MT-45 is a piperazine derivative with potent analgesic activity comparable to morphine despite being structurally unrelated to most other opioids. (S)-(+)-MT-45 is an enantiomer of MT-45 that displays analgesic potency similar to that of morphine (ED50s = 0.35 and 0.4 μg/kg, i.v., respectively, in Haffner’s mouse tail-pinch method). This contrasts with the relatively weak activity of (R)-(?)-MT-45 s a piperazine derivative with potent analgesic activity comparable to morphine despite being structurally unrelated to most other opioids. (S)-(+)-MT-45 is an enantiomer of MT-45 that displays analgesic potency similar to that of morphine (ED50s = 0.35 and 0.4 μg/kg, i.v., respectively, in Haffner’s mouse tail-pinch method). This contrasts with the relatively weak activity of (R)-(?)-MT-45 s a piperazine derivative with potent analgesic activity comparable to morphine despite being structurally unrelated to most other opioids. (S)-(+)-MT-45 is an enantiomer of MT-45 that displays analgesic potency similar to that of morphine (ED50s = 0.35 and 0.4 μg/kg, i.v., respectively, in Haffner’s mouse tail-pinch method). This contrasts with the relatively weak activity of (R)-(?)-MT-45 s a piperazine derivative with potent analgesic activity comparable to morphine despite being structurally unrelated to most other opioids. (S)-(+)-MT-45 is an enantiomer of MT-45 that displays analgesic potency similar to that of morphine (ED50s = 0.35 and 0.4 μg/kg, i.v., respectively, in Haffner’s mouse tail-pinch method). This contrasts with the relatively weak activity of (R)-(?)-MT-45 s a piperazine derivative with potent analgesic activity comparable to morphine despite being structurally unrelated to most other opioids. (S)-(+)-MT-45 is an enantiomer of MT-45 that displays analgesic potency similar to that of morphine (ED50s = 0.35 and 0.4 μg/kg, i.v., respectively, in Haffner’s mouse tail-pinch method). This contrasts with the relatively weak activity of (R)-(?)-MT-45 s a piperazine derivative with potent analgesic activity comparable to morphine despite being structurally unrelated to most other opioids. (S)-(+)-MT-45 is an enantiomer of MT-45 that displays analgesic potency similar to that of morphine (ED50s = 0.35 and 0.4 μg/kg, i.v., respectively, in Haffner’s mouse tail-pinch method). This contrasts with the relatively weak activity of (R)-(?)-MT-45 s a piperazine derivative with potent analgesic activity comparable to morphine despite being structurally unrelated to most other opioids. (S)-(+)-MT-45 is an enantiomer of MT-45 that displays analgesic potency similar to that of morphine (ED50s = 0.35 and 0.4 μg/kg, i.v., respectively, in Haffner’s mouse tail-pinch method). This contrasts with the relatively weak activity of (R)-(?)-MT-45 s a piperazine derivative with potent analgesic activity comparable to morphine despite being structurally unrelated to most other opioids. (S)-(+)-MT-45 is an enantiomer of MT-45 that displays analgesic potency similar to that of morphine (ED50s = 0.35 and 0.4 μg/kg, i.v., respectively, in Haffner’s mouse tail-pinch method). This contrasts with the relatively weak activity of (R)-(?)-MT-45 s a piperazine derivative with potent analgesic activity comparable to morphine despite being structurally unrelated to most other opioids. (S)-(+)-MT-45 is an enantiomer of MT-45 that displays analgesic potency similar to that of morphine (ED50s = 0.35 and 0.4 μg/kg, i.v., respectively, in Haffner’s mouse tail-pinch method). This contrasts with the relatively weak activity of (R)-(?)-MT-45 s a piperazine derivative with potent analgesic activity comparable to morphine despite being structurally unrelated to most other opioids. (S)-(+)-MT-45 is an enantiomer of MT-45 that displays analgesic potency similar to that of morphine (ED50s = 0.35 and 0.4 μg/kg, i.v., respectively, in Haffner’s mouse tail-pinch method). This contrasts with the relatively weak activity of (R)-(?)-MT-45 s a piperazine derivative with potent analgesic activ
