21905-73-7Relevant academic research and scientific papers
Hydrophobicity constants for several xanthones and flavones
Pogodaeva,Medvedeva,Sukhov,Shishmareva
, p. 38 - 42 (2011)
The octanol-water distribution of several xanthones and flavones was studied. Their hydrophobicity constants (log P) were determined. The lipophilicity constants (π) of the substituents were calculated. The relationship between the structure and hydrophobicity constants of the gamma-pyrone derivatives was found.
Electrochemical Reductive Smiles Rearrangement for C-N Bond Formation
Chang, Xihao,Zhang, Qinglin,Guo, Chang
, p. 10 - 13 (2019/01/04)
A conceptually new and synthetically valuable radical Smiles rearrangement reaction is reported under undivided electrolytic conditions. This protocol employs an entirely new strategy for the electrochemical radical Smiles rearrangement. Remarkably, an amidyl radical generated from the cleavage of the N-O bond under reductive electrolytic conditions plays a crucial role in this transformation. Various hydroxylamine derivatives bearing different substituents are suitable in this electrochemical transformation, furnishing the corresponding amides in up to 86% yield.
Formal Aniline Synthesis from Phenols through Deoxygenative N-Centered Radical Substitution
Lardy, Samuel W.,Luong, Kristine C.,Schmidt, Valerie A.
supporting information, p. 15267 - 15271 (2019/12/11)
Phenolic, lignin-derived substrates have emerged as desirable biorenewable chemical feedstocks for coupling reactions. A radical-mediated conversion of phenol derivatives to anilines is reported, using unfunctionalized hydroxamic acids as the N-centered radical source. The applicability of this triethyl phosphite mediated O-atom transfer approach, which tolerates a range of steric and electronic demands to naturally occurring phenols and lignin models, has been demonstrated in this work to access the corresponding aniline derivatives.
Design, synthesis and cardiovascular evaluation of some aminoisopropanoloxy derivatives of xanthone
Kubacka,Szkaradek,Mogilski,Pańczyk,Siwek,Grybo?,Filipek,?mudzki,Marona,Waszkielewicz
, p. 3773 - 3784 (2018/05/04)
A series of aminoisopropanoloxy derivatives of xanthone has been synthesized and their pharmacological properties regarding the cardiovascular system has been evaluated. Radioligand binding and functional studies in isolated organs revealed that title compounds present high affinity and antagonistic potency for α1-(compound 2 and 8), β-(compounds 1, 3, 4, 7), α1/β-(compounds 5 and 6) adrenoceptors. Furthermore, compound 7, the structural analogue of verapamil, possesses calcium entry blocking activity. The title compounds showed hypotensive and antiarrhythmic properties due to their adrenoceptor blocking effect. Moreover, they did not affect QRS and QT intervals, and they did not have proarrhythmic potential at tested doses. In addition they exerted anti-aggregation effect. The results of this study suggest that new compounds with multidirectional activity in cardiovascular system might be found in the group of xanthone derivatives.
A photoredox-neutral Smiles rearrangement of 2-aryloxybenzoic acids
Gonzalez-Gomez, Jose C.,Ramirez, Nieves P.,Lana-Villarreal, Teresa,Bonete, Pedro
, p. 9680 - 9684 (2017/11/30)
We report on the use of visible light photoredox catalysis for the radical Smiles rearrangement of 2-aryloxybenzoic acids to obtain aryl salicylates. The method is free of noble metals and operationally simple and the reaction can be run under mild batch or flow conditions. Being a redox neutral process, no stoichiometric oxidants or reductants are needed.
Efficient Aryl Migration from an Aryl Ether to a Carboxylic Acid Group To Form an Ester by Visible-Light Photoredox Catalysis
Wang, Shao-Feng,Cao, Xiao-Ping,Li, Yang
, p. 13809 - 13813 (2017/10/24)
We have developed a highly efficient aryl migration from an aryl ether to a carboxylic acid group through retro-Smiles rearrangement by visible-light photoredox catalysis at ambient temperature. Transition metals and a stoichiometric oxidant and base are avoided in the transformation. Inspired by the high efficiency of this transformation and the fundamental importance of C?O bond cleavage, we developed a novel approach to the C?O cleavage of a biaryl ether to form two phenolic compounds, as demonstrated by a one-pot, two-step gram-scale reaction under mild conditions. The aryl migration exhibits broad scope and can be applied to the synthesis of pharmaceutical compounds, such as guacetisal. Primary mechanistic studies indicate that the catalytic cycle occurs by a reductive quenching pathway.
Design, synthesis, and anticonvulsant activity of some derivatives of xanthone with aminoalkanol moieties
Waszkielewicz, Anna M.,S?oczyńska, Karolina,P?kala, El?bieta,?mudzki, Pawe?,Siwek, Agata,Grybo?, Anna,Marona, Henryk
, p. 339 - 352 (2017/04/03)
A series of new xanthone derivatives have been synthesized and evaluated for their anticonvulsant properties in the maximal electroshock, subcutaneous metrazole tests and for neurotoxicity in the rotarod in mice, i.p. and rats, p.o. Compound 9: R,S-2-{2-[(1-hydroxybutan-2-yl]amino)ethoxy}-9H-xanthen-9-one and compound 12: R,S-2-{3-[(1-hydroxybutan-2-yl)amino]propoxy}-9H-xanthen-9-one exerted activity in rats, p.o. 2 and 4?h after administration, respectively. Therefore, metabolic stability of the compounds was evaluated with use of rat microsomes, resulting in half-life t1/2 136 and 108?min, respectively, indicating that either the metabolites are very active or the parent compounds exert ADME properties other than metabolism which influence the late onset of activity.
Carboxyl radical-assisted 1,5-aryl migration through Smiles rearrangement
Hossian, Asik,Jana, Ranjan
, p. 9768 - 9779 (2016/10/31)
We report herein, a silver(i)-catalyzed Smiles rearrangement of 2-aryloxy- or 2-(arylthio)benzoic acids to provide aryl-2-hydroxybenzoate or aryl-2-mercaptobenzoate dimer, respectively, through 1,5-aryl migration from oxygen or sulfur to carboxylate oxygen. Mechanistically, the aryl ether moiety undergoes an intramolecular ipso attack by the carboxyl radical followed by a C-O or C-S bond cleavage. Aryl-2-mercaptobenzoates undergo oxidative dimerization through a thiol moiety in situ.
Anti-Helicobacter pylori activity of some newly synthesized derivatives of xanthone
Klesiewicz, Karolina,Karczewska, Elzbieta,Budak, Alicja,Marona, Henryk,Szkaradek, Natalia
, p. 825 - 834 (2016/12/09)
A series of 20 xanthone derivatives was synthesized and evaluated for anti-Helicobacter pylori (H. pylori) activity. Qualitative and quantitative in vitro tests using the Kirby-Bauer method (agar disc-diffusion method) were performed. The tested compounds were screened against clarithromycin- and/or metronidazole-resistant strains of H. pylori. As a reference, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterial strains were examined. On the basis of microbiological assays, xanthones can be considered as potential anti-H. pylori agents. They displayed significant activity against the examined strains, which was higher against the bacteria resistant to metronidazole than clarithromycin. The lowest MIC values ranging up to 20 mg l-1 were observed for the following compounds: 3, 4, 8, 9, 12, 19 (against the metronidazole-resistant strains) and the compound 10 (against the clarithromycin-resistant strain). These preliminary results for screening of xanthone derivatives form a part of an ongoing study of the structure-activity relationships of a large group of compounds. Microbiological assays will be conducted afterwards to determine the mechanism of xanthones' action against H. pylori.
Cardiovascular activity of the chiral xanthone derivatives
Szkaradek, Natalia,Rapacz, Anna,Pytka, Karolina,Filipek, Barbara,Zelaszczyk, Dorota,Szafrański, Przemys?aw,S?oczyńska, Karolina,Marona, Henryk
, p. 6714 - 6724 (2015/10/19)
A series of 6 derivatives of xanthone were synthesized and evaluated for cardiovascular activity. The following pharmacological experiments were conducted: the binding affinity for adrenoceptors, the influence on the normal electrocardiogram, the effect on the arterial blood pressure, the effect on blood pressor response and prophylactic antiarrhythmic activity in adrenaline induced model of arrhythmia (rats, iv). Two compounds revealed nanomolar affinity for α1-adrenoceptor which was correlated with the strongest cardiovascular (antiarrhythmic and hypotensive) activity in animals' models. They were enantiomers of previously described (R,S)-4-(2-hydroxy-3-(4-(2-methoxyphenyl)piperazin-1-yl)propoxy)-9H-xanthen-9-one hydrochloride and revealed similar antiarrhythmic potential in adrenaline induced model of arrhythmia in rats after intravenous injection (ED50 = 0.53 mg/kg and 0.81 mg/kg, respectively). These values were lower than values obtained for reference drug urapidil. These compounds were more active in this experiment than urapidil (ED50 = 1.26 mg/kg). The compound 5 administered iv at doses of 0.62-2.5 mg/kg at the peak of arrhythmia prevented and/or reduced the number of premature ventricular beats in a statistically significant manner. The ED50 value was 1.20 mg/kg. The S-enantiomer (6) given at the same doses did not show therapeutic antiarrhythmic activity in this model. These compounds significantly decreased the systolic and diastolic blood pressure throughout the whole observation period in anesthetized, normotensive rats. The studied enantiomers showed higher toxicity than urapidil, but imperceptibly higher that another cardiovascular drugs, that is, carvedilol or propranolol. They were also evaluated for mutagenic potential in the Ames (Salmonella) test. It was found that at the concentrations tested the compounds were non mutagenic when compared to solvent control. Results were quite promising and suggested that in the group of xanthone derivatives new potential antiarrhythmics and hypotensives might be found.
