Optimization of yield

This highly flexible process allows the best optimization of yields in desirable products and it features a high degree of selectivity. 

For a viable commercial process, the selection of materials and the choice of synthetic route is governed primarily by cost, not by overall yield. The selection of starting material is dictated usually by the desked C-3 substituent. For cephalosporins containing 3-acetoxymethyl or 3-(substituted)methyl such as 3-thiomethyl and 3-aminomethyl derived moieties, the most dkect synthetic route is from cephalosporin C, whereas pencillin V or G is the preferred starting material for the synthesis of the C-3 methyl cephalosporins. The three chemical transformations (2), (5), and 6) can potentially be carried out in a variety of ways, the precise sequence being determined by a balance of competing factors such as cost and optimization of yield (87). 

Minimum Variance Purity Control of Preparative Chromatography with Simultaneous Optimization of Yield An On-Line Species-Specific Detector... 

Slizyte, R., Rustad, T., and Storro, I. 2005c. Enzymatic hydrolysis of cod (Gadus morhua) by-products optimization of yield and properties of lipid and protein fractions. Process Biochem., 40, 3680-3692. 

Basic data and assumptions for reactor-design example dealing with optimization of yields for benzene chlorinator... 

The gluing experiments were done with commercially available starch, proteins (casein, glutin) and tannins of mimosa Acacia spp.), Pinus radiatay and quebracho (Schinopsis spp.) and with tannins extracted from the bark of spruce (Picea abies) and common pine (Pinus sylvestris). The extractions were carried out with water or organic solvents under alkali and/or sulphite conditions on a laboratory scale aiming at optimization of yield and polyphenolic extract content. After extraction, the solutions were concentrated under reduced pressure and freeze dried. One pine bark extract was modified with phenol. A summary of the tannin extracts and their properties is given in Table I. 

Improved sharpness of product particle size distribution and optimization of yield. Particularly if the primary granulator (22) has been installed in the... 

Industrial Chemists. Mechanistic knowledge allows the prediction of new reagents and reaction conditions which may affect desired transformations. It also allows optimization of yields, cutting down on raw materials costs and waste material which may be expensive to dispose of. For example, Augmentin is a broad-spectrum antibiotic, marketed by GlaxoSmithKline, with sales of over 2 billion in 2001. If, say, 5% of the costs are in raw materials, a 1 % improvement in reaction yield would save GSK at least a million dollars per annum. 

Finally, an often overlooked use of pathway analysis is in drug production. Many drugs can be synthesized by genetic engineering (e.g., insulin) or metabolic engineering (e.g., penicillin) of microorganisms or plants [Stephanopoulos, Aristidou, and Nielsen 1998]. The optimization of yield quantity and purity involves many of the same tools as are employed in understanding disease mechanisms. 

The dependence of the expression of secondary metabolites on external parameters in microorganism cultures is well known in the fermentation industry. The rationale behind this phenomenon has, however, apparently not been recognized resulting in empirical "trial and error" approaches to optimization of yield in production cultures (see Section 7.2). In these cases it should be borne in mind that the physical and chemical parameters are as a rule far removed from the natural conditions, and in this way the systems are artificial and not necessarily primarily governed by the Darwinian laws. 

Beddows, C.G. J. Wong. Optimization of yield and properties of silken tofu from soybeans. I. The watenbean ratio. Int l. J. FoodSci. Technol. 1987a, 22, 15—21. 

Sheintuch M, Dessau RM (1996) Observation, modeling and optimization of yield, selectivity and activity during dehydrogenation of isobutene and propane in a Pd membrane reactor. Chem Eng Sci 51 535-547... 

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