0 mL, including 4.6 mmol of NH2) was reacted with mild stirring using 1-bromooctadecane (4.56 g, 13.7 mmol) in the presence of Na2CO3 (1.45 g, 13.7 mmol) at 70°C for 69 h in dimethylacetamide under nitrogen atmosphere. Particles were recovered by filtration and washed see more with water, warm ethyl acetate, ethanol, and water successively. Changes in the appearance and porous structure were not observed by SEM. In the IR spectra (KBr pellet), ν CH of CH2 2,925 and 2,850 cm-1 was observed. Ion-exchange capacity was 2.3 meq g-1 dry particles. Using this value, the colloidal equivalent of chitosan (5.0 meq g-1, pH 4.0) used for the preparation of the cross-linked porous chitosan and the
ion-exchange capacity of the cross-linked porous chitosan (3.8 meq g-1) which was cross-linked by 1,6-diisocyanatohexane, GlcN of the cross-linked porous chitosan, and GlcNC18 of the resulting directly alkylated porous supports were calculated as 69 and 47 mol%, respectively. Therefore, about half of the monosaccharide units of the support particles are deemed to be octadecylated. Column-wise adsorption of LPS from protein solutions Purified water and buffer solutions were sterilized using an autoclave at 115°C to 121°C for 15 min. Glass wares were Caspase-independent apoptosis also sterilized using the autoclave at 250°C for 2 h. LPS aqueous solution, which was prepared by vortex
mixing and dilution with water, was added to HSA preparation. The solution was filtered with a filter disk having 0.2-μm-diameter pores and diluted with a buffer solution to a desired concentration for column-wise experiments. Phosphate buffer was used for https://www.selleckchem.com/HDAC.html experiments at pH 7.0 and 8.0, and acetic acid buffer was used for those at pH 4.3 and 5.3. Buffer solutions were prepared by adding NaOH solution of a predetermined concentration to phosphoric acid or acetic acid to obtain the desired ionic strength (μ). Column-wise adsorption was done at 20°C. Adsorbents were suspended in water and fed into a glass column (8 mm i.d. × 100 mm length) using a LC-6A pump (Shimadzu Corp.,
Kyoto, Japan). diglyceride The length of the gel bed was between 930 and 980 mm. The resulting column was washed with 0.5 M NaOH, at 10 mL h-1 for 3 h, and left overnight filled with 0.5 M NaOH to decompose LPS in the column (depyrogenation). After washing with water for 3 h, 0.1 M acetic acid was passed through for 1.5 h to convert amino groups of N-octadecylchitosan immobilized on the supports to their ammonium forms. After the buffer solution was passed through for 6.5 h, HSA solution was passed through at 5 mL h-1 for 15 to 16 h. The eluted solution was collected immediately as ten fractions of 7.5 mL each. Fractions of 2, 4, 6, 8, and 10 were analyzed for the concentrations of LPS and HSA. Chemical stability Porous supports bearing lipid membranes of N-octadecylchitosan were immersed in 0.5 M NaOH or 0.1 M HCl at ambient temperature overnight and then washed with water and subjected to IR spectroscopic analysis.