Selective separation of flavonoids with a polyvinyl alcohol membrane

Yoshizuka, Kazuharu; Ohta, Hiroaki; Inoue, Katsutoshi; Kitazaki, Hironori; Ishimaru, Masayuki

doi:10.1016/0376-7388(96)00075-0

Cited by 22 publications

(9 citation statements)

References 8 publications

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“…19,20 However, following intravenous administration of baicalin has a short biological half life of 0.16 h 21,22 for its relative high molecular weight (MW ¼ 447) and typical physical property (dissociation constant pK a of 2.9, water solubility of 0.091 g/L at 208C and partition coefficient P 1-octanol-water of 1.29). 23 Furthermore, significant hepatic first-pass metabolism has been observed, and the bioavailability is only 54% after oral administration. 24 These undesirable side effects could be offset by using the transdermal route.…”

Section: Introductionmentioning

confidence: 99%

Effect of Low Molecular Weight Chitosans on Drug Permeation through Mouse Skin: 1. Transdermal Delivery of Baicalin

Zhou

Liu

et al. 2010

Journal of Pharmaceutical Sciences

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Section: Introductionmentioning

confidence: 99%

Effect of Low Molecular Weight Chitosans on Drug Permeation through Mouse Skin: 1. Transdermal Delivery of Baicalin

Zhou

Liu

et al. 2010

Journal of Pharmaceutical Sciences

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“…The estimated CL d equals the true passive diffusion clearance when 1/P ABL ϭ 0 or Ͻ Ͻ 1/P M . Although Ba is lipophilic (log P ϭ 3.31), the 4-H-benzopyran-4-one group confers considerable acidity (pK a ϭ 5.3) to the three phenolic groups (Yoshizuka et al, 1996), resulting in ϳ83% ionization of Ba at the pH (6.0) of the transport buffer. The high ionization of Ba will likely reduce the effect of the ABL that tends to retard the transport of nonionized, lipophilic moiety.…”

Section: Discussionmentioning

confidence: 99%

A Catenary Model to Study Transport and Conjugation of Baicalein, a Bioactive Flavonoid, in the Caco-2 Cell Monolayer: Demonstration of Substrate Inhibition

Sun

Zhang²,

Chow³

et al. 2008

The Journal of Pharmacology and Experimental Therapeutics

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The transport and metabolism of baicalein (Ba) was studied in vitro and in Caco-2 cells. Protein binding of Ba with Caco-2 lysate showed that Ba was bound to two classes of sites: a higher affinity, lower capacity site (K A1 ϭ 27.6 Ϯ 4.7 M Ϫ1 , n 1 ϭ 10.6 Ϯ 0.6 nmol/mg) and lower affinity, higher capacity site (K A2 ϭ 0.015 Ϯ 0.0013 M Ϫ1, n 2 ϭ 413 Ϯ 21 nmol/mg). Incubation studies of Ba with Caco-2 lysate showed substrate inhibition of both glucuronidation and sulfation, with K m values of 0.14 Ϯ 0.034 and 0.015 Ϯ 0.0053 M, and K I values of 6.75 Ϯ 1.70 and 0.37 Ϯ 0.16 M, respectively. In the Caco-2 monolayer, Ba (8 -47 M) displayed good apparent permeabilities (P app ) across the membrane; P app was found to be increased with elevated loading concentration in both the absorptive and secretory directions. However, the efflux ratio was less than unity, negating the involvement of apical efflux transporters. The concentration ratios of Ba sulfate (BS) and glucuronide (BG) decreased with increased loading Ba concentration, suggesting that BS and BG are apically excreted via transporters, likely breast cancer resistance protein and multidrug resistance-associated protein 2, respectively. Data fit to the catenary model, composed of basolateral, cellular, and apical compartments, showed a low cellular unbound fraction (0.0019 Ϯ 0.00018), a high passive diffusion clearance (0.012 Ϯ 0.00029 ml/min/mg), and substrate inhibition, with sulfation being more readily saturated and inhibited than glucuronidation, as evidenced by smaller K m value (0.35 Ϯ 0.078 versus 1.95 Ϯ 0.57 M) and K I value (0.58 Ϯ 0.20 versus 7.90 Ϯ 1.10 M); these patterns paralleled those observed in the lysate incubation studies. The results showed that the catenary model aptly predicts substrate inhibition kinetics and offers significant and mechanistic insight into the transport and atypical metabolism of drugs in the Caco-2 monolayer.Flavonoids are polyphenolic compounds that are widely distributed in both edible plant and derived foods (Yang et al., 2001). Flavonoids possess anticarcinogenic activity and other beneficial effects, including the prevention of oxidation of low-density lipoproteins and development of coronary heart disease. These activities have aroused increasing interest among scientists (Yang et al., 2001). However, several studies have demonstrated that the oral bioavailabilities of flavonoids are low and associated with extensive first-pass metabolism, including glucuronidation, sulfation, and methylation (Kroon et al., 2004;Manach and Donovan, 2004 ABBREVIATIONS: MRP, multidrug resistance-associated protein; Ba, baicalein; BG, baicalein-7-O-␤-glucoronide; UGT, UDP-glucuronosyltransferase; BS, baicalein sulfate; HPLC, high-performance liquid chromatography; PBS, phosphate-buffered saline; A, apical; B, basolateral; P app , apparent permeability; EfR, efflux ratio; n 1 , n 2 , the number of binding sites in the first and second class of binding sites, respectively; CLЈ int,sec and CLЈ d2 {BG or BS}, net efflux clearance of...

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“…Because of its biological activities, many studies of separation and purification puerarin have been reported. A large number of methods and technical processes including solvent extraction, molecularly imprinted solid-phase extraction (MISPE), membrane separation, and adsorption with macroporous resin have been developed [6][7][8][9]. On account of the high concentrating ability of typical adsorbents, adsorption with macroporous resin is proved to be one of the most attractive and effective techniques for purification and separation puerarin from P. lobata.…”

Section: Introductionmentioning

confidence: 99%

Enhanced adsorption of puerarin onto a novel hydrophilic and polar modified post-crosslinked resin from aqueous solution

Zeng

Chen

Zheng

et al. 2012

Journal of Colloid and Interface Science

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Selective separation of flavonoids with a polyvinyl alcohol membrane

Cited by 22 publications

References 8 publications

Effect of Low Molecular Weight Chitosans on Drug Permeation through Mouse Skin: 1. Transdermal Delivery of Baicalin

Effect of Low Molecular Weight Chitosans on Drug Permeation through Mouse Skin: 1. Transdermal Delivery of Baicalin

A Catenary Model to Study Transport and Conjugation of Baicalein, a Bioactive Flavonoid, in the Caco-2 Cell Monolayer: Demonstration of Substrate Inhibition

Enhanced adsorption of puerarin onto a novel hydrophilic and polar modified post-crosslinked resin from aqueous solution

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