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Removal of Pharmaceutical Pollutants from Municipal Sewage Mediated by Laccases
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2020
Thomas Hahn, Fabian Haitz, Jan Gajewski, Marius Mohr, Marc Beckett, Susanne Zibek
Paracetamol (PCM) is a substance that can be oxidized by laccases due to a redox potential E0 of ~ 0.5 V (Bisby and Tabassum, 1988). The oxidation of non-phenolic substances (with E0 > 1.1 V), on the other hand, is more difficult due to the low redox potential of laccases (E0 = 0.5–0.8 V for laccases from fungi, lower for bacterial and herbal laccases) (Alcade, 2007; Canas and Camerero, 2010; Husain and Husain, 2008). In order to oxidize these substrates, the laccases need so-called mediators (E0 > 0.9 V). Mediators are small, mostly organic molecules that form stable radicals and act as so-called electron shuttle. These molecules considerably extend the scope of application. In this way, even space-filling substrates, such as lignin, can be oxidized. In addition, molecules with a redox potential E0 > 0.8 V or non-phenolic molecules can also be oxidized (Canas and Camarero, 2010). The transmission of the electron can be mediated either by natural mediators such as vanillin, syringylaldehyde or p-coumaric acid (Nousiainen et al., 2008) or by synthetic mediators such as 2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2,6,6-Tetramethylpiperidine 1-oxyl (TEMPO) and 1-Hydroxy-benzotriazole (HOBt) (see Fig. 8.7).
Experimental Description of Chemical Reactions
Published in John Andraos, Reaction Green Metrics, 2018
Preparation of 5-(4-Chloro phenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxylic Acid Piperdin-1-yl Amide (1). A mixture of 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxylic acid (4, 45.0 g, 1 mol) in dichloromethane (450 mL) and hydroxybenztriazole (HOBt, 18.7 g, 1.2 mol) was stirred about 10 min. To this solution was added a solution of dicyclohexyl carbodiimide (DCC, 29.3 g, 1.2 mol) in dichloromethane (900 mL) over a period of 15–30 min, and the mixture was stirred about 1.5 h at ambient temperature. On completion of reaction (TLC), the solution was cooled to 0–5°C, stirred about 45 min, then the dicyclohexyl urea was filtered and washed with dichloromethane (135 mL), and the solvent of the filtrate was removed under reduced pressure. A mixture of the above crude, dichloromethane (900 mL), and potassium carbonate (15.4 g, 1 mol) was stirred for min, a solution of 1-amino piperidine (11.8 g, 1.0 mol) in dichloromethane (450 mL) was added over a period of 15–30 min, and the mixture was stirred for 45–60 min at ambient temperature. On completion of reaction (TLC), the reaction mixture was cooled to 0–5°C and stirred for 45 min, and precipitated hydroxy benztriazole was filtered, washed with dichloromethane (135 mL), and the solvent of the filtrate was removed under reduced pressure. To the above crude was added petroleum ether (450 mL), and the mixture was stirred for 45 min at 50°C, filtered, washed with petroleum ether (225 mL), and dried in air to constant weight.
Hyaluronan-Based Hydrogels as Functional Vectors for Standardised Therapeutics in Tissue Engineering and Regenerative Medicine
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
Alexandre Porcello, Alexis Laurent, Nathalie Hirt-Burri, Philippe Abdel-Sayed, Anthony de Buys Roessingh, Wassim Raffoul, Olivier Jordan, Eric Allémann, Lee Ann Applegate
Exploiting the aqueous solubility of hyaluronan, various conjugation reactions have been proposed in water (Schanté et al. 2011a; López-Ruiz et al. 2019). Hyaluronan carboxylic acid modification in aqueous solution with active amino groups via carbodiimides (e.g. 1-ethyl-3-[3-(dimethylamino)-propyl]-carbodiimide, or EDC) has been widely used since almost 50 years and was well described (Danishefsky and Siskovic 1971). Activation of hyaluronan carboxyl groups with EDC in the pH range of 4–7 forms an active intermediate (i.e. O-acylisourea) which reacts promptly with primary amines (i.e. nucleophiles) to form stable amide bonds. To prevent rapid hydrolysis of the active intermediate, N-hydroxysuccinimide (NHS), 1-hydroxybenzotriazole (HOBt), or highly reactive N-hydroxysulfosuccinimide (Sulfo-NHS) may be added to the reaction, favouring the formation of an NHS ester intermediate. This intermediate is more stable and reacts slowly with primary amines to eventually form stable amide bonds. Depending on the specific manufacturing needs, reaction yields in water may be modulated by adjustment of pH, reagent quantities, and availability of amino groups (Schanté et al. 2011b; Maudens et al. 2018). To attain high relative reaction yields (i.e. >80%), the use of solvents such as dimethyl sulfoxyde (DMSO) or dimethylformamide in anhydrous conditions is necessary (Schneider et al. 2007; Schanté et al. 2011a). Hyaluronan carboxyl groups are furthermore known to be specifically recognised by HYAL-2 enzymes. This characteristic allows for degradation protection by means of chemical carboxyl conjugation (Aruffo et al. 1990; Schanté et al. 2011a).
Preparation and characterization of polyamidoamine dendrimers conjugated with cholesteryl-dipeptide as gene carriers in HeLa cells
Published in Journal of Biomaterials Science, Polymer Edition, 2022
Le Thi Thuy, Minyoung Choi, Minhyung Lee, Joon Sig Choi
The following compounds were purchased from Sigma-Aldrich (Seoul, South Korea): branched polyethyleneimine (PEI, 25 kDa), ethidium bromide, polyamidoamine-generation 2 (PAMAM G2), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N,N-diisopropylethylamine (DIPEA), piperidine, trifluoroacetic acid (TFA), triisopropylsilane (TIS), HEPES, Tris, EDTA, cholesterol chloroformate, agarose, and methanol. N-Hydroxybenzotriazole (HOBt) and 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetra-methyluronium (HBTU) and Fmoc-L-His (trt)-OH were purchased from Anaspec (San Jose, CA, USA). Fmoc-L-Arg (pbf)-OH was purchased from Novabiochem (San Diego, CA, USA). EZ-Cytox reagent was purchased from DaeilLab Service (Seoul, South Korea). Luciferase 1000 assay kit and 5X Reporter Lysis Buffer were purchased from Promega (Madison, WI, USA). The Micro BCA Protein Assay kit was purchased from Pierce (Rockford, IL, USA). The luciferase reporter plasmid DNA (pCN-Luci, 8320 bp) was prepared as previously reported. Picogreen reagent, Alexa Fluor 546, and Hoechst 33342 were obtained from Invitrogen (Seoul, South Korea). Fetal bovine serum (FBS), 100X antibiotic-antimycotic agent, and Dulbecco’s modified Eagle’s medium (DMEM) were purchased from Gibco (Gaithersburg, MD, USA). HeLa cells were obtained from Korea Cell Line Bank.
Nonviral gene delivery using PAMAM dendrimer conjugated with the nuclear localization signal peptide derived from human papillomavirus type 11 E2 protein
Published in Journal of Biomaterials Science, Polymer Edition, 2021
Jeil Lee, Yong-Eun Kwon, Jaegi Kim, Dong Woon Kim, Hwanuk Guim, Jehyeong Yeon, Jin-Cheol Kim, Joon Sig Choi
The polyamidoamine dendrimer (ethylenediamine core, generation 2, PAMAM G2), polyethylenimine (branched, 25 kDa), N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), N,N-diisopropylethylamine (DIPEA), ninhydrin, piperidine, triisopropylsilane (TIS), trifluoroaceticacid (TFA), and 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES) were purchased from Sigma-Aldrich (Seoul, South Korea). N-Hydroxybenzotriazole (HOBt), 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetra-methyluronium (HBTU), Fmoc-His(trt)-OH, Fmoc-Ala-OH, Fmoc-Lys(Boc)-OH, and Fmoc-Arg(pbf)-OH were purchased from Anaspec (San Jose, CA, USA). The Dual-Luciferase® Reporter 1000 Assay System and Reporter Lysis 5× Buffer were purchased from Promega (Seoul, South Korea). Fetal bovine serum (FBS) was purchased from Welgene Inc. (Gyeongsan, South Korea). Lipofectamine® 2000, Dulbecco's phosphate-buffered saline (DPBS), Dulbecco’s modified Eagle’s medium (DMEM), 100× antibiotic-antimycotic reagent, 0.5% Trypsin-EDTA 10×, Quant-iT™ PicoGreen™ dsDNA Reagent, bisbenzimide (Hoechst 33342), Alexa 546 Nucleic Acid Labeling Kit, and Micro BCA Protein Assay Kit were purchased from Thermo Fisher Scientific (Seoul, South Korea). The Quanti-MAXTM WST-8 cell viability assay kit was purchased from Biomax, Ltd. (Seoul, South Korea).
Enhanced transfection efficiency of low generation PAMAM dendrimer conjugated with the nuclear localization signal peptide derived from herpesviridae
Published in Journal of Biomaterials Science, Polymer Edition, 2021
Jeil Lee, Yong-Eun Kwon, Younjin Kim, Joon Sig Choi
Polyamidoamine dendrimer, ethylenediamine core, generation 2 solution (PAMAM G2), polyethylenimine (branched, 25 kDa), N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), N,N-diisopropylethylamine (DIPEA), ninhydrin, piperidine, triisopropylsilane (TIS), and trifluoroaceticacid (TFA), were purchased from Sigma-Aldrich (Seoul, South Korea). N-Hydroxybenzotriazole (HOBt), 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetra-methyluronium (HBTU), Fmoc-His(trt)-OH, Fmoc-Leu-OH, Fmoc-Ile-OH, and Fmoc-Arg(pbf)-OH were purchased from Anaspec (San Jose, CA, USA). Dual-Luciferase® Reporter 1000 Assay System and Reporter Lysis 5X Buffer were purchased from Promega (Madison, WI, USA). The luciferase expression plasmid DNA (pCN-Luci) was prepared as reported previously [14]. Fetal bovine serum (FBS) was purchased from WELGENE Inc. (Gyeongsan, South Korea). Dulbecco's phosphate-buffered saline (DPBS), Dulbecco’s modified eagle’s medium (DMEM), 100X antibiotic-antimycotic reagent, 0.5% Trypsin-EDTA 10X, Quant-iT™ PicoGreen™ dsDNA Reagent, bisbenzimide (Hoechst 33342), and Alexa 546 Nucleic Acid Labeling Kit were purchased from Thermo Fisher Scientific (Seoul, South Korea). The Micro BCA Protein Assay Kit was purchased from Pierce (Rockford, IL, USA). EZ-Cytox was purchased from DAEILLAB SERVICE Co, Ltd. (Seoul, South Korea).