A-Allocryptopine

Certain berberine alkaloids can also be directly prepared from the appropriately substituted protopine alkaloid by photolysis in ethanol.387 Berberine itself (359) is obtained in this way from a-allocryptopine (360), and similar preparations of epiberberine and coptisine have been recorded. 

Thus far the pharmacologically investigated alkaloids of this group (protopine, cryptopine, and a-allocryptopine) affect the heart activity. They are active dilators of the coronary vessels (573). After i.v. administration to rabbits and guinea pigs, a slight increase in blood pressure and a greater tendency to the development of cardiac arrhythmia induced by epinephrine are observed. 

Of the seven alkaloids isolated from this plant four were identified as protopine, ophiocarpine, a-allocryptopine, and berberine (62). 

Alborine, a-allocryptopine, amurensinine, amurine, nudaurine. pavanoline, protopine, reframidine... 

Teitel et al. prepared tetracyclic benzazepineisoindole, i.e., Schopf s base VI (104a), from /3-hydrastine (100, 675). This base is a convenient intermediate for further chemical transformation into the protopine skeleton Hofmann degradation of the base VI yields the compounds 105 (isoindoline structure) and 106. The 10-membered trans- (108b) and cis-dibenzazecine (106) were converted via 107 into a -allocryptopine (101b) in poor yield (Scheme 38). 

Redemann, Wisegarver, and Alles (35, c.f. 36) have identified a-fagarine or fagarine I, from Zanthoxylum coco Gill.), as a-allocryptopine. This compound is also known as /3-homochelidonine. A higher-melting isomer... 

Protopine group a-Allocryptopine, a-fagarine, corycavamine, corycavine, cryptopine, protopine... 

There are several protopine-type alkaloids including protopine (7), cryptopine, a-allocryptopine and 13-oxocryptopine. These alkaloids are of Uttle importance and have no analgaesic activity. Protopine does have a sedative effect on laboratory animals. 

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