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Volume 57, Issue 2
Displaying 1-22 of 22 articles from this issue
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Regular Articles
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Parandis Daneshgar, Parviz Norouzi, Mohammad Reza GanjaliArticle type: Regular Article
2009 Volume 57 Issue 2 Pages 117-121
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSAn electroanalytical method has been developed for the determination of the ketotifen by continuous square wave adsorptive stripping voltammetry on a ultra-gold microelectrode (Au UME) in aqueous solution with phosphate buffer as supporting electrolyte. The best adsorption conditions were found to be pH 2.3, an accumulation potential of 300 mV (Au vs. Ag: AgCl–KCl 3 M) and an accumulation time of 400 ms. Variation of admittance in the detection process is created by inhibition of oxidation reaction of the electrode surface, by adsorption of ketotifen. Furthermore, signal-to-noise ratio was significantly increased by application of discrete fast Fourier transform (FFT) method, background subtraction and two-dimensional integration of the electrode response over a selected potential range and time window. Also in this work some parameters such as square-wave frequency, eluent pH, and accumulation time were optimized. Effects of square-wave frequency, step potential and pulse amplitude were examined for the optimization of instrumental conditions. The calibration curve is linear in the range 2.0×10−7—5.0×10−12 M with a detection limit of 2.0×10−12 M (ca. 0.7 pg/ml). The method maybe applied direct determination of the drug in pharmaceutical and biological samples. For a concentration of 5.0×10−8 M a recovery value of 99.89% is obtained.View full abstractDownload PDF (387K) -
Wei He, Li-Fang Fan, Qing Du, Bai Xiang, Chun-Lei Li, Min Bai, Yong-Zh ...Article type: Regular Article
2009 Volume 57 Issue 2 Pages 122-128
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThe purpose of the study is to perform the in vitro and in vivo evaluation of multi-layer film coatings for omeprazole. The system consists of drug-layered or drug-containing core pellets coated with salt (sodium chloride and disodium hydrogen phosphate), hydroxypropyl methyl cellulose (HPMC), and enteric film-coating layer, respectively. The drug-layered core pellets were prepared by a coating layer of omeprazole on inert pellet cores in fluidized bed coater. An in vitro/in vivo gastro-resistance study was conducted, and a dissolution study was performed in pH 7.4 phosphate buffer for omeprazole release. The multi-layer coated pellets were stable in gastric pH conditions and upper gastrointestinal (GI) tract in rats. Salt layer improved the drug stability, and its coating levels had little influence on the dissolution profiles of omeprazole. The rate of drug release was significantly delayed by HPMC layer. The salt layer could function as a separated layer, and substitute part of the HPMC layer and decrease the coating levels of HPMC. The bioavailability (AUC) of the multi-layer coated drug-layered and drug-containing pellets was 3.48±0.86 and 2.97±0.57 μg·h/ml, respectively. The drug-layered pellets with multi-layer film coatings not only provided delayed and rapid release of omeprazole, but also could provide a good stable property for omeprazole. It was confirmed that rapid in vitro drug release rate resulted in better absorption.View full abstractDownload PDF (370K) -
Fumihiko Ogata, Naohito Kawasaki, Mineaki Kabayama, Kazuaki KakehiArticle type: Regular Article
2009 Volume 57 Issue 2 Pages 129-133
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThe adsorption properties of As(III) and Cr(VI) by gibbsite (GB) calcined at 200 to 1150 °C was investigated on basis of their specific surface area, number of hydroxyl groups, surface pH and adsorption isotherms. The amount of As(III) and Cr(VI) adsorbed on the calcined GB at 300 or 400 °C was the highest. In the case of the calcination temperature was more than 700 °C, the amount adsorbed decreased with the increasing calcination temperature. In a single solution system, the amount of As(III) adsorbed on calcined GB was higher than that of Cr(VI). The amount of As(III) and Cr(VI) adsorbed on calcined GB was higher in a binary solution system than those in a single solution system. The pH in solution after As(III) and Cr(VI) adsorption was greater than that before adsorption. These results indicated that the adsorption mechanism of As(III) and Cr(VI) was as followed: the hydroxyl groups on calcined GB were exchanged to As(III) and Cr(VI) and they adsorbed n the calcined GB surface. In the case of coexistence of As(III) and Cr(VI), they could be removed better by calcined GB because the pH in binary solution was lower than that in single solution. Both As(III) and Cr(VI) in water environment could be removed by the calcined GB simultaneously.View full abstractDownload PDF (259K) -
Jin Qi, Jing-Jing Lu, Ji-Hua Liu, Bo-Yang YuArticle type: Regular Article
2009 Volume 57 Issue 2 Pages 134-137
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSFrom the leaves of Aquilaria sinensis (LOUR.) GILG, a novel benzophenone glucoside, designated as aquilarinoside A (1), and a new flavonoid, as 7-β-D-glucoside of 5-O-methylapigenin (2), along with eight known compounds (3—10) were isolated. The structures of 1 and 2 were fully characterized by spectroscopic methods (1D, 2D NMR and MS) and the relative stereochemistry was assigned based on nuclear Overhauser effect spectroscopy (NOESY) correlations and analyses of coupling constants. The new compounds showed inhibition activity against polymorphonuclear neutrophils (PMNs) respiratory burst stimulated by PMA.View full abstractDownload PDF (121K) -
Wuxiao Ding, Yoshiyuki Hattori, Xianrong Qi, Dai Kitamoto, Yoshie Mait ...Article type: Regular Article
2009 Volume 57 Issue 2 Pages 138-143
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThe surface properties of cationic liposomes and lipoplexes largely determine the cellular association and gene transfection efficiency. In this study, we measured the surface properties, such as zeta potentials, surface pH and hydration levels of MHAPC- and OH-Chol-lipoplexes and their cellular association, without and with the modification of biosurfactant mannosylerythritol lipid-A (MEL-A) or Tween 80 (MHAPC=N,N-methyl hydroxyethyl aminopropane carbamoyl cholesterol; OH-Chol=cholesteryl-3β-carboxyamindoethylene-N-hydroxyethylamine). Compared to OH-Chol-lipoplexes, the higher cellular association of MHAPC-lipoplexes correlated with the significantly higher zeta potentials, lower surface pH levels and “drier” surface, as evaluated by the generalized polarization of laurdan. Both MEL-A and Tween 80 modification of MHAPC-lipoplexes did not significantly change zeta potentials and surface pH levels, while MEL-A modification of OH-Chol-lipoplexes seriously decreased them. MEL-A hydrated the liposomal surface of MHAPC-lipoplexes but dehydrated that of OH-Chol-lipoplexes, while Tween 80 hydrated those of MHAPC- and OH-Chol-lipoplexes. In all, cationic liposomes composed of lipids with secondary and tertiary amine exhibited different surface properties and cellular associations of lipoplexes, and modification with surfactants further enlarged their difference. The strong hydration ability of Tween 80 may relate to the low cellular association of lipoplexes, while the dehydration of MEL-A-modified OH-Chol-lipoplexes seemed to compensate the negative zeta potential for the cellular association of lipoplexes.View full abstractDownload PDF (256K) -
Kang-De Bao, Ping Li, Lian-Wen Qi, Hui-Jun Li, Ling Yi, Wei Wang, Ya-Q ...Article type: Regular Article
2009 Volume 57 Issue 2 Pages 144-148
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSA highly specific and sensitive method using high performance liquid chromatography coupled with diode-array detection and ion-trap mass spectrometry (HPLC-DAD-MSn) was developed for study of the constituents of flavonoid extract of jujube seeds and the metabolites in rat plasma, urine, and feces samples after oral administration of flavonoid extract of jujube seeds. Two major flavonoids (spinosin and 6′′′-feruloylspinosin) with content >60% in the flavonoid extract of jujube seeds were detected and confirmed by comparison with the reference standards. Furthermore, five metabolic components in plasma, seven in urine, and four in feces were detected and elucidated. The scientific and plausible biotransformation pathways of the main components in flavonoid extract of jujube seeds were also proposed, together with presentation of clues for potential bioactive mechanisms. This convenient HPLC-DAD-MSn method could be used to identify the chemical components of flavonoid extract of jujube seeds as well as their metabolites, and to reveal their possible metabolic mechanism of action in vivo.View full abstractDownload PDF (248K) -
Sang Hyup Lee, Harold KohnArticle type: Regular Article
2009 Volume 57 Issue 2 Pages 149-157
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThe multimerization of functional DNA alkylating agents has drawn significant, recent interest because these compounds are expected to generate enhanced levels of DNA cross-linked adducts, compared with their monomeric agents. Here we report the evaluation of 7-N,7′-N′-(1″,2″,9″,10″-tetrathia-cyclohexadecanyl-3″,8″,11″,16″-tetramethylenyl)tetrakismitomycin C (8), in which four mitomycin units are attached to the novel bis-disulfide linker, 3,8,11,16-tetrakis(aminomethyl)-1,2,9,10-tetrathia-cyclohexadecane. Compound 8 was designed to undergo preferential C(1) mitomycin activation under nucleophilic as well as under acidic and reductive conditions. We anticipated that treating 8 with nucleophiles would lead to bis-disulfide cleavage thus producing two mitomycin dimers (9) capable of generating DNA interstrand cross-links (ISC). The mitomycin units in 9 are tethered by a stable carbon backbone linkage. According to the procedure reported by Lee and coworkers (Tetrahedron, 61, 1749–1754 (2005)), we synthesized 8 and the reference mitomycin dimer, 7-N,7′-N′-(2″,7″-dihydroxy-1″,8″-octanediyl)bismitomycin C (15). Compound 8 was activated under acidic conditions thereby generating mitosene product 16, in which all four mitomycin units within the 16-membered ring were activated. Using the nucleophile Et3P, we found that 8 underwent significantly enhanced mitosene production compared with its reference compound 15. We further demonstrated that under nucleophilic activation conditions 8 generated higher levels of DNA ISC than either 1 or 15. The cytotoxicities of 8 and 15 in a select tumor cell line were evaluated and compared with mitomycin C (1).View full abstractDownload PDF (465K) -
Lei Song, Xiao-Yu Liu, Qiao-Hong Chen, Feng-Peng WangArticle type: Regular Article
2009 Volume 57 Issue 2 Pages 158-161
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThree new C19-diterpenoid alkaloids, anthriscifoldines A—C (1—3), and two new C18-diterpenoid alkaloids, anthriscifolcines F and G (5, 6), were obtained from the whole herbs of Delphinium anthriscifolium var. savatieri during our further investigation on a larger scale of recollected plants. Their structures were elucidated based on the interpretation of NMR and high-resolution ESI-MS data, and chemical transformation. In addition, five known C19-diterpenoid alkaloids were also isolated and identified as nudicaulamine (4), delbruninol (7), blacknine (8), winkleriline (9), and deltaline (10).View full abstractDownload PDF (135K) -
Shin-Pin Chen, Jui-Hsin Su, Hsiao-Chien Yeh, Atallah Fouad Ahmed, Chan ...Article type: Regular Article
2009 Volume 57 Issue 2 Pages 162-166
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSA novel skeletal norhumulene (1) and six xeniaphyllane-derived compounds, including norditerpenoids (2, 3) and diterpenoids (4—7), were isolated from the EtOAc extract of the Formosan soft coral Sinularia gibberosa. Their structures were elucidated by spectroscopic analysis. In vitro cytotoxic evaluation of the above metabolites revealed that 2 and 4 showed weak cytotoxicity toward a few cancer cell lines.View full abstractDownload PDF (134K) -
Yasushi Arakawa, Naomi Yagi, Yukimi Arakawa, Ken-ichi Tanaka, Shigeyuk ...Article type: Regular Article
2009 Volume 57 Issue 2 Pages 167-176
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThe Grignard, Wittig, Tebbe, Horner–Emmons, and Reformatsky reactions of the 4-oxoproline esters gave the corresponding 4-alylated or 4-alkylidenated products, respectively. The products were properly treated with bases to cause aromatization, giving 4-substituted pyrrole-2-carboxylic acid esters such as methyl 4-methylpyrrole-2-carboxylate, which is a trail pheromone of Atta texana.View full abstractDownload PDF (297K) -
Tsutomu Warashina, Tadataka NoroArticle type: Regular Article
2009 Volume 57 Issue 2 Pages 177-184
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSTwenty new pregnane glycosides were obtained from the roots of Asclepias syriaca L. (Asclepiadaceae). These glycosides were confirmed to contain ikemagenin, 12-O-nicotinoyllineolon, 5α,6-dihydroikemagenin, and 12-O-tigloylisolineolon, as their aglycones, using both spectroscopic and chemical methods.View full abstractDownload PDF (185K) -
Takashi Hasegawa, Kazunaga Takahashi, Masaaki Saijo, Toshiyasu Ishii, ...Article type: Regular Article
2009 Volume 57 Issue 2 Pages 185-189
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSA new sildenafil analogue, cyclopentynafil (1) and a new tadalafil analogue, N-octylnortadalafil (2) were isolated from a dietary supplement illegally marketed for erectile dysfunction. The structures of the sildenafil and tadalafil analogues were elucidated by using HPLC-photodiode array (PDA), LC-MS, high-resolution MS, NMR and circular dichroism (CD). These compounds were determined to be 5-[2-ethoxy-5-(4-cyclopentylpiperazin-1-ylsulfonyl)phenyl]-1-methyl-3-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one and (6R,12aR)-2-octyl-6-(1,3-benzodioxol-5-yl)-2,3,6,7,12,12a-hexahydropyrazino[1′,2′:1,6]pyrido[3,4-b]indole-1,4-dione, respectively. Recently, a large number of phosphodiesterase-5 (PDE-5) inhibitors, including their analogues, have been isolated from dietary supplements, while cyclopentynafil and N-octylnortadalafil are the first compounds reported to be new sildenafil and tadalafil analogues, respectively. Quantitative HPLC analysis showed that the contents of 1 and 2 in the product were about 130 mg/tablet (301 μg/mg) and about 27 mg/tablet (64.1 μg/mg), respectively.View full abstractDownload PDF (179K)
Notes
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Kosuke Dodo, Taro Minato, Yuichi HashimotoArticle type: Notes
2009 Volume 57 Issue 2 Pages 190-194
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSGreen tea and (−)-epigallocatechin gallate (EGCG: one of main components of green tea) are well known to have preventive activities against human cancers. Previously, using a galloyl group as a core structure derived from EGCG, we developed alkyl gallate and gallamide derivatives, which showed strong antiproliferative activity towards human leukemia HL-60 cells by inducing apoptosis. Here, as a further structural development study, we planned to introduce an additional galloyl group into alkyl gallates and gallamides. According to this strategy, various bisgallate and bisgallamide derivatives were synthesized and tested for antiproliferative activity towards HL-60 cells. In gallamide derivatives having a short alkyl chain, the additional galloyl group enhanced the antiproliferative activity. In contrast, in the gallate derivatives, the additional galloyl group had no effect on the antiproliferative activity.View full abstractDownload PDF (288K) -
Xia Wu, Jun-Shan Yang, Ming YanArticle type: Notes
2009 Volume 57 Issue 2 Pages 195-197
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSIn the previous work we reported five lanostane-type triterpenes from the CHCl3 soluble fraction of Fomes officinalis. In further study on the isolation of constituents from the CHCl3 soluble fraction, four new triterpenes, fomefficinic acids F (1), G (2) and fomefficinols A (3), B (4), together with seven known compounds officinalic acid (5), fomlactone A (6), fomlactone B (7), fomlactone C (8), laricinolic acid (9), ergosterol (10), ergota-7,22,dien-3β-ol (11) were isolated. The structures of new compounds were determined by spectroscopic analyses and chemical methods including NMR spectroscopic techniques (13C, 1H, heteronuclear multiple quantum coherence (HMQC), heteronuclear multiple bonding correlation (HMBC), correlation spectroscopy (COSY) and nuclear Overhauser effect spectroscopy (NOESY)).View full abstractDownload PDF (102K) -
Yasunobu Asao, Toshio Morikawa, Yuanyuan Xie, Masaki Okamoto, Makoto H ...Article type: Notes
2009 Volume 57 Issue 2 Pages 198-203
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThe methanolic extract and its saponin fraction (methanol-eluted fraction) of the pericarps of Sapindus rarak DC. were found to suppress plasma triglyceride elevation in olive oil-treated mice. From the active fraction, three new acylated oleanane-type triterpene saponins, rarasaponins IV (1), V (2), and VI (3), were isolated. The structures of 1—3 were elucidated on the basis of chemical and spectroscopic evidence. The principle saponin constituents, hederagenin 3-O-α-L-arabinopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside (4) and hederagenin 3-O-(3,4-di-O-acetyl-α-L-arabinopyranosyl)-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside (5), showed inhibitory effects on plasma triglyceride elevation at a dose of 200 mg/kg, per os.View full abstractDownload PDF (106K) -
Masanori Inagaki, Takeshi Saito, Tomofumi Miyamoto, Ryuichi HiguchiArticle type: Notes
2009 Volume 57 Issue 2 Pages 204-206
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSA hematoside-type ganglioside, LLG-1 (1), has been obtained from the polar lipid fraction of the chloroform/methanol extract of the starfish Linckia laevigata. The structure of the ganglioside has been determined on the basis of chemical and spectroscopic evidence as 1-O-[N-glycolyl-α-D-neuraminosyl-(2→3)-β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl]-ceramide. The ceramide moiety was composed of heterogeneous 2-hydroxy fatty acid and phytosphingosine units. This is the first report on the isolation and structure elucidation of naked hematoside-type ganglioside from echinoderms.View full abstractDownload PDF (89K) -
Peng Fu, Chun-Chao Zhao, Jian Tang, Yun-Heng Shen, Xi-ke Xu, Wei-Dong ...Article type: Notes
2009 Volume 57 Issue 2 Pages 207-210
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSSeparation of ethyl acetate fractionation of Dracocephalum peregrinum afforded three new flavonoid glucosides (1—3), and a new cyanogenic glucoside (4). Their structures were elucidated based on HR-electron spray ionization (ESI)-MS, EI-MS, UV, IR, 1D-, and 2D-NMR data. 1—4 were tested in vitro for their antiinflammatory activity against the RAW 264.7, 293 cells. Among the compounds tested, 1—4 shown good antiinflammatory activity at 100 μg/ml by the measurement of nitric oxide (NO) in lipopolysaccharide (LPS) activated macrophages. But only 2 and 3 shown weak antiinflammatory activity at 100 μg/ml during the nuclear factor (NF)-κB activation assay.View full abstractDownload PDF (138K) -
Takenao Odagami, Yuko Tsuda, Yuji Kogami, Hiroyuki Kouji, Yoshio OkadaArticle type: Notes
2009 Volume 57 Issue 2 Pages 211-213
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThe deprotection of the indole (Nind)-formyl (For) group on Trp was achieved in a 95% yield using N,N′-dimethylethylendiamine (DMEDA) (1.5, 2.0, 3.0 eq) in water at room temperature. A new reagent was successfully applied to the deprotection of a model peptide, H-Phe-Trp(Nind-For)-Lys-Tyr-OH, to give H-Phe-Trp-Lys-Tyr-OH in a 91% yield.View full abstractDownload PDF (126K) -
Rajiv Dahiya, Akhilesh Kumar, Rajul GuptaArticle type: Notes
2009 Volume 57 Issue 2 Pages 214-217
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSPresent study describes the first total synthesis of a cyclic heptapeptide, stylisin 1 (8) via coupling of tetrapeptide Boc-L-tyrosinyl-L-prolyl-L-leucyl-L-proline-OH and tripeptide L-phenylalanyl-L-isoleucyl-L-proline-OMe followed by cyclization of linear heptapeptide segment. Structure elucidation of synthesized cyclopeptide was done on basis of detailed spectral as well as elemental analysis. From the results of pharmacological screening, it was concluded that cyclopeptide 8 possessed moderate cytotoxicity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines with IC50 (inhibitory concentration, 50%) values of 10.6 and 14.6 μM. Furthermore, cyclopeptide 8 exhibited moderate to good antimicrobial activity against Gram −ve (negative) bacteria Klebsiella pneumoniae and Pseudomonas aeruginosa, dermatophytes and Candida albicans with minimum inhibitory concentration (MIC) of 6 μg/ml.View full abstractDownload PDF (97K) -
Yan Li, Chun-Lan Wang, Ya-Jun Wang, Shun-Xing Guo, Jun-Shan Yang, Xiao ...Article type: Notes
2009 Volume 57 Issue 2 Pages 218-219
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThree new compounds were isolated from the stems of Dendrobium candidum: (S)-3,4,4′-trihydroxy-5,α-dimethoxybibenzyl (1), named dendrocandin C; (S)-3,4,4′-trihydroxy-5-methoxy-α-ethoxybibenzyl (2), named dendrocandin D; and 3,3′,4,4′-tetrahydroxy-5-methoxybibenzyl (3), named dendrocandin E. Their structures were elucidated by 1D- and 2D-NMR spectroscopy and mass spectroscopy. The isolated compounds exhibited potent antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test, with IC50 values of 34.2, 34.5, and 15.6 μM for compounds 1, 2, and 3, respectively. Vitamin C was used as positive control with IC50 23.2 μM.View full abstractDownload PDF (74K) -
Lin Du, Tianjiao Zhu, LiYuan Li, Shengxin Cai, Boyu Zhao, Qianqun GuArticle type: Notes
2009 Volume 57 Issue 2 Pages 220-223
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSFour sorbicillinoids (1—4) and seven bisorbicillinoids (5—11), including two new compounds, 6-demethylsorbicillin (1) and 10,11-dihydrobisvertinolone (6), were isolated from a marine-derived fungus Trichoderma sp. Their cytotoxic activities against HL-60 cell line were evaluated by Sulforhodamine B (SRB) assay method and flow cytometric analysis.View full abstractDownload PDF (113K) -
Akiko Nozaki, Mami Hori, Toshikiro Kimura, Hideyuki Ito, Tsutomu Hatan ...Article type: Notes
2009 Volume 57 Issue 2 Pages 224-228
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThe binding of (−)-epigallocatechin gallate (EGCG), a representative natural polyphenol, to human serum albumin (HSA) and bovine serum albumin (BSA) was investigated using induced circular dichroism (CD). The site of the binding EGCG-HSA was analyzed based on the competition with drugs with known binding sites on HSA, such as phenylbutazone (PB) and diazepam (DP). Double-reciprocal plot analyses showed the competitive relations with the site-I- (PB and tolbutamide, TB) and site-II-binding drugs (DP and ibuprofen, IP) indicating the binding of EGCG to sites I and II on HSA, while digitoxin (DG), a site-III-binding drug, did not affect the binding of EGCG. In an analogous way, the competitive relations were observed between EGCG and the site-I- (PB and TB) and site-II-binding (ethacrynic acid, EA) drugs for the binding of EGCG and BSA. The site-III drug DG also showed competitive binding with EGCG to BSA. The binding of EGCG to the albumins indicated its affinity to sites I and II on HSA, while competitive binding for all three sites was observed on BSA.View full abstractDownload PDF (369K)
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