Determination of the overlapping pKa values of chrysin using UV–vis spectroscopy and ab initio methods

Castro, G.T.; Ferretti, F.H.; Blanco, Susana

doi:10.1016/j.saa.2005.02.013

Cited by 21 publications

(22 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A possible reason for this discrepancy may be the low aqueous solubility and low bioavailability of chrysin, although additional causes cannot be excluded [13-15]. Chrysin is soluble in some organic solvents but is practically insoluble in water [14-17]. Therefore, effective solubilization of chrysin is critical for its pharmaceutical application as an absorption enhancer via inhibition of BCRP-mediated drug efflux.…”

Section: Introductionmentioning

confidence: 99%

Improved In vivo Effect of Chrysin as an Absorption Enhancer Via the Preparation of Ternary Solid Dispersion with Brij®L4 and Aminoclay

Lee

Song

et al. 2018

CDD

View full text Add to dashboard Cite

Background: Chrysin is a strong inhibitor of breast cancer resistance protein (BCRP) but it is practically insoluble in water. Effective solubilization of chrysin is critical for its pharmaceutical application as an absorption enhancer via inhibition of BCRP-mediated drug efflux. Objective: This study aimed to develop an effective oral formulation of chrysin to improve its in vivo effect as an absorption enhancer. Method: Solid dispersions (SDs) of chrysin were prepared with hydrophilic carriers having surface acting properties and a pH modulator. In vitro and in vivo characterizations were performed to select the optimal SDs of chrysin. Results: SDs with Brij&®L4 and aminoclay was most effective in increasing the solubility of chrysin by 13-53 fold at varying drug-carrier ratios. Furthermore, SDs significantly improved the dissolution rate and extent of drug release. SDs (chrysin: Brij&®L4: aminoclay=1:3:5) achieved approximately 60% and 83% drug release within 1 h and 8 h, respectively, in aqueous medium, while the dissolution of the untreated chrysin was less than 13%. XRD patterns indicated the amorphous state of chrysin in SDs. The SD formulation was effective in improving the bioavailability of topotecan, a BCRP substrate in rats. Following oral administration of topotecan with the SDs of chrysin, the Cmax and AUC of topotecan was enhanced by approximately 2.6- and 2-fold, respectively, while the untreated chrysin had no effect. Conclusion: The SD formulation of chrysin with Brij&®L4 and aminoclay appeared to be promising in improving the dissolution of chrysin and enhancing its in vivo effect as an absorption enhancer.

show abstract

Section: Introductionmentioning

confidence: 99%

Improved In vivo Effect of Chrysin as an Absorption Enhancer Via the Preparation of Ternary Solid Dispersion with Brij®L4 and Aminoclay

Lee

Song

et al. 2018

CDD

View full text Add to dashboard Cite

show abstract

“…Therefore, the pH value was adjusted to 6.0 in the following experiments. The species of luteolin were assigned to the neutral form (pH 2–5), mono‐anion (pH 5–7) and di‐anion (pH 7–9), and those of chrysin and apigenin were mainly kept the neutral form when the pH value under 6.0 . Moreover, the zeta potential of MIL‐101 became negative and unstable when the pH value exceeded 9.6 .…”

Section: Resultsmentioning

confidence: 99%

Metal‐organic framework MIL‐101 as sorbent based on double‐pumps controlled on‐line solid‐phase extraction coupled with high‐performance liquid chromatography for the determination of flavonoids in environmental water samples

Liu

et al. 2016

Electrophoresis

View full text Add to dashboard Cite

A novel method with high sensitivity for the rapid determination of chrysin, apigenin and luteolin in environment water samples was developed by double-pumps controlled on-line solid-phase extraction (SPE) coupled with high-performance liquid chromatography (HPLC). In the developed technique, metal organic framework MIL-101 was synthesized and applied as a sorbent for SPE. The as-synthesized MIL-101 was characterized by scanning electron microscope, X-ray diffraction spectrometry, thermal gravimetric analysis and micropore physisorption analysis. The MIL-101 behaved as a fast kinetics in the adsorption of chrysin, apigenin and luteolin. On-line SPE of chrysin, apigenin and luteolin was processed by loading a sample solution at a flow rate of 1.0 mL/min for 10 min. The extracted analytes were subsequently eluted into a ZORBAX Bonus-RP analytical column (25 cm long × 4.6 mm i.d.) for HPLC separation under isocratic condition with a mobile phase (MeOH: ACN: 0.02 M H PO = 35:35:30) at a flow rate of 1.0 mL/min. Experimental conditions, including ionic strength, sample pH, sample loading rates, sample loading time and desorption analytes time, were further optimized to obtain efficient preconcentration and high-precision determination of the analytes mentioned above. The method achieved the merits of simplicity, rapidity, sensitivity, wide linear range and high sample throughput. The possible mechanism for the adsorption of flavonoids on MIL-101 was proposed. The developed method has been applied to determine trace chrysin, apigenin and luteolin in a variety of environmental water samples.

show abstract

“…Finally, the halfneutralization potential values were determined by drawing the ml (TBAH)-mV graphic, and corresponding pK a values were calculated. [37,38] Results and discussion For the determination of pK a values, some spectroscopic methods such as potentiometric titration, [14] UV-VIS spectroscopy, [15] CE [17] and LC [18] were used. These methods were used commonly because of giving high certainty results, being available commercially and automation concurrency.…”

Section: Potentiometric Titrationsmentioning

confidence: 99%

“…This method is a technique about NMR active nucleus chemical shift value for the protonation of adjacent center. [21] In the determination of pK a , special approaches based on 31 P, 15 N, 19 F or 33 S NMR spectroscopy are also used. [12,[22][23][24] However, pH-dependent chemical shift values of 13 C and especially 1 H are more common, and they are used successfully in determining pK a values.…”

Section: Introductionmentioning

confidence: 99%

Determination of pK_a values of some novel benzimidazole salts by using a new approach with ¹H NMR spectroscopy

Mumcu

Küçükbay

2015

Magnetic Reson in Chemistry

View full text Add to dashboard Cite

Benzimidazoles and their derivatives including imidazole are studied widely because they exist in the structure of natural products and different drugs. pKa values are extremely important for drug discovery and improvement in order to determine pharmacokinetic and pharmacodynamic features such as permeation through biological barriers, interactions with the target area or side effects. Acid-base features (pKa ) have great importance not only for physiological characteristics but also for being used as a ligand or changing physico-chemical features by turning benzimidazoles into salts. Within the scope of this study, a variety of new benzimidazole salts were synthesized, and their characterizations were made by NMR spectroscopy, FTIR spectroscopy and element analysis techniques. The pKa values of synthesized benzimidazole salts were determined by inflection point approach using integration values obtained with (1) H NMR spectroscopy and Henderson-Hasselbalch analysis. pKa values of some benzimidazole salts were also determined by potentiometric methods in order to compare those of NMR spectroscopy results.

show abstract

Determination of the overlapping pKa values of chrysin using UV–vis spectroscopy and ab initio methods

Cited by 21 publications

References 21 publications

Improved In vivo Effect of Chrysin as an Absorption Enhancer Via the Preparation of Ternary Solid Dispersion with Brij®L4 and Aminoclay

Improved In vivo Effect of Chrysin as an Absorption Enhancer Via the Preparation of Ternary Solid Dispersion with Brij®L4 and Aminoclay

Metal‐organic framework MIL‐101 as sorbent based on double‐pumps controlled on‐line solid‐phase extraction coupled with high‐performance liquid chromatography for the determination of flavonoids in environmental water samples

Determination of pK_a values of some novel benzimidazole salts by using a new approach with ¹H NMR spectroscopy

Contact Info

Product

Resources

About

Determination of the overlapping pKa values of chrysin using UV–vis spectroscopy and ab initio methods

Cited by 21 publications

References 21 publications

Improved In vivo Effect of Chrysin as an Absorption Enhancer Via the Preparation of Ternary Solid Dispersion with Brij&#174;L4 and Aminoclay

Improved In vivo Effect of Chrysin as an Absorption Enhancer Via the Preparation of Ternary Solid Dispersion with Brij&#174;L4 and Aminoclay

Metal‐organic framework MIL‐101 as sorbent based on double‐pumps controlled on‐line solid‐phase extraction coupled with high‐performance liquid chromatography for the determination of flavonoids in environmental water samples

Determination of pKa values of some novel benzimidazole salts by using a new approach with 1H NMR spectroscopy

Contact Info

Product

Resources

About

Improved In vivo Effect of Chrysin as an Absorption Enhancer Via the Preparation of Ternary Solid Dispersion with Brij®L4 and Aminoclay

Improved In vivo Effect of Chrysin as an Absorption Enhancer Via the Preparation of Ternary Solid Dispersion with Brij®L4 and Aminoclay

Determination of pK_a values of some novel benzimidazole salts by using a new approach with ¹H NMR spectroscopy