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Jun Haginaka - One of the best experts on this subject based on the ideXlab platform.
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addition of n carbobenzyloxy l tryptophan as a co template molecule to molecularly imprinted polymer monoliths for Nilvadipine
Journal of Chromatography A, 2008Co-Authors: Jun Haginaka, Aya FutagamiAbstract:Molecularly imprinted polymer (MIP) monoliths for (+)-Nilvadipine have been prepared using 4-vinylpyridine as a functional monomer and toluene/1-dodecanol as a porogen without or with addition of N-carbobenzyloxy-l-tryptophan (Cbz-l-Trp) as a co-template molecule. The MIP monoliths prepared with (+)-Nilvadipine as a sole template molecule had no macro through-pores, while those could be formed by addition of Cbz-l-Trp as the co-template molecule. Furthermore, on the former Nilvadipine enantiomers could not be separated, but on the latter they could. The presence of Cbz-l-Trp affected the polymerization process and resulted in forming macro through-pores of the MIP monoliths for (+)-Nilvadipine and attaining separation of Nilvadipine enantiomers. These results suggest that co-addition of Cbz-l-Trp could be effective for preparing MIP monoliths for (+)-Nilvadipine, whose preparation is difficult.
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Addition of N-carbobenzyloxy-l-tryptophan as a co-template molecule to molecularly imprinted polymer monoliths for (+)-Nilvadipine
Journal of chromatography. A, 2008Co-Authors: Jun Haginaka, Aya FutagamiAbstract:Molecularly imprinted polymer (MIP) monoliths for (+)-Nilvadipine have been prepared using 4-vinylpyridine as a functional monomer and toluene/1-dodecanol as a porogen without or with addition of N-carbobenzyloxy-l-tryptophan (Cbz-l-Trp) as a co-template molecule. The MIP monoliths prepared with (+)-Nilvadipine as a sole template molecule had no macro through-pores, while those could be formed by addition of Cbz-l-Trp as the co-template molecule. Furthermore, on the former Nilvadipine enantiomers could not be separated, but on the latter they could. The presence of Cbz-l-Trp affected the polymerization process and resulted in forming macro through-pores of the MIP monoliths for (+)-Nilvadipine and attaining separation of Nilvadipine enantiomers. These results suggest that co-addition of Cbz-l-Trp could be effective for preparing MIP monoliths for (+)-Nilvadipine, whose preparation is difficult.
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Retentivity and enantioselectivity of uniformly-sized molecularly imprinted polymers for (S)-Nilvadipine in aqueous and non-aqueous mobile phases.
Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 2005Co-Authors: Haruyo Sambe, Kaori Hoshina, Jun HaginakaAbstract:Uniformly-sized molecularly imprinted polymers (MIPs) for (S)-Nilvadipine have been prepared by a multi-step swelling and polymerization method using methacrylic acid or 4-vinylpyridine (4-VPY) as a functional monomer, ethylene glycol dimethacrylate (EDMA) as a cross-linker, and toluene, chloroform, cyclohexanol or phenylacetonitrile as a porogen. The chiral recognition abilities of the MIPs for Nilvadipine were evaluated using aqueous and non-aqueous mobile phases. Among the MIPs, the (S)-Nilvadipine-imprinted 4-VPY-co-EDMA polymers prepared using toluene as a porogen showed the highest recognition ability for Nilvadipine in both aqueous and non-aqueous mobile phases. In addition to molecular shape recognition, hydrogen-bonding interactions of the NH proton of Nilvadipine with a pyridyl group of the (S)-Nilvadipine-imprinted 4-VPY-co-EDMA polymers could play an important role in the retention and chiral recognition of Nilvadipine in aqueous and non-aqueous mobile phases. Furthermore, the MIP for (S)-Nilvadipine gave the highest molecular recognition ability when a porogenic solvent during polymerization was used as the mobile phase modifier.
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Uniformly Sized Molecularly Imprinted Polymer for (S)-Nilvadipine. Comparison of Chiral Recognition Ability with HPLC Chiral Stationary Phases Based on a Protein
Analytical chemistry, 2003Co-Authors: Haruyo Sanbe, Chino Kagawa, § And Ko-ki Kunimoto, Jun HaginakaAbstract:Uniformly sized molecularly imprinted polymers (MIPs) for (S)-Nilvadipine have been prepared by a multistep swelling and polymerization method using methacrylic acid, 2-(trifluoromethyl)acrylic acid, 2-vinylpyridine, or 4-vinylpyridine (4-VPY) as a functional monomer and ethylene glycol dimethacrylate (EDMA) as a cross-linker. The chiral recognition abilities of the MIPs for Nilvadipine and other dihydropyridine calcium antagonists were evaluated using a mixture of sodium phosphate buffer (or water) and acetonitrile or only acetonitrile as the mobile phase. The (S)-Nilvadipine-imprinted 4-VPY-co-EDMA polymers gave the highest resolution for Nilvadipine among the MIPs prepared. In addition, the enantioseparation of Nilvadipine was attained using the (S)-Nilvadipine-imprinted EDMA polymers, without use of a functional monomer. 1H NMR and molecular modeling studies suggested a one-to-one hydrogen-bonding-based complex formation of (S)-Nilvadipine with 4-VPY in chloroform. These results reveal that the (S)-ni...
Aya Futagami - One of the best experts on this subject based on the ideXlab platform.
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addition of n carbobenzyloxy l tryptophan as a co template molecule to molecularly imprinted polymer monoliths for Nilvadipine
Journal of Chromatography A, 2008Co-Authors: Jun Haginaka, Aya FutagamiAbstract:Molecularly imprinted polymer (MIP) monoliths for (+)-Nilvadipine have been prepared using 4-vinylpyridine as a functional monomer and toluene/1-dodecanol as a porogen without or with addition of N-carbobenzyloxy-l-tryptophan (Cbz-l-Trp) as a co-template molecule. The MIP monoliths prepared with (+)-Nilvadipine as a sole template molecule had no macro through-pores, while those could be formed by addition of Cbz-l-Trp as the co-template molecule. Furthermore, on the former Nilvadipine enantiomers could not be separated, but on the latter they could. The presence of Cbz-l-Trp affected the polymerization process and resulted in forming macro through-pores of the MIP monoliths for (+)-Nilvadipine and attaining separation of Nilvadipine enantiomers. These results suggest that co-addition of Cbz-l-Trp could be effective for preparing MIP monoliths for (+)-Nilvadipine, whose preparation is difficult.
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Addition of N-carbobenzyloxy-l-tryptophan as a co-template molecule to molecularly imprinted polymer monoliths for (+)-Nilvadipine
Journal of chromatography. A, 2008Co-Authors: Jun Haginaka, Aya FutagamiAbstract:Molecularly imprinted polymer (MIP) monoliths for (+)-Nilvadipine have been prepared using 4-vinylpyridine as a functional monomer and toluene/1-dodecanol as a porogen without or with addition of N-carbobenzyloxy-l-tryptophan (Cbz-l-Trp) as a co-template molecule. The MIP monoliths prepared with (+)-Nilvadipine as a sole template molecule had no macro through-pores, while those could be formed by addition of Cbz-l-Trp as the co-template molecule. Furthermore, on the former Nilvadipine enantiomers could not be separated, but on the latter they could. The presence of Cbz-l-Trp affected the polymerization process and resulted in forming macro through-pores of the MIP monoliths for (+)-Nilvadipine and attaining separation of Nilvadipine enantiomers. These results suggest that co-addition of Cbz-l-Trp could be effective for preparing MIP monoliths for (+)-Nilvadipine, whose preparation is difficult.
Sayuri Mizukoshi - One of the best experts on this subject based on the ideXlab platform.
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systemic administration of Nilvadipine delays photoreceptor degeneration of heterozygous retinal degeneration slow rds mouse
Experimental Eye Research, 2008Co-Authors: Kimio Takeuchi, Mitsuru Nakazawa, Sayuri MizukoshiAbstract:To investigate the effect of Nilvadipine, a calcium channel blocker, upon the retina of retinal degeneration slow (rds) mouse, Nilvadipine was intraperitoneally injected into heterozygous rds mice for up to 200 days. The effect of Nilvadipine was evaluated by electroretinography (ERG), light and electron microscopies, DNA microarray, quantitative reverse transcriptase polymerase chain reaction (RT-PCR), and western-blot analysis. After Nilvadipine treatment, both a- and b-waves of ERG were significantly higher than in the control group ( p < 0.01). Although there was no difference in histological findings by light microscopy between the Nilvadipine treated group and control group, apparent preservation of photoreceptor disc was demonstrated by electron microscopy in the treated group. Rhodopsin level was also increased in the treated group comparing to the control group. The DNA microarray analysis detected increased expression of genes encoding proteins which function in protein synthesis, growth factors and neurotrophic factor like ciliary neurotrophic factor (CNTF) and fibroblast growth factors (FGFs22 and 13). Decreased expression of genes coding for proteins related to proteolysis, apoptosis and growth factor (FGF18) was also demonstrated. Increased expression of CNTF, FGF22 and FGF13 and decreased expression of FGF18 were confirmed by both quantitative RT-PCR and western-blot analysis. In addition, FGF2 was constitutively expressed in both treated and control groups. Since CNTF has been known to retard retinal degeneration by rds mouse or other models of inherited retinal degeneration, it is possible that Nilvadipine has a photoreceptor survival effect on rds retinal degeneration partly by enhancing expression of endogenous CNTF in the retina.
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Systemic administration of Nilvadipine delays photoreceptor degeneration of heterozygous retinal degeneration slow (rds) mouse
Experimental eye research, 2007Co-Authors: Kimio Takeuchi, Mitsuru Nakazawa, Sayuri MizukoshiAbstract:To investigate the effect of Nilvadipine, a calcium channel blocker, upon the retina of retinal degeneration slow (rds) mouse, Nilvadipine was intraperitoneally injected into heterozygous rds mice for up to 200 days. The effect of Nilvadipine was evaluated by electroretinography (ERG), light and electron microscopies, DNA microarray, quantitative reverse transcriptase polymerase chain reaction (RT-PCR), and western-blot analysis. After Nilvadipine treatment, both a- and b-waves of ERG were significantly higher than in the control group ( p
Mitsuru Nakazawa - One of the best experts on this subject based on the ideXlab platform.
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systemic administration of Nilvadipine delays photoreceptor degeneration of heterozygous retinal degeneration slow rds mouse
Experimental Eye Research, 2008Co-Authors: Kimio Takeuchi, Mitsuru Nakazawa, Sayuri MizukoshiAbstract:To investigate the effect of Nilvadipine, a calcium channel blocker, upon the retina of retinal degeneration slow (rds) mouse, Nilvadipine was intraperitoneally injected into heterozygous rds mice for up to 200 days. The effect of Nilvadipine was evaluated by electroretinography (ERG), light and electron microscopies, DNA microarray, quantitative reverse transcriptase polymerase chain reaction (RT-PCR), and western-blot analysis. After Nilvadipine treatment, both a- and b-waves of ERG were significantly higher than in the control group ( p < 0.01). Although there was no difference in histological findings by light microscopy between the Nilvadipine treated group and control group, apparent preservation of photoreceptor disc was demonstrated by electron microscopy in the treated group. Rhodopsin level was also increased in the treated group comparing to the control group. The DNA microarray analysis detected increased expression of genes encoding proteins which function in protein synthesis, growth factors and neurotrophic factor like ciliary neurotrophic factor (CNTF) and fibroblast growth factors (FGFs22 and 13). Decreased expression of genes coding for proteins related to proteolysis, apoptosis and growth factor (FGF18) was also demonstrated. Increased expression of CNTF, FGF22 and FGF13 and decreased expression of FGF18 were confirmed by both quantitative RT-PCR and western-blot analysis. In addition, FGF2 was constitutively expressed in both treated and control groups. Since CNTF has been known to retard retinal degeneration by rds mouse or other models of inherited retinal degeneration, it is possible that Nilvadipine has a photoreceptor survival effect on rds retinal degeneration partly by enhancing expression of endogenous CNTF in the retina.
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Systemic administration of Nilvadipine delays photoreceptor degeneration of heterozygous retinal degeneration slow (rds) mouse
Experimental eye research, 2007Co-Authors: Kimio Takeuchi, Mitsuru Nakazawa, Sayuri MizukoshiAbstract:To investigate the effect of Nilvadipine, a calcium channel blocker, upon the retina of retinal degeneration slow (rds) mouse, Nilvadipine was intraperitoneally injected into heterozygous rds mice for up to 200 days. The effect of Nilvadipine was evaluated by electroretinography (ERG), light and electron microscopies, DNA microarray, quantitative reverse transcriptase polymerase chain reaction (RT-PCR), and western-blot analysis. After Nilvadipine treatment, both a- and b-waves of ERG were significantly higher than in the control group ( p
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study of pharmacological effects of Nilvadipine on rcs rat retinal degeneration by microarray analysis
Biochemical and Biophysical Research Communications, 2003Co-Authors: Motoya Sato, Hiroshi Ohguro, Ikuyo Ohguro, Kazuhisa Mamiya, Yoshiko Takano, Hitoshi Yamazaki, Tomomi Metoki, Yasuhiro Miyagawa, Fotoshi Ishikawa, Mitsuru NakazawaAbstract:In our recent study, we found that the Ca2+ antagonist, Nilvadipine caused significant preservation of photoreceptor cells in The Royal College of Surgeons (RCS) rats [Invest. Ophthalmol. Vis. Sci. 43 (2002) 919]. Here, to elucidate the mechanisms of Nilvadipine-induced effects we analyzed altered gene expression of 1101 genes commonly expressed in rodent by DNA microarray analysis in the retinas of Nilvadipine-treated and untreated RCS rats and SD rat. In the total number of genes, the expression of 30 genes was altered upon administration of Nilvadipine to RCS rats, including several genes related to the apoptotic pathway and other mechanisms. Remarkably, neurotrophic factors, FGF-2 and Arc, known to suppress the apoptosis in the central nervous system, were up-regulated. These changes were also confirmed by real-time quantitative (Taqman) RT-PCR and Western blot analysis. Therefore, our present data suggested that administration of Nilvadipine to RCS rats increases the expression of endogenous FGF-2 and Arc in retina, and potentially has a protective effect against retinal degeneration.
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pharmacological aspects of Nilvadipine induced preservation of retinal degeneration in rcs rat analyzed by mrna profiling assay
The Keio Journal of Medicine, 2003Co-Authors: Futoshi Ishikawa, Motoya Sato, Hiroshi Ohguro, Kazuhisa Mamiya, Yoshiko Takano, Hitoshi Yamazaki, Tomomi Metoki, Yasuhiro Miyagawa, Ikuyo Maruyama, Mitsuru NakazawaAbstract:In our study, we found that the Ca2+ antagonist Nilvadipine was beneficial for the preservation of photoreceptor cells in The Royal College of Surgeons (RCS) rats. Here, in order to elucidate mechanisms of its Nilvadipine-induced photoreceptor preservation, we analyzed altered gene expressions of the retina in RCS rats administered Nilvadipine by mRNA profiling assay. Total RNA isolated from the retina with or without Nilvadipine was converted into cDNA. Utilizing DNA microarray analysis methods, we compared the overall expression patterns for 1101 genes that were commonly expressed in rodent. Of the total genes, the expression of less than 30 genes was altered significantly including that of several genes involved in cellular regulation. On the basis of these data, it is suggested that microarray analysis is a useful tool and applicable for studying the pharmacological effects of several drugs including Ca2+ channel blockers to retinal degeneration.
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Preservation of retinal morphology and functions in royal college surgeons rat by Nilvadipine, a Ca(2+) antagonist.
Investigative ophthalmology & visual science, 2002Co-Authors: Hitoshi Yamazaki, Mitsuru Nakazawa, Hiroshi Ohguro, Yoshiko Takano, Tomomi Metoki, Ikuyo Maruyama, Tadao Maeda, Hajime Sawada, Mari DezawaAbstract:PURPOSE The Royal College of Surgeons (RCS) rat is the most extensively studied animal model for understanding the molecular pathology in inherited retinal degeneration, such as retinitis pigmentosa (RP). The purpose of the present study was to evaluate the pharmacologic effects of several Ca(2+) antagonists on the retinal degeneration of RCS rats. METHODS Several Ca(2+) antagonists, diltiazem, nicardipine, Nilvadipine, and nifedipine, were intraperitoneally administered and retinal morphology and functions analyzed. RESULTS Among the Ca(2+) antagonists, only intraperitoneally administered Nilvadipine preserved retinal morphology and electroretinogram responses in RCS rats during the initial stage of retinal degeneration. Studies using immunohistochemistry, RT-PCR, and Western blot analysis revealed significant enhancement of rhodopsin kinase and alphaA-crystallin expression and suppression of caspase 1 and 2 expression in the retina of Nilvadipine-treated rats. CONCLUSIONS These data suggest that Nilvadipine is beneficial for the preservation of photoreceptor cells in RCS rats and can be used to treat some patients with RP.
Haruyo Sanbe - One of the best experts on this subject based on the ideXlab platform.
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Uniformly Sized Molecularly Imprinted Polymer for (S)-Nilvadipine. Comparison of Chiral Recognition Ability with HPLC Chiral Stationary Phases Based on a Protein
Analytical chemistry, 2003Co-Authors: Haruyo Sanbe, Chino Kagawa, § And Ko-ki Kunimoto, Jun HaginakaAbstract:Uniformly sized molecularly imprinted polymers (MIPs) for (S)-Nilvadipine have been prepared by a multistep swelling and polymerization method using methacrylic acid, 2-(trifluoromethyl)acrylic acid, 2-vinylpyridine, or 4-vinylpyridine (4-VPY) as a functional monomer and ethylene glycol dimethacrylate (EDMA) as a cross-linker. The chiral recognition abilities of the MIPs for Nilvadipine and other dihydropyridine calcium antagonists were evaluated using a mixture of sodium phosphate buffer (or water) and acetonitrile or only acetonitrile as the mobile phase. The (S)-Nilvadipine-imprinted 4-VPY-co-EDMA polymers gave the highest resolution for Nilvadipine among the MIPs prepared. In addition, the enantioseparation of Nilvadipine was attained using the (S)-Nilvadipine-imprinted EDMA polymers, without use of a functional monomer. 1H NMR and molecular modeling studies suggested a one-to-one hydrogen-bonding-based complex formation of (S)-Nilvadipine with 4-VPY in chloroform. These results reveal that the (S)-ni...