Molecular modeling methods compared

With the aid of molecular modelling methods we have developed and compared models for the antagonist binding site of the receptor, based on steric, electrostatic and hydrophobic properties of various adenosine receptor antagonists [44,45]. In one of the favoured models theophylline binds to the adenosine receptor in a flipped orientation, i.e. the ring atoms Nl, N3, N7 and N9 in adenosine coincide with C2, C6, N9 and N7, respectively, in theophylline (Fig. 2). This implicates that the domain where the ribose moiety of adenosine binds must be adjacent to N7 in xanthines. 

In the third type of correlation (C), experimental rate or equilibrium data are compared with reactivity indices calculated by some (usually) semiem-pirical method of theoretical chemistry. The main problem here is in the design of a suitable molecular model as the basis for calculation. 

A relatively recent development in QSAR research is molecular reference (MOLREF). This molecular modelling technique is a method that compares the structures of any number of test molecules with a reference molecule, in a quantitative structure-activity relationship study (27). Partial least squares regression analysis was used in molecular reference to analyse the relation between X- and Y-matrices. In this paper, forty-two disubstituted benzene compounds were tested for toxicity to Daphnia... 

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