- Specificities of Calreticulin Transacetylase to acetoxy derivatives of 3-alkyl-4-methylcoumarins: Effect on the activation of nitric oxide synthase
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Calreticulin Transacetylase (CRTAase) catalyzes the transfer of acetyl groups from polyphenolic acetates (PAs) to the receptor proteins and modulates their biological activities. CRTAase was conveniently assayed by the irreversible inhibition of cytosolic glutathione S-transferase (GST) by the model acetoxycoumarin, 7,8-diacetoxy-4-methylcoumarin (DAMC). We have studied earlier, the influence of acetoxy groups on the benzenoid ring, the effect of reduction of double bond at C-3 and C-4 position, the effect of methyl/phenyl group at C-4, and the influence of position of carbonyl group with respect to oxygen heteroatom in the benzopyran nucleus, for the catalytic activity of CRTAase. In this communication, we have extended our previous work; wherein we studied the influence of an alkyl group (ethyl, hexyl and decyl) at the C-3 position of the acetoxy coumarins on the CRTAase activity. The substitution at C-3 position of coumarin nucleus resulted in the reduction of CRTAase activity and related effects. Accordingly the formation of NO in platelets by C-3 alkyl substituted acetoxy coumarins was found to be much less compared to the unsubstituted analogs. In addition the alkyl substitution at C-3 position exhibited the tendency to form radicals other than NO.
- Kathuria, Abha,Gupta, Anjali,Priya, Nivedita,Singh, Prabhjot,Raj, Hanumantharao G.,Prasad, Ashok K.,Parmar, Virinder S.,Sharma, Sunil K.
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- Synthesis and bioactivity of novel coumarin derivatives containing (E)-methyl 2-(methoxyimino)-2-phenylacetates
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Ten coumarin derivatives containing (E)-methyl 2-(methoxyimino)-2- phenylacetate were synthesized and bioassayed. The compounds were identified by IR, 1H NMR and elemental analyses. The test results indicated that compound 5j (R1 is methyl and R2 is n-C6H 13) was the optimal structure in this paper with good fungicidal activity against CDM (85%) at 6.25 mg/L concentration.
- Guan, Ai Ying,Liu, Chang Ling,Li, Zhi Nian,Zhang, Ming Xing
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- Synthesis of Potential Bioactive Novel 7-[2-Hydroxy-3-(1,2,3-triazol-1-yl) propyloxy]-3-alkyl-4-methylcoumarins
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A series of 50 novel 7-[2-hydroxy-3-(1,2,3-triazol-1-yl)propyloxy]-3-alkyl-4-methylcoumarins had been designed and synthesized in good to excellent yields via Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction "click chemistry" of 7-(3-azido-2-hydroxypropyloxy)-3-alkyl-4-methylcoumarins with variety of acetylene derivatives. In turn, the precursor compound, that is, 7-(3-azido-2-hydroxypropyloxy)-3-alkyl-4-methylcoumarin, was synthesized by condensation of epichlorohydrin with 7-hydroxy-3-alkyl-4-methylcoumarins followed by opening of the epoxide ring in the resulted 7-epoxymethoxy-3-alkyl-4-methylcoumarins with sodium azide. All the synthesized compounds were unambiguously identified on the basis of their spectral data analyses (IR, 1H-NMR, 13C-NMR spectra, and HRMS).
- Arya, Anu,Kumar, Vinod,Mathur, Divya,Singh, Sukhdev,Brahma, Raju,Singh, Rajpal,Singh, Seema,Sharma,Parmar, Virinder S.,Prasad, Ashok K.
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- Acetamide Derivatives of Chromen-2-ones as Potent Cholinesterase Inhibitors
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Alzheimer's disease (AD), a neurodegenerative disorder, is a serious medical issue worldwide with drastic social consequences. Inhibition of cholinesterase is one of the rational and effective approaches to retard the symptoms of AD and, hence, consistent efforts are being made to develop efficient anti-cholinesterase agents. In pursuit of this, a series of 19 acetamide derivatives of chromen-2-ones were synthesized and evaluated for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potential. All the synthesized compounds exhibited significant anti-AChE and anti-BChE activity, with IC50 values in the range of 0.24–10.19 μM and 0.64–30.08 μM, respectively, using donepezil hydrochloride as the standard. Out of 19 compounds screened, 3 compounds, viz. 22, 40, and 43, caused 50% inhibition of AChE at 0.24, 0.25, and 0.25 μM, respectively. A kinetic study revealed them to be mixed-type inhibitors, binding with both the CAS and PAS sites of AChE. The above-selected compounds were found to be effective inhibitors of AChE-induced and self-mediated Aβ1–42 aggregation. ADMET predictions demonstrated that these compounds may possess suitable blood–brain barrier (BBB) permeability. Hemolytic assay results revealed that these compounds did not lyse human RBCs up to a thousand times of their IC50 value. MTT assays performed for the shortlisted compounds showed them to be negligibly toxic after 24 h of treatment with the SH-SY5Y neuroblastoma cells. These results provide insights for further optimization of the scaffolds for designing the next generation of compounds as lead cholinesterase inhibitors.
- Prasad, Suchita,Kumar, Bipul,Kumar, Shiv,Chand, Karam,Kamble, Shashank S.,Gautam, Hemant K.,Sharma, Sunil K.
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- Quaternary ammonium and amido derivatives of pyranochromenones and chromenones: Synthesis and antimicrobial activity evaluation
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Infectious diseases and the development of their resistance to antimicrobial agents are alarming issues worldwide and consistent efforts are being made to develop efficient antimicrobial agents. In this perspective, a series of novel ammonium and amide derivatives of pyranocoumarin and coumarin were synthesized and evaluated for their antimicrobial activity. Among them, six compounds exhibited significant activity against gram-positive bacteria Bacillus cereus (MTCC 430) and Bacillus subtilis (MTCC 121) and a gram-negative bacterium Pseudomonas aeruginosa (MTCC 741). The compound N,N,N-triethyl-10-(4,8,8-trimethyl-2-oxo-2,6,7,8-tetrahydropyrano[3,2-g]chromen-10-yloxy)decan-1-aminium bromide (16) exhibited the highest antibacterial activity with MIC value of 5 μg/ml in MDA. Compounds 17 and 18 exhibited modest antifungal activity with MIC of 6.25 μg/ml against Trichophyton rubrum (clinical isolate) in MDA. Haemolytic assay results demonstrated that three out of six compounds were safe at their respective MIC values. These results provide insights for further optimization of the scaffolds for designing the next generation of compounds as lead antimicrobial agents.
- Prasad, Suchita,Kumar, Shiv,Kumar, Bipul,Singh, Abhishek Kumar,Gautam, Hemant K.,Sharma, Sunil K.
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p. 2297 - 2313
(2015/02/19)
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- BENZOPYRONE COMPOUNDS, PREPARATION METHOD AND USE THEREOF
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The invention relates to pesticide and bactericide, specifically to the benzopyrone compounds and its preparation method and use thereof. The benzopyrone compounds of the invention having general formula (I): The present invention, having good pesticide activity and broad bactericide activity, applied for controlling various pests in plants such as army worm, diamond backmoth and aphid, carmine spider mite, two-spotted spider mite, ladybeetle, mites and mosquito larvae. Various disease in plants can be controlled by the invention and that of grape downy mildew, rice sheath and culm blight, rice blast, tomato early blight, tomato late blight ,wheat leaf rust, wheat leaf blotch, wheat powdery mildew, cucumber powdery mildew, cucumber downy mildew, cucumber grey mold and so on.
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Page/Page column 19
(2008/06/13)
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- Discovery and structure-activity relationship of coumarin derivatives as TNF-α inhibitors
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The discovery and structure-activity relationship of a novel series of coumarin-based TNF-α inhibitors is described. Starting from the initial lead 1a, various derivatives were prepared surrounding the coumarin core structure to optimize the in vitro inhibitory activity of TNF-α production by human peripheral blood mononuclear cells (hPBMC), stimulated by bacterial lipopolysaccharide (LPS). Selected compounds also demonstrated in vivo inhibition of TNF-α production in rats.
- Cheng, Jie-Fei,Chen, Mi,Wallace, David,Tith, Sovouthy,Arrhenius, Thomas,Kashiwagi, Hirotaka,Ono, Yoshiyuki,Ishikawa, Akira,Sato, Haruhiko,Kozono, Toshiro,Sato, Hediki,Nadzan, Alex M.
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p. 2411 - 2415
(2007/10/03)
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