Background: Dextromethorphan (DM), the d-isomer of the codeine analog levorphanol, is an active ingredient present in a variety of cough and cold remedies. Recently, data generated from a study in ...

4 d), so that loop conformations without a definitive ... in the absence of superhelicity, a stable H-y5 isomer is formed with a high association rate. In contrast, for the H-y3 isomer this ...