MOLECULAR RECOGNITION - ALPHA-CYCLODEXTRIN AND PENICILLIN-V INCLUSION COMPLEXATION

Specific molecular recognition between alpha-cyclodextrin (1) and a beta-lactam antibiotic, penicillin V (2), was systematically determined. A stable 1:1 inclusion complex was established in the solid state, gaseous phase, and solution. The distinct structure of this inclusion complex was rigorously elucidated by FT-IR, FAB-MS, CP/MAS solid-state C-13 NMR, and 500-MHz H-1 NMR. Based on strictly determined H-1 NMR data, a time-averaged conformation of the alpha-CD-penicillin V inclusion complex was proposed, which was supported by CPK model studies and the intermolecular NOE results. Moreover, alpha-cyclodextrin exhibited significant catalytic activity toward the hydrolysis of penicillin V in weakly alkaline solution. These findings imply that the initial molecular recognition and the concomitant molecular association are essential in a biomimetic process.