Search

A computer program for comparison of the conformations of a number of related molecular structures is described. The comparisons are performed on either interatomic distances or torsion angles. The comparisons are accomplished on ordered pairs of distances or torsion angles, and the distance comparisons can be performed in a manner that allows permutation of the distance pairs being compared. The algorithm utilizes bit-string Boolean operations that allow the comparisons to be performed rapidly. The program should be useful for computer-assisted molecular modeling studies in which the viable conformers of bioactive analogues are compared in order to locate those conformers that place key substituents in the same spatial orientation.

Comprehensive conformational analysis of the 4- to 12-membered ring hydrocarbon series cyclobutane through cyclododecane has been carried out. The complete set of minima and saddle points has been located on the MM2 potential energy hypersurface using systematic and Monte Carlo conformational search techniques associated with a combination of Newton-type energy minimization methods. The complete network of conformational interconversions has also been identified.It has been found that the different modes of conformational interconversion associated with the lowest barriers between minimum energy conformers display fascinating patterns of well-coordinateds atomic movement