Proton launching

AstraZeneca launched omeprazole in 1988. It is a safe and effective drug for acid reflux, functioning as a proton pump inhibitor. However, the patent has expired and AstraZeneca has to compete against generics. The company developed the active isomer and called it esomeprazole. It was approved by the Mutual Recognition process in Europe in July 2000, and by the US Food and Drug Administration in February 2001. The chemical formulas for omeprazole and esomeprazole are shown below. 

AstraZeneca (formerly Astra) has launched the proton-pump inhibitor esomeprazole (19) (as Nexium) as a treatment for peptic ulcer, gastroesophageal reflux disease, duodenal ulcer, and esophagitis. Esomeprazole is the (S)-enantiomer of omeprazole and was developed as a result of its improved pharmokinetic profile and better potency after oral dosing than (f )-form of omeprazole or the racemate. The dosage is higher than would be expected for a simple chiral switch. The stereogenic center is at sulfur. Detailed accounts of the development of the process have been published.189190... 

On January 19, 1923, an article by Thomas Martin Lowry (1874—1936) was pubhshed in the English journal Chemistry and Industry, in which the idea of proton transfer between acids and bases was launched. In spite of... 

Omeprazole (Prilosec, 21), the first H /K -ATPase inhibitor, also known as a proton pump inhibitor (PPI), was marketed as a treatment for gastric ulcers since 1988. It functions by preventing acid production in the mucosa. Omeprazole was the best-selling drug for several years until its patent expiration in 2001, at which time, esomeprazole (Nexium, 22), tihe (S)-enantiomer of racemic omeprazole (21), was launched. The mechanism of... 

The ISS program may well be the largest single international engineering project in history. It involves the direct participation of 16 nations, 88 launches (37 Shuttle, 9 Proton, 31 Progress, and 11 Soynz), and 160 space walks (over twice the total number of space walk hours completed by NASA since Ed White s initial walk in 1964). As of September 2000, the station consists of the Russian-built Zarya and Zvezda modules and the U.S.-built Unity Node. The station begins permanent operations with the arrival of the Expedition One crew in November 2000, and, once completed, will provide an unprecedented capability for cooperative international research—both pnblicly and privately fnnded. 

Type n aldolases are found predominantly in bacteria and fungi, and are Zn " -dependent enzymes (Scheme 2.182) [1378]. Their mechanism of action was recently affirmed to proceed through a metal-enolate [1379] an essential Zn " atom in the active site (coordinated by three nitrogen atoms of histidine residues [1380]) binds the donor via the hydroxyl and carbonyl groups. This facilitates pro-(/ )-proton abstraction from the donor (presumably by a glutamic acid residue acting as base), rendering an enolate, which launches a nucleophilic attack onto the aldehydic acceptor. 

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