Solid glycol esters

Chemical ligation methods for peptide synthesis using thioester chemistry in solution have been previously documented (see Vol. E 22a, Section 4.1.5). Generalized procedures for solid-phase ligation have been developed that simplify the overall procedure. One method uses a safety-catch acid labile linker at the C-terminus and was used for the synthesis of a 71-amino acid chemokine, vMIP I (Section 5.3.2.1). Another procedure uses a selectively cleavable glycolate ester linkage (Section 5.3.2.2). 

Niiya, I, T Maruyama, M Imamura, M Okada, T Matsumoto. (1973b). Effect of emulsifiers on the crystal growth of edible solid fats. Part IV. Effect of propylene glycol ester of fatty acid and unsaturated fatty acid monoglycerides. Jpn J Food Sci Technol 20(5) 191-198. 

Chem. Descrip. Glycol ester-based Chem. Analysis 39.0 - 41.0% solids Uses Defoamer in aq. coatings... 

Ionic Nature Nonionic CAS 120-40-1 EINECS/ELINCS 204-393-1 Uses Detergent, thickener, foam stabilizer for liq. detergents Properties Solid sol. in alcohols, glycols, esters dens. 8.3 Ib/gal 100% cone. Nitrene N [Cognis]... 

Diethylene glycol method. Place 0-5 g. of potassium hydroxide pellets, 3 ml. of diethylene glycol and 0 5 ml. of water in a 10 or 25 ml. distilling flask heat the mixture gently until the alkali has dissolved and cool. Add 1-2 g. of the ester and mix well. Fit the flask with a thermometer and a small water-cooled condenser in the usual way. Heat the flask over a small flame whilst shaking gently to mix the contents. When only one liquid phase, or one hquid phase and one solid phase, remains in the flask, heat the mixture more strongly so that the alcohol distils. Identify the alcohol in the distillate by the preparation of the 3 5 dinitrobenzoate (Section 111,27,2). 

The residue in the flask is either a solution or a suspension of the potassium salt of the acid derived from the ester in diethylene glycol. Add 10 ml. of water and 10 ml. of ethyl alcohol to the residue and shake until thoroughly mixed. Then add a drop or two of phenolphthalein and dilute sulphuric acid, dropwise, until just acid. Allow the mixture to stand for about 5 minutes and then filter the potassium sulphate. Use the clear filtrate for the preparation of a solid derivative or two of the acid (see Section 111,85,4). 

SFE has been used extensively in the analysis of solid polymers. Supercritical fluid extraction of liquid samples is undertaken less widely because dissolution or entrainment of the matrix can occur. As illustrated elsewhere SFE has also been applied for the analysis of liquid poly(alkylene glycol) (PAG) lubricants and sorbitan ester formulations [370]. The analysis of PAG additives (antioxidants, biocides and anticorrosion, antiwear and antifoaming agents) is hindered by the presence of the low molecular weight PAG matrix (liquid) and therefore a method for the selective separation of additives from PAG is required. The PAG... 

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