Ajmaline

Experiments with animals have revealed that ajmaline (L, Fig. 4) has promising quinidine-like anti-arrhythmic properties and an apparently favourable therapeutic index [1105-1120], but neither the alkaloid itself nor any of its less toxic semi-synthetic derivatives [1121-1129] has gained a firm place in clinical medicine, although ajmaline has seen occasional application in the control of extrasystoles [1130, 1131]. 

Ajmaline also induces a transitory hypotension [1132,1133] which has been attributed to diminished cardiac output [1134-1336], but since a durable hypo- 

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Aldehyde 198 served as a key intermediate in a synthesis of the alkaloid ajmaline. The. Mannich aminomethylation transform triggers disconnection of two bonds in 198 to form dialdehyde 199, which by connective transform application can be converted to cyclopentene 200.58,59 The reduction in functional group reactivity and in structural complexity are both apparent by comparison of 198 and 200. 

R. serpentina Benth. Ajmalicine, ajmaline, ajmalinine, serpentine, serpentinine (Siddiqui and Siddiqui ). From a geographical variety of the species, Moajmaline, neoajmaline and unnamed alkaloids, m.p. 220° and m.p. 234 (S. Siddiqui ). From the same species van Itallie and Steenhauer isolated alkaloids B, C and A (rauwolfine) which may be identical with Siddiqui s serpentine, aimalinine and ajmaline respectively. 

R. vomitoria Afz. (sample from French Guinea). Ajmaline, iso-ajmaline, ajmalicine, ajmalinine and possibly serpentinine, cf. R. serpentina (Paris ). 

ISO Ajmaline was subsequently found to occur naturally in a specimen ol the drug collected in the Dun Valley (item 6, see above) along with a third isomeride, weoajmaline, m.p. 205-7°, which is convertible into iso-ajmaline by heating at 270° or by the action of alcoholic potash (Siddiqui ). 

It is unfortunate that the name rauwolfine has been used for two distinct alkaloids, but if van Itallie and Steenhauer s rauwolfine proves to be ajmaline, the difficulty will disappear. 

Raymond-Hamet has given much attention to the action of the Rauwolfia alkaloids. Using Siddiqui s ajrhalinine, he found that it provokes hypotension accompanied by renal dilatation and exerts a true sympathi-colytic action. 1 Ajmaline and serpentine also induce hypotension and a decrease in intestinal action serpentinine diminishes the renal constrictive action of adrenaline, but does not alter its hypertensive effects. ... 

I a With prolongation of action potential Quinidine, Procainamide, Disopyramide, Ajmaline, Prajmaline... 

Ajmaline (intravenously only) and its orally applicable propyl-substituted prodrug prajmaline are classified as class IA drugs, but due to their long dissociation time constant can also be considered as class IC compounds. 

During the enantiospecihc total synthesis of ajmalin-related alkaloids, (-)-suaveoline and (-)-raumacline, N-debenzylation of the hydrochloride salt of the alkaloids was performed with 10% Pd/C (0.12 mol Pd/mol compound) in absolute EtOH at room temperature and 1 atm of hydrogen for 1 or 2 hours. When this catalytic debenzylation was performed, however, using 10% Pd/C (0.28 mol Pd/mol compound) in MeOH for 5 hours, N-methyl derivatives were produced in good yield (Scheme 4.91).339,340... 

On the other hand, ( )-corynantheine was achieved from key intermediate 301, used previously in the synthesis of ajmaline (167). The fra/u-tosylhydrazone derivative 302 afforded the desired vinyl-substituted indolo[2,3-o]quinolizine 304 in moderate yield along with the corresponding ethylidene-substituted isomer. Formylation and methylation of 304 afforded finally ( )-corynantheine (164). 

Air-water flow regimes, 22 773 Air-water interface, molecular recognition at, 26 799-800 AISI 403 alloys, 23 511 AISI alloy steels, 23 299-300 Ajmalicine, 2 94, 95, 96, 100 Ajmaline, 2 94, 95, 96-97 AK-UFVE contactor, 20 768 A1203 surface scale, 23 507-508 Alabaster, 4 583... 

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