Page 46 - Academic Press Encyclopedia of Physical Science and Technology 3rd Organic Chemistry

P1: LDK Revised Pages
Encyclopedia of Physical Science and Technology EN001F-21 May 7, 2001 13:44

Alkaloids 485

the quinoline and the isoquinoline system. An example of CH 2 OH
a quinoline alkaloid is the cinchona alkaloid cinchonine. H

N
N
N ( )-Lupinine
Quinoline Isoquinoline (from Anabasis
and Lupinus
Natural isoquinoline alkaloids are very abundant; ex- sp.)
amples are papaverine, norlaudanosoline, emetine, and
H 3 C
morphine. Although morphine cannot be classified as an
HN N
isoquinoline alkaloid on the basis of its structure, biosyn- H
C 6 H 5
O CH 2 OH
H 3 CO C
H
O
N
H 3 CO Tropane ( )-Atropine
H (racemate of hyoscyamine)
CH 3
The nitrogen atom can also be common to three rings
as in coccinelline. In addition to the heterocyclic systems
OCH 3
HN mentioned above, some others occur as parts of alkaloids.
OCH 3
B. Alkaloids with an Exocyclic Nitrogen Atom
( )-Emetine and Aliphatic Amines

HO Ephedrine and mescaline are two well-known representa-
tives of this class. Capsaicine was isolated from Piper and
Capsicum species.
O H H
H 3 CO
N CH 3
CH 3 H C C H
NH 2
HO HO N CH 3 H 3 CO
H
( )-Morphine H 3 CO
thetically it is derived from an isoquinoline alkaloid. Two ( )-Ephedrine Mescaline
nitrogen atoms in one six-membered ring are present in O
pyocyanine. H 3 CO
In quite a number of heterocyclic alkaloids, the nitrogen N (CH 2 ) 4 CH CH CH(CH 3 ) 2
H
atom is common to two rings; some basic skeletal types
HO
and corresponding examples are the following:
Capsaicine
N N N C. Putrescine, Spermidine,
and Spermine Alkaloids
Pyrrolizidine Indolizidine Quinolizidine
The alkaloids in this class contain putrescine, spermi-
dine, and spermine as the basic backbone; typical ex-
H 3 C HO O amples are paucine, inandenin-12-one, and aphelandrine,
CH 3
HO respectively.
O H CH 3
O O
CH 3 NH 2 NH 2
O H O H 2 N H 2 N N
N H
H 2 N Putrescine Spermidine
N H
N NH 2
( )-Monocrotaline ( )-Slaframine H 2 N N
H
(from Crotolaria (from Rhizoctonia
sp.) leguminicola) Spermine