- Stereoinversion in the diastereoselective acylation of benzoxazine derivatives with 2-aryloxypropionyl chlorides
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A comparative study of the kinetic resolution of racemic derivatives of 3,4-dihydro-3-methyl-2H-[1,4]benzoxazine using racemic 2-aryloxypropionyl chlorides was performed. It was found that the acylation of racemic amines with racemic 2-(1-naphthyloxy)propionyl chloride leads to amides enriched with (3R*,2′R*)-diastereomers, while the acylation with 2-phenoxypropionyl chloride gives predominantly (3R*,2′S*)-amides. Quantum chemical modeling of the process of kinetic resolution at the COSMO-CH2Cl2-B3LYP-D3-gCP/def2-TZVP//B3LYP-D3-gCP/def2-SVP level of theory was performed. The computational results are in a good agreement with the experimental data.
- Vakarov,Korolyova,Gruzdev,Pervova,Levit,Krasnov
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- Synthesis of Naphthyl-, Quinolin- and Anthracenyl Analogues of Clofibric Acid as PPARα Agonists
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PPARα is a ligand activated transcription factor belonging to the nuclear receptor subfamily, involved in fatty acid metabolism in tissues with high oxidative rates such as muscle, heart and liver. PPARα activation is important in steatosis, inflammation and fibrosis in preclinical models of non-alcoholic fatty liver disease identifying a new potential therapeutic area. In this work, three series of clofibric acid analogues conjugated with naphthyl, quinolin, chloroquinolin and anthracenyl scaffolds were synthesized. In an effort to obtain new compounds active as PPARα agonists, these molecules were evaluated for PPARα transactivation activity. Naphthyl and quinolin derivatives showed a good activation of PPARα; noteworthy, optically active naphthyl derivatives activated PPARα better than corresponding parent compound.
- Giampietro, Letizia,Ammazzalorso, Alessandra,Bruno, Isabella,Carradori, Simone,De Filippis, Barbara,Fantacuzzi, Marialuigia,Giancristofaro, Antonella,Maccallini, Cristina,Amoroso, Rosa
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- Access to Optically Enriched α-Aryloxycarboxylic Esters via Carbene-Catalyzed Dynamic Kinetic Resolution and Transesterification
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Optically active α-aryloxycarboxylic acids and their derivatives are important functional molecules. Disclosed here is a carbene-catalyzed dynamic kinetic resolution and transesterification reaction for access to this class of molecules with up to 99% yields and 99:1 er values. Addition of a chiral carbene catalyst to the ester substrate leads to two diastereomeric azolium ester intermediates that can quickly epimerize to each other and thus allows for effective dynamic kinetic resolution to be realized. The optically enriched ester products from our reaction can be quickly transformed to chiral herbicides and other bioactive molecules.
- Liu, Bin,Song, Runjiang,Xu, Jun,Majhi, Pankaj Kumar,Yang, Xing,Yang, Song,Jin, Zhichao,Chi, Yonggui Robin
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supporting information
p. 3335 - 3338
(2020/04/30)
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- Finding new elicitors that induce resistance in rice to the white-backed planthopper Sogatella furcifera
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Herein we report a new way to identify chemical elicitors that induce resistance in rice to herbivores. Using this method, by quantifying the induction of chemicals for GUS activity in a specific screening system that we established previously, 5 candidate elicitors were selected from the 29 designed and synthesized phenoxyalkanoic acid derivatives. Bioassays confirmed that these candidate elicitors could induce plant defense and then repel feeding of white-backed planthopper Sogatella furcifera.
- He, Xingrui,Yu, Zhaonan,Jiang, Shaojie,Zhang, Peizhi,Shang, Zhicai,Lou, Yonggen,Wu, Jun
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supporting information
p. 5601 - 5603
(2015/11/17)
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- Optimization of benzoxazole-based inhibitors of Cryptosporidium parvum inosine 5′-monophosphate dehydrogenase
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Cryptosporidium parvum is an enteric protozoan parasite that has emerged as a major cause of diarrhea, malnutrition, and gastroenteritis and poses a potential bioterrorism threat. C. parvum synthesizes guanine nucleotides from host adenosine in a streamlined pathway that relies on inosine 5′-monophosphate dehydrogenase (IMPDH). We have previously identified several parasite-selective C. parvum IMPDH (CpIMPDH) inhibitors by high-throughput screening. In this paper, we report the structure-activity relationship (SAR) for a series of benzoxazole derivatives with many compounds demonstrating CpIMPDH IC50 values in the nanomolar range and >500-fold selectivity over human IMPDH (hIMPDH). Unlike previously reported CpIMPDH inhibitors, these compounds are competitive inhibitors versus NAD +. The SAR study reveals that pyridine and other small heteroaromatic substituents are required at the 2-position of the benzoxazole for potent inhibitory activity. In addition, several other SAR conclusions are highlighted with regard to the benzoxazole and the amide portion of the inhibitor, including preferred stereochemistry. An X-ray crystal structure of a representative E·IMP·inhibitor complex is also presented. Overall, the secondary amine derivative 15a demonstrated excellent CpIMPDH inhibitory activity (IC 50 = 0.5 ± 0.1 nM) and moderate stability (t1/2 = 44 min) in mouse liver microsomes. Compound 73, the racemic version of 15a, also displayed superb antiparasitic activity in a Toxoplasma gondii strain that relies on CpIMPDH (EC50 = 20 ± 20 nM), and selectivity versus a wild-type T. gondii strain (200-fold). No toxicity was observed (LD 50 > 50 μM) against a panel of four mammalian cells lines.
- Gorla, Suresh Kumar,Kavitha, Mandapati,Zhang, Minjia,Chin, James En Wai,Liu, Xiaoping,Striepen, Boris,Makowska-Grzyska, Magdalena,Kim, Youngchang,Joachimiak, Andrzej,Hedstrom, Lizbeth,Cuny, Gregory D.
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p. 4028 - 4043
(2013/06/27)
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- Triazole inhibitors of Cryptosporidium parvum inosine 5′- monophosphate dehydrogenase
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Cryptosporidium parvum is an important human pathogen and potential bioterrorism agent. This protozoan parasite cannot salvage guanine or guanosine and therefore relies on inosine 5′-monophosphate dehydrogenase (IMPDH) for biosynthesis of guanine nucleoti
- Maurya, Sushil K.,Gollapalli, Deviprasad R.,Kirubakaran, Shivapriya,Zhang, Minjia,Johnson, Corey R.,Benjamin, Nicole N.,Hedstrom, Lizbeth,Cuny, Gregory D.
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experimental part
p. 4623 - 4630
(2010/03/01)
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- Presynaptic cholinergic modulators as potent cognition enhancers and analgesic drugs. 2. 2-Phenoxy-, 2-(phenylthio)-, and 2-(phenylamino)alkanoic acid esters
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Further modifications of the leads ((R)-(+)-hyoscyamine and (p- chlorophenyl)propionic acid α-tropanyl ester), which show analgesic and nootropic activities as a consequence of increased central presynaptic ACh release, are reported. 2-Phenoxy- and 2-(phenylthio)alkanoic acid esters showed the best results. Several members of these classes possess analgesic properties which are comparable to that of morphine and at the same time are able to reverse dicyclomine-induced amnesia. Confirmation was found that the mechanism of action is due to an increase in ACh release at central muscarinic synapses and that both auto- and heteroreceptors controlling ACh release are very likely involved. According to the results obtained with (R)- (+)-hyoscyamine, analgesic activity is stereochemistry dependent, since the R-(+)-enantiomers are always more efficacious than the corresponding S-(-)- ones. On the basis of their potency and acute toxicity, compounds (±)-28 (SM21) and (±)-42 (SM32) were selected for further study.
- Gualtieri,Bottalico,Calandrella,Dei,Giovannoni,Mealli,Romanelli,Scapecchi,Teodori,Galeotti,Ghelardini,Giotti,Bartolini
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p. 1712 - 1719
(2007/10/02)
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