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Ilia Manolov – One of the best experts on this subject based on the ideXlab platform.
Investigation of the antioxidant properties of some new 4–Hydroxycoumarin derivativesEuropean Journal of Medicinal Chemistry, 2008Co-Authors: Stancho Stanchev, Vera Hadjimitova, T. Traykov, T. Boyanov, Ilia ManolovAbstract:
Abstract The aim of this investigation was to measure the activity of four 4–Hydroxycoumarin derivatives – three of them were described before and one was newly synthesized. The substances were ethyl 2-[(4-hydroxy-2-oxo-2 H -chromen-3-yl)(4-hydroxyphenyl)methyl]-3-oxobutanoate ( SS-14 ), 4-[1-(4-hydroxy-2-oxo-2 H -chromen-3-yl)-2-(ethoxycarbonyl)-3-oxobutyl]benzoic acid ( SS-17 ), ethyl 2-[(4-hydroxy-2-oxo-2 H -chromen-3-yl)(3-nitrophenyl)methyl]-3-oxobutanoate ( SS-21 ) and ethyl 2-[(3,4,5-trimethoxyphenyl)(4-hydroxy-2-oxo-2 H -chromen-3-yl)methyl]-3-oxobutanoate ( T-2 ). The synthesis of T-2 consists of two steps. First step was Knoevenagel reaction between 3,4,5-trimethoxybenzaldehyde and ethylacetoacetate. Ethyl 2-(3,4,5-trimethoxy)-phenylmethyleneacetoacetate was the product. Second step was Michael addition reaction between the latter product and 4–Hydroxycoumarin. All the compounds were tested in vitro for antioxidant activity in hypochlorous system. The assay was based on the luminol-dependent chemiluminescence of free radicals, which decreased in the presence of 4–Hydroxycoumarin derivative. Compound SS-14 (ethyl 2-[(4-hydroxy-2-oxo-2 H -chromen-3-yl)(4-hydroxyphenyl)methyl]-3-oxobutanoate) expresses the best scavenger activity at the highest concentration (10 −4 mol/L).
synthesis computational study and cytotoxic activity of new 4 Hydroxycoumarin derivativesEuropean Journal of Medicinal Chemistry, 2008Co-Authors: Stancho Stanchev, Georgi Momekov, Frank Jensen, Ilia ManolovAbstract:
Abstract Six new 4–Hydroxycoumarin derivatives have been synthesized. They were characterized by UV–vis, IR, 1 H NMR, 13 C NMR, mass spectral data, elemental analysis, TLC and melting point determination. The new 4–Hydroxycoumarin derivatives are studied by computational methods – DFT (B3LYP) and force field methods (MM2 and OPLS), in order to optimize their geometry and calculate quantum-chemical properties and conformational analysis. Five new 4–Hydroxycoumarin derivatives were tested for cytotoxic activity in two tumor cell lines – HL-60 and EJ. The obtained results are compared with the utilized anticancer drug melphalan. Two of these compounds – ethyl 2-[(3,4-dihydroxyphenyl)(4-hydroxy-2-oxo-2 H -chromen-3-yl)methyl]-3-oxobutanoate ( SS – 16 ) and ethyl 2-[(4-hydroxy-2-oxo-2 H -chromen-3-yl)(3-nitrophenyl)methyl]-3-oxobutanoate ( SS – 21 ) show comparatively good cytotoxic properties. Their activity is weaker than melphalan. SS – 16 seems to be more active than SS – 21 .
Synthesis, Structure and Acid-Base Behaviour of Some 4–Hydroxycoumarin DerivativesZeitschrift für Naturforschung B, 2007Co-Authors: Stancho Stanchev, Cäcilia Maichle-mössmer, Ilia ManolovAbstract:
The compound 3,3′-[(4-hydroxy-3-methoxy-5-nitrophenyl)methylene]-bis(4-hydroxy-2H-1benzopyran-2-one) (1) crystallizes in the monoclinic system, space group P21/n, with cell constants a = 16.859(4), b = 6.1624(15), c = 25.164(4) A, β = 98.019(19)◦ . The two 4–Hydroxycoumarin fragments are intramolecularly hydrogen-bonded between hydroxyl and carbonyl groups. The pHdependent color changes of 4–Hydroxycoumarin derivatives were studied by means of potentiometric and spectrophotometric titration. On the basis of the results obtained, the use of 3,3′-[(4-hydroxy-3methoxy-5-nitrophenyl)methylene]-bis(4-hydroxy-2H-1-benzopyran-2-one) as an indicator in alkalimetry and acidimetry is proposed.
Marc Lemaire – One of the best experts on this subject based on the ideXlab platform.
field assessment of 4 Hydroxycoumarin as an attractant for anthropophilic anopheles spp vectors of malaria in madagascarScientific Reports, 2020Co-Authors: Tovo Mbolatiana Andrianjafy, Marc Lemaire, Voahangy Vestalys Ramanandraibe, Elodie Toavina Andrianarijaona, Niry Hasinandrianina Ramarosandratana, Lala Harivelo Ravaomanarivo, Patrick MavinguiAbstract:
Mosquito-borne diseases like malaria are a major public health problem in tropical countries, such as Madagascar. Female Anopheles mosquito vectors the human malaria parasites (Plasmodium spp.) and is important indicator in malaria surveillance activities. Among the various means of vector control in Madagascar, the use of attractants for mass trapping of target species could be an alternative to insecticides. The aim of this study is to evaluate whether 4–Hydroxycoumarin can be used as an attractant for anthropophilic Anopheles spp. vectors of malaria. For this, a field study was conducted using CDC light traps in the village of Ambohidray, Madagascar. 16 days of trapping was conducted and four replicates nights were performed for each product tested. 4–Hydroxycoumarin, octenol and two types of blend of these products were tested. The results showed that 4–Hydroxycoumarin (2 mg) have a significant attractive effect on Anopheles spp. and significant selectivity towards Anopheles gambiae s.l, and Anopheles mascarensis which are both significant malaria vectors in Madagascar. A synergy of 4–Hydroxycoumarin with octenol was found to attract these mosquito vectors. A significant decrease in vector populations was observed during this experiment. These results suggest that 4–Hydroxycoumarin could be useful for malaria surveillance and the control of vector populations.
3 methylene 2 4 chromandione in situ trapping introducing molecular diversity on 4 HydroxycoumarinRSC Advances, 2016Co-Authors: Adrien Montagutromans, Marc Lemaire, Manon Boulven, Florence PopowyczAbstract:
3-Methylene-2,4-chromandione trapped in a solid-state stable Mannich adduct, is released in solution. In the presence of different nucleophiles, this highly reactive intermediate allows the introduction of molecular diversity on C-3 position of 4–Hydroxycoumarin.
efficient c 3 reductive alkylation of 4 Hydroxycoumarin by dehydrogenative oxidation of benzylic alcohols through ruthenium catalysisChemInform, 2014Co-Authors: Marc Lemaire, Adrien Montagutromans, F Popowycz, Manon BoulvenAbstract:
Only benzylic alcohols react with 4–Hydroxycoumarin in the presence of Wilkinson′s catalyst.
Allan E Rettie – One of the best experts on this subject based on the ideXlab platform.
pharmacogenomics of 4 Hydroxycoumarin anticoagulantsDrug Metabolism Reviews, 2008Co-Authors: Nicholas T Au, Allan E RettieAbstract:
Oral anticoagulants of the 4–Hydroxycoumarin class, typified by warfarin, are used worldwide to treat thromboembolic disease. These drugs show the beneficial attributes of high efficacy and low cost, but patient management can be complicated by their narrow therapeutic index and wide inter-individual variability in dosing. Our understanding of the latter complication has improved significantly in recent years due to intense investigation of genetic factors influencing drug pharmacokinetics (CYP2C9) and pharmacodynamic response (VKORC1). In particular, the discovery of polymorphisms in the VKORC1 gene that strongly impact oral anticoagulant dose has heightened expectations that genetic testing for a relatively small cadre of warfarin-response genes might substantially enhance patient care in this area, especially during the initiation phase of therapy. However, enthusiasm for genotype-based dosing of oral anticoagulants must be balanced against the ready availability of both a simple phenotypic test (proth…