NAG-thiazoline (NGT) and its derivatives are well-known inhibitors against most b-acetylglucosaminidases (b-GlcNAcases) except for insect and bacterial chitinolytic b-GlcNAcase. Among them, NGT was the only one specifically designed to be an analog of the oxazolinium reaction intermediate based on the substrate-assisted mechanism, an attractive starting point to develop potent inhibitors. It is a major building block for the synthesis of potential inhibitors of transglycosylases involved in bacterial cell wall biosynthesis.

Betiatide (CAS 103725-47-9; aka S-benzoylmercapto¬acetyltriglycine or 2-[[2-[[2-[(2-benzoylsulfanylacetyl)¬amino]¬acetyl]¬amino]¬acetyl]¬amino] acetic acid) is the API in TechneScan MAG3™; a kit for the preparation of technetium Tc 99m mertiatide. It is used in the diagnosis of congenital and acquired abnormalities, renal failure, urinary tract obstruction and calculi. Furthermore it is used in providing renal function, split function, renal angiograms and renogram curves for whole kidney and renal cortex. Betiatide is light sensitive and must be protected as such.

N-Acetyltyrosine is an acetylated derivative of the amino acid L-tyrosine. Ordinary L-tyrosine is less stable and also less soluble in water, which may result in reduced bioavailability. Acetylation enhances the solubility and stability of certain amino acids. N-Acetyltyrosine is commonly used in place of tyrosine in parenteral nutrition. It converts to tyrosine and then can be used in neurotransmitter treatment as a precursor of cathecholamine. N-Acetyltyrosine supports brain function by supporting the synthesis of the catecholamines norepinephrine and dopamine (neurotransmitters). N-Acetyltyrosine supplements are used to improve memory and cognitive performance in humans while they are experiencing psychological stress.

Taurine is a semi-essential amino acid and is not incorporated into proteins. Taurine is considered conditionally essential because it cannot be synthesized by infants younger than 4-6 weeks, and it may not be adequately synthesized in patients receiving long-term parenteral nutrition and patients with short-term hypermetabolic conditions. In mammalian tissues, taurine is ubiquitous and is the most abundant free amino acid in the heart, retina, skeletal muscle, brain, and leukocytes. Taurin occurs naturally in fish and meat. The mean daily intake from omnivore diets was determined to be around 58 mg. Taurine is a component of energy drinks, with many contain 1000 mg per serving. In medicine, taurine supplementation demonstrated efficacy in relieving symptoms of heart failure, hepatitis, hypertension and psychotic disorder. Taurine exerts many physiological functions, including membrane stabilization, osmoregulation and cytoprotective effects, antioxidant and anti-inflammatory actions as well as modulation of intracellular calcium concentration and ion channel function. In addition taurine may control muscle metabolism and gene expression, through yet unclear mechanisms. The cellular and biochemical mechanisms mediating the actions of taurine are not fully known.

Acetyltryptophan,DL- functions readily as a component of the food in place of the free amino acid - a greater amount of acetyltryptophane,DL- than dl-tryptophane may be available to man. Acetyltryptophan,DL- is used as an additive in the protein microbubbles, used in various biomedical applications such as contrast imaging, targeted drug and gene delivery, delivery of drugs through blood brain barrier (BBB) and IV O2 delivery etc. In the breast cancer biomarkers search, lower levels of endogenous metabolite Acetyltryptophan, DL- was identified in the fluid from the affected breasts compared to the control breast fluid.

Somatostatin (also known as growth hormone-inhibiting hormone) is a naturally-occurring peptide hormone that regulates the endocrine system. Somatostatin is produced in gastrointestinal (GI) tract, pancreas, hypothalamus, and central nervous system (CNS) and some other organs. Somatostatin is initially secreted as a 116 amino acid precursor, preprosomatostatin, which undergoes endoproteolytic cleavage to prosomastatin. Prosomastatin is further process into two active forms, shorter isoform somatostatin-14 works primarily in the brain, while the longer somatostatin-28 (SST-28) form operates in the GI tract. Somatostatin produces predominantly neuroendocrine inhibitory effects across multiple systems. It is known to inhibit GI, endocrine, exocrine, pancreatic, and pituitary secretions, as well as modify neurotransmission and memory formation in the CNS. Somatostatin binds to six different receptors in various systems and cells throughout the body to produce its regulatory effect. These receptors are specific to somatostatin and classify as G-protein coupled receptors (GPCR). Somatostatin half-life is between 1 to 3 minutes. Due to its short half-life, somatostatin has been formulated exogenously in much more stable forms with a longer half-life; this allows for its primary clinical use, which is the treatment of neuroendocrine tumors.

Acemetacin is a non-steroidal anti-inflammatory drug used for the treatment of osteoarthritis, rheumatoid arthritis, lower back pain, and relieving post-operative pain. It is manufactured by Merck KGaA under the tradename Emflex and is available in the UK as a prescription-only drug. Other brand names for acemetacin include Rheutrop (Austria), Acemetadoc, Acephlogont, Azeat, Rantudil (Germany, Hungary, Mexico, Portugal, Turkey), Gamespir (Greece), Oldan, Reudol (Spain), Tilur (Switzerland), Ost-map (Egypt). Acemetacin is a glycolic acid ester of indomethacin. The pharmacological activity resulting from acemetacin administration in man is derived from the presence of both acemetacin and indomethacin. The precise pharmacological mode of action of acemetacin is not known. However, unlike other NSAIDs, acemetacin is only a relatively weak inhibitor of prostaglandin synthetase. Prostaglandins are known to have an antisecretory and cytoprotective effect on the gastric mucosa. Acemetacin shows activity in many of the established in vitro tests of anti-inflammatory activity including inhibition of the release of a number of mediators of inflammation. Acemetacin is well absorbed after oral administration. Its major metabolite is indomethacin, which, after repeated administration is present at levels in excess of those of acemetacin. Acemetacin is bound to plasma protein to a slightly lesser extent than indomethacin and has a relatively short plasma elimination half-life. It is eliminated by both hepatic and renal mechanisms. The pharmacokinetics appear to be linear at recommended therapeutic doses, unaffected by moderate renal or hepatic impairment, and unchanged in the elderly.

Sitaxentan (TBC11251, trade name Thelin) is a potent and selective Endothelin A receptor antagonist. Sitaxentan was under development by Encysive Pharmaceuticals (now Pfizer) for use in the treatment of pulmonary hypertension, congestive heart failure and asthma. It was launched in the major markets of the European Union (EU) under name Thelin for the treatment of pulmonary arterial hypertension. In December 2010, Pfizer discontinued clinical trials of sitaxentan worldwide and initiated voluntary product withdrawal from markets where it is approved due to life-threatening idiosyncratic risk of liver injury.

Casopitant (GW679769) is a novel substituted piperidine derivative that competitively binds with NK1 receptors. The full occupancy of the receptor by their piperidine compound inhibits its binding with tachykinin neurotransmitters, including SP. Casopitant, in a series of in vitro and in vivo experimentations, has exhibited a potent NK1 receptor antagonism. On 29 May 2008, GlaxoSmithKline announced the submission of a new drug application to the FDA for intravenous and oral formulations of casopitant mesylate. This drug was proposed for the prevention of chemotherapy-induced nausea and vomiting as an add-on therapy to the standard dual therapy of 5-HT3 receptor antagonists + dexamethasone. The submission also included a proposed indication for postoperative nausea and vomiting prevention. Rezonic™ is the proposed trade name for casopitant mesylate in the United States; Zunrisa™ is the proposed trade name for casopitant mesylate for GlaxoSmithKline’s global group of companies. In September 2009, GlaxoSmithKline decided to discontinue all regulatory filings for casopitant based on an estimate of the amount of additional safety data.