Distance substructure restriction

Substructure restriction distance For two atoms i, 7 it an interval [a, b] c N of positive natural numbers is given that restricts the distance of the two atoms in the embedding of the ambiguous molecular graph into M. 

When used for relative similarity and diversity, only potential pharmacophores that contain the defined special centre-type are used. The frame of reference for similarity/diversity studies is thus changed to one that is focused on the feature of interest distances are now measured relative to this special centre. For example, the special centre could be the centroid of a substructure [10] such as biphenyl tetrazole or diphenylmethane, enabling the calculation and comparison of all 3D pharmacophoric shapes that contain this substructure the substructure is said to be privileged . For structure-based design, the potential pharmacophores in a site can be restricted to those that contain a specific site point (e.g. in a pocket, or at the entrance to a pocket). In the context of combinatorial library design, the relative measure can be those pharmacophoric shapes that contain a special site-point that represents where the attachment point for a reagent would be. In figure 1, the special point would be centre-type number 3, which can be reserved for this purpose. 

It specifies the presence of a para-chlorotoluene moiety and excludes any orthosubstituents. Bond qualifiers define a particular bond configuration, cis or trans for a double bond. Descriptor qualifiers can be used to restrict values of, for instance, physicochemical descriptors of an atom a qualifier like (-0.2 < q) identifies a charge descriptor with a partial atomic charge less than 0.2. In addition to predefined descriptors, reserved key can be used for dynamic descriptors that depend on the screen context. Examples are the reserved key enumerate, which denotes the frequency of the preceding substructure occurring in a molecule, and distance, which denotes the distance between the geometric centers of two substructures. 

The structure elucidation problem focuses on the relationship between chemical spectra, structure, and additional sub-structural information. The structure generator provides all possible structures consistent with the constraints. If the chemical spectra can be replaced with different restrictions, the structure generator can be utilized for other purposes. For example, the introduction of biologically effective substructures and the distance relations between specific substructures to a structure generator may lead to proposals for new, draft structures in molecular design. Furthermore, these structures can be evaluated by log P values and so on. The structure generator certainly shows potential ability in application fields dependent on the contents of good list, bad list, other structural requirements, and the evaluation items. 

For the determination of the intensity distribution in two-dimensions, i.e. in the x and z-directions, a modified mask with a stripe substructure as shown in Fig. 9.37 is used. The z-coordinate, representing the depth into the glass sample, starts at the mask plane. The -coordinate is orthogonal to the 2-direction, and the /-coordinate nms parallel to the stripes of the mask. Edge effects in x and y-directions are not included into the calculation i.e. the extension is infinite but the calculation is locally restricted. 10,000 elemental waves start at a distance of a = 200 pm at the absorber structure of the... 

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