Lactams

Omapatrilat (INN, proposed trade name Vanlev) is an experimental antihypertensive agent that was never marketed. It inhibits both neprilysin (neutral endopeptidase, NEP) and angiotensin-converting enzyme (ACE). NEP inhibition results in elevated natriuretic peptide levels, promoting natriuresis, diuresis, vasodilation, and reductions in preload and ventricular remodeling.

Hesperadin is an aurora kinase inhibitor.

class of pigments

Panadiplon (U-78875) is an anxiolytic drug with a novel chemical structure that is not closely related to other drugs of this type. It has a similar pharmacological profile to the benzodiazepine family of drugs, but with mainly anxiolytic properties and relatively little sedative or amnestic effect, and so is classified as a nonbenzodiazepine anxiolytic.

Linopirdine is a putative cognition-enhancing drug with a novel mechanism of action. Linopirdine blocks the KCNQ2\3 heteromer M current with an IC50 of 2.4 micromolar disinhibiting acetylcholine release, and increasing hippocampal CA3-schaffer collateral mediated glutamate release onto CA1 pyramidal neurons. In a murine model linopirdine is able to nearly completely reverse the senescence-related decline in cortical c-FOS, an effect which is blocked by atropine and MK-801, suggesting Linopirdine can compensate for the age related decline in acetylcholine release. Linopirdine also blocks homome

L-655,708 (FG-8094) is a nootropic drug invented in 1996 by a team working for Merck, Sharp and Dohme, that was the first compound developed which acts as a subtype-selective inverse agonist at the α5 subtype of the benzodiazepine binding site on the GABAA receptor. It acts as an inverse agonist at the α1, α2, α3 and α5 subtypes, but with much higher affinity for α5, and unlike newer α5 inverse agonists such as α5IA, L-655,708 exerts its subtype selectivity purely via higher binding affinity for this receptor subtype, with its efficacy as an inverse agonist being around the same at all the sub

'''N-Methylspiperone (NMSP''') is a derivate of spiperone that is used to study the dopamine and serotonin neurotransmitter systems. Labeled with the radioisotope carbon-11, it can be used for positron emission tomography.

Revospirone (Bay Vq 7813) is an azapirone drug which was patented as a veterinary tranquilizer but was never marketed. It acts as a selective 5-HT1A receptor partial agonist. Similarly to other azapirones such as buspirone, revospirone produces 1-(2-pyrimidinyl)piperazine (1-PP) as an active metabolite. As a result, it also acts as an α2-adrenergic receptor antagonist to an extent.

Fenmetramide is a drug which was patented as an antidepressant by McNeil Laboratories in the 1960s. The drug was never marketed. It is the 5-ketone derivative of phenmetrazine and would similarly be expected to produce psychostimulant effects, though pharmacological data is lacking.

Halofuginone, sold under the brand name Halocur, is a coccidiostat used in veterinary medicine. It is a synthetic halogenated derivative of febrifugine, a natural quinazolinone alkaloid which can be found in the Chinese herb Dichroa febrifuga (Chang Shan). Collgard Biopharmaceuticals is developing halofuginone for the treatment of scleroderma and it has received orphan drug designation from the U.S. Food and Drug Administration.

Diclazuril (trade name Vecoxan) is a coccidiostat. In 2025 diclazuril has also been reported to interact with tubulin and inhibit its polymerization.

Paraxazone is an antidepressant. It acts as a reversible inhibitor of the enzyme monoamine oxidase (MAO). It was never marketed.

chemical compound

Ergocryptine is an ergopeptine and one of the ergoline alkaloids. It is isolated from ergot or fermentation broth and it serves as starting material for the production of bromocriptine. Two isomers of ergocryptine exist, α-ergocryptine and β-ergocryptine. The beta differs from the alpha form only in the position of a single methyl group, which is a consequence of the biosynthesis in which the proteinogenic amino acid leucine is replaced by isoleucine. β-Ergocryptine was first identified in 1967 by Albert Hofmann. Ergot from different sources have different ratios of the two isomers.

Tolimidone (CP-26154; MLR-1023) is a compound which was discovered by scientists at Pfizer, was found to stimulate secretion of gastric mucosa, and was in development by Pfizer as a drug candidate to treat gastric ulcers but was abandoned. After the patent on the compound expired, scientists at the company Melior Discovery identified it as a potential drug candidate for diabetes through a phenotypic screen. The company proceeded to show that MLR-1023 is an allosteric activator of Lyn kinase with an EC50 of 63 nM. As of 2012 Melior was repurposing it for diabetes. In June 2016, the company repo

Ro48-6791 is a drug, an imidazobenzodiazepine derivative developed by Hoffman-LaRoche in the 1990s.

CX-614 is an ampakine drug developed by Cortex Pharmaceuticals. It has been investigated for its effect on AMPA receptors.

Zaprinast was an unsuccessful clinical drug candidate that was a precursor to the chemically related PDE5 inhibitors, such as sildenafil (Viagra), which successfully reached the market. It is a phosphodiesterase inhibitor, selective for the subtypes PDE5, PDE6, PDE9 and PDE11. IC50 values are 0.76, 0.15, 29.0, and 12.0 μM, respectively.

Ro48-8684 is a water-soluble benzodiazepine derivative developed by Hoffman-LaRoche in the 1990s, which was designed along with Ro48-6791 as an improved replacement for midazolam, but ultimately proved to have little advantages over the parent drug and has not been introduced into clinical practice.

Elzasonan (CP-448,187) is a selective 5-HT1B and 5-HT1D receptor antagonist that was under development by Pfizer for the treatment of depression but was discontinued, possibly due to poor efficacy. By preferentially blocking 5-HT1B and 5-HT1D autoreceptors, elzasonan is thought to enhance serotonergic innervations originating from the raphe nucleus, thereby improving signaling to limbic regions like the hippocampus and prefrontal cortex and ultimately resulting in antidepressant effects.

Suproclone is a sedative and anxiolytic drug in the cyclopyrrolone family of drugs, developed by the French pharmaceutical company Rhône-Poulenc. Other cyclopyrrolone drugs include zopiclone, pagoclone and suriclone.