Lactate medium, preparation

Medium Boiling Esters. Esterification of ethyl and propyl alcohols, ethylene glycol, and glycerol with various acids, eg, chloro- or bromoacetic, or pyruvic, by the use of a third component such as benzene, toluene, hexane, cyclohexane, or carbon tetrachloride to remove the water produced is quite common. Benzene has been used as a co-solvent in the preparation of methyl pyruvate from pyruvic acid (101). The preparation of ethyl lactate is described as an example of the general procedure (102). A mixture of 1 mol 80% lactic acid and 2.3 mol 95% ethyl alcohol is added to a volume of benzene equal to half that of the alcohol (ca 43 mL), and the resulting mixture is refluxed for several hours. When distilled, the overhead condensate separates into layers. The lower layer is extracted to recover the benzene and alcohol, and the water is discarded. The upper layer is returned to the column for reflux. After all the water is removed from the reaction mixture, the excess of alcohol and benzene is removed by distillation, and the ester is fractionated to isolate the pure ester. 

Very recently, Isik et al. [127] proposed the preparation of biocompatible ion gels by photopolymerization of the cholinium lactate methacrylic monomer inside the cholinium lactate IL and can be used as drug delivery agents, electrochemical transistors for biosensors, and mediums for biocatalysis. Conversely, the same BIL monomer, 2-cholinium lactate methacrylate, was used to obtain poly(IL)-cellulose composites by a fast UV curing process, which are the major component of plant cell walls, the most abundant biopolymer on earth, and also one of the most exploited natural resources. The use of ILs to replace organic solvents in biocatal54ic processes has gained much attention. Cull et al. [205] used l-butyl-3-methylimidazolium... 

In fact, early reports underlined that chitosan is useful as a vector for gene delivery. The level of transfection with plasmid/chitosan complexes was found to be highest when the molecular mass of chitosan was 40 or 84 kDa, the N/P ratio was 5, and the transfection medium contained 10% serum at pH 7.0 (Ishii et al., 2001). Similarly, Romoren et al. (2003) found that the in vitro transfection in Epithelioma papulosum cyprini cells was affected by the DNA concentration in the complexes as well as the molecular weight and degree of acetylation of the chitosans. Also Weecharangsan et al. (2006) proposed the chitosan lactate salt for in vitro gene transfection, considering the ease of preparation of polymer/DNA complexes and their low cytotoxicity. 

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