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Regression

Linear Regression Models

General remarks

Moloc provides the possibility to generate linear regression models on the basis of topological similarity descriptors in a rather automated way. The prerequisites to generate such models are: The most straightforward type of model is the minimal model that minimizes the loading defect of a test compound with a similarity model consisting of a minimal number of test compounds. The loading defect is the fraction of pharmacophoric content of the test compound that cannot be described by the set of training compounds.
Alternatively, a partitioned model can be generated. In this case, a similarity analysis of the model compounds is used to partition the compounds in order to produce several submodels. A test compound then gets attributed a value for each submodel, together with corresponding confidentiality limits and loading defects.
In this tutorial we make again use of the files hdrqn.sd and hdrqn.lst which can be found in the moloc/dat directory. They contain the model structures and plasma protein binding data, respectively.

Generation of Models

Model Results for Structures

Evaluation can also be performed within the 'dTp' menu (option 'v') to facilitate structure evaluation during design. In this case, options are taken as set in the present menu.

For batch mode operation use the program Mtprmp, where results can also be added as additional data fileds in the .sd file.

The Program 'Mdls'

Minimal linear models can be located in a subdirectory, called 'mdl', of the installation directory 'moloc'. If the .mdl files are equipped with additional key lines, these models can be directly called with the program 'Mdls'. Tag lines must be at the beginning of the .mdl file. The following tags, located at the beginning of a line, are undestood: The command 'Mdls ?' lists the available models with associated help text (if available), in our case:
...
-m<number> My Pet Model [0]
Help text
...
For a set of structures contained in an .sd file 'strct.sd' model predictions can be calculated with the command:
Mdls -m0 strct.sd
which produces a result file 'strct.txt'.