Nitrogen acids solubilization

Hall et at. 300) described an indirect method for the determination of urinary a-amino nitrogen. Copper is solubilized from insoluble copper phosphate by complexing with a-amino groups at slightly alkaline pH. The remaining copper phosphate is removed by filtration and the filtrate is diluted 1 10 or 1 20 with 0. IN hydrochloric acid to measure the dissolved copper by atomic absorption. Standards are prepared using alanine. 

Solubilization of Membrane Proteins. A modification of the procedure of Hjelmeland et al. (30) was employed. A 300-g portion of liquid-nitrogen frozen, 6-day Nicotiana silvestris cultured cells was suspended in 200 ml of 50 mM N-(2-hydroxyethyl)-piperazine-N -3-propanesulfonic acid (EPPS-KOH) buffer, 1 mM dithiothreitol (DTT), and 0.1 mM EDTA extraction buffer with constant stirring until completely suspended (20 min). The slurry was centrifuged in a Sorvall SS 34 rotor at 9,000g for 20 min at 4°C. The supernatant was passed through miracloth (Calbiochem). An aliquot... 

Despite the fact that crude APPL s are totally soluble in DMF, an important residue is obtained at the end of the solvent sequence (0 100, THF DMF) indicating that the protein-rich fractions require association with the polyphenolic part for their solubilization in DMF (Table VI). Because each APPL has a different amino acid composition, its solubility distribution is also different, but in both cases, the THF fraction is the most lignin-like, with only 1% nitrogen. This is confirmed by FTIR analysis (Fig. 7). As the fractionation proceeds with increasing solvent polarity, the lignin characteristic bands at 1515, 1460, 1265, 1095, 1035, and 810 cm-1 disappear, while the amide characteristic bands at 3290 and 3080 cm-1 appear. 

Fontaine et al. (31) presented data comparing the solubility behavior of proteins of peanut and cottonseed meals, proteins of corresponding dialyzed meals, and isolated proteins. While the shapes of the pH/solubility curves for cottonseed and peanut meals differed, the response of proteins to the removal of dialyzable meal constituents was similar. Data indicated the presence of natural materials in both meals which decreased the solubility of meal nitrogen at certain acid pH values but exerted no effect at alkaline pH values. Thus procedures for solubilizing proteins by treatment with proteolytic enzymes should also be designed with consideration of the influence of non-protein constituents. 

Hijji and Benjamin also accomplished a microwave synthesis of thalidomide in acceptable yield in 2004 (Scheme 5) [36-39]. Ammonium chloride was found to be an effective source for nitrogen. Namely, phthalic anhydride (4), glutamic acid (8), and ammonium chloride were mixed in 1 1 1 ratio with a catalytic amount of DMAP and heated in a conventional microwave oven for 6.5 min. The mixture melted to a brown liquid. The heating continued for an additional 1 min to give thalidomide (1) in 52% yield in this two-step, one-pot reaction after solubilization, precipitation, and recrystal-lization. 

RFG RME Rust inhibitor Reformulated gasoline. Repassed methyl ester. Lubricant additive minimizes rust by preferential adsorption of polar compounds on metal surface to provide a protective film and/or neutralization of corrosive acids, e.g., fatty acids, nitrogen compounds, carbonate-alkylbenzenosulfonate.RMs. Water is solubilized by soft-core Rms. 

Bradford Particle Design patented another way to perform the SEDS. In this method, nitrogen was the antisolvent, while the substrate to be micronized was solubilized in CO2. Salicylic acid was processed by means of this approach (140) Table 4 provides additional examples (15,16,132-134,136, 137,141-156). 

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