CHEMICAL COMPOUNDS aspirin

The proportion of ionized and unionized forms of a chemical compound can be readily calculated according to the above equation. It can be easily seen that pK is also a pH value at which 50% of the compound exists in ionized form. The ionization of weak acids increases as the pH increases, whereas the ionization of weak bases increases when the pH decreases. As the proportion of an ionized chemical increases, the diffusion of the chemical through the biological membranes is greatly impaired, and this attenuates toxicokinetic processes. For example, the common drug acetosalicylic acid (aspirin), a weak acid, is readily absorbed from the stomach because most of its dose is in an unionized form at the acidic pH of the stomach. 

Two of the most important classes of chemical compounds are acids and bases. A small sampling of acids and bases found around the home demonstrates their importance in daily life. A few of these include fruit juice, aspirin, milk, ammonia, baking soda, vinegar, and soap. Beyond their presence in numerous household items, acids and bases are key ingredients in the chemical process industry. More sulfuric acid is produced than any other chemical in the United States with an annual production of 40 million tons. While the commercial applications of acids and bases illustrate their importance in everyday life, on a more fundamental level each one of us inherited our characteristics and genetic make-up through the acid DNA, deoxyribonucleic acid. 

Many of the fragrances and tastes from plants are due to esters. The smells we perceive are generally due to a combination of esters, but often one ester fragrance will dominant. By mimicking these natural esters, the food industry has synthesized hundreds of different flavoring agents. Three of these are shown in Figure 15.14. Many pheromones are esters. Pheromones are chemical compounds used by animals for communication. Many medications are also esters. Aspirin is an ester of salicylic acid (see Chapter 13). 

One of the early pain-relieving drugs, aspirin, was introduced in 1899 by Felix Hoffman, working for the German pharmaceutical firm Bayer. In 1898 Bayer also introduced heroin as a pain killer. Aspirin2-4 is a man-made synthetic chemical compound, acetylsalicylic acid. It is made from salicylic acid. The ancient Greeks and native South Americans, among others, found that the bark of the willow tree eased fever and pain. We now know that this is because the bark contains salicylic acid. Salicylic acid is bitter and irritates the stomach (see also Chapter 1). 

There are numerous decisions that hold product claims to chemical compounds as compositions of matter to be valid within the meaning of the patent statutes. With few exceptions there are no specific references to the rule that products of nature are unpatentable. The statements in the decisions are in sharp contrast with the thought that the rule was at all applicable. For example in the Kuehmsted case (tf), the pure chemical compound known generally as aspirin was held to be patentable because of its new utility. The court held that whatever may have been its antecedents chemically, aspirin in pure form was a new thing. The formerly known crude material was legally a different material in that it had no utility as a medicinal. The court held that aspirin was an article of manufacture within the meaning of the patent law. 

Willow bark has been a remedy for pain and fever for hundreds of years. In the late eighteenth century, scientists isolated the compound in willow bark that is responsible for its effects. They then converted it to a similar compound, salicylic acid, which is even more effective. In the late nineteenth century, a German chemist, Felix Hoffmann, did research to find a pain reliever that would help his father s arthritis, but not cause the nausea that is a side effect of salicylic acid. Because the technologies used to synthesize chemicals had improved, he had a number of more effective ways to work with chemical compounds than the earlier chemists. The compound that he made, acetylsalicylic acid, is known as aspirin. It is still one of the most common pain relievers more than 100 years later. 

In 1874, British chemist Alder Wright published reports of experiments that produced a new chemical compound based on an alteration of morphine diacetylmorphine. Wright s discovery went unnoticed until 1898, when the great German pharmacologist Heinrich Dreser (who also discovered aspirin see Chapter 14) rediscovered the compound and noted that it was twice as potent as morphine. Because this new compound was so powerful, it was viewed as a new treatment with heroic possibilities and was christened heroin. Heroin was used immediately as a cough suppressant and pain reliever. Not until many years later was it recognized that heroin was even more likely than morphine to produce dependence. 

Hippocrates, the father of modern medicine, who lived sometime between 460 and 377 bce, left historical records of a powder made from the bark and leaves of the willow tree. He used this powder to relieve headaches and other pains. Native Americans also recognized the medical properties of the willow tree they chewed the willow s leaves and inner bark or boiled a tea made from them to relieve fever or other minor pain like toothaches, headaches, or arthritis. By 1829, scientists discovered that it was the compound called salicin in willow plants that provided the pain relief.A German company called Bayer patented aspirin on March 6, 1889.The folks at Bayer came up with the name aspirin, using the a in acetyl chloride (the chemical compound contained in salicin), the spir in spiraea ulmaria (the genus of plant containing this compound) and in, which was a then familiar name ending for medicines. Aspirin was first sold as a powder, but in 1915, the first aspirin tablets were made. 

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. 

The primary eUtil tools of most interest to PubChem users are eSearch, eFetch, ePost, eLink, eHistory, and einfo. eSearch performs an Entrez search, with the same query syntax as web-based Entrez queries (e.g., to query PubChem Compound for the chemical name "aspirin"). eFetch returns an ID list from a prior search (e.g., the list of PubChem Compound identifiers (CIDs) from the aforementioned query of "aspirin"). ePost creates a new ID list by upload of a list of identifiers (e.g., substance identifiers (SIDs)). eLink follows a given link type to create a new ID list from an existing one (e.g., to find all PubChem BioAssay identifiers (AIDs) associated with a list of SIDs). eHistory returns information on current Entrez History entries, einfo lists available Entrez indices and links for a given database. 

As early as the fifth century b.c., it was known that chewing willow bark could relieve pain. But it wasn t until 1860 that the chemical compound responsible for the analgesic effect, salicylic acid, was isolated. It had a very sour taste and caused irritation of the stomach. In 1875, chemists created sodium salicylate. It caused stomach irritation, but it was less bitter than the salicylic acid. Finally, in 1899, the German Bayer Company began marketing acetylsali-cylic acid, made by reacting salicylic acid with acetic anhydride, under the trade name of aspirin. Figure 17-9 traces the history of aspirin. 

Water, ammonia, carbon monoxide, and carbon dioxide—all familiar substances—are rather simple chemical compounds. Only slightly less familiar are sucrose (cane sugar), acetylsalicylic acid (aspirin), and ascorbic acid (vitamin C). They too are chemical compounds. In fact, the study of chemistry is mostly about chemical compounds, and, in this chapter, we will consider a number of ideas about compounds. 

There are several hundred reported NF-kB inhibitors (see www.nf-kb.org for a complete and updated list). These inhibitors include natural products, chemicals, metabolites, and synthetic compounds. A large majority of these products, in particular commonly used antiinflammatory drugs such as corticosteroids and the nonsteroidal antiinflammatory drugs (NSADDs) aspirin, sulindac, ibuprofen and sulphasalazine, have the ability to partially inhibit NF-kB activity in cell culture. However, the precise mechanism of action and the specific molecular targets of most of these inhibitors remain unclear. 

Dedicated plants predominate in the bulk chemicals industry. They suit the manufacture of well-defined products using a determined technology. Any change of the product or the production process usually produces problems, which illustrates the inflexibility of a dedicated plant. A batch plant may also be operated as a dedicated plant to produce a single chemical. Some fermentation plants (with reactors of up to 200 m volume) are examples of dedicated batch plants for the production of a family of similar products. So-called bulk fine chemicals, i.e. compounds that are produced in larger quantities, are also manufactured in dedicated plants, e.g. vitamin C and aspirin (see Fig. 7.1-1). The va.st majority of batch plants, however, produce several chemicals. 

A simple compound to begin our presentation is acetylsalicylic acid (aspirin, 7.44), the well-known analgesic and anti-inflammatory drug whose primary metabolite, salicylic acid (7.45), is also an anti-inflammatory agent but not an analgesic. Extensive kinetic data have been published on the chemical hydrolysis of acetylsalicylic acid as a function of temperature and... 

Most of the NSAIDs are organic acids but they form a heterogeneous group of compounds with few further chemical relationships. At least 10 different groups can be distinguished. Some of the most frequently used groups are listed in Table 3. The prototype is aspirin and therefore the term aspirin-like drugs is frequently used. 

Rx Butalbital/aspirin/caffeine Butalgen, Fiorinal, Fiorgen, Fiormor, Fortabs, Iso-butal. Isobutyl, Isolin, Isollyl, Laniroif, Lanorinal, Marnal, Tecnal, Virbutal Rx Butalbital/aspirin/caffeine wifh codeine Ascomp with Codeine No3, Butalbital Compound with Codeine, Butinal with Codeine NoB, Fiorinal with Codeine NoB, Idenal with Codeine, Isollyl with Codeine Chemical Class Barbituric acid derivative... 

Was this your answer No. Although benzene and aspirin both contain a benzene ring, these two molecules have different overall structures, which means the properties of one are quite different from the properties of the other. Each carbon-containing organic compound has its own set of unique physical, chemical, and biological properties. While benzene may cause cancer, aspirin is a safe remedy for headaches. 

Carboxylic acids, compounds of the type RCOH, constitute one of the most frequently encountered classes of organic compounds. Countless natural products are carboxylic acids or are derived from them. Some carboxylic acids, such as acetic acid, have been known for centuries. Others, such as the prostaglandins, which are powerful regulators of numerous biological processes, remained unknown until relatively recently. Still others, aspirin for example, are the products of chemical synthesis. The therapeutic effects of aspirin, welcomed long before the discovery of prostaglandins, are now understood to result from aspirin s ability to inhibit the biosynthesis of prostaglandins. 

---