Reserpic acid
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| General | |||||||||||||
| Surname | Reserpic acid | ||||||||||||
| other names |
Reserpic acid |
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| Molecular formula | C 22 H 28 N 2 O 5 | ||||||||||||
| Brief description |
crystalline solid |
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| properties | |||||||||||||
| Molar mass | 400.6 g · mol -1 | ||||||||||||
| Physical state |
firmly |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | |||||||||||||
When Reserpinsäure is an indole alkaloid from the series of Epiallo yohimbanes . The structure was elucidated in 1954 as part of an intensive study of the Rauvolfia alkaloids. It was not until 1982 that reserpic acid was isolated from plant material from Rauvolfia vomitoria . Before that, it was only known as a metabolite of the medicinally used reserpine , from which it arises through hydrolysis of the two ester bonds and whose basic structure it forms. Like the other breakdown products of reserpine, reserpic acid is essentially pharmacologically inactive, although there are indications that it binds to vesicular monoamine transporters - albeit to a very small extent - and thus interferes with the uptake of catecholamines in storage granules.
Reactions
Reserpic acid forms the basic structure of reserpine. Because of this structural similarity, conclusions can be drawn about the reserpine structure from their reactions. Two reactions in particular contributed to their elucidation and assignment to the epialloyohimbanes:
Lactone formation
Since the carboxy group on C-16 and the hydroxyl group on C-18 of reserpic acid react easily with one another and form a lactone with elimination of water , both must be on the same side of the ring.
Quaternization
If the C-16-position carboxy group, first with lithium aluminum hydride to a primary alcohol is reduced and this alcohol in a second step with tosyl chloride condenses , is the C-22 (the carbon atom of the reduced former carboxy) spontaneous binding a with the nitrogen atom in position 4 which gives it a positive charge . Together with the outgoing tosylate - anion gives the resulting quaternary ammonium ion is a salt .
In order for the partially positively charged C-22 to attack the lone pair of electrons of the N-4 in this form, the hydrogen atoms bonded to carbon atoms 15 and 20 must be in the α position, the hydrogen atoms bonded to C-3 in the β position.
Individual evidence
- ↑ a b Malik, Afza: Reserpic Acid, Gallic Acid, and Flavonoids from Rauwolfia vomitoria . In: Journal of Natural Products (1983), Vol. 46, pp. 939-941. doi : 10.1021 / np50030a024
- ^ Entry on reserpic acid in the ChemIDplus database of the United States National Library of Medicine (NLM), accessed on October 28, 2016.
- ↑ a b c Reserpic acid data sheet (PDF) from Carl Roth , accessed on October 28, 2016.
- ↑ a b Chaplin, Cohen, Huettl, Kennedy, Njus, Temperley: Reserpic Acid as an Inhibitor of Norepinephrine Transport into Chromaffin Vesicle Ghosts . (PDF; 539 kB) In: The Journal of Biological Chemistry (1985), Vol. 260, pp. 10981-10985.
- ↑ Huebner, MacPhillamy, André, Schlittler: Rauwolfia Alkaloids. XV. The Constitution of Reserpic Acid: Position of Substituents in ring E . In: Journal of the American Chemical Society (1955), Vol. 77, pp. 472-475.
- ^ Cohen: Reserpine . In: Sadée (Ed.): Drug Level Monitoring . John Wiley & Sons, New York / Chichester / Brisbane / Toronto, 1980. ISBN 0-471-04881-X . Pp. 415-417.
- ↑ Hansel, Sticher: Pharmacognosie - Phytopharmazie . Springer, Heidelberg, 2007. ISBN 3-540-26508-2 . P. 1421.
- ^ A b Auterhoff: Textbook of Pharmaceutical Chemistry . Wissenschaftliche Verlagsgesellschaft, Stuttgart, 1983. ISBN 3-8047-0714-9 . P. 399.