Aspirin, chemical structure

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]. 

If youve got a headache by now, you might take some acetyl salicylic acid. Thats aspirin, and it has the chemical structure ... 

Benorylate (315) [4 -(acetamido)phenyl-2-acetoxybenzoate] is another example. It is the ester between two well-known antiinflamatory drugs, aspirin and paracetamol, and is employed in rheumatoid arthritis therapy. In view of the chemical structure with three photolabile groups (two esters and one amide), its possible phototoxicity has been investigated. From the preparative irradiations, it has been concluded that the PFR takes place with breaking of the central C—O bond to yield 5-acetamido-2 -acetoxy-2-hydroxybenzophenone (316). This product undergoes transacetylation to 5 -acetamido-2 -acetoxy-2-hydroxy-benzophenone (318) (Scheme 80) [300]. 

Oxycodone is available alone or in combination with either acetaminophen or aspirin. Its chemical structure is most closely related to codeine, but it has strong painkilling effects equal to those of morphine. 

Figure 2.2 The chemical structure of aspirin (acetylsalicylic acid) is shown here.

In 1859, a chemist named Herman Kolbe identified the chemical structure of the compound that made willow hark an effective herbal medicine. Unfortunately, many people who took the medicine suffered upset stomachs from it. One such person was the father of a chemist named Felix Hoffman. To help his father, Hoffman changed the compound in such a way that it eased his father s arthritis without irritating his stomach. The new compound was acetyl-sahcyhc acid, now known as aspirin. 

Chemical compound entity extraction is a different type of entity extraction. One cannot refer to a complete dictionary or thesaurus of chemical compound names, as there is practically an infinite number of compound names. Systematic names, such as the International Union of Pure and Applied Chemistry (IUPAC) nomenclature system [54], are created from a set of rules that determine the name of a chemical compound based on the chemical structure. As an example we show aspirin, which has the common chemical name acetyl salicylic acid and the IUPAC name 2-acetyloxybenzoic acid. The common names, including aspirin, can be found using a thesaurus-based approach with low levels of ambiguity. The IUPAC name is a systematically determined name that must be tagged in the text using a heuristics-based approach (rules based). In many cases, one will have only the IUPAC name, not a known common name, for a compound. 

AH and B are the unionized acid and base, respectively, and A" and BH+ are the ionized forms. The lipid solubility of AH and B are dependent on the chemical structure of the drugs. In most instances, they are of sufficient solubility to diffuse across the cell membranes. However, as the equations show, the pH environment affects the ionization of a drug. We illustrate this with aspirin (a weak acid drug, pKa = 3.5) as an example and apply Equation (4) ... 

Aspirin and NSAIDs inhibit the COX enzymes and prostaglandin production they do not inhibit the lipoxygenase pathways of AA metabolism and hence do not suppress LT formation (see Chapter 25). Table 26-1 provides a classification of NSAIDs and other analgesic and antipyretic agents based on their chemical structures. 

Figure 2. Chemical structures of aspirin 5 and the sulfadimidine-anthranilic acid co-crystal 6.

Sarah informs her customer that aspirin is acetylsali-cylic acid and has the chemical formula, C9H8O4. Aspirin is a molecular compound, often referred to as an organic molecule because it contains the nonmetals carbon (C), hydrogen (H), and oxygen (0). Sarah shows her customer the chemical structure of aspirin, and explains that aspirin is used to relieve minor pains, to reduce inflammation and fever, and to slow blood clotting. Some potential side effects of aspirin may include heartburn, upset stomach, nausea, and an increased risk of a stomach ulcer. 

The most prominent NS AID is aspirin. Nonaspirin NSAIDs can be classified based on the chemical structure as follows ... 

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