Lysine solution preparation

Hi. Lysine. Gamma radiolysis of aerated aqueous solution of lysine (94) has been shown, as inferred from iodometric measurements, to give rise to hydroperoxides in a similar yield to that observed for valine and leucine. However, attempts to isolate by HPLC the peroxidic derivatives using the post-column derivatization chemiluminescence detection approach were unsuccessful. This was assumed to be due to the instability of the lysine hydroperoxides under the conditions of HPLC analysis. Indirect evidence for the OH-mediated formation of hydroperoxides was provided by the isolation of four hydroxylated derivatives of lysine as 9-fluoromethyl chloroformate (FMOC) derivatives . Interestingly, NaBILj reduction of the irradiated lysine solutions before FMOC derivatization is accompanied by a notable increase in the yields of hydroxylysine isomers. Among the latter oxidized compounds, 3-hydroxy lysine was characterized by extensive H NMR and ESI-MS measurements whereas one diastereomer of 4-hydroxylysine and the two isomeric forms of 5-hydroxylysine were identified by comparison of their HPLC features as FMOC derivatives with those of authentic samples prepared by chemical synthesis. A reasonable mechanism for the formation of the four different hydroxylysines and, therefore, of related hydroperoxides 98-100, involves initial OH-mediated hydrogen abstraction followed by O2 addition to the carbon-centered radicals 95-97 thus formed and subsequent reduction of the resulting peroxyl radicals (equation 55). 

Four sugar-lysine solutions were prepared and heated in a water bath. In addition, a pentosan-lysine solution and the pentosan, lysine, and sugars alone were heated (Table II). 

Immunoglobulin preparation, 5 mg/ml in saline Carbonate-bicarbonate buffer, 0.5 M, pH 9.5 Lysine solution, 1.0 M pH 7 Phosphate-buffered saline, pH 7.5 (PBS) Saturated ammonium sulfate Glycerol Procedure... 

Two stock solutions are prepared, one with lysine (solution A) and one with formaldehyde (solution B). 

In a completely different vein, Zhu et al. [141] evaluated the feasibility of BC/poly-lysine nanocomposites, prepared by immersion of BC tubes in a polylysine solution, as potential bacteriostatic food casings. 

Despite the open structure of the hyperbranched stiff macromolecules, they are rather compact with radius of gyration, Rq, far smaller than that for the linear analogues. The compactness is mirrored in the modest change in solution viscosity upon the addition of more than 1 g Li-carboxylate terminated polyphenylene to 1 ml water [363], and in the brittleness and inability to form films [383] exhibited by these polymers. A similar very modest effect on solution viscosity was previously observed by Aharoni et al [370] on solutions of the highly branched and very compact poly((x,e-L-lysine) molecules prepared by Denkewalter et al. [332]. 

The fermentation wastes Corynebacterium glutamicum biomass) were obtained in a dried powder form from a lysine fermentation industry (BASF-Korea, Kunsan, Korea). The protonated biomass was prepared by treating the raw biomass with a 1 N HNO3 solution for 24 h, thereby replacing the natural mix of ionic species with protons. The resulting C glutamicum biomass was dried and stored in a desiccator and used as a biosorbent for the sorption experiments. 

Prepare 0.01 M solutions of leucine, methionine, valine, and lysine using a solvent that is 70% isopropyl alcohol and 30% water. Liquid food samples, such as fruit juice samples, can be used directly. Solid food samples must be soluble in the isopropyl alcohol-water solvent. Prepare solutions of solid samples as concentrated as possible. 

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