Mitoflaxone, also known as flavone acetic acid is a synthetic flavonoid that has been studied as an antitumor agent. Mitoflaxone was involved in phase II clinical trials in Europe for patients with advanced colorectal carcinoma and for patients with advanced malignant melanoma. Despite the promising preclinical activity, this drug didn’t demonstrate any clinical activity. Further studies of the drug were suspended.

Iclazepam (also known as Clazepam) was used as a tranquilliser.

Clocoumarol is a synthetic antagonist of vitamin K, developed in the 1970s. Clocoumarol exhibits strong anticoagulant properties in rat and rabbit.

Meletimide (R 5183) is a powerful anticholinergic agent with pronounced peripheral and central action.

Pobilukast is the Leukotriene D4 receptor antagonist. Pobilukast significantly attenuated the Salmonella enteritidis endotoxin-induced thrombocytopenia but had no effect on either the endotoxin-induced early leukopenia or late leukocytosis. Additionally, Pobilukast significantly reduced the endotoxin-induced hemoconcentration and improved survival to 30% at 48 hr. Pobilukast dose-dependently inhibited the immediate hemodynamic changes after leukotriene D4 (LTD4) injections. Pobilukast also attenuated the increase in vascular permeability and the prolonged decrease in CO, suggesting that the observed cardiac and vascular effects of LTs were mediated by stimulation of LT receptors. A shift toward the right of the dose-response curves to histamine with pobilukast compared to that with placebo in three subjects was demonstrated, whereas the active compound did not exhibit any protective effect against histamine in the remaining nine subjects. It was concluded that there is a leukotriene component to the bronchial responses to histamine in some, but not all, subjects. Pobilukast had been in phase II clinical trial for the treatment of asthma. However, this development was discontinued.

Perafensine is an isoquinoline derivative shown to be active in tests predictive of antidepressant activity. Perafensine is a potent antagonist of reserpine-induced effects and inhibits norepinephrine uptake into rat hypothalamic synaptosomes. Perafensine induced the biosynthesis of microsomal drug-metabolizing enzymes – in treated rats methylayapanine O-demethylase, ethoxycoumarin O-deethylase and cytochrome P-450 contents were increased and ketamine N-demethylase was decreased.

Enrasentan is an orally active mixed endothelin A/B receptor antagonist with a 100-fold greater affinity for the endothelin A receptor. In an animal model of hypertension and cardiac hypertrophy the drug has reduced blood pressure, prevented cardiac hypertrophy and preserved myocardial function. In rats with hyperinsulinemia and hypertension enrasentan normalized blood pressure and prevented cardiac and renal damage. In rats with stroke the drug reduced the ischemic area in the brain. Enrasentan had been in phase II clinical trial for the treatment of heart failure but the results suggested that enrasentan does not appear to have favorable effects on ventricular remodeling.

Ebselen is a small molecule mimic and inducer of glutathione peroxidase activity and possesses antioxidant and anti-inflammatory properties. This drug has been investigated in phase II clinical trials for the treatment of Meniere's disease, bipolar disorder and in the prevention of hearing loss. Besides, experiments on mice have shown that ZIKV infection could be on the list for potential use of ebselen. It alleviates testicular pathology in mice with Zika virus infection and prevents its sexual transmission. Ebselen has various mechanisms of action. It binds to the N-terminal domain of soluble epoxide hydrolase and chemically reacts with the enzyme to quickly and irreversibly inhibit one of the enzymes' activity: phosphatase (Nterm-phos). Besides, ebselen inhibits inositol monophosphatase and thus exhibits lithium-like on human central nervous system (CNS) function. In addition, ebselen inhibits the G4 isoform of acetylcholinesterase. It is a well-known relationship between the cholinergic system and learning, memory and other common cognitive processes, thus ebselen can be studied for the treatment of memory impairment diseases.

Metesind (AG-331) is a lipophilic thymidylate synthase inhibitor. It inhibits the cofactor binding site of the enzyme. It exerts cytotoxic properties. Metesind was being developed as an anticancer and antimetabolite agent.