Biocytin is a biotin-lysine complex of low molecular weight containing about 65% biotin, which retains a high affinity for avidin. Biocytin is also used in scientific research as a histological stain for nerve cells. Biocytin is a versatile marker used in anterograde, retrograde and intracellular neuroanatomical investigations and in biotinidase assays. Biocytin displays high solubility in aqueous solutions and has a low molecular weight facilitating injection using micropipettes. Biocytin can be incorporated with a variety of avidin and streptavidin conjugates for detection by light, fluorescence or electron microscope. In vitro injection of biocytin into explanted brain hemispheres provides a quick and easy method for tract tracing in developing brains. Biocytin can be used to measure the biotinidase activity and therefore diagnose biotinidase deficiency.

MF63, a lead compound from a series of phenanthrene imidazole inhibitors made by Merck Frost, Quebec, Canada, with antipyretic and analgesic properties, is a candidate anti-inflammatory drug. MF63 is a selective inhibitor of mPGES-1 with high degree of selectivity over mPGES-2, PGI2, PGD2, and thromboxane (TX) synthases, Cox-1, Cox-2, 5-lipoxygenase, and various prostanoid and leukotriene receptors. It is a potent inhibitor of human (IC50 of 1.3 nM) and guinea pig (IC50 of 0.9 nM) mPGES-1, but displays little activity toward the rat or mouse enzyme. In a knock-in (KI) mouse, expressing human mPGES-1 and in guinea pig the compound selectively suppressed the synthesis of PGE(2), but not other prostaglandins inhibitable by nonsteroidal anti-inflammatory drugs (NSAIDs), yet retained NSAID-like efficacy at inhibiting lipopolysaccharide-induced pyresis, hyperalgesia, and iodoacetate-induced osteoarthritic pain. MF63 demonstrated effective relief of both pyresis and inflammatory pain in mice or nonhuman primates’ preclinical models of inflammation. In the guinea pig, MF63 strongly inhibited LPS-induced pyresis and hyperalgesia and relieved chronic osteoarthritic pain at 30–100 mg/kg. MF63 did not cause NSAID-like gastrointestinal toxic effects, such as mucosal erosions or leakage in mice.

Thiadiazole-pyridazine derivative MF-438 has been identified as a potent stearoyl-CoA desaturase 1 (SCD1) inhibitor. Recently it has been shown that the upregulation of lung-cancer stem cell (CSC) markers can be reverted with a combination of MF-438 and cisplatin. The combination of MF-438 and cisplatin strongly synergizes the inhibition of 3D spheroid formation and induces CSC apoptosis.

5,6-Dihydro-6-methyl-4h-thieno(2,3-b)thiopyran-4-ol 7,7-dioxide, (4S,6S)- is an intermediate for the synthesis of topically-active carbonic anhydrase inhibitor MK-0507.

L-760735 is a non-peptide substance P receptor (Neurokinin 1 (NK1) receptor) antagonist. It exerts anxiolytic, antidepressant and antinociceptive actions in animals. Merck was developing an L- 760735 as a potential antidepressant.

L-365,260 is an antagonist of gastrin and brain CCK-B receptor. In vivo, oral administration of L-365,260 antagonized gastrin-stimulated acid secretion. L-365,260 is used as a tool compound to investigate gastrin and brain CCK-B and their role in psysiology and disease. In a double-blind placebo-controlled study L-365,260 did not augment the analgesic effect of morphine in subjects with chronic neuropathic pain. Preclinical studies demonstrated modes activity of L-365,260 in models of anxiety and ulcers.

Rofecoxib is a nonsteroidal anti-inflammatory drug which selectively inhibits COX-2 and subsequent prostaglandin synthesis. The drug was developed by Merk and approved by FDA in 1999 for relief of signs and symptoms of arthritis, acute pain in adults, and painful menstrual cycles under the name Vioxx. Later on Merck voluntarily withdrawn Vioxx from the market due to safety concerns (high risk of heart attack and stroke).

Indinavir is an antiretroviral drug for the treatment of HIV infection. Indinavir is a protease inhibitor with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Protease inhibitors block the part of HIV called protease. HIV-1 protease is an enzyme required for the proteolytic cleavage of the viral polyprotein precursors into the individual functional proteins found in infectious HIV-1. Indinavir binds to the protease active site and inhibits the activity of the enzyme. This inhibition prevents cleavage of the viral polyproteins resulting in the formation of immature non-infectious viral particles. Protease inhibitors are almost always used in combination with at least two other anti-HIV drugs.

Aniledrine is a narcotic pain reliver. The drug was prescribed as an analgesic in anaesthesia (Leritine brand name), however, it is no longer available on the market. Although the exact mechanism is not fully understood, aniledrine appears to elicit its action by binding to endorphine receptors in CNS.

Methbarbital is a barbiturate anticonvulsant, discovered by Merck in 1905. It was introduced to market for treatment of epolepsy by Abbott in 1952, and discontinued in 1990.