Aspirin structure

A second and even more common type of toxicity reflects that of unwanted side-effects where the loci for the observed toxicity is at some other biological surface than that of the targeted therapeutic site. An example of this type of toxicity can be found in aspirin (structure 11 in Figure 19.10), which long has been used to treat headache, fever, and several other shortterm maladies without significant incidence of side... 

Fig. 1.2 JChemPaint graphical user interface displaying aspirin structure...

FIGURE 25.29 (a) The structures of several commou analgesic agents. Acetaminophen is marketed under the tradename Tylenol. Ibuprofen is sold as Motrin, Nuprin, and Advil, (b) Acetylsalicylate (aspirin) inhibits the cyclooxygenase activity of endoperoxide synthase via acetylation (covalent modification) of Ser ... 

In this bromoaspirin-inactivated structure, Ser , which lies along the wall of the tunnel, is bromoacetylated, and a molecule of salicylate is also bound in the tunnel. Deep in the tunnel, at the far end, lies Tyr, a catalytically important residue. Heme-dependent peroxidase activity is implicated in the formation of a proposed Tyr radical, which is required for cyclooxygenase activity. Aspirin and other NSAIDs block the synthesis of prostaglandins by filling and blocking the tunnel, preventing the migration of arachidonic acid to Tyr in the active site at the back of the tunnel. 

The acid itself (or the sodium salt) is a valuable drug in the treatment of arthritis. But the most widely known derivative of salicylic acid is aspirin, which has ihe following structure ... 

You will see, by examining this structure, that aspirin is an ester of acetic acid. Aspirin is mankind s most widely used drug. Somewhat over 20 million pounds of aspirin are manufactured each year in the United States alone This amounts to something like ISO five-grain tablets for every person in the country ... 

NSAIDs are of diverse chemical structures salicylates (aspirin, sulphasalazine), indole acetic acids (indomethacin, etodolac), heteroaryl acetic acids (diclofenac), arylpropionic acids (ibuprofen, naproxen), anthranilic acids (mefenamic acid) and enolic acids (piroxicam, meloxicam). 

A non-allergic mechanism imderlying precipitation of asthmatic attacks by aspirin in hypersensitive patients was proposed over 30 years ago [4]. It was founded on pharmacological inhibition of COX of arachidonic acid and explained a cross-reactivity between different NSAIDs varying in chemical structure. This COX theory was confirmed by several studies [11] and was further refined following discovery of the second COX isoenzyme - COX-2. At least two COX isoenzymes, COX-1 and COX-2, are coded by separate genes. Their role in inflammation, asthma and anaphylaxis has been reviewed previously [12]. 

Observing and Inferring What structural shape do aspirin, acetaminophen, and ibuprofen have in common ... 

Collecting and Interpreting Data Compare the appearance of the drawn structure of aspirin with the model. 

Predicting Predict the possibility of other medicines that might have the same common structural shape as aspirin, acetaminophen, and ibuprofen. 

Loll P. J., Picot D., Garavito M. The structured basis of aspirin activity inferred from the crystal structure of inactivated prostaglandin H2 synthase. Nature Struct Biol 1995 2,637-43. 

This example will illustrate the quantitative analysis of aspirin (acetylsalicylic acid), phenacetin and caffeine in a mixture. The structures of these three are shown in Fig. 4.4a. 

Figure 9.1.3 The molecular structure of aspirin or acetylsalicylic acid.

Figure 13.4.4 The molecular structure of aspirin, acetylsalicylic acid.

FIGURE 29.21 Structures of lactate, aspirin, L-arginine, and taurine. 

Keywords Quantum chemical calculations, Aspirin, Paracetamol, Electronic structure, Net atomic charges, Bond length, Dipole moment. 

Fig. land Fig.2 are the optimized structure of Aspirin and Paracetamol with DFT/6-3 lG(d)... 

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