L.,Palaninathan, Satheesh K.,Sacchettini, James C.,Kelly, Jeffery W.
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p. 355 - 374
(2007/10/03)
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- Antibiotic derivatives of 7-phenyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids
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1-Substituted-6-fluoro-7-aryl-(8-fluoro)-1,4-dihydroquinol-4-one 3-carboxylic acids having antibacterial activity are prepared by reacting the corresponding alkyl 1-substituted-6-fluoro-7-bromo-(8-fluoro)-1,4-dihydroquinol-4-one-3-carboxylate with an arylmetallic compound and hydrolyzing the ester formed.
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- The Effects of Substituents on the Rate of Saponification of Biphenyl-4-carboxylates
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Second-order rate constants have been measured for the saponification of methyl 2'-, 3'-, and 4'-substituted biphenyl-4-carboxylates at several temperatures in 85percent (w/w) methanol-water and activation parameters have been calculated.The Hammett equation applies very well to the saponification of 3'- and 4'-substituted biphenyl-4-carboxylates with ?-constants evaluated by the FMMF method.The effect of 2'-substituents is understandable in terms of ?-electron steric effects.
- Ananthakrishnanadar, Ponnambalanad.,Kannan, Nagarathnam
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