Epinephrine chemical structure

FIG. 17 Chemical structures of (a) epinephrine hydrochloride, (b) dopamine hydrochloride, (c) isoproterenol hydrochloride, (d) phenylephrine hydrochloride, (e) tolazoline hydrochloride, (f) oxyprenolol hydrochloride, (g) alprenolol hydrochloride, and (h) propranolol hydrochloride. 

In terms of chemical structure, amphetamines are very close to epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine, differing in the absence of a hydroxyl group in the aromatic ring and in the aliphatic chain. 

The adrenomimetic drugs can be divided into two major groups on the basis of their chemical structure the catecholamines and the noncatecholamines. The catecholamines include norepinephrine, epinephrine, and dopamine, all of which are naturally occurring, and several synthetic substances, the most important of which is isoproterenol (isopropyl norepinephrine). The skele-... 

Fig. 2. Chemical structure of the endogenous catecholamines, epinephrine (8), and norepinephrine (7), and several synthetic phenethanolamines that alter...

This alkaloid was first isolated from Ephedra equisetina, a plant (ma huang) that has been used as medicine by the Chinese since antiquity. Most of the present supply is probably synthetic. Its chemical structure is closely related to epinephrine and tyramine, and differs from epinephrine chiefly by the absence of the two phenolic hydroxyls. Its effects on the circulation, intestines, bronchi, iris, etc., are superficially similar to those of epinephrine. It requires that larger doses be given but they are more lasting, due probably to ephedrine s much greater stability and resistance to oxidation. The effects can be produced by oral administration. Unlike epinephrine, it is not sensitized by cocaine or by denervation. From this, it has been argued that its point of attack is not sympathomimetic but muscular. It also stimulates the CNS. A number of isomers with similar actions are known. Ephedrine is used therapeutically in hay fever and asthma, in which it is less... 

Monoamine oxidases (MAO-A and MAO-B) are mitochondrial enzymes that oxidatively deaminate endogenous biogenic amine neurotransmitters such as dopamine, serotonin, norepinephrine, and epinephrine. MAOs are like EMOs in that they catalyze the oxidation of drugs to produce drug metabolites that are identical in chemical structures to those formed by CYPs. Because the resulting structures are... 

Fig. 1. Chemical structure of (-)-epinephrine. Individual moieties, including the meta- and para-hydroxyls, catechol ring, protonated amine, alcoholic chiral p-carbon hydroxyl, and A-methyl group are indicated.

Hormones are transported from the sites of their synthesis to the sites of action by the bloodstream (Figure 24.5). In terms of their chemical structure, some typical hormones are steroids, such as estrogens, androgens, and mineralocorticoids (Section 21.8) polypeptides, such as insulin and endorphins (Section 3.5) and amino acid derivatives, such as epinephrine and norepinephrine (Table 24.3). 

In 1914, the major hormone of the thyroid gland, thyroxine, was isolated by Henry S. Plummer (1874-1936) of the Mayo Clinic. This was the second hormone to be isolated pure (adrenalin or epinephrine was isolated in 1901). Thyroxin-containing extracts, as well as the crystalline material, were successful in treatments of Graves disease ( goiter ). The chemical structure of thyroxin would be reported in 1926. 

Adrenoceptors interact not only with norepinephrine but also with the adrenal medullary hormone epinephrine and a number of chemically related drugs. However, the responses produced by the drugs in different autonomic structures differ quantitatively or qualitatively from one another. 

In ophthalmic research, a prodrug is designed to be inactive with some degree of biphasic solubility as the cornea is a biphasic tissue in structure. It will be transformed into the active drug by either an enzymatic or a chemical processes in the eye. Dipivefrin is an epinephrine prodrug. Due to its increased lipophilicity,... 

It had been recognized early on (71) that there were similarities between the effects of administration adrenal gland extracts and stimulation of the sympathetic nervous system. Elliot (72) suggested that adrenaline might be released by sympathetic nerve stimulation and over the years the term adrenergic nerves became effectively synonymous with sympathetic nerves. In 1910 Barger and Dale (73) reported a detailed structure-activity relationship study of epinephrine analogs and introduced the term sympathomimetic for chemicals that mimicked the effects of sympathetic nerve stimulation, but they also noted some important differences between the effects of administered adrenaline and stimulation of sympathetic nerves. It was not until... 

Norepinephrine and epinephrine are members of a class of pharmacologically active substances known as catecholamines, because they contain within their structures both an amine and ortho-dihydroxybenzene, which is known by the common chemical name of catechol. Many adrenergic drugs also are catecholamines, and their structure-activity-relationships (SARs) will be discussed. 

I mentioned that the hallucinogen mescaline looks very similar to the neurotransmitters in Scheme 1.2. There are many other drugs that have similar structures to PEA or epinephrine or norepinephrine, all containing the six-membered ring called phenyl, a variable short chain of carbon atoms, and an aminic tail. The small differences between all these molecules translate to significant differences in their function compared with that of the brain chemicals. Let me give just three examples, which one can pick up easily from the Web. ... 

Neurotransmitters are compounds which are stirred in nerve terminals and which are secreted by these neurons to relate information from one neuron to another neuron. The structures of several well identified neurotransmitters are given in Figure 2. As recognized by Ralph Adams in the early 1970 s, dopamine, serotonin, norepinephrine, and epinephrine are of particular interest from an electrochemical point of view because they are easily oxidized and, thus, can be detected by the amperometric and voltammetric techniques[20]. It also turns out that these chemicals are of particular importance in normal neuronal function. For example, serotonin is thought to be important in the regulation of sleep mechanisms. Dopamine is thought to be important in the regulation of motor function as well as the control of mood and emotion[21]. Therefore, it would be desirable to measure the concentration of these species in extracellular fluid and relate this to neuronal activity. 

A significant contribution to the understanding to the mechanism of hormone action was made by the American biochemist Earl Wilbur Sutherland (1915-1973) through his study of cyclic AMP cyclic adenosine monophosphate). While he was investigating the effect of the hormone epinephrine on liver and muscle cells he found a new chemical substance that acts as an intermediate between the hormone and the cell, transmitting the message from the hormone to the machinery of the cell. He called it a second messenger. He identified the substance as cyclic AMP, with the structure... 

Ephedrine is an alkaloid, a sympathomimetic amine with molecular formula Cjo Hi5 NOi, a molecular mass of 165.2, and the stmctural name (IR, 25)-2-methylamino-l-phenylpropan-l-ol. This bitter colorless or white solid-crystal is completely soluble in water, alcohol, chloroform, ether, and glycerol. Ephedrine is also produced by chemical synthesis and there is significant documentation of commercial ephedrine production using microbial biotransformation techniques [42]. Ephedrine has a structure close to methamphetamines, and its stimulant actions are comparable to epinephrine (adrenaline), a hormone produces by the adrenal glands that enhances heart rate and constriction of blood vessels in high-stress situations. Medicinal use of ephedrine began around 3000 B.C with the Chinese from md hudng, but its isolation was first reported in 1855 and its pharmaceutical application started in 1930 [22]. Studies on ephedrine s molecular structure show that two asynunetric carbon atoms are involved in ephedrine s molecular skeleton therefore, four optically active stereoisomers forms naturally occur as follows (IR, 2S)-(—)-ephedrine, (IS, 2R)-(+)-ephedrine, (IR, 2R)-( )-pseudoephedrine, (IS, 2S)-(+)-pseudoephedrine (Fig. 27.2). 

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