Chemical arrays defined

Structural keys describe the chemical composition and structural motifs of molecules represented as a Boolean array. If a certain structural feature is present in a molecule or a substructure, a particular bit is set to 1 (true), otherwise to 0 (false). A bit in this array may encode a particular functional group (such as a carboxylic acid or an amidelinkage), a structural element (e.g., a substituted cyclohexane), or at least n occurrences of a particular element (e.g., a carbon atom). Alternatively, the structural key can be defined as an array of integers where the elements of this array contain the frequency of a specific feature in the molecule. 

Genuine exposition of the chemical properties of an aromatic carbene comes from the fusion of all of the types of experiment described above. The significance of each type becomes clear when considered within the context of the whole array of theoretical and experimental findings. The chemical properties of a particular carbene, in turn, become categorizable only with respect to other related examples. Finally, a pattern connecting structure to reactivity emerges when an entire host of clearly understood cases are compared. A pattern of structure and reactivity for the carbenes listed in Table 1 will be developed. The analysis begins at one extreme with BA, and then jumps, for contrast, to another extreme with an account of XA. With the boundaries defined, the other examples fall clearly into place. 

Coenzymes facilitate chemical reactions through a range of different reaction mechanisms, some of which will be discussed in detail in this review. However, in all cases structural features of the coenzyme allow particular reactions to proceed along a mechanistic pathway in which reaction intermediates are more thermodynamically and kinetically accessible. When incorporated into apoen-zyme active sites, the coenzyme reactivity is influenced by a well-defined array of amino acid functional groups. For a given coenzyme, the particular array of amino acids presented by the different apoenzymes can drastically alter the degree of rate acceleration and product turnover and can specify the nature of the reaction catalyzed. 

Arrays of biological data can form the basis for uniquely informative molecular descriptors. By defining the relationships between compounds using biological descriptors (in vitro profiles) in addition to chemical structures, medicinal chemists are given new perspectives to support lead optimization. 

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