Natural biotechnological methods

Rigaut, G., Shevchenko, A., Rutz, B., Wihn, M Mann, M. and Seraphin, B. (1999) A generic protein purification method for protein complex characterization and proteome exploration. Nature Biotechnology, 17 (10), 1030-1032. 

In addition to the raw materials commonly used for the production of flavours, such as synthetic flavouring substances, uniform natural flavouring substances (gained by fermentation respectively biotechnological methods), essential oils, absolutes, essences etc., aqueous alcoholic distillation and extraction are processes which are specifically used today for the production of raw materials for the sector of alcoholic beverages, just as they have been for many years in the spirits industry. 

In general, three major biotechnological methods are used in the production of natural flavors use of enzymes, microorganisms, and of plant tissue or cell cultures (32-34). In the following, the use of these techniques for the biotechnological production of C 13-compounds will be discussed. 

Both enantiomers of lactic acid (2-hydroxypropanoic acid) are natural products and easily obtained by biotechnological methods, so there is no need for their synthesis in the laboratory. Even their esters with alkanols, e.g.. 1, are comparatively inexpensive and, therefore, convenient starting materials for derivatization to chiral reagents and auxiliaries. If necessary, such esters can be obtained by any convenient esterification technique. O-Acylated derivatives of lactic esters have been used very successfully as chiral auxiliaries in diastereoselective Diels-Alder reactions (Section D.1.6.1.1.1.1.2.). The acrylate 2 and methacrylate 31-3 and the fu-marate 43 give very high enantiomeric excesses. These are obtained from the lactic ester by treatment with an acid chloride. 

C. Kirby, G. Gregoriadis, Dehydration-rehydration vesicles a simple method for high yield drug entrapment in liposomes. Nature BioTechnology, 1984, 2, 979-984. 

Other than looking for the enzymes which exist in natine, biotechnological methods enable us to modify the character of natural enzymes. One method is to... 

KEP 03] Keppler A., GENDREizig S., Gronemeyer T. et al, A general method for the covalent labeling of fusion proteins with small molecules in vivo . Nature Biotechnology, vol. 21, pp. 86-89, 2003. 

Sedoheptulose (o-a/tro-heptulose) is a natural ketose that plays an important role in metabolism. Its content in natural sources, however, rarely exceeds 1 % [59] so that its synthesis rather than its isolation is preferred. Until now, biochemical and biotechnological methods have been exploited to perform the synthesis [60]. 

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