S-(+)-Rolipram inhibits human monocyte cyclic AMP-specific PDE4 with IC50 of 0.75 μM, has anti-inflammatory and anti-depressant activity in the central nervous system, less potent than its R enantiomer.

Aloenin B, a compound isolated from the leaves and roots of Aloe vera, has neuroprotective activity against glutamate-induced neuronal death in HT22 cells.

CGP 29030A is a new piperazine derivative with analgesic activity and significant inhibitory effect on potentially nociceptive dorsal horn neurons, which can be used to study painful disorders.