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Subject: **Anesthetic
Replies: 8 Views: 767
oxide_vx 16.01.12 - 08:51pm
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oxide_vx 16.01.12 - 08:53pm
An anesthetic is a drug that causes reversible loss of sensation. They contrast with an*lgesics (painkillers), which relieve pain without eliminating sensation. These drugs are generally administered to facilitate surgery. *
oxide_vx 16.01.12 - 08:56pm
Cocaine (benzoylmethylecgonine)...
is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic. *
oxide_vx 16.01.12 - 08:58pm
FormulaC17H21NO4,
Systematic (IUPAC) name
methyl (1R,2R,3S,5S)-3- (benzoyloxy)-8-methyl-8-azabicyclo[3.2.1] octane-2-carboxylate
Melt. point98 C (208 F)
Boiling point187 C (369 F)
Solubility in waterHCl: 1800-2500 mg/mL (20 C) *
oxide_vx 16.01.12 - 09:01pm
Biosynthesis of cocaine
The additional carbon atoms required for the synthesis of cocaine are derived from acetyl-CoA, by addition of two acetyl-CoA units to the N-methyl-&916;1-pyrrolinium cation. *
oxide_vx 16.01.12 - 09:01pm
The first addition is a Mannich-like reaction with the enolate anion from acetyl-CoA acting as a nucleophile towards the pyrrolinium cation. The second addition occurs through a Claisen condensation. This produces a racemic mixture of the 2-substituted pyrrolidine, with the retention of the thioester from the Claisen condensation. In formation of tropinone from racemic ethyl [2,3-13C2]4(Nmethyl-2-pyrrolidinyl)-3-oxobutanoate there is no preference for either stereoisomer. *
oxide_vx 16.01.12 - 09:02pm
In the biosynthesis of cocaine, however, only the (S)-enantiomer can cyclize to form the tropane ring system of cocaine. The stereoselectivity of this reaction was further investigated through study of prochiral methylene hydrogen discrimination. *
oxide_vx 16.01.12 - 09:02pm
This process occurs through an oxidation, which regenerates the pyrrolinium cation and formation of an enolate anion, and an intramolecular Mannich reaction. The tropane ring system undergoes hydrolysis, SAM-dependent methylation, and reduction via NADPH for the formation of methylecgonine. The benzoyl moiety required for the formation of the cocaine diester is synthesized from phenylalanine via cinnamic acid. *
oxide_vx 16.01.12 - 09:03pm
Benzoyl-CoA then combines the two units to form cocaine. *
