Functional group-based

Selected Acid-Base Titrimetric Procedures for Organic Functional Groups Based on the Production or Consumption of Acid or Base... 

Functional Group-based Strategy. The use of functional groups to guide the retrosynthetic reduction of molecular complexity. 

Cimetidine contains an imidazole ring comparable to histamine, a sulfur atom (thioether group) in the side-chain, and a terminal functional group based upon a guanidine (see Section 4.5.4). Ranitidine bears considerable similarity to cimetidine, but there are some important differences. The heterocycle is now furan rather than imidazole, and the guanidine has been modified to an amidine (see Section 4.5.4). A newer drug, nizatidine, is a variant on ranitidine with a thiazole heterocyclic ring system. 

Cyclopropanations are known for several other carbanionic intermediates of the general type (7), in which the substituent G is ultimately lost as an anionic leaving group in the last step of the ring-forming pathway (see Scheme 3 above). The substituent G is most often a functional group based upon sulfur, selenium or nitrogen. Halide-substituted derivatives probably react via the a-elimination pathway in most cases (see Section 4.6.3.1), but in some reactions with electron deficient alkenes as substrates, the normal order of steps may be altered (e.g. Table 10, ref. 162). 

The concept of hybridization of AOs to give new hybrid AOs involved in the bonding patterns of atoms is a useful and practical way to describe the way in which functional groups are constructed. It provides a rationale for the structure as well as the geometry and electron distribution in functional groups and molecules in which they are found. It can also be used to predict reactivity patterns of functional groups based on these considerations. 

The fingerprint region of the R spectrum is unique to nearly all compounds, but it is very difficult to read iL You should know about the fingerprint region, but you should use IR to identify functional groups based upon the region from t600 to 3500 cm... 

Certain residues with a variable degree of conservation can be investigated for their usefulness as evolutionary markers that can provide insight into the history of each enzyme family or clan and allow comparative analysis with other families or clans. Krem and Di Cera [75] identified several such markers with proven evolutionary usefulness. In addition to the use of these markers for rooting the phylogenetic trees, attempts were made to classify serine proteases into functional groups based on these markers or their coding sequences. 

Ducrot, V., Usseglio-Polatera, P., Peiy, A.R.R., Mouthon, M., Laffont, M., Roger, M.C., Garric, J. and Ferard, J.F. (2005) Functional grouping based on species traits contribution to improvement of relevance in the selection of test species for ecotoxicology, Environmental Toxicology and Chemistry (in press). 

We can identify the nucleophilic and electrophilic centres in common functional groups, based on the relative electronegatives of the atoms present. The following guidelines are helpful in this ... 

As well as the histamine-like portion of the molecule, Tagamet has a sulfur atom and then, at the end of a short chain of carbon atoms, a complicated functional group based on guanidine. It is easy to add the sulfur atom and the short carbon chain to the heterocyclic building block (see Chapter 43 for more about this) so that the only problem is how to build on the guanidine at the end of the molecule. 

Shape Similarity Measures of Functional Groups Based on Local Shapes... 

Hann et al. used a similar, multilevel approach when pooling compounds for HTS. These authors applied three types of filters. Basic filters were used to remove molecules with non-drug-like features. Next functional group-based hard filters were utilized... 

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