Literatura académica sobre el tema "'.3-Dihydroxyflavone"

Paclitaxel is a widely used cancer chemotherapeutic agent for many solid tumors; but peripheral neuropathy is a major limitation for its clinical use. Studies have demonstrated the usefulness of flavone derivatives in chemotherapy induced peripheral neuropathy. The present study evaluates the anti-neuropathic effect of 3′, 4′-dihydroxyflavone on paclitaxel-induced peripheral neuropathy and the underlying mechanisms. Paclitaxel was administered to mice in a single dose of 10 mg/kg, i.p.The neuropathic behavioural parameters such as mechanical allodynia, cold allodynia and thermal hyperalgesia were assessed 24 h later. The test compound 3′, 4′-dihydroxyflavone (50,100 or 200 mg/kg,s.c) was administered 30 min prior to the assessment of behavioral parameters. The possible mechanisms involving KATP channels, adenosine and GABAA receptors were explored by employing suitable interacting drugs. Molecular docking studies to predict the binding interactions of 3′, 4′-dihydroxyflavone at the above targets were also carried out. The test compound 3′, 4′-dihydroxyflavoneexhibited a significant reduction in paw withdrawal response score in both mechanical and cold allodynia and also increased the tail flick response time in thermal hyperalgesia due to paclitaxel-induced neuropathy. The anti-neuropathic effect of 3′, 4′-dihydroxyflavonewas significantly reversed by pre-treatment with glibenclamide, caffeine or bicuculline revealing the involvement of KATP channels, adenosine and GABAA receptors respectively. Furthermore, the molecular docking studies indicated a favourable binding affinity and good H-bond interaction of 3′, 4′-dihydroxyflavone at these targets. The findings of the present study suggests that, 3′, 4′-dihydroxyflavone has anti-neuropathic effect against paclitaxel-induced peripheral neuropathy through mechanisms that involve KATP channels, adenosine (A3) and GABAA (α2 subunit) receptors.

In the present paper, we are interested, for the first time, to separate and identify two glycosyl the flavones from Sedum villosum L, family Crassulaceae collected in the flowering phase in Lakhdar Oued, village of Tlemcen (Algeria). The crude methanolic extract of the flowers part was fractionated on column chromatography, and eluted with dichloromethane/methanol each time with increasing polarity of methanol; 24 fractions were separated. One of these fractions named F16 showed more antioxidant activity to scavenge DPPH free radical with percentage inhibition of 94.849 %. F16 was separated by thin-layer chromatography (TLC) to give 10 compounds. We were chosen the sub-fractions F16.8, which has antioxidative activity of 77.02 %, provided two major molecules of glycosyl the flavones, analysed by ultra-highperformance liquid chromatography coupled to mass spectrometry (UHPLC-DAD-HRSM). Compound 1 was identified as 7, 3'-dihydroxyflavone-5-O-dihexosyl-4'-O-deoxyhexose and compound 2 was 7, 3'-dihydroxyflavone-5-O-hexose- 4'-O-deoxyhexose.

ABSTRACT Trypanosomiasis and leishmaniasis are important parasitic diseases affecting millions of people in Africa, Asia, and South America. In a previous study, we identified several flavonoid glycosides as antiprotozoal principles from a Turkish plant. Here we surveyed a large set of flavonoid aglycones and glycosides, as well as a panel of other related compounds of phenolic and phenylpropanoid nature, for their in vitro activities against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, and Leishmania donovani. The cytotoxicities of more than 100 compounds for mammalian L6 cells were also assessed and compared to their antiparasitic activities. Several compounds were investigated in vivo for their antileishmanial and antitrypanosomal efficacies in mouse models. Overall, the best in vitro trypanocidal activity for T. brucei rhodesiense was exerted by 7,8-dihydroxyflavone (50% inhibitory concentration [IC50], 68 ng/ml), followed by 3-hydroxyflavone, rhamnetin, and 7,8,3′,4′-tetrahydroxyflavone (IC50s, 0.5 μg/ml) and catechol (IC50, 0.8 μg/ml). The activity against T. cruzi was moderate, and only chrysin dimethylether and 3-hydroxydaidzein had IC50s less than 5.0 μg/ml. The majority of the metabolites tested possessed remarkable leishmanicidal potential. Fisetin, 3-hydroxyflavone, luteolin, and quercetin were the most potent, giving IC50s of 0.6, 0.7, 0.8, and 1.0 μg/ml, respectively. 7,8-Dihydroxyflavone and quercetin appeared to ameliorate parasitic infections in mouse models. Generally, the test compounds lacked cytotoxicity in vitro and in vivo. By screening a large number of flavonoids and analogues, we were able to establish some general trends with respect to the structure-activity relationship, but it was not possible to draw clear and detailed quantitative structure-activity relationships for any of the bioactivities by two different approaches. However, our results can help in directing the rational design of 7,8-dihydroxyflavone and quercetin derivatives as potent and effective antiprotozoal agents.

Three additional flavonoids such as 5,7,4?-trihydroxy-3,8,3?-trimethoxy flavonol (1), 5,7-dihydroxyflavone (chrysin, 2) and 5,6,7-trihydroxyflavone (baicalein, 3) were obtained from the methanol extract of whole plant of Polygonum viscosum. The structure of the isolated compounds was established exclusively by ultraviolet (UV) spectroscopy, mass spectrometry (MS) and a series of Nuclear Magnetic Resonance (NMR) analysis.Dhaka Univ. J. Pharm. Sci. 15(1): 27-30, 2016 (June)

Introduction: Amyotrophic lateral sclerosis (ALS) is a fatal neurological disease characterized by progressive degeneration of both upper and lower motor neurons, resulting in paralysis and eventually leads to death from respiratory failure typically within 3 to 5 years of symptom onset. The aim of this work was to predict the pharmacokinetics and identify unique protein targets that are associated with potential anti-ALS phytochemicals and FDA-approved drugs, by in silico approaches. Materials and methods: Standard computational tools (webserver and software) were used, and the methods used are clustering analysis, pharmacokinetics and molecular target predictions, and molecular docking simulation. Results and discussion: The results show that riluzole, β-asarone, cryptotanshinone, harmine and 7,8-dihydroxyflavone have similar pharmacokinetics properties. Riluzole and harmine show 95% probability of target on norepinephrine transporter. Huperzine-A and cryptotanshinone show 100% probability of target on acetylcholinesterase. 7,8-dihydroxyflavone shows 35% probability of target on several carbonic anhydrases, 40% probability of target on CYP19A1, and 100% probability of target on inhibitor of nuclear factor kappa B kinase beta subunit and neurotrophic tyrosine kinase receptor type 2, respectively. Harmine also shows 95% probability of target on dual specificity tyrosine-phosphorylation-regulated kinases, threonine-protein kinases (haspin and PIM3), adrenergic receptors, cyclin-dependent kinases (CDK5 and CDK9), monoamine oxidase A, casein kinase I delta, serotonin receptors, dual specificity protein kinases (CLK1, CLK2, and CLK4), and nischarin, respectively. Also, the results of gene expression network show possible involvement of CDK1, CDK2, CDK4, ERK1, ERK2 and MAPK14 signaling pathways. This study shows that riluzole and harmine have closely similar physicochemical and pharmacokinetics properties as well as molecular targets, such as norepinephrine transporter (SLC6A2). Harmine, huperzine-A and cryptotanshinone could modulate acetylcholinesterase (AChE), which is involved in ALS-pathogenesis. The impact of 7,8-dihydroxyflavone on several carbonic anhydrases (CA) I, II, VII, IX, XII, and XIV, as well as CYP19A1, could help in remediating the respiratory failure associated with ALS. Conclusion: Overall, harmine is found to be superior to riluzole, and the combination of harmine with 7,8-dihydroxyflavone can provide more effective treatment for ALS than the current regime. Further work is needed to validate the predicted therapeutic targets of harmine identified in this study on ALS model or clinical trials, using in silico, in vitro and in vivo techniques. Graphical abstract:

Flavones such as 7,8-dihydroxyflavone (tropoflavin), 5,6,7-trihydroxyflavone (baicalein), 3′,4′,5,6-tetrahydroxyflavone (luteolin), 3,3′,4′,5,5′,7-hexahydroxyflavone (myricetin), 4′,5,7-trihydroxyflavone (apigenin), and 5,7-dihydroxyflavone (chrysin) are important both for their presence in natural products and for their pharmacological applications. However, due to their chemical characteristics and their metabolic processes, they have low solubility and low bioavailability. Knowledge about the physicochemical properties of nanocarriers and the possible mechanisms of covalent and non-covalent interaction between nanoparticles (NPs) and drugs is essential for the design of nanocarriers to improve the bioavailability of molecules with pharmacological potential, such as tropoflavin, baicalein, luteolin, myricetin, apigenin, and chrysin. The parameters of characterization of some NPs of these flavones, such as size, polydispersity index (PDI), zeta potential, encapsulation efficiency (EE), and % release/time, utilized in biomedical applications and the covalent and non-covalent interactions existing between the polymeric NPs and the drug were analyzed. Similarly, the presence of functional groups in the functionalized carbon nanotubes (CNTs), as well as the effect of pH on the % adsorption of flavonoids on functionalized multi-walled carbon nanotubes (MWCNT-COOH), were analyzed. Non-covalent interaction mechanisms between polymeric NPs and flavones, and covalent interaction mechanisms that could exist between the NPs and the amino and hydroxyl functional groups, are proposed.

Abstract Dimethyl sulfoxide (DMSO) is an aprotic organic solvent widely used in laboratory practice due to its ability to dissolve both polar and nonpolar compounds. However, DMSO is also commonly known as a strongly coordinating solvent, especially towards transition metal containing complexes. In this study, estimation of the coordination ability of DMSO towards the Cu(II) ion was attempted, employing a model system composed of 3′,4′-dihydroxyflavone-Cu(II) complex in the presence of explicit DMSO molecules, using the density functional theory (DFT). Nature of the Cu-DMSO chemical interaction (i.e. Cu-O bonding) was studied within the framework of quantum theory of atoms in molecules (QTAIM). Impact of DMSO coordination on the charge and spin distribution at Cu(II) ion was inspected using Mulliken population and QTAIM analysis.

Ce manuscrit présente les résultats d'une étude expérimentale et théorique de deux systèmes moléculaires d'intérêt environnemental : la 2',3-dihydroxyflavone (2'3HF) et les hydrocarbures aromatiques polycycliques (HAP). Ces systèmes ont été étudiés par une combinaison de techniques de spectroscopies électroniques (absorption et fluorescence) et de calculs de chimie quantique (DFT et TD-DFT). Dans une première partie de cette thèse, il est montré que la 2'3HF présente des propriétés acido-basiques singulières par rapport aux autres flavonols. La diminution de plusieurs unités de la valeur du pKa est attribuée à la présence d'un réseau de liaisons hydrogènes. A l'état-excité, un transfert de proton intramoléculaire est à l'origine d'une fluorescence duale. Une bande d'émission supplémentaire, semblant provenir d'une forme tautomère perturbée par interaction avec le solvant, a été mise en évidence. Enfin, une étude exhaustive des complexes de Ca(II), Mn(II) et Zn(II) a montré la formation de chélates avec la fonction α-hydroxycétone. Dans la deuxième partie, trois hypothèses structurales pour expliquer l'observation expérimentale de fluorescence induite par laser (LIF) dans le visible ont été explorées. Une étude sur les dimères de van der Waals (vdW) des HAPs a permis de mieux comprendre la nature de l'interaction entre monomères et de mettre en évidence la difficulté de modéliser ces systèmes, cependant, les transitions électroniques calculées suggèrent que ces espèces ne peuvent pas être responsables des signaux de LIF. Ensuite, une étude identique de HAP liés par ponts aliphatiques a montré des résultats très similaires aux dimères de vdW, excluant leur implication dans la fluorescence observée. Enfin, l'hypothèse de l'émission provenant de radicaux de HAPs a été explorée. Cette dernière est très prometteuse et ouvre la voie à des études expérimentales et théoriques ultérieures
This manuscript reports the results of an experimental and theoretical study of two molecular systems of environmental interest: 2',3-dihydroxyflavone (2'3HF) and polycyclic aromatic hydrocarbons (PAH). These systems were studied by a combination of electronic spectroscopic techniques (absorption and fluorescence) and quantum chemical calculations (DFT and TD-DFT). In the first part of this thesis, it is shown that 2'3HF has singular acid-base properties compared to other flavonols. The decrease of the pKa by several units is attributed to the presence of a hydrogen-bond network. In the excited state, an intramolecular proton transfer causes a dual fluorescence. An additional emission band, seemingly originating from a tautomeric form perturbed by interaction with the solvent, was revealed. Finally, an exhaustive study of the Ca(II), Mn(II) and Zn(II) complexes showed the formation of chelates with the α-hydroxyketone function. In the second part, three structural hypotheses to explain the experimental observation of visible-range laser-induced fluorescence (LIF) were explored. A study of van der Waals (vdW) dimers of PAHs provided insights into the nature of the monomer interaction and highlighted the difficulty of modelling these systems. However, the calculated electronic transitions suggest that these species cannot be responsible for the LIF signals. Secondly, an identical study of aliphatically bridged PAHs showed very similar results to vdW dimers, ruling out their involvement in the observed fluorescence. Finally, the hypothesis of emission from PAH radicals was explored. The latter is very promising and opens the way for further experimental and theoretical studies