- Synthesis of novel amino and acetyl amino-4-methylcoumarins and evaluation of their antioxidant activity
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The six novel 4-methylcoumarins bearing different functionalities such as amino, hydroxy, N-acetyl, acetoxy and nitro have been synthesized and confirmed on the basis of their spectral data (1H-, 13C-NMR, UV, IR and EI mass). They were examined for the first time for their effect on NADPH dependent liver microsomal lipid peroxidation in vitro, and the results were compared with other model 4-methylcoumarin derivatives to establish the structure-activity relationship. Our studies demonstrated that amino group is an effective substitute for the hydroxyl group for antioxidant property and produced a dramatic inhibition of lipid peroxidation. Ortho dihydroxy and ortho hydroxy-amino coumarins were found to possess highest antioxidant and radical scavenging activities.
- Tyagi, Yogesh K.,Kumar, Ajit,Raj, Hanumantharao G.,Vohra, Parag,Gupta, Garima,Kumari, Ranju,Kumar, Pankaj,Gupta, Rajinder K.
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- New angular oxazole-fused coumarin derivatives: synthesis and biological activities
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Twelve angular oxazole-fused coumarin derivatives were designed, synthesised and characterised by 1H NMR, 13C NMR and HRMS. The structure of compound 4a was further confirmed by X-ray single-crystal diffraction. The bioassay experiment results indicated that compounds 4f and 4l have high antifungal activity on the mycelium growth of 4 plant disease fungi. Especially, compound 4l has a stronger antifungal activity compare to the commercial fungicide, Carbendazim. The herbicidal activity experiment showed that 4a and 4b can significantly inhibit the taproot and caulis development of Chenopodium album seedling and have better activities than the commercial herbicide, Acetochlor.
- Wei, Yan,Li, Shi-qiang,Hao, Shuang-hong
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- Synthesis and structure-activity relationship of coumarins as potent Mcl-1 inhibitors for cancer treatment
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Myeloid cell leukemia-1 (Mcl-1) is a validated and attractive target for cancer therapy. Over-expression of Mcl-1 in many cancers allows cancer cells to evade apoptosis and contributes to their resistance to current chemotherapeutics. In this study, more than thirty coumarin derivatives with different substituents were designed and synthesized, and their Mcl-1 inhibitory activities evaluated using a fluorescence polarization-based binding assay. The results showed that the catechol group was a key constituent for Mcl-1 inhibitory activity of the coumarins, and methylation of the catechol group led to decreased inhibitory activity. The introduction of a hydrophobic electron-withdrawing group at the C-4 position of 6,7-dihydroxycoumarin, enhanced Mcl-1 inhibitory capacity, and a hydrophilic group in this position was unbeneficial to the inhibitory potency. In addition, the introduction of a nitrogen-containing group to the C-5 or C-8 position, which allowed an intramolecular hydrogen bond, was also unfavorable for Mcl-1 inhibition. Among all coumarins tested, 4-trifluoromethyl-6,7-dihydroxycoumarin (Cpd 4) displayed the most potent inhibitory activity towards Mcl-1 (Ki = 0.21 ± 0.02 μM, IC50 = 1.21 ± 0.56 μM, respectively), for which the beneficial effect on taxol resistance was also validated in A549 cells. A strong interaction between Cpd 4 and Mcl-1 in docking simulations further supported the observed potent Mcl-1 inhibition ability of Cpd 4. 3D-QSAR analysis of all tested coumarin derivatives further provides new insights into the relationships linking the inhibitory effects on Mcl-1 and the steric-electrostatic properties of coumarins. These findings could be of great value for medicinal chemists for the design and development of more potent Mcl-1 inhibitors for biomedical applications.
- Xia, Yang-Liu,Wang, Jing-Jing,Li, Shi-Yang,Liu, Yong,Gonzalez, Frank J.,Wang, Ping,Ge, Guang-Bo
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- Novel 4-methylumbelliferone amide derivatives: Synthesis, characterization and pesticidal activities
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A series of novel 4-methylumbelliferone amide derivatives were designed, synthesized and characterized by 1H NMR, 13C NMR and HR-ESI-MS. The structures of compounds 4bd and 4be (compounds named by authors) were further confirmed by X-ray single crystal diffraction. The acaricidal, herbicidal and antifungal activities of the synthesized compounds were assayed for their potential use as pesticide. The results indicated that compounds 4bi, 4ac and 4bd were strong acaricidals against Tetranychus cinnabarinus, with 72h corrected mortalities of greater than 80% at 1000 mg/L. Meanwhile, compounds 4bh and 4bf exhibit the strongest inhibition against the taproot development of Digitaria sanguinalis and Chenopodium glaucum, and were even more potent than the commercial herbicide Acetochlor against D. sanguinalis. In addition, compounds 4bk, 4bh and 4bp showed the highest antifungal activity against the mycelium growth of Valsa Mali, which makes them more effective than commercial fungicide Carbendazim.
- Wei, Yan,Miao, Kai-Long,Hao, Shuang-Hong
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- Synthesis of Fused Oxazolocoumarins from o-Hydroxynitrocoumarins and Benzyl Alcohol Under Gold Nanoparticles or FeCl3 Catalysis
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Synthesis of fused oxazolocoumarins has been achieved from the one-pot tandem reactions of o-hydroxynitrocoumarins with benzyl alcohol in toluene under catalysis in a sealed tube at 150°C. The catalysis was performed by gold nanoparticles supported on TiO
- Vlachou, Evangelia-Eirini N.,Armatas, Gerasimos S.,Litinas, Konstantinos E.
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p. 2447 - 2453
(2017/07/25)
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- Synthesis and biological evaluation of coumarinyl sydnone derivatives
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A novel series of compounds containing coumarinyl sydnone derivatives from 4-methyl-7-hydroxy-8-nitro coumarin were synthesized. The formed compounds have been evaluated by physical methods (melting point, thin layer chromatography, elemental analysis) an
- Patel, Keshav C.,Patel, Himanshu D.
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experimental part
p. 113 - 118
(2012/02/03)
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- Regioselective mononitration of coumarins using claycop reagent
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Coumarins are nitrated by claycop (cupric nitrate impregnated on the K10 montmorillonite) in acetic anhydride at room temperature to give corresponding regioselective mononitro coumarins in good to excellent yields. Among the products three nitrocoumarins are new.
- Kanodia, Saraswati,Thapliyal, Prakash Chander
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experimental part
p. 241 - 244
(2012/03/11)
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- Chemical uncouplers for the treatment of obesity
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This invention relates to chemical uncouplers with a broader safety window making the use of them in treating obesity and, consequently, in the treatment of obesity related diseases and conditions such as atherosclerosis, hypertension, diabetes, especially type 2 diabetes (NIDDM (non-insulin dependent diabetes mellitus)), impaired glucose tolerance, dyslipidemia, coronary heart disease, gallbladder disease, osteoarthritis and various types of cancer such as endometrial, breast, prostate and colon cancers and the risk for premature death as well as other conditions, such as diseases and disorders, which conditions are improved by an increase in mitochondrial respiration, more attractive.
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- Guanidinium nitrate: A novel reagent for aryl nitrations
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Nitration of various aromatic compounds utilising guanidinium nitrate in 85% sulfuric acid as a nitrating agent has been studied.
- Ramana,Malik,Parihar
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p. 8681 - 8683
(2007/10/03)
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- Regioselective mononitration of coumarins using chromium nitrate as nitrating agent
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A very efficient and simple method is presented for the regio-selective mononitration of coumarins, using chromium nitrate in acetic anhydride, in high yields at room temperature.
- Bansal, Vandana,Khanna
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p. 1345 - 1350
(2007/10/03)
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