Urocanic acid is a breakdown (deamination) product of histidine. In the liver, urocanic acid is an intermediate in the conversion of histidine to glutamic acid, whereas in the epidermis, it accumulates and may be both a UV protectant and an immunoregulator. Urocanic acid (UA) exists as a trans isomer (t-UA, approximately 30 mg/cm2) in the uppermost layer of the skin (stratum corneum). t-UA is formed as the cells of the second layer of skin become metabolically inactive. During this process, proteins and membranes degrade, histidine is released, and histidase (histidine ammonia lyase) catalyzes the deamination of histidine to form t-UA. t-UA accumulates in the epidermis until removal by either the monthly skin renewal cycle or sweat. Upon absorption of UV light, the naturally occurring t-UA isomerizes to its cis form, c-UA. Because DNA lesions (e. g. , pyrimidine dimers) in the lower epidermis can result from UV-B absorption, initial research proposed that t-UA acted as a natural sunscreen absorbing UV-B in the stratum corneum before the damaging rays could penetrate into lower epidermal zones. c-UA also suppresses contact hypersensitivity and delayed hypersensitivity, reduces the Langerhans cell count in the epidermis, prolongs skin-graft survival time, and affects natural killer cell activity. It has also been proposed that c-UA may mediate the transient alteration in immune surveillance resulting in immunosuppression induced after UV-irradiation, by interacting with immune cells locally and/or systemically to generate T cells with suppressor function.

Trigonellamide (1-Methylnicotinamide) is a metabolite of nicotinamide and is produced primarily in the liver by nicotinamide N-methyltransferase. Trigonellamide may be an endogenous activator of prostacyclin (PGI2) production and thus may regulate thrombotic as well as inflammatory processes in the cardiovascular system. The mechanisms of action of Trigonellamide involve the activation of PGI2 release driven by cyclooxygenase 2 (COX-2). PGI2 releasing capacity of 1- Trigonellamide was shown to afford not only anti-thrombotic but also fibrinolytic, anti-inflammatory and gastroprotective effects. Interestingly, Trigonellamide did not directly either affect the activity of leucocytes or release PGI2 in the perfused rat hindquarters model. Still, Trigonellamide, due to its PGI2 releasing capacity, might serve as a hepatoprotective agent that protects against Concanavalin-A induced liver injury through the downregulation of interleukin-4 (IL-4) and tumor necrosis factor-α signalization (TNF-α). In addition to its anti-platelet, anti-thrombotic and anti-inflammatory activities, 1-MNA has also been shown to restore endothelial function in diabetic hyperglycemic rats, as well as to improve endothelial function in humans. PGI2 displays anti-metastatic activity, and the PGI2 releasing activity of Trigonellamide, the potential application of exogenous Trigonellamide to prevent metastatic cancer.

Methylenedioxymethamphetamine (or 3,4-methylenedioxymethamphetamine (MDMA)), a synthetic, psychoactive drug also known as ecstasy that was used as a recreational drug. This drug acts as both a stimulant and psychedelic and exerts its effects in the brain on neurons that use the chemicals serotonin, dopamine and norepinephrine to communicate with other neurons. In spite of the presence of this compound in the List of control and forbidden compounds, it was studied in psychotherapy for patients with chronic, treatment-resistant posttraumatic stress disorder. Initial results showed efficacy for the treatment approach, although further studies are needed.

Declopramide is an apoptosis inducer. Also, it inhibits NFkappaB activation by inhibition of IkappaBbeta breakdown. In preclinical research, Declopramide demonstrated strong antitumor properties. It had been in phase II clinical trials for the treatment of colorectal cancer. However, this research has been discontinued.

MK-0941 is selective, allosteric glucokinase activator (GKA) that activates glucokinase (hexokinase subtype IV) with greater selectivity than over different hexokinase isoforms. In chronic oral toxicity studies in animals with MK-0941, cataracts were observed in rats and dogs at drug exposures of 3 and 1.5 times, respectively, the maximum predicted human exposure based on doses planned for further clinical development. No cataracts were observed in either species at drug exposures equal to the maximum predicted human exposure. In patients receiving stable-dose insulin glargine, the glucokinase activator MK-0941 led to improvements in glycemic control that were not sustained. MK-0941 was associated with an increased incidence of hypoglycemia and elevations in triglycerides and blood pressure.

Icomucret (15(S)-HETE) is an hydroxyeicosatetraenoic acid developed by Alcon Research, Ltd for treatment Ophthalmic Disorders. In vitro Icomucret has been shown to inhibit LTB4 formation, 12-HETE formation and specifically inhibits the neutrophil chemotactic effect of LTB4. The inhibition of LTB4 formation is probably due to modulation of the 5- lipoxygenase (LO) because no changes in PGE2 formation have been determined. In vivo, Icomucret inhibits LTB4-induced erythema and edema, and reduces LTB4 in the synovial fluid of carragheenan-induced experimental arthritis in dogs. Icomucret has also some immunomodulatory effects. It inhibits the mixed lymphocyte reaction, induces generation of murine cytotoxic suppressor T cells, and it decreases interferon production by murine lymphoma cells. Furthermore, IL-4 and IL-13 have recently been shown to be potent activators of the 15-LO in mononuclear cells. Icomucret induces the secretion of membrane-bound mucins from human conjunctival and corneal epithelial cells. Icomucret was evaluated in clinical trials for Dry Eye Syndrome treatment. However from 2007 no future development reported, and Icomucret development sims to be discontinued.

Alitame [l-α-aspartyl-N-(2,2,4,4-tetramethyl-3-thioethanyl)-d-alaninamide] is an amino acid-based sweetener developed by Pfizer Central Research from l-aspartic acid, d-alanine, and 2,2,4,4-tetraethylthioethanyl amine. A terminal amide group instead of the methyl ester constituent of aspartame was used to improve the hydrolytic stability. The incorporation of d-alanine as a second amino acid in place of l-phenylalanine has resulted in optimum sweetness. The increased steric and lipophilic bulk on a small ring with a sulfur derivative has provided a very sweet product and good taste qualities. Alitame is noncariogenic. From an oral intake, 7–22% is unabsorbed and excreted in the feces. The remainder is hydrolyzed to aspartic acid and alanine amide. The aspartic acid is normally metabolized, and the alanine amide is excreted in the urine as a sulfoxide isomer, sulfone, or conjugated with glucuronic acid. U.S. Food and Drug Administration has approved alitame for use as per acceptable daily intake (ADI) value.

Swainsonine is an indolizidine alkaloid found in Australian Swainsona canescens, North American plants of the genera Astragalus and Oxytropis and also in the fungus Rhizoctonia leguminocola. It is competitive inhibitor of Golgi alpha-mannosidase II and lysosomal alpha-mannosidases. This compound has been reported to be a potent antiproliferative and immunomodulatory agent. However, no evidence of anti-tumor activity of swainsonine was seen in phase II clinical trial, in patients with locally advanced or metastatic renal cell carcinoma. Adverse events such as fatigue, nausea and diarrhea were common but generally mild. Swainsonine is locoweed toxin. Locoweed poisoning is seen throughout the world and annually costs the livestock industry millions of dollars. Swainsonine inhibits lysosomal alpha-mannosidase and Golgi mannosidase II. Poisoned animals are lethargic, anorexic, emaciated, and have neurologic signs that range from subtle apprehension to seizures.

Mafosfamide is a synthetic oxazaphosphorine derivative with antineoplastic properties. Mafosfamide alkylates DNA, forming DNA cross-links and inhibiting DNA synthesis. The effects of mafosfamide on various types of cancer cells were determined during preclinical investigations and clinical trials. Its development has been discontinued.

LAROTAXEL is a taxoid with potential antineoplastic activity. It prevents microtubule depolymerization, thereby inhibiting cell proliferation. It displays a broad spectrum of antitumor activity in vitro and in vivo, including activity against P-glycoprotein expressing tumors. LAROTAXEL was in phase III clinical trials for the treatment of breast cancer, pancreatic cancer, and bladder cancer. However, its development was discontinued.