Sympathomimetics chemical structures

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... 

As an example I cite our early searches on the chemical structure properties indole and ethyiamine and the medical use properties sympathomimetic and parasympathomimetic 8). These searches revealed two sets ot intersecting hyperspace axes. One ot these intersections contains compounds with ethyiamine structures (Property A in Table IV) which have the medical use property sympathomimetic the other cluster indicates organic ammonium ions... 

Chemical/Pharmaceutical/Other Class A synthetic sympathomimetic drug structurally related to ephedrine and amphetamine... 

Chemical/Pharmaceutical/Other Class Speed generally contains one or more agents belonging to the drug class of sympathomimetics Chemical Formulas C10H15NO (Ephedrine) C9H13NO (Synephrine) C8H10N4O2 (Caffeine) Chemical Structures ... 

Figure 34-19 Chemical structure of sympathomimetic amines. Ephedrine and pseudoephedrine are diastereoisomers.

Chemical Structures and Main Clinical Uses of Important Sympathomimetic Drugs ... 

Many sympathomimetics have strong excitatory effects on the central nervous system. These are mostly synthetic compounds and include amphetamines. The chemical structures and abusive potential of amphetamines are discussed separately in the following section. 

They examined the adrenaline-like effect of a large number of compounds, and they found, on the whole, that approximation to adrenaline in the chemical structure is linked with an increase and a sharper specificity of the action. Barger and Dale introduced the term sympathomimetic, which means that the effects produced resemble those obtained by stimulation of the so-called sympathetic system of nerves. The study of the sympathomimetic amines represents one of the earliest and most successful attempts to correlate pharmacological action with chemical structure. The sympathomimetic action includes rise of arterial blood pressure, stimulation of the heart muscle, constriction of the arterioles and either stimulation or inhibition of smooth muscle. Some of the drugs also stimulate the central nervous system. 

When Barger and Dale (1910) prepared a long series of amines and investigated their actions in whole mammals or isolated tissues, they were able to deduce some relation between chemical structure and sympathomimetic activity. Other series of analogues related to noradrenaline are blocking agents because their structure allows them to flrmly occupy for a long time the specific receptors for this transmitter (see p. 401). 

Phentolamine is also a derivative of imidazoline that exhibits a direct a-adrenoblocking, muscle-relaxant effect on smooth muscle as well as cholinomimetic, histamine, and sympathomimetic effects. The chemical variation of its stmcture permits a few of its properties to be more expressed. For example, the aforementioned tolazoline, 2-benzyl-2-imidazoline, a structural analog of phentolamine, has more of an expressed muscle-relaxant effect on smooth muscle than an a-adrenoblocking effect. 

Therapeutic Function Hemostatic, Sympathomimetic, Vasoconstrictor Chemical Name Ethanone, l-(3,4-dihydroxyphenyl)-2-(methylamino)-Common Name Adrenalone Adrenone Structural Formula ( ... 

Therapeutic Function Sympathomimetic Bronchodilator Chemical Name Benzenemethanol, a-(l-(methylamino)ethyl)-, (R-(R, S ))-Common Name Efedrin Ephedrine Structural Formula ... 

PS,PS)-2-Phenyl-2-(piperidin-2-yl)acetic acid methyl ester (INN methyl-phenidate) is a centrally acting sympathomimetic used in the treatment of attention-deficit/hyperactivity disorder in children. Dexmethylphenidate is the pure (and significantly more active) enantiomer with the R,R configuration available in the USA. The diastereomeric racemate with the RS,SR configuration whilst a commercially available chemical is not used as a pharmaceutical. (Note the small structural difference between these compounds and levofacetoperane, question 149). 

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... 

Give the structure, chemical name and uses of of any three important sympathomimetic drugs and discuss the synthesis of one such compoimd selected by you. 

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). 

Indeed, PDC catalyzes mainly the reaction of pyruvate with benzaldehyde for the formation of (R)-PAC 27. This C—C bond formation, a two-carbon unit elongation, is coupled to the concomitant decarboxylation of pyruvate 26. This reaction is industrially developed for the synthesis of (—)-ephedrine by adding a second step, a reductive amination. Ephedrine (marketed by Merck especially) is a sympathomimetic amine commonly used as a stimulant, appetite suppressant, concentration aid, and decongestant, and it is used to treat hypotension associated with anesthesia. It is similar in structure to the (semisynthetic) derivatives amphetamine and meth-amphetamine. Chemically, it is an alkaloid derived from various plants in the genus Ephedra (family Ephedra-ceae). It works mainly by increasing the activity of noradrenaline on adrenergic receptors. ... 

---