Anxiolytic activities of pentanthrene type heterocyclic compounds

A series of pentanthrene type heterocyclic compounds were synthesized and evaluated for anxiolytic activities by three kinds of behavioral pharmacological tests. Several compounds showed anxiolytic activities. In particular, s-triazolo[3,4-a]phthalazine (Tri-P) and 3-propyl derivatives of Tri-P(PTP) showed remarkable activities, although the activities were slightly lower than those of diazepam. The results suggested that Tri-P or PTP is a useful lead compound for the development of the antianxietic agents. The relationship between the structure and anxiolytic activity, and the inducing mechanism of the activity was discussed.