Electroreduction of lichexanthone

Carvalho, Adriana Evaristo de; Alcantara, Glaucia Braz; Oliveira, Sebastião M.; Micheletti, Ana Camila; Honda, Nobuaki

doi:10.1016/j.electacta.2008.10.035

Cited by 11 publications

(5 citation statements)

References 15 publications

(25 reference statements)

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“…We obtained two values of (7.29±0.45)x10 -6 and (4.78±0.31)x10 -6 cm 2 /s for both ACN and DMF, respectively. These values are in good agreement with the viscosity relationship between the two solvents (D decreases with an increase in viscosity) and with similar tri-cyclic components found in the literature in organic solvents [15,16].…”

Section: Cyclic Voltammetry (Cv)supporting

confidence: 79%

Electrochemical Behaviour of Carbamazepine in Acetonitrile and Dimethylformamide Using Glassy Carbon Electrodes and Microelectrodes

et al. 2010

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The electrochemical reduction of carbamazepine in acetonitrile (ACN) and dimethylformamide (DMF) using a glassy carbon electrode and microelectrodes has been studied. The reduction process is consistent with an Electrochemical-Chemical mechanism (EC) involving a two electron transfer followed by a first order reaction, as shown by the cyclic voltammetry and differential pulse voltammetry. Halfwave potential, number of electron transfer, diffusion coefficient and rate constant of the associated chemical reaction are reported. Detection limits are in DPV: LoD=0.92 and 0.76 μg mL -1 in ACN and DMF, respectively. Precision (%RSD) and recovery (%) values when pharmaceutical compounds (200mg carbamazepine tablets) and spiked plasma samples were tested ranged from 1.09 to 9.04% and % recoveries ranged from 96 to 104.1%.

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Section: Cyclic Voltammetry (Cv)supporting

confidence: 79%

Electrochemical Behaviour of Carbamazepine in Acetonitrile and Dimethylformamide Using Glassy Carbon Electrodes and Microelectrodes

et al. 2010

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“…On the basis of TLC analysis, 11 fractions were combined. From FCPC fraction 4 (5 mg), 1.0 mg of lichexanthone ( 8 ) , was separated from an n -hexane and MeOH(aq) mixture (10:1:9). FCPC fraction 5 (57.4 mg) was further fractionated by FCPC (elution-extrusion mode) using MeCN/TBME/ n -hexane (10:1:10) in descending mode (288 mL, 800 rpm, 4 mL/min), yielding three fractions.…”

Section: Methodsmentioning

confidence: 99%

“…The remaining material was fractionated by SPE C-18 (2 g) using a MeOH/H 2 O gradient from 50:50 to 100:0 and CH 2 Cl 2 to yield four subfractions. Subfraction 3 (184 mg) was separated by preparative HPLC using MeCN/H 2 O under isocratic conditions (85:15) to yield 4.9 mg of lichexanthone ( 8 ) , ( t R approximately 25 min). The residual HPLC eluent was evaporated (92 mg) and further fractionated by PTLC using n -hexane/acetone (8:2), which furnished 26.8 mg of betulone ( 11 ). , …”

Section: Methodsmentioning

confidence: 99%

Antiparasitic Compounds from Cupania cinerea with Activities against Plasmodium falciparum and Trypanosoma bruceirhodesiense

et al. 2011

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In a survey of plants from Ecuador with antiprotozoal activity, Cupania cinerea was found to show significant in vitro activity against the Plasmodium falciparum K1 strain and Trypanosoma brucei rhodesiense. Subsequently, activity-guided isolation of the n-hexane and dichloromethane extracts from the bark of C. cinerea afforded two diterpene glycosides (1 and 2), named cupacinoside and 6'-de-O-acetylcupacinoside, and a lactonized triterpene bearing an oxepin moiety named cupacinoxepin (3), together with the known compounds scopoletin (4), caryophyllene oxide (5), two bisabolane sesquiterpenes (6 and 7), lichexanthone (8), gustastatin (9), lupenone (10), betulone (11), 17β,21β-epoxyhopan-3-one (12), taraxerol (13), and taraxerone (14). For compound 3, X-ray crystallography was employed to elucidate the relative configuration. For cupacinosides (1) and (2) and cupacinoxepin (3), in vitro activities against the P. falciparum K1 strain (IC(50)1, 1.3; 2, 1.8; and 3, 8.7 μM) and T. b. rhodesiense (IC(50)1, 4.5; 2, 15.8; and 3, 71.6 μM) were found. Cytotoxicity toward L-6 cells is discussed for all the compounds isolated.

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“…The structures were confirmed through analysis of 1 H, 13 C and distortionless enhancement by polarization transfer (DEPT) 135° spectra, and data were in agreement with references. [29][30][31][32][33][34][35] The degree of purity of all compounds surpassed 95%, as determined by TLC and NMR.…”

Section: Methodsmentioning

confidence: 99%

Cytotoxic Evaluation of Phenolic Compounds from Lichens against Melanoma Cells

et al. 2013

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Atranorin, lichexanthone, and the (+)-usnic, diffractaic, divaricatic, perlatolic, psoromic, protocetraric, and norstictic acids isolated from the lichens Parmotrema dilatatum (Vain.) Hale, Usnea subcavata Motyka, Usnea sp., Ramalina sp., Cladina confusa (Sant.) FolMM. & aHti, Dirinaria aspera HäSänen, and Parmotrema lichexanthonicum eliaSaro & adler were evaluated against UACC-62 and B16-F10 melanoma cells and 3T3 normal cells. Sulforhodamine B assay revealed significant cytotoxic activity in protocetraric, divaricatic, and perlatolic acids on UACC-62 cells (50% growth inhibitory concentration (GI 50 ) 0.52, 2.7, and 3.3 µg/mL, respectively). Divaricatic and perlatolic acids proved the most active on B16-F10 cells (GI 50 4.4, 18.0 µg/mL, respectively) and the most cytotoxic to 3T3 normal cells. Diffractaic, usnic, norstictic, and psoromic acids were cytotoxic to UACC-62 cells in the 24.7 to 36.6 µg/mL range, as were protocetraric and diffractaic acids to B16-F10 cells (GI 50 24.0, 25.4 µg/mL, respectively). Protocetraric acid was highly selective (selectivity index (SI*) 93.3) against UACC-62 cells, followed by norstictic, perlatolic, psoromic, and divaricatic acids, while norstictic and divaricatic acids were more selective against B16-F10 cells. The high SI* value obtained for protocetraric acid on UACC-62 cells makes it a potential candidate for the study of melanomas in experimental models. Chemometric analysis was performed to evaluate the general behavior of the compounds against the cell lines tested.

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Electroreduction of lichexanthone

Cited by 11 publications

References 15 publications

Electrochemical Behaviour of Carbamazepine in Acetonitrile and Dimethylformamide Using Glassy Carbon Electrodes and Microelectrodes

Electrochemical Behaviour of Carbamazepine in Acetonitrile and Dimethylformamide Using Glassy Carbon Electrodes and Microelectrodes

Antiparasitic Compounds from Cupania cinerea with Activities against Plasmodium falciparum and Trypanosoma bruceirhodesiense

Cytotoxic Evaluation of Phenolic Compounds from Lichens against Melanoma Cells

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