STRUCTURE-ACTIVITY RELATIONSHIP FOR SOME XANTHINES AS ADENOSINE-A1-RECEPTOR ANTAGONISTS, BRONCHODILATORS AND PHOSPHODIESTERASE INHIBITORS -AN ELECTRIC-FIELD MAPPING APPROACH

Some alkylxanthines which are known as adenosine receptor antagonists or bronchodilators and phosphodiesterase (PDE) inhibitors have been st udied using geometry optimisation by the AM1 molecular orbital method and electric field mapping using Mulliken charges. The possible atomic sites of these molecules which may be involved in interaction with th e adenosine receptor and with the receptor related to bronchodilatory activity have been identified, and thus structure-activity relationshi ps have been established for them. PDE inhibitor and bronchodilatory a ctivities seem to have similar molecular structural requirements.