Decongestant, ephedrine ephedra

Many alkaloids have pronounced biological properties, and a substantial number of the pharmaceutical agents used today are derived from naturally occurring amines. As a few examples, morphine, an analgesic agent, is obtained from the opium poppy Papaver somnifemm. Cocaine, both an anesthetic and a central nervous system stimulant, is obtained front the coca bush Erythroxylon coca, endemic to upland rain forest areas of Colombia, Ecuador, Peru, Bolivia, and western Brazil. Reserpine, a tranquilizer and antihypertensive, comes from powdered roots of the semitropical plant Rauwolfia serpentina. Ephedrine, a bronchodilator and decongestant, is obtained front the Chinese plant Ephedra sinica. 

Ephedrine and pseudoephediine are a vasodilator and decongestant respectively used widely in the treatment of asthma and the symptoms of colds and influenza. These pharmaceuticals were derived originally fi om the plant Ephedra sinica and used in traditional Chinese medicinal preparations. Although some are still produced fi om such sources, the major production is via a fermentation process followed by a chemical catalytic reaction. As shown in Figure 1, the intermediate / -phenylacetylcarbinol (PAC) is produced by decarboxylation of pyruvate followed by ligation to benzaldehyde. 

Ephedrine is the main alkaloid produced in the roots of Ephedra sinica, preparations of which have found medical application in China for at least 5000 years. It was first purified from its natural source in 1887, and its chemical synthesis was achieved in 1927. It was initially used in cardiovascular medicine, but subsequently found wider application in the treatment of mild hayfever and asthma. It is also used as a nasal decongestant and cough suppressant. 

Ephedrine is found in the ephedra plant (Ephedra sinica— the Chinese herb Ma Huang). It is used as a nasal decongestant... 

N.A. Ephedra nevadensis Wats. Pseudoephedrine, 1-ephedrine, d-pseudoephedrine.100 A decongestant and asthma remedy, for hypertension, hay fever. 

Ephedrine is a component of the traditional Chinese remedy Ma Huang, extracted from Ephedra species, it is also used in nasal sprays as a decongestant. Pseudoephedrine is the active component of the decongestant Sudafed (so should that be Pseudephed ). 

Ephedrine and pseudoephedrine Sympathomimetic/decongestant Ephedra sinica Mahuang... 

Speed is the nomenclature used for a number of preparations that resemble and are often misrepresented as prescription amphetamines. They are used as substitutes for amphetamines. Speed is commonly composed of ephedrine, caffeine, synephrine, or a combination of these agents. Ephedrine is probably the most frequently encountered component of street speed. Elerbal weight loss products containing ephedra, which is made up a number of sympathomimetic alkaloids, were removed from the US market in 2003. Phenypropanolamine, previously marketed as a weight loss supplement and oral decongestant and abused as a look alike , was removed from the US market in 2002. 

Since there are two possible configurations for an asymmetrically substituted carbon atom, a structure containing n such centres will, in theory, possess 2 stereoisomers. The actual number of stereoisomers that exist may be less than this due to steric effects. Compounds that have the same stereochemistry at one chiral centre but different stereochemistry at the others are known as diastereoisomers (diastereomers) a good example is given by the alkaloids ephedrine and pseudoephedrine. Ephedrine (the (1R, 2S) diastereoisomer) is a natural product isolated from Ephedra (the Ma Huang plant) and known to Chinese medicine for over 3000 years. It was used in the last century for the treatment of asthma. Pseudoephedrine (the (IS, 2S) diastereoisomer) is a decongestant and a constituent of several over-the-counter cold and flu remedies (Figure 4.12). 

Nature Ma-huang is one of many names given to extracts from various plants of the genus Ephedra, the major chemical constituents of which are ephedrine and pseu-doephedrine. Ephedrine is a prescription drug in the USA pseudoephedrine is available in over-the-counter decongestants. 

Pharmacology The actions of ephedra products are those of ephedrine and pseudoephedrine, which release norepinephrine from sympathetic nerve endings. In addition to nasal decongestion, the established clinical use of ephedrine is as a pressor agent Ephedra herbal products are commonly used for treatment of respiratory dysfunction (including bronchitis and asthma) and as mild CNS stimulants. In Chinese medicine, ephedra products are also used for relief of cold and flu symptoms, for diuresis, and for bone or Joint pain. 

Ephedrine and pseudoephedrine (2-methylamino-l-phenylpropan-l-ol) are natural epimeric amino alcohols extracted from various species of the family of plants Ephedra. These plants have been used for millennia in China as stimulants and nasal decongestants. The structures of natural (—)-ephedrine and (+)-pseudoephedrine are depicted in Figure 3.3. The figure also shows norephedrine, which is the nitrogen-unsubstituted counterpart of ephedrine. These compounds are nowadays commercially available as inexpensive crystalline white solids and have been extensively used in phosphorus chemistry, as detailed in the next sections. 

Considering the chemical characteristics, ephedrine has two chiral centers, and therefore four isomers can be identified ( )-ephedrine and ( )-pseudoephedrine [39]. (lR,2S)-(—)-ephedrine is the major isomer found in Ephedra sp., and pharmacological studies have shown it as responsible for the pharmacological activities of ephedra. Not only (—)-ephedrine has the widespread use but also (+)-pseudoephedrine is added in over-the-counter decongestant preparations [40]. The four isomers of ephedrine may be naturally present in Ephedra species, and they are usually used as a hydrochloride form, being the classical purification method for ephedrine hydrochloride a combination of conventional infusion and organic solvent extraction or adsorption [41]. Other alkaloids are also present in smaller amounts, and the minor ephedrine alkaloids include (+)-pseudoephedrine and the demethyl analogues (—)-norephedrine and (+)-norpseudoephedrine [40]. 

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. ... 

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