Search results for "Cyclic compound"
showing 10 items of 819 documents
Molecular docking and oxidation kinetics of 3-phenyl coumarin derivatives by human CYP2A13.
2021
CYP2A13 enzyme is expressed in human extrahepatic tissues, while CYP2A6 is a hepatic enzyme. Reactions catalysed by CYP2A13 activate tobacco-specific nitrosamines and some other toxic xenobiotics in lungs.To compare oxidation characteristics and substrate-enzyme active site interactions in CYP2A13 vs CYP2A6, we evaluated CYP2A13 mediated oxidation characteristics of 23 coumarin derivatives and modelled their interactions at the enzyme active site.CYP2A13 did not oxidise six coumarin derivatives to corresponding fluorescent 7-hydroxycoumarins. The Km-values of the other coumarins varied 0.85-97 µM, Vmax-values of the oxidation reaction varied 0.25-60 min-1, and intrinsic clearance varied 26-…
Acute toxicity of some chlorinated phenolic compounds toSelenastrum capricornutum and phytoplankton
1985
Acute toxicity of several chlorinated phenolic compounds detected in waste waters of bleached pulp was determined forSelenastrum capricornutum and indigenous phytoplankton using bioassays. Five of the phenolic compounds were chlorocatechols, four were chloroguaiacols and one was chlorosyringol. The response ofSelenastrum capricornutum to chemicals was measured by cell counting and phytoplankton14C-uptake. Chlorinated catechols inhibited the growth ofSelenastrum cultures in lower concentrations than chlorinated guaiacols. The increasing number of chlorine substituents on the phenolic ring increased the toxicity of both chlorinated catechols and guaiacols. The EC50-values (0-96 hr) of the com…
Oxidation of melatonin by oxoferryl hemoglobin: A mechanistic study
2002
Reaction of melatonin with the hypervalent iron centre of oxoferryl hemoglobin, produced in aqueous solution from methemoglobin and H2O2, has been investigated at 37 degrees C and pH 7.4, by absorption spectroscopy. The reaction results in reduction of the oxoferryl moiety with formation of a heme-ferric containing hemoprotein. Stopped-flow spectrophotometric measurements provide evidence that the reduction of oxoferryl-Hb by melatonin is first-order in oxoferryl-Hb and first-order in melatonin. The bimolecular reaction constant at pH 7.4 and 37 degrees C is 112 +/- 1.0 M(-1) s(-1). Two major oxidation products from melatonin have been found by gas chromatography-mass spectroscopy: the cycl…
DESIGN AND SYNTHESIS OF NEW QUINAZOLIN-4(3H)-ONE HYBRIDS AS DUAL INHIBITORS OF TUBULIN AND DIHYDROFOLATE REDUCTASE
New strategies are needed for fighting cancer with the goal to improve efficacy of anti-cancer therapy and to limit the onset of drug resistance. Indeed, cancer cells are able to set cellular mechanisms for survival and multiple pathways support their survival. The inhibition of one pathway may then result in the activation of an alternative pathway. One strategy useful for combatting this phenomenon is represented by multi-target drugs. Herein we will present our work aim at identifying new anticancer compounds, which combine dihydrofolate reductase (DHFR) properties with tubulin inhibition. DHFR is a key enzyme involved in the synthesis of raw material for cell proliferation and the inhib…
SINTESI ED ATTIVITÀ ANTINEOPLASTICA DI NUOVI COMPOSTI ETEROCICLICI
2004
New efficient artemisinin derived agents against human leukemia cells, human cytomegalovirus and Plasmodium falciparum: 2nd generation 1,2,4-trioxane…
2015
Abstract In our ongoing search for highly active hybrid molecules exceeding their parent compounds in anticancer, antimalaria as well as antiviral activity and being an alternative to the standard drugs, we present the synthesis and biological investigations of 2nd generation 1,2,4-trioxane-ferrocene hybrids. In vitro tests against the CCRF-CEM leukemia cell line revealed di-1,2,4-trioxane-ferrocene hybrid 7 as the most active compound (IC50 of 0.01 μM). Regarding the activity against the multidrug resistant subline CEM/ADR5000, 1,2,4-trioxane-ferrocene hybrid 5 showed a remarkable activity (IC50 of 0.53 μM). Contrary to the antimalaria activity of hybrids 4–8 against Plasmodium falciparum …
Identification of biological markers of liver X receptor (LXR) activation at the cell surface of human monocytes.
2012
Background Liver X receptor (LXR) α and LXR β (NR1H3 and NR1H2) are oxysterol-activated nuclear receptors involved in the control of major metabolic pathways such as cholesterol homeostasis, lipogenesis, inflammation and innate immunity. Synthetic LXR agonists are currently under development and could find applications in various fields such as cardiovascular diseases, cancer, diabetes and neurodegenerative diseases. The clinical development of LXR agonists requires the identification of biological markers for pharmacodynamic studies. In this context, monocytes represent an attractive target to monitor LXR activation. They are easily accessible cells present in peripheral blood; they expres…
Die Herstellung einer molekulareinheitlichen Tetramethacrylsäure mittels verschiedener Matrizen. VI. Mitt. Modelle für Matrizenreaktionen
1968
Es wurde aus einer phenolischen Zweikernverbindung eine cyclische Verbindung IV hergestellt, die bei der alkalischen Hydrolyse eine molekulareinheitliche Tetramethacrylsaure (VII) und die phenolische Ausgangsverbindung gab. Die Synthese der gleichen Saure (VII) gelang auch mit strukturell verschiedenen Zweikernverbindungen, wenn nur bei den verwendeten Matrizen der innermolekulare Abstand der beiden phenolischen Hydroxylgruppen fur die Reaktion gunstig war. Alkaline hydrolysis of a cyclic compound (IV) which was prepared out of a dinuclear phenolic compound gave a molecularly homogeneous tetra-methacrylic acid (VII) and the original phenolic compound. The synthesis of the same acid could al…
Selective Synthesis of New Fluorinated Alicyclic β-Amino Ester Stereoisomers (Eur. J. Org. Chem. 26/2011)
2011
The cover picture shows a waterfall located in the Eastern Carpathians in Transylvania, near Bicaz Canyon. Although fluorinated organic compounds are nonexistent in nature, an increasing number of drugs (25 %) on the market contain at least one fluorine atom. Cyclic fluorinated β-amino acid derivatives have been synthesized by selective hydroxylation and hydroxy?fluorine exchange. Details are discussed in the article by F. Fulop et al. on p. 4993 ff.
Tetrathiafulvalene-Capped Hybrid Materials for the Optical Detection of Explosives
2013
[EN] Mesoporous silica microparticles capped with TTF moieties and containing a ruthenium dye in the pores were used for the turn-on optical detection of the nitroaromatic explosives Tetryl and TNT via a selective pore uncapping and release of the entrapped dye.