High number of compounds

Markush structures rcprcHL-uts compound families - widespread in patents nianual in/ontput convertible into otlicr representations high number of compounds less compact code ambiguous difficult to extract individual compounds... 

It may now be observed that the binary system of oxygen with Ti (as those of other metals close to Ti in the Periodic Table such as vanadium) is very complex and contains a high number of compounds. Many of these have rutile-related structures. For the Ti-0 region around the 50 at.% composition, with NaCl-type structure, see Fig. 3.38. 

However, the sensibility of the Caco-2 monolayers to the different standard operation procedures used for its culture increases the inter-laboratory variability and complicates the combination of data coming from different laboratories and the interpretation of results. Animal in vivo models reproduce the real situation better, as those models include all the physiological variables but, of course, have a low throughput capacity and are not adequate for screening a high number of compounds. 

In conclusion, for difficulty separation problems the application of 2-D TLC is necessary because the power of 1-D TLC is often inadequate for complete separation of the complex samples with a high number of compounds. The main advantage of 2-D TLC separation process is that compounds are distributed widely over two-dimensional space with high zone (peak) capacity (ca. 1500). The separation efficiency of 2-D TLC can be substantially increased in the future by a combination of the stationary... 

In spite of the high number of compounds, targets and assays, the development pipeline of new chemical entities as drug substances has not got fuller in the past 20 years for possible explanations, see below the discussion of drug targets and Ref. [9]. 

As, 48 monomer Bs, and 96 monomer Cs. A high number of compounds that are decoded with... 

The chemical composition of fuel oil is extremely complex, and an extremely high number of compounds can be present through the hydrocarbon types, the range of isomeric hydrocarbons (Table 9.2), and the various types and isomers of heteroatom constituents. Therefore, it is not practical to perform individual compound analyses but it is often helpful to define the compounds present under broad classifications, such as aromatics, paraffins, naphthenes, and olefins. 

The hyphenation of UHPLC to MS, carried out generally with electrospray (Table 2.1), requires volatile and low-viscosity solvents to favor the ionic evaporation, as was the case in HPLC-MS, and to keep the pressures low, which is particularly important in UHPLC. These requirements restrict the composition of the mobile phase however, the separation of high number of compounds is still achieved. The conditions compiled in Table 2.1 show that the aqueous phase is generally constituted by water, 0.02-0.2% formic in water, or 2-10 mM ammonium acetate, and methanol or acetonitrile are the solvents chosen for the organic phase, like in conventional LC. The separation has been carried out at a higher temperature than room temperature, up to 50°C [75], to keep viscosity of the solvent low, which reduces the pressure in the chromatograph. 

The use of LC with conventional LC columns (5 jm) is a common and well-established technique in food analysis. However, the limitations of the use of this type of column do not solve all analytical problems. This fact is especially critical in food metabolomics because of the complexity of food matrices and the high number of compounds of interest. Therefore, the use of ultra-high-pressure liquid chromatography (UHPLC) can overcome the limitations of conventional LC, providing... 

For forensic applicatimis, elution is normally carried out in gradient, especially when a high number of compounds are intended to be separated in a reasonable time. However, isocratic elution has also been successfully carried out for opioids analysis, as reflected in Table 33.2. Methanol and acetonitrile are the most common organic components of the employed mobile phases. Regarding the acidity, acid mobile phases are the most common for the analysis of opium alkaloids. Although more scarcely, neutral [72] and basic [77] mobile phases have been also employed. 

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