1-[2-Amino-1-(4-methoxyphenyl)ethyl]cyclohexanol (N,N-didesmethylvenlafaxine, also known as Venlafaxine EP Impurity C) is an intermediate in the synthesis of N,O-Didesmethylvenlafaxine and a metabolite of Venlafaxine, a serotonin-norepinephrine reuptake inhibitor (SNRI).

6-alpha-Naloxol is active metabolite of naloxone. 6-alpha-Naloxol was shown to be neutral antagonist at the mu receptor in vitro, with no affect on cAMP levels or GTPitalic gammaS binding, regardless of morphine pretreatment. It elicits withdrawal behaviour and conditioned place aversion in morphine pretreated rodents.

Norcyclobenzaprine (aka desmethylcyclobenzaprine) is one of the major metabolites of cyclobenzaprine which is a muscle relaxant marketed under the brand name Flexeril. Both cyclobenzaprine and norcyclobenzaprine are known to be potent antagonists of the serotonin 2a receptor.

4-{2-[5-methyl-1-(naphthalen-2-yl)-1H-pyrazol-3-yloxy]ethyl}morpholine (S1RA, E-52862) is an 1-arylpyrazole class of sigma-1 receptor antagonist. Formalin-induced nociception (both phases), capsaicin-induced mechanical hypersensitivity and sciatic nerve injury-induced mechanical and thermal hypersensitivity were dose-dependently inhibited by systemic administration of S1RA. Occupancy of sigma-1 receptors in the CNS was significantly correlated with the antinociceptive effects. As a mechanistic correlate, electrophysiological recordings demonstrated that pharmacological antagonism of sigma-1 receptors attenuated the wind-up responses in spinal cords sensitized by repetitive nociceptive stimulation. Esteve is developing E 52862 for the treatment of several pain indications, including diabetic neuropathies, chemotherapy-induced neuropathic pain, postherpetic neuralgia, postoperative pain. Phase II development of this first-in-class agent is underway in Romania, Spain and Greece.

ATC-0065 is an oral antagonist of melanin concentrating hormone receptor 1. In preclinical testing ATC-0065 demonstrated anxiolytic and antidepressant activity.

ATC-0175 is a potent antagonist with a high affinity for MCH1R and additional affinities for 5-HT1A and 5-HT2B receptors. The receptor binding and the functional assay (MCH-induced increase in [Ca2+]i) indicated that ATC0175 is a noncompetitive antagonist at MCH1Rs. ATC-0175 exhibited anxiolytic effects in numerous animal models of anxiety including the elevated plus-maze test, social interaction test, stress-induced hyperthermia and maternal separation-induced vocalization. ATC-0175 also exhibited antidepressant effects in the forced swimming test. ATC-0175 increased swimming performance without altering climbing behavior, as observed with selective serotonin reuptake inhibitors. ATC0175 has adequate ADME profile (reasonable oral bioavailability and brain penetration) and potent oral activity in animal models. In contrast, ATC-0175 did not affect spontaneous locomotor activity, hexobarbital-induced sleeping time and did not impair rotarod performance. Thus, ATC-0175 may be devoid of unwanted central nervous system side effects, which are sometimes observed with current medications. ATC-0175 has the potential to be effective in the treatment of patients with depression and/or anxiety disorders.

J 113863 is a potent and high selective CKR-1 (CCR1) and CKR-3 (CCR3) chemokine receptor antagonist, which is also behaved as a full agonist of CCR2 and as a very partial agonist of CCR5. This compound was investigated for the treatment of multiple sclerosis and rheumatoid arthritis, but the status of these studies are not known.