A STUDY ON GAMMA-AMINOBUTYRIC-ACID (GABA) AND ITS ANALOGS BY USING MOLECULAR-ORBITAL METHODS - ON EPILEPTOGENICITY OF NEW QUINOLONES

Using the molecular orbital methods, we examined molecular structure, electron density distribution, electrostatic potential field and recep tor structure of gamma-aminobutyric acid (GABA), and its analogues. Th e following findings were obtained: a comparison of the biological act ivity and the morphology electrostatic potentials of GABA analogues di sclosed that the active site is the amino group, and the biological ac tivity correlates closely with the electrostatic potential structure a round the amino group. The active sites were compared between the rece ptor-binding molecules and the GABA uptake inhibitory molecules, and t he results suggested that the receptor structure differed between the two groups of molecules and that the GABA A receptors had two subtypes . On these results, the epileptogenicity of new quinolones was studied using this method. These results suggested that the new quinolones bl ockaded the GABA receptor-binding system and that the important active site of the new quinolones for GABA receptor-binding was the the pipe razyl amino group. These results suggested that the concentration of z witterion type of the new quinolones was very important clinically.