Structure of Chelerythrine Base

Dostál, Jiřı́; Táborská, Eva; Slavík, Jiří; Potáček, Milan; Hoffmann, Edmond de

doi:10.1021/np50119a010

Cited by 45 publications

(39 citation statements)

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“…3 The formation parts of the A-pH curves (and of course the corresponding pK R+ values) were shifted to the more alkaline medium with increasing concentration of acids and in dependence on type of anion. The corresponding pK R+ values calculated using a numerical interpretation of the A-pH curves by the SQUAD-G program (see Table 2) changed from 7.21 to 8.16 in the same manner (in agreement with published data [15][16][17][18][19][20][21][22] Due to the low stability of solutions, the A-pH curves for DHSA were measured at a constant concentration of dihydrosanguinarine c = 12 μmol L -1 in the presence of HCl in 60% (v/v) methanol and pK R+ value of 2.32 was estimated in agreement with the value 2.3-2.6 acc. [21]).…”

Section: Absorbance-ph Curvessupporting

confidence: 84%

“…The reported pK R+ values of SA (7.32 -8.16) [8,9,11,[15][16][17][18][19][20][21][22] and our previous experience with electrophoretic behaviour of SA [20,23] imply that at least some of the published pK R+ values are distorted by the abovementioned experimental conditions. Thus, in some cases an organic solvent was added to the solutions to improve the alkaloid solubility.…”

Section: Discussionmentioning

confidence: 99%

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Acid-base behaviour of sanguinarine and dihydrosanguinarine

et al. 2009

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Acid-base and optical properties of sanguinarine and dihydrosanguinarine were studied in the presence of HCl, HNO 3 , H 2 SO 4 , H 3 PO 4 , CAPSO and acetic acid (HAc) of different concentrations and their mixtures. The equilibrium constants pK R+ of the transition reaction between an iminium cation Q + of sanguinarine and its uncharged QOH (pseudo-base, 6-hydroxy-dihydroderivative) form were calculated. A numerical interpretation of the A-pH curves by a SQUAD-G computer program was used. Remarkable shifts of formation parts of absorbance-pH (A-pH) curves to alkaline medium were observed. The shifts depend on the type and concentration of inert electrolyte (the most remarkable for HNO 3 and HCl ). The corresponding pK R+ values ranged from 7.21 to 8.16 in the same manner (ΔpK R+ = 0.81 and 0.73 for HNO 3 and HCl, respectively). The priority effect of ionic species and ionic strength was confirmed in the presence of NaCl and KCl. The strength of interaction of SA with bioactive compounds (i.e. receptors, transport proteins, nucleic acids etc.) may be affected because of the observed influence of both cations and anions of the inert electrolytes. Warsaw and Springer-Verlag Berlin Heidelberg. © Versita

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Section: Absorbance-ph Curvessupporting

confidence: 84%

Section: Discussionmentioning

confidence: 99%

Acid-base behaviour of sanguinarine and dihydrosanguinarine

et al. 2009

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“…b Intensity abbreviations: vw, very weak; w, weak; mw, medium-weak; m, medium; ms, medium-strong; s, strong. c Assignments derived from Ref [29,30,31] …”

Section: Resultsmentioning

confidence: 99%

“…As shown in Table 2, the CET cytosolic concentrations were quite close to that of the bathing medium of 50 μM, raising the question as to whether CET might equilibrate across the plasma membrane, as a positively charged monomer (CET + ) or as pseudo base that does exist at higher pH values [30]. For the sake of the argument, if CET traversed the membrane as CET + , then, according to the Nernst Equation: log [CET + ] i = log [CET] o - E m /61.5, the free intracellular CET concentration, [CET] i , should have been 5 fold above equilibrium at 244 μM, assuming a membrane potential, E m , of - 40 mV typical in epithelial cells, where [CET] o is the external CET concentration = 50 μM, and 61.5 mV = 2.3 RT/zF at 37 °C with the usual meanings.…”

Section: Discussionmentioning

confidence: 99%

Surface-Enhanced Raman Spectroscopy (SERS) Tracking of Chelerythrine, a Na⁺/K⁺Pump Inhibitor, into Cytosol and Plasma Membrane Fractions of Human Lens Epithelial Cell Cultures

Dorney

Sizemore

Alqahtani

et al. 2013

Cell Physiol Biochem

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Background/Aims: The quaternary benzo-phenanthridine alkaloid (QBA) chelerythrine (CET) is a pro-apoptotic drug and Na⁺/K⁺ pump (NKP) inhibitor in human lens epithelial cells (HLECs). In order to obtain further insight into the mechanism of NKP inhibition by CET, its sub-cellular distribution was quantified in cytosolic and membrane fractions of HLEC cultures by surface-enhanced Raman spectroscopy (SERS). Methods: Silver nanoparticles (AgNPs) prepared by the Creighton method were concentrated, and size-selected using a one-step tangential flow filtration approach. HLECs cultures were exposed to 50 μM CET in 300 mOsM phosphate-buffered NaCl for 30 min. A variety of cytosolic extracts, crude and purified membranes, prepared in lysing solutions in the presence and absence of a non-ionic detergent, were incubated with AgNPs and subjected to SERS analysis. Determinations of CET were based on a linear calibration plot of the integrated CET SERS intensity at its 659 cm^-1 marker band as a function of CET concentration. Results: SERS detected chemically unaltered CET in both cytosol and plasma membrane fractions. Normalized for protein, the CET content was some 100 fold higher in the crude and purified plasma membrane fraction than in the soluble cytosolic extract. The total free CET concentration in the cytosol, free of membranes or containing detergent-solubilized membrane material, approached that of the incubation medium of HLECs. Conclusion: Given a negative membrane potential of HLECs the data suggest, but do not prove, that CET may traverse the plasma membrane as a positively charged monomer (CET⁺) accumulating near or above passive equilibrium distribution. These findings may contribute to a recently proposed hypothesis that CET binds to and inhibits the NKP through its cytosolic aspect.

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“…The structures were determined using NMR spectroscopy and MS and confirmed by comparison against literature data as 7,9-dimethoxy-2,3-methylene dioxybenzophenanthridine (Sukari et al, 1999) (3.4 mg), N-nornitidine (Martin et al, 2005) (6.8 mg) isolated from the hexane extract; zanthomamide (88.2 mg), lemairamide (5.0 mg) (Adesina & Reisch 1989;Adesina et al, 1997;Simeray et al, 1985) isolated from the dichloromethane extract; bis[6-(5,6-dihydrochelerythrinyl] ether (Dostal et al, 1995) (6.6 mg) isolated from the methanol extract.…”

Section: Resultsmentioning

confidence: 75%

Low antiplasmodial activity of alkaloids and amides from the stem bark ofZanthoxylum rubescens(Rutaceae)

et al. 2007

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Summary :The stem bark of Zanthoxylum rubescens (syn. Fagara rubescens) is used for treating fevers associated with malaria in the Ivory Coast. Three alkaloids: N-nornitidine, 7,9-dimethoxy-2,3-methylenedioxybenzophenanthridine, and bis[6-(5,6-dihydrochelerythrinyl)] ether; and two amides: zanthomamide and lemairamide, were isolated from the stem bark of this plant. These compounds were screened in vitro against the chloroquine-sensitive 3D7 strain and the chloroquine-resistant FCM29 strain of P. falciparum. N-nornitidine was found to be inactive. 7,9-dimethoxy-2,3-methylenedioxybenzophenanthridine, lemairamide and zanthomamide showed weak activity with average IC 50 values ranging from 45.6 µM to 149.9 µM. Bis [6-(5,6-dihydrochelerythrinyl)] ether was the most active of the tested compounds with mean IC 50s of 14.9 ± 1.4 µM in FCM29 strain and 15.3 ± 3.4 µM in 3D7 strain (~58 to ~1130 times less active than chloroquine respectively). The anti-Plasmodium activities of the tested alkaloids of Z. rubescens were low; and do not encourage the use of this plant as antimalarial. (N-nornitidine, 7,9-dimethoxy-2,3-methylenedioxybenzophenanthridine et bis[6-(5,6-dihydrochelerythrinyl) (Fish et al., 1974), or to prevent abortion in pregnant women (Penali, personal communication). Since bitter compounds such as alkaloids have shown antiplasmodial activity (Addae- Kyereme et al., 2001;Andrade-Neto et al., 2003;Kassim et al., 2005;Randrianarivelojosia et al., 2003;Sener et al., 2003), we isolated and assessed the in vitro antiplasmodial properties of alkaloids and amides from, Z. rubescens. The purpose of the investigation was to identify the schizonticidal effects of these compounds against P. falciparum. Résumé MATERIALS AND METHODS PLANT MATERIALT he stem bark of Zanthoxylum rubescens Planch.Ex. Hook f. (syn. Fagara rubescens Engl.) (Rutaceae) was collected from the Lamto forest in the M alaria, known as djèkoidjo or ahankan according to Baoulé and Agnis dialects, remains a major public health problem in the Ivory Coast. Our ethnobotanical survey in the southern part of the country (Aboisso region) revealed that the decoction from the stem bark of Zanthoxylum rubescens -an Ivorian indigenous plant -is used to treat and to prevent djèkoidjo (mainly fever). Also, this plant is CHEMICAL ANALYSISAir dried, milled stem bark of Zanthoxylum rubescens (562.6 g) was extracted successively with hexane, dichloromethane, ethyl acetate and methanol in a Soxhlet apparatus for 24 hours with each solvent. Isolation and purification of compounds from the crude extracts were performed using gravity column chromatography over silica gel (Merck Art. 9385). Thin layer chromatographic analysis was carried out on 0.2 mm silicagel, aluminium-backed plates (Merck Art. 5554) and spots were visualized under UV light and then by spraying with anisaldehyde spray reagent followed by heating. The hexane extract was separated using a hexane/ethyl acetate solvent mixture (85/15); the dichloromethane extract was separated with a dichloromethane/methan...

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Structure of Chelerythrine Base

Cited by 45 publications

References 14 publications

Acid-base behaviour of sanguinarine and dihydrosanguinarine

Acid-base behaviour of sanguinarine and dihydrosanguinarine

Surface-Enhanced Raman Spectroscopy (SERS) Tracking of Chelerythrine, a Na⁺/K⁺Pump Inhibitor, into Cytosol and Plasma Membrane Fractions of Human Lens Epithelial Cell Cultures

Low antiplasmodial activity of alkaloids and amides from the stem bark ofZanthoxylum rubescens(Rutaceae)

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Structure of Chelerythrine Base

Cited by 45 publications

References 14 publications

Acid-base behaviour of sanguinarine and dihydrosanguinarine

Acid-base behaviour of sanguinarine and dihydrosanguinarine

Surface-Enhanced Raman Spectroscopy (SERS) Tracking of Chelerythrine, a Na+/K+Pump Inhibitor, into Cytosol and Plasma Membrane Fractions of Human Lens Epithelial Cell Cultures

Low antiplasmodial activity of alkaloids and amides from the stem bark ofZanthoxylum rubescens(Rutaceae)

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Surface-Enhanced Raman Spectroscopy (SERS) Tracking of Chelerythrine, a Na⁺/K⁺Pump Inhibitor, into Cytosol and Plasma Membrane Fractions of Human Lens Epithelial Cell Cultures