Methylmalonic acid (MMA) is a C-methylated derivative of malonate. Elevated levels of methylmalonic acid result from inherited defects of enzymes involved in MMA metabolism or inherited or acquired deficiencies of vitamin B12 or its downstream metabolites. MMA is also a specific diagnostic marker for the group of disorders collectively called methylmalonic acidemia.

Fluquinconazole, a fungicide, that is approved under the name Jockey as a seed dressing in Australia.

HDAC-IN-2 (also known as citarinostat or ACY-241) was developed as a selective histone deacetylase (HDAC) 6 inhibitor with potential antineoplastic activity. Inhibition of HDAC leads to the inhibition of tumor oncogene transcription, and the selective transcription of tumor suppressor genes, which inhibit tumor cell division and induce tumor cell apoptosis. HDAC-IN-2 participates in phase 1b clinical trial in patients with multiple myeloma to determine the maximum tolerated dose (MTD) and evaluate the safety and preliminary antitumor activity. Besides, HDAC-IN-2 in combination with paclitaxel participates in phase Ib in patients with advanced solid tumors. In addition, HDAC-IN-2 in combination with nivolumab participates in phase I in patients with unresectable non-small cell lung cancer to determine the safety, tolerability, dose-limiting toxicities (DLTs), and maximum tolerated dose (MTD) of the drug.

Naxagolide (MK-458; L 647,339; (+)-PHNO) is a dopamine D2/D3-receptor agonist, which was studied for the treatment of patients with Parkinson's disease, but further study was discontinued. In addition, was discovered, that Naxagolide C-11 ([(11)C]-(+)-PHNO) was a potential radiotracer for imaging the high-affinity state of dopamine D2 receptors with positron emission tomography (PET) in human subjects. This radiotracer is a suitable for imaging the agonist binding sites (denoted D(2HIGH) and D(3)) of these receptors. PET studies in nonhuman primates documented that, in vivo, [(11)C]-(+)-PHNO displays a relative selectivity for D(3) compared with D(2HIGH) receptor sites and that the [(11)C]-(+)-PHNO signal is enriched in D(3) contribution compared with conventional ligands such as [(11)C] raclopride. Recently was published article reflects the relationship between social attachment and dopamine D2/3 receptor availability in the brains of healthy humans using [11C]-(+)-PHNO.

Guaithylline (or Guaifylline), a xanthine derivative that was studied as a bronchodilator and expectorant, however, has never been marketed.

Tanomastat (previously known as BAY 12-9566) is an inhibitor of angiogenesis and a biphenyl matrix metalloprotease (MMP). The drug was selective towards MMPs 2,3, and 9 and no activity against MMP1. Tanomastat was developed for the treatment of cancer and arthritis. Tanomastat participated in phase III clinical trials as maintenance therapy in patients with advanced ovarian cancer, and in patients with pancreatic, lung cancers. However, all studied were discontinued after the recommendation of the independent data safety monitoring board.

Trefentanil is a short-acting synthetic opioid of the piperidine class. The drug caused potent analgesia with the peak effect occurring 3 min after injection. There was no significant difference in analgesic potency of trefentanil and alfentanil as measured by tolerance to tibial pressure at 3 min. Trefentanil had a pharmacokinetic and pharmacodynamic profile similar to alfentanil, with a small extent of tissue distribution and a rapid blood/brain equilibration. Trefentanil caused significant respiratory depression at doses of 32 ug/kg and 64 ug/kg. It is a mu-opioid receptor agonist. Trefentanil produced naloxone reversible anti-nociception equi-efficacious to that of fentanyl.

Synthetic compound Erteberel (LY500307) is a highly potent and selective ERβ agonist; it has a 12-fold higher affinity for ERβ than ERα and exhibits 32-fold more functional potency. LY500307 was well tolerated in benign prostatic hypertrophy (BPH) patients with no side effects and it is currently being tested in phase 2 clinical trials for improving negative symptoms and cognitive impairment associated with Schizophrenia. In BPH clinical trial incidence of adverse events was comparable between treatment groups, and no clinically meaningful changes in laboratory tests were observed.

Onapristone is a type I progesterone receptor (PR) antagonist that prevents PR- mediated DNA transcription and was studied as an antitumor agent. This drug possessed activity in breast cancer and is participating in phase II clinical trials to test any good and bad effect for the treatment of endometrial cancer, ovarian cancer, peritoneal cancer, and prostate cancer.